Talking markets: Oclaro on 100 gigabits and beyond
Oclaro’s chief commercial officer, Adam Carter, discusses the 100-gigabit market, optical module trends, silicon photonics, and why this is a good time to be an optical component maker.
Oclaro has started its first quarter 2017 fiscal results as it ended fiscal year 2016 with another record quarter. The company reported revenues of $136 million in the quarter ending in September, 8 percent sequential growth and the company's fifth consecutive quarter of 7 percent or greater revenue growth.
Adam CarterA large part of Oclaro’s growth was due to strong demand for 100 gigabits across the company’s optical module and component portfolio.
The company has been supplying 100-gigabit client-side optics using the CFP, CFP2 and CFP4 pluggable form factors for a while. “What we saw in June was the first real production ramp of our CFP2-ACO [coherent] module,” says Adam Carter, chief commercial officer at Oclaro. “We have transferred all that manufacturing over to Asia now.”
The CFP2-ACO is being used predominantly for data centre interconnect applications. But Oclaro has also seen first orders from system vendors that are supplying US communications service provider Verizon for its metro buildout.
The company is also seeing strong demand for components from China. “The China market for 100 gigabits has really grown in the last year and we expect it to be pretty stable going forward,” says Carter. LightCounting Market Research in its latest optical market forecast report highlights the importance of China’s 100-gigabit market. China’s massive deployments of FTTx and wireless front haul optics fuelled growth in 2011 to 2015, says LightCounting, but this year it is demand for 100-gigabit dense wavelength-division multiplexing and 100 Gigabit Ethernet optics that is increasing China’s share of the global market.
The China market for 100 gigabits has really grown in the last year and we expect it to be pretty stable going forward
QSFP28 modules
Oclaro is also providing 100-gigabit QSFP28 pluggables for the data centre, in particular, the 100-gigabit PSM4 parallel single-mode module and the 100-gigabit CWDM4 based on wavelength-division multiplexing technology.
2016 was expected to be the year these 100-gigabit optical modules for the data centre would take off. “It has not contributed a huge amount to date but it will start kicking in now,” says Carter. “We always signalled that it would pick up around June.”
One reason why it has taken time for the market for the 100-gigabit QSFP28 modules to take off is the investment needed to ramp manufacturing capacity to meet the demand. “The sheer volume of these modules that will be needed for one of these new big data centres is vast,” says Carter. “Everyone uses similar [manufacturing] equipment and goes to the same suppliers, so bringing in extra capacity has long lead times as well.”
Once a large-scale data centre is fully equipped and powered, it generates instant profit for an Internet content provider. “This is very rapid adoption; the instant monetisation of capital expenditure,” says Carter. “This is a very different scenario from where we were five to ten years ago with the telecom service providers."
Data centre servers and their increasing interface speed to leaf switches are what will drive module rates beyond 100 gigabits, says Carter. Ten Gigabit Ethernet links will be followed by 25 and 50 Gigabit Ethernet. “The lifecycle you have seen at the lower speeds [1 Gigabit and 10 Gigabit] is definitely being shrunk,” says Carter.
Such new speeds will spur 400-gigabit links between the data centre's leaf and spine switches, and between the spine switches. “Two hundred Gigabit Ethernet may be an intermediate step but I’m not sure if that is going to be a big volume or a niche for first movers,” says Carter.
400 gigabit CFP8
Oclaro showed a prototype 400-gigabit module in a CFP8 module at the recent ECOC show in September. The demonstrator is an 8-by-50 gigabit design using 25 gigabaud optics and PAM-4 modulation. The module implements the 400Gbase-LR8 10km standard using eight 1310nm distributed feedback lasers, each with an integrated electro-absorption modulator. The design also uses two 4-wide photo-detector arrays.
“We are using the four lasers we use for the CWDM4 100-gigabit design and we can show we have the other four [wavelength] lasers as well,” says Carter.
Carter says IP core routers will be the main application for the 400Gbase-LR8 module. The company is not yet saying when the 400-gigabit CFP8 module will be generally available.
We can definitely see the CFP2-ACO could support 400 gigabits and above
Coherent
Oclaro is already working with equipment customers to increase the line-side interface density on the front panel of their equipment.
The Optical Internetworking Forum (OIF) has already started work on the CFP8-ACO that will be able to support up to four wavelengths, each supporting up to 400 gigabits. But Carter says Oclaro is working with customers to see how the line-side capacity of the CFP2-ACO can be advanced. “We can definitely see the CFP2-ACO could support 400 gigabits and above,” says Carter. “We are working with customers as to what that looks like and what the schedule will be.”
And there are two other pluggable form factors smaller than the CFP2: the CFP4 and the QSFP28. “Will you get 400 gigabits in a QSFP28? Time will tell, although there is still more work to be done around the technology building blocks,” says Carter.
Vendors are seeking the highest aggregate front panel density, he says: “The higher aggregate bandwidth we are hearing about is 2 terabits but there is a need to potentially going to 3.2 and 4.8 terabits.”
Silicon photonics
Oclaro says it continues to watch closely silicon photonics and to question whether it is a technology that can be brought in-house. But issues remain. “This industry has always used different technologies and everything still needs light to work which means the basic III-V [compound semiconductor] lasers,” says Carter.
“Producing silicon photonics chips versus producing packaged products that meet various industry standards and specifications are still pretty challenging to do in high volume,” says Carter. And integration can be done using either silicon photonics or indium phosphide. “My feeling is that the technologies will co-exist,” says Carter.
OFC 2015 digest: Part 2
- CFP4- and QSFP28-based 100GBASE-LR4 announced
- First mid-reach optics in the QSFP28
- SFP extended to 28 Gigabit
- 400 Gig precursors using DMT and PAM-4 modulations
- VCSEL roadmap promises higher speeds and greater reach
OFC 2014 product round-up - Final part
The industry is moving at a clip to fill the void in 100 Gig IEEE standards for 100m to 2km links. Until now, the IEEE 10km 100GBASE-LR4 and the 10x10 MSA have been the interfaces used to address such spans.
But responding to data centre operators, optical players are busy developing less costly, mid-reach MSAs, as was evident at the OFC exhibition and conference, held in San Francisco in March.
Meanwhile, existing IEEE 100 Gigabit standards are skipping to the most compact CFP4 and QSFP28 form factors. The -LR4 standard was first announced in a CFP in 2010, and moved to the CFP2, half the size of the CFP, in 2013. Now, several companies have detailed CFP4 -LR4 products, while Source Photonics has gone one better, announcing the standard in a QSFP28.
The CFP4 is half the size of the CFP2, while the QSFP28 is marginally smaller than the CFP4 but has a lower power consumption: 3.5W compared to the CFP4's 6W.
Timeline of some pluggable announcements at recent OFCs. Source: Gazettabyte
The mid-reach landscape
Several interfaces for mid-reach interconnect were detailed at OFC. And since the show, two MSAs have been detailed: the CWDM4 and the CLR4 Alliance.
At OFC, the OpenOptics MSA backed by Mellanox Technologies and Ranovus, was announced. Skorpios Technologies demoed its CLR4 module that has since become the CLR4 Alliance. And vendors discussed the Parallel Single Mode (PSM4) initiative that was first detailed in January.
Switch vendor Mellanox Technologies and module start-up Ranovus announced the OpenOptics MSA at OFC. The QSFP-based MSA uses a single-mode fibre and WDM transmission around 1550nm to address data centre links up to 2km.
Saeid Aramideh of Ranovus says that the MSA using its laser and silicon photonics technologies will deliver significant cost, power and size advantages {add link}. "But the 1550nm WDM connection is open to any technology," says Aramideh, chief marketing and sales officer at Ranovus. "It does not have to be silicon photonics."
The first MSA product, a 100 Gig QSFP28, uses 4x25 Gig channels. "The channel spacing for the MSA is flexible to be 50GHz or more," says Aramideh. The MSA is scalable to 400 Gig and greater rates. The 100 Gig QSFP28 technology is several months away from sampling.
Skorpios Technologies demonstrated its QSFP28-CLR4 transceiver although the details of the MSA have yet to be detailed. Skorpios is a silicon photonics player and uses heterogenous integration where the lasers, modulators, detectors and optical multiplexer and de-multiplexer are monolithically integrated on one chip.
The PSM4 MSA is another initiative designed to tackle the gap between IEEE short and long reach standards. Backed by players such as Avago Technologies, Brocade, JDSU, Luxtera, Oclaro, and Panduit, the 100 Gig standard is defined to operate in the 1295-1325nm spectral window and will have a reach of at least 500m.
ColorChip demonstrated a 100 Gig (4x25 Gig) QSFP28 with a 2km reach at the show. The design uses uncooled directly modulated lasers to achieve the 3.5W power consumption. Since the show Colorchip is one of the member companies backing the CLR4 Alliance and the demoed QSFP matches the first details of the new MSA's spec.
100GBASE-LR4 moves to CFP4 and QSFP28
The IEEE 100GBASE-LR4 standard is transitioning to the smallest modules. At OFC, vendors detailed the first CFP4s while Source Photonics announced the -LR4 in a QSFP28.
Source Photonics says its transceiver consumes 3.5W. The QSFP28 form factor achieves up to a fourfold increase in face plate density compared to the CFP2: up to 48 modules compared to a dozen CFP2 modules, says the company, which expects first QSFP28 -LR4 samples in mid-2014.
Meanwhile, Avago Technologies, Finisar, Fujitsu Optical Components and JDSU all detailed their first CFP4 -LR4 modules.
JDSU says that when it developed the optics for its CFP2 -LR4, it was already eyeing the transition to the CFP4 and QSFP28 form factors. To achieve the -LR4 spec in the 6W CFP4, a key focus are the clock data recover (CDR), driver and trans-impedance amplifier chips. "A decent amount of the power consumption is wrapped up in the ICs that do the CDR and a variety of the digital functions behind the photonics," says Brandon Collings, JDSU's CTO for communications and commercial optical products. JDSU expects general availability of its CFP4 -LR4 later this year.
Finisar's -LR4 is its second CFP4 product; at ECOC 2013 it showcased a 100m, 100GBASE-SR4 CFP4. Finisar says its -LR4 uses distributed feedback (DFB) lasers and consumes 4.5W, well within the CFP4's 6W power profile. At OFC, the CFP4 was demonstrated working with CFP2 and CFP -LR4 modules. Finisar's CFP4 will sample later this year.
Avago announced availability of its -LR4 transmit optical subassembly (TOSA) and receive optical subassembly (ROSA) products for the CFP4, along with its CFP4 module which it says will be available next year. Fujitsu Optical Components also used OFC to demo its CFP4 -LR4.
40km Extended Reach Lite
Oclaro and Finisar detailed a tweak to the 100 Gig Extended Reach standard: the 40km, 100GBASE-ER4.
The IEEE standard uses a power-hungry semiconductor optical amplifier (SOA) prior to the PIN photodetector to achieve 40km. The module vendors have proposed replacing the SOA and PIN with an avalanche photo diode (APD) and external forward error correction to reduce the power consumption while maintaining the optical link budget. The changed spec is dubbed 100GBASE-ER4 Lite.
"Trying to achieve the power envelopes required for the CFP4 and QSFP28 using SOAs is going to be too hard," says Kevin Granucci, vice president of strategy and marketing at Oclaro.
Oclaro demonstrated a ER4-Lite in a CFP2. The module supports 100 Gigabit Ethernet and the Optical Transport Network (OTN) OTU-4 rates, and consumes less than 9W. "We are using the CFP2 as the first proof-of-concept," says Granucci. "For the 6W CFP4 and the 3.5W QSFP28, we think this is the only solution available."
At OFC Finisar demonstrated the link's feasibility, which it refers to as ER4f, using four 28 Gig lasers and four 28 Gig APDs.
Oclaro says it is seeing customer interest in the ER4 Lite, and points out that there are many 10 Gig 40km links deployed, especially in China. "The ER4 Lite will provide an update path to 100 Gig," says Granucci.
VCSELs: serial 40 Gig and the 400 Gig CDFP
Finisar showcased a VCSEL operating at 40 Gig at OFC. State-of-the-art VCSEL interfaces run up to 28 Gig. Finisar's VCSEL demonstration was to show the commercial viability of higher-speed VCSELs for single channel or parallel-array applications. "We believe that VCSELs have not run out of steam," says Rafik Ward, vice president of marketing at Finisar. The 40 Gig VCSEL demonstration used non-return-to-zero (NRZ) signalling, "no higher-order modulation is being used", says Ward.
IBM T.J.Watson Research Center has published an IEEE paper with Finisar involving a 56Gbps optical link based on an 850nm VCSEL.
Finisar also demonstrated an CDFP-based active optical cable. The CDFP is a 400 Gig MSA that uses 16 x 25 Gig VCSEL channels in each direction. Such an interface will address routing, high-performance computing and proprietary interface requirements, says Finisar. The demonstration showcased the technology; Finisar has yet to announce interface products or reaches.
Short reach 100G and 4x16 Gig Fibre QSFPs
Avago Technologies announced a 100GBASE-SR4 implemented using the QSFP28. Avago's I Hsing Tan, segment marketing manager for Ethernet and storage optical transceivers, says there has been a significant ramp in data centre demand for the 40GBASE-SR4 QSFP+ in the last year. "Moving to the next generation, the data centre operator would like to keep the same [switch] density as the QSFP+, and the QSFP28 MSA offers the same form factor," he says.
The QSFP28 differs from the QSFP+ is that its electrical connector is upgraded to handle 28 Gigabit-per-lane data rates. Avago says the -SR4 module will be generally available next year.
Avago also announced a 4x16 Gigabit Fibre Channel QSFP+ transceiver. The industry is transitioning from 8 to 16 Gig Fibre Channel, says Avago, and this will be followed by 32 Gig serial and 4x32 Gig Fibre Channel modules.
The company has announced a 4x16 Gig QSFP+ to continue the increase in platform channel density while the industry transitions from 16 to 32 Gig Fibre Channel. "This solution is going to provide the switch vendor a 3x increase in density at half the power dissipation per channel for 16 Gig Fibre Channel, before the 32 bit Fibre Channel come to maturity in three to five years," says Tan.
Avago has just announced that it has shipped over half a million QSFP+ modules.
Optical engines
TE Connectivity announced its 25 Gig-per-channel optical engine technology. The Coolbit optical engine will be included in four TE Connectivity products planned for this year: 100 Gig QSFP28 active optical cables (AOCs), 100 Gig QSFP28 transceivers, 300 Gig mid-board optical modules, and 400 Gig CDFP AOCs.
Meanwhile, Avago's MiniPod and MicroPod optical engine products now have a reach of 550m when coupled with Corning's ClearCurve OM4 fibre.
"This allows customers in the data centre to go a little bit further and not have to go to single-mode fibre," says Sharon Hall, product line manager for embedded optics at Avago.
For Part 1, click here
Further reading:-
TE Connectivity White Paper: End-to-end Communications with Fiber Optic Technologies, click here
LightCounting: Reflections on OFC 2014: The industry is approaching a critical junction, click here
Ovum at OFC 2014, click here
LightWave OFC 2014 Podcast, click here
Ethernet Alliance Blog: OFC 2014 show and best in class, click here
OFC 2014 product round-up - Part 1
Part 1: Line-side technologies
Technologies for 100 Gigabit were prominent at this year's OFC conference and exhibition held in San Francisco earlier this month.
The transition to smaller pluggable modules – client-side CFP2, CFP4 and QSFP28 interfaces - was one 100 Gig trend, another was the first 100 Gig pluggable modules for metro and metro-regional networks. Acacia Communications detailed its low-power AC-100 CFP, while Oclaro demonstrated coherent optics in the smaller CFP2 pluggable module.
To fit within the CFP2, Oclaro has developed a transmitter that combines two tunable lasers (one being for the coherent receiver) and an indium phosphide modulator, and a micro intradyne coherent receiver (micro ICR).
Having 100 Gig coherent optics in a CFP2 will enable equipment makers to double the 100 Gig line ports on their platforms. The optics will also support polarisation multiplexed, 16-quadrature amplitude modulation (PM-16-QAM) and hence 200 Gig transmission. However, given the CFP2's limited power profile, the coherent DSP-ASIC will need to reside on the line card, external to the module. Oclaro says samples of its 'analogue CFP2' will be with customers from the second quarter of the year.
The same coherent optics will also be used for Oclaro's 100 Gig coherent CFP module. "If you combine the [transmitter and micro ICR] optics, you get the CFP2, and the power target is 12W," says Robert Blum, director, product management, 40 and 100 Gig line-side modules at Oclaro. "Combining the optics with a [coherent] DSP in the CFP, the power target is 32W, the highest CFP [power] class."
Oclaro's 100 Gig CFP will be available by year-end, coinciding with a new generation of merchant coherent DSP-ASIC designs. ClariPhy Communications is sampling its LightSpeed-II devices, implemented using a 28nm CMOS process, while NTT Electronics (NEL) is developing its next-generation DSP-ASIC, expected to use an even more advanced CMOS process.
Integrating the DSP chip and optics in a CFP simplifies a line card design and adds flexibility: the same CFP port can be used for line-side or client-side modules. But given that the coherent optics consumes 12W, the next-generation DSP-ASIC must consume no more than 18W typically, with the remaining 2W to accommodate the physical layer ICs, if the CFP's maximum power profile is not to be exceeded.
Acacia Communications' AC-100 coherent CFP module uses the company's DSP-ASIC and photonic integrated circuit (PIC) implemented using silicon photonics. The resulting 100 Gig CFP consumes 24-26W, well within the CFP's maximum 32W.
Meanwhile, Fujitsu Optical Components demonstrated all the components needed to make a 100 Gig coherent CFP, using its indium phosphide modulator to generate a 100 Gig polarisation multiplexed, quadrature phase-shift keying (PM-QPSK) signal, and a micro ICR.
Considering that the 5x7-inch Optical Internetworking Forum (OIF) multi-source agreement (MSA) 100 Gig transponder for long-haul consumes some 80W, with the DSP-ASIC alone consuming over half that, the advent of the coherent CFP and analogue CFP2 highlights the industry’s recent progress in shrinking the size and power consumption of coherent optics.
"Our focus long term is the CFP2. It is where we think the market is going to go in the next two years."
Ferris Lipscomb, NeoPhotonics
Coherent components
NeoPhotonics detailed an integrated coherent transmitter that combines a narrow-linewidth tunable laser and a PM-QPSK modulator in one package. The device joins NeoPhotonics' micro Integrable Tunable Laser Assembly (ITLA) and micro ICR that have already been announced. "These are the next generation, smaller form factor coherent optical components," says Ferris Lipscomb, vice president of marketing at NeoPhotonics. The transmitter supports PM-QPSK and PM-16-QAM such that it can be used for 100, 200 and even as an element to enable 400 Gig transmission.
The device is suited for line card, OIF MSA modules, and pluggable CFP and CFP2 designs. "Our focus long term is the CFP2," says Lipscomb. "It is where we think the market is going to go in the next two years." NeoPhotonics says its coherent devices has been sampling to customers and will be generally available in the second half of the year.
Oclaro announced that its micro ITLA, first detailed at ECOC 2013, now supports a flexible grid; the tunable laser's wavelength can be set independent of the ITU Grid spanning the C-band. Such a capability is required for advanced optical networks based on flexible-grid ROADMs and spectrally-efficient super-channels. "The flexible-grid micro ITLA gives peace of mind [to operators] even if it is not widely used yet," says Oclaro's Blum. The technology used for the micro ITLA is also used for Oclaro's CFP and CFP2 line side modules.
Fujitsu Optical Components announced a lithium niobate modulator that supports 100 Gig PM-QPSK and 400 Gig PM-xQAM signals. The new modulator has the same drive voltage as its existing 100 Gig lithium niobate modulator but is half the size. The company also announced an accompanying ICR that also supports 100 and 400 Gig transmissions in core networks. The company says both devices will be available from July.
Sumitomo Electric Industries detailed its micro ITLA at OFC. The micro ITLA uses a narrower line width laser and reduces power consumption by a fifth. The company also showcased a micro ICR that supports 100 and 200 Gig transmissions, and an indium phosphide based Mach-Zehnder modulator that is smaller and has lower power than a lithium niobate-based version.
Avago Technologies announced its micro ICR at OFC, a demonstration of Avago's broad component portfolio following its acquisition of CyOptics. Finisar was another company that showcased a new portfolio of high-speed optical components following its acquisition of u2t Photonics. These include indium phosphide-based Mach-Zehnder modulators and 100 Gig receivers and photodetectors.
Tunable SFP+
Both JDSU and Oclaro detailed their latest 10 Gigabit tunable SFP+ optical modules. Moving the tunable laser design from an XFP to the SFP+ has been a challenge, meeting the SFP+'s smaller dimensions and 1.5W power consumption.
Oclaro's latest tunable SFP+ now meets the 1.5W SFP+ specification. Oclaro says that to achieve the specification, it produced a more compact integrated laser Mach-Zehnder chip. Oclaro demonstrated the tunable SFP+ operating at 85oC. Beta samples of the tunable SFP+ are being shipped and the module will soon undergo qualification.
JDSU has had a tunable SFP+ product for over a year but its power consumption is 2W. The SFP+ length is also elongated by 4mm to fit the tunable laser. Now, JDSU has announced a revised design that no longer needs the extra 4mm and achieves a power consumption of 1.6W. "We will achieve the 1.5W specification in the near future," says Brandon Collings, JDSU's CTO for communications and commercial optical products.
"The reason why there is a lot of talk about hybrid EDFA-Raman in the industry is that it works very well with coherent."
Rafik Ward, Finisar
Pump lasers and hybrid amplifiers
JDSU also announced pump laser designs. The motivation for these latest pump products is the more demanding link budgets required for 100 Gig-and-greater transmission speeds while still achieving long-distance reaches.
JDSU announced Raman pump lasers for hybrid EDFA-Raman amplifiers. These are more power-efficient and cover the Raman pump wavelengths required, says JDSU: a 600mW output between 1425-1470nm and 550mW at 1470-1495nm. The company has also detailed higher-power 980nm pumps for EDFAs. "More power is almost always a good thing as it allows you a lot more design freedom and performance in your amp," says Collings.
Finisar demonstrated a hybrid EDFA-Raman amplifier for the first time. The hybrid amp is capable of spanning 220km and has a 44dB link loss. "The reason why there is a lot of talk about hybrid EDFA-Raman in the industry is that it works very well with coherent," says Rafik Ward, vice president of marketing at Finisar. Amplifier span distances of 80km are commonly used but the purpose of the demonstration was to showcase the product's capability, says Ward.
WSSes and multicast switches
NeoPhotonics has announced a modular multicast switch that allows an operator to grow a ROADM's node according to demand. The multicast switch is used to add colourless, directionless and contentionless (CDC) attributes to the ROADM. "You can have any wavelength [colourless] from any direction come out at any port [directionless]," says Lipscomb. "And if you have two identical wavelengths coming from different directions, you can drop them through the same switch [contentionless]."
Lipscomb cites as an example an 8-degree ROADM node, with each direction fibre carrying 100 dense WDM channels. Even if only a quarter of the channels are dropped, that is 200 channels, he says: "What we are announcing is a modular multicast switch; you can start with 4 channels and 4 drops and keep adding modular line cards as needed to add more drop ports and more directions."
NeoPhotonics modular multicast switches include such dimensions as 4x4, 4x16 and 8x16. "Carriers don't want to limit their future deployment but they also don't want to spend a lot of money now because they might want to drop 100 channels later," says Lipscomb.
JDSU announced its second-generation twin 1x20 wavelength-selective switch (WSS) that fits on a single-slot card. The twin WSS is used for advanced flexible-grid CDC-ROADM nodes.
The latest twin 1x20 WSS has the same functionality as JDSU's current twin 1x20 WSS that has been available for a year but which occupies two chassis slots. "It has the same capability but is considerably smaller," says Collings.
Indeed, the twin WSS is sufficiently compact that other functions can be added to the card such as amplification, optical power monitoring and optical service channels, communication channels between nodes used for such tasks as provisioning, power management and firmware updates.
For the OFC 2014 product round-up - Part 2, click here
MACOM acquires Mindspeed to boost 100 Gig offerings
Ray MoroneyThe Mindspeed acquisition increases the serviceable addressible market for MACOM, both geographical - the company will strengthen its presence in Asia Pacific - and by gaining new equipment vendor accounts. It also broadens MACOM's 100 Gigabit physical device portfolio.
"We are targeting the 100 Gig buildout and the growth coming from that," says Ray Moroney, product line manager, opto-device business unit at MACOM.
Mindpeed also makes a broad portfolio of crosspoint switches used in datacom equipment, and several families of communications processors.
With the acquisition of Mindspeed we have the full electronics bill-of-materials for CFP2 and CFP4 [module] client-side applications
MACOM entered opto-electronics with the acquisition of Optimai in 2011 that had long-haul and client-side modulator drivers and trans-impedance amplifiers (TIAs). Now with Mindspeed's products, MACOM can capture client-side designs with clock data recovery chips and quad-channel TIAs for 100 Gig modules. "With the acquisition of Mindspeed we have the full electronics bill-of-materials for CFP2 and CFP4 [module] client-side applications," says Moroney.
MACOM also gains silicon germanium technology alongside its indium phosphide and gallium arsenide technologies. Silicon germanium has a lower cost structure once a design is being made in volume production, says Moroney, but the R&D and mask costs are generally higher. Silicon germanium also allows significant integration. "It is BiCMOS in nature," says Moroney. "You can integrate full CMOS functionality into a design too." For example digital control can be added alongside analogue functions. Moroney says the company will use silicon germanium for high-performance analogue designs like TIAs as well as high-frequency millimeter wave and microwave applications.
The company is considering its options regarding the future of the communications processors arm of Mindspeed's business. "MACOM is very much an analogue/ RF company," says Moroney. "It [communications processors] is certainly not seen as a core area of investment for MACOM."
Verizon on 100G+ optical transmission developments
Source: Gazettabyte
Feature: 100 Gig and Beyond. Part 1:
Verizon's Glenn Wellbrock discusses 100 Gig deployments and higher speed optical channel developments for long haul and metro.
The number of 100 Gigabit wavelengths deployed in the network has continued to grow in 2013.
According to Ovum, 100 Gigabit has become the wavelength of choice for large wavelength-division multiplexing (WDM) systems, with spending on 100 Gigabit now exceeding 40 Gigabit spending. LightCounting forecasts that 40,000, 100 Gigabit line cards will be shipped this year, 25,000 in the second half of the year alone. Infonetics Research, meanwhile, points out that while 10 Gigabit will remain the highest-volume speed, the most dramatic growth is at 100 Gigabit. By 2016, the majority of spending in long-haul networks will be on 100 Gigabit, it says.
The market research firms' findings align with Verizon's own experience deploying 100 Gigabit. The US operator said in September that it had added 4,800, 100 Gigabit miles of its global IP network during the first half of 2013, to total 21,400 miles in the US network and 5,100 miles in Europe. Verizon expects to deploy another 8,700 miles of 100 Gigabit in the US and 1,400 miles more in Europe by year end.
"We expect to hit the targets; we are getting close," says Glenn Wellbrock, director of optical transport network architecture and design at Verizon.
Verizon says several factors are driving the need for greater network capacity, including its FiOS bundled home communication services, Long Term Evolution (LTE) wireless and video traffic. But what triggered Verizon to upgrade its core network to 100 Gig was converging its IP networks and the resulting growth in traffic. "We didn't do a lot of 40 Gig [deployments] in our core MPLS [Multiprotocol Label Switching] network," says Wellbrock.
The cost of 100 Gigabit was another factor: A 100 Gigabit long-haul channel is now cheaper than ten, 10 Gig channels. There are also operational benefits using 100 Gig such as having fewer wavelengths to manage. "So it is the lower cost-per-bit plus you get all the advantages of having the higher trunk rates," says Wellbrock.
Verizon expects to continue deploying 100 Gigabit. First, it has a large network and much of the deployment will occur in 2014. "Eventually, we hope to get a bit ahead of the curve and have some [capacity] headroom," says Wellbrock.
We could take advantage of 200 Gig or 400 Gig or 500 Gig today
Super-channel trials
Operators, working with optical vendors, are trialling super-channels and advanced modulation schemes such as 16-QAM (quadrature amplitude amplitude). Such trials involve links carrying data in multiples of 100 Gig: 200 Gig, 400 Gig, even a Terabit.
Super-channels are already carrying live traffic. Infinera's DTN-X system delivers 500 Gig super-channels using quadrature phase-shift keying (QPSK) modulation. Orange has a 400 Gigabit super-channel link between Lyon and Paris. The 400 Gig super-channel comprises two carriers, each carrying 200 Gig using 16-QAM, implemented using Alcatel-Lucent's 1830 photonic service switch platform and its photonic service engine (PSE) DSP-ASIC.
"We could take advantage of 200 Gig or 400 Gig or 500 Gig today," says Wellbrock. "As soon as it is cost effective, you can use it because you can put multiple 100 Gig channels on there and multiplex them."
The issue with 16-QAM, however, is its limited reach using existing fibre and line systems - 500-700km - compared to QPSK's 2,500+ km before regeneration. "It [16-QAM] will only work in a handful of applications - 25 percent, something of this nature," says Wellbrock. This is good for a New York to Boston, he says, but not New York to Chicago. "From our end it is pretty simple, it is lowest cost," says Wellbrock. "If we can reduce the cost, we will use it [16-QAM]. However, if the reach requirement cannot be met, the operator will not go to the expense of putting in signal regenerators to use 16-QAM do, he says.
Earlier this year Verizon conducted a trial with Ciena using 16-QAM. The goals were to test 16-QAM alongside live traffic and determine whether the same line card would work at 100 Gig using QPSK and 200 Gig using 16-QAM. "The good thing is you can use the same hardware; it is a firmware setting," says Wellbrock.
We feel that 2015 is when we can justify a new, greenfield network and that 100 Gig or versions of that - 200 Gig or 400 Gig - will be cheap enough to make sense
100 Gig in the metro
Verizon says there is already sufficient traffic pressure in its metro networks to justify 100 Gig deployments. Some of Verizon's bigger metro locations comprise up to 200 reconfigurable optical add/ drop multiplexer (ROADM) nodes. Each node is typically a central office connected to the network via a ROADM, varying from a two-degree to an eight-degree design.
"Not all the 200 nodes would need multiple 100 Gig channels but in the core of the network, there is a significant amount of capacity that needs to be moved around," says Wellbrock. "100 Gig will be used as soon as it is cost-effective."
Unlike long-haul, 100 Gigabit in the metro remains costlier than ten 10 Gig channels. That said, Verizon has deployed metro 100 Gig when absolutely necessary, for example connecting two router locations that need to be connected using 100 Gig. Here Verizon is willing to pay extra for such links.
"By 2015 we are really hoping that the [metro] crossover point will be reached, that 100 Gig will be more cost effective in the metro than ten times 10 [Gig]." Verizon will build a new generation of metro networks based on 100 Gig or 200 Gig or 400 Gig using coherent receivers rather than use existing networks based on conventional 10 Gig links to which 100 Gig is added.
"We feel that 2015 is when we can justify a new, greenfield network and that 100 Gig or versions of that - 200 Gig or 400 Gig - will be cheap enough to make sense."
Data Centres
The build-out of data centres is not a significant factor driving 100 Gig demand. The largest content service providers do use tens of 100 Gigabit wavelengths to link their mega data centres but they typically have their own networks that connect relatively few sites.
"If you have lots of data centres, the traffic itself is more distributed, as are the bandwidth requirements," says Wellbrock.
Verizon has over 220 data centres, most being hosting centres. The data demand between many of the sites is relatively small and is served with 10 Gigabit links. "We are seeing the same thing with most of our customers," says Wellbrock.
Technologies
System vendors continue to develop cheaper line cards to meet the cost-conscious metro requirements. Module developments include smaller 100 Gig 4x5-inch MSA transponders, 100 Gig CFP modules and component developments for line side interfaces that fit within CFP2 and CFP4 modules.
"They are all good," says Wellbrock when asked which of these 100 Gigabit metro technologies are important for the operator. "We would like to get there as soon as possible."
The CFP4 may be available by late 2015 but more likely in 2016, and will reduce significantly the cost of 100 Gig. "We are assuming they are going to be there and basing our timelines on that," he says.
Greater line card port density is another benefit once 100 Gig CFP2 and CFP4 line side modules become available. "Lower power and greater density which is allowing us to get more bandwidth on and off the card." sats Wellbrock.
Existing switch and routers are bandwidth-constrained: they have more traffic capability that the faceplate can provide. "The CFPs, the way they are today, you can only get four on a card, and a lot of the cards will support twice that much capacity," says Wellbrock.
With the smaller form factor CFP2 and CFP4, 1.2 and 1.6 Terabits card will become possible from 2015. Another possible development is a 400 Gigabit CFP which would achieve a similar overall capacity gains.
Coherent, not just greater capacity
Verizon is looking for greater system integration and continues to encourage industry commonality in optical component building blocks to drive down cost and promote scale.
Indeed Verizon believes that industry developments such as MSAs and standards are working well. Wellbrock prefers standardisation to custom designs like 100 Gigabit direct detection modules or company-specific optical module designs.
Wellbrock stresses the importance of coherent receiver technology not only in enabling higher capacity links but also a dynamic optical layer. The coherent receiver adds value when it comes to colourless, directionless, contentionless (CDC) and flexible grid ROADMs.
"If you are going to have a very cost-effective 100 Gigabit because the ecosystem is working towards similar solutions, then you can say: 'Why don't I add in this agile photonic layer?' and then I can really start to do some next-generation networking things." This is only possible, says Wellbrock, because of the tunabie filter offered by a coherent receiver, unlike direct detection technology with its fixed-filter design.
"Today, if you want to move from one channel to the next - wavelength 1 to wavelength 2 - you have to physically move the patch cord to another filter," says Wellbrock. "Now, the [coherent] receiver can simply tune the local oscillator to channel 2; the transmitter is full-band tunable, and now the receiver is full-band tunable as well." This tunability can be enabled remotely rather than requiring an on-site engineer.
Such wavelength agility promises greater network optimisation.
"How do we perhaps change some of our sparing policy? How do we change some of our restoration policies so that we can take advantage of that agile photonics later," says Wellbroack. "That is something that is only becoming available because of the coherent 100 Gigabit receivers."
Part 2, click here
The CDFP 400 Gig module
- The CDFP will be a 400 Gig short reach module
- Module will enable 4 Terabit line cards
- Specification will be completed in the next year
A CDFP pluggable multi-source agreement (MSA) has been created to develop a 400 Gigabit module for use in the data centre. "It is a pluggable interface, very similar to the QSFP and CXP [modules]," says Scott Sommers, group product manager at Molex, one of the CDFP MSA members.
Scott Sommers, MolexThe CDFP name stands for 400 (CD in Roman numerals) Form factor Pluggable. The MSA will define the module's mechanical properties and its medium dependent interface (MDI) linking the module to the physical medium. The CDFP will support passive and active copper cable, active optical cable and multi-mode fibre.
"The [MSA member] companies realised the need for a low cost, high density 400 Gig solution and they wanted to get that solution out near term," says Sommers. Avago Technologies, Brocade Communications Systems, IBM, JDSU, Juniper Networks, TE Connectivity along with Molex are the founding members of the MSA.
Specification
Samples of the 400 Gig MSA form factor have already been shown at the ECOC 2013 exhibition held in September 2013, as were some mock active optical cable plugs.
"The width of the receptacle - the width of the active optical cable that plugs into it - is slightly larger than a QSFP, and about the same width as the CFP4," says Sommers. This places the width of the CDFP at around 22mm. The CDFP however will use 16, 25 Gigabit electrical lanes instead of the CFP4's four.
"We anticipate a pitch-to-pitch such that we could get 11 [pluggables] on one side of a printed circuit board, and there is nothing to prohibit someone doing belly-to-belly," says Sommers. Belly-to-belly refers to a double-mount PCB design; modules mounted double sidedly. Here, 22 CDFPs would achieve a capacity of 8.8 Terabits.
The MSA group has yet to detail the full dimensions of the form factor nor has it specified the power consumption the form factor will accommodate. "The target applications are switch-to-switch connections so we are not targeting the long reach market that require bigger, hotter modules," says Sommers. This suggests a form factor for distances up to 100m and maybe several hundred meters.
The MSA members are working on a single module design and there is no suggestion of future additional CDFP form factors as this stage.
"The aim is to get this [MSA draft specification] out soon, so that people can take this work and expand upon it, maybe at the IEEE or Infiniband," says Sommers. "Within a year, this specification will be out and in the public domain."
Meanwhile, companies are already active on designs using these building blocks. "In a complex MSA like this, there are pieces such as silicon and connectors that all have to work together," says Sommers.
ECOC 2013 review - Part 1
Gazettabyte surveys some of the notable product announcements made at the recent European Conference on Optical Communication (ECOC) held in London.
Part 1: Highlights
- First CFP4 module demonstration from Finisar
- Acacia Communications unveils first 100 Gig coherent CFP
- Oplink announces a 100 Gig direct detection CFP
- Second-generation coherent components take shape
100 Gigabit pluggables
Finisar used the ECOC exhibition to demonstrate the first CFP4 optical module, the smallest of the CFP MSA family of modules. The first CFP4 supports the 100GBASE-SR4 standard comprising four electrical and four optical channels, each at 25 Gigabit-per-second (Gbps).
The CFP4 is a quarter of the width of the CFP while the CFP2 is about a half the CFP's width. The CFP4 thus promises to quadruple the faceplate port density compared to using the CFP. Finisar says the CFP4 does even better, supporting line cards with 3.6 Terabits of capacity.
"It is not just the [CFP4's] width but the length and height that are shorter," says Rafik Ward, vice president of marketing at Finisar. The CFP4s can be aligned in two columns - belly-to-belly - on the card, achieving 3.6Tbps, each row comprising 18 CFP4 modules.
We see the CFP4 as a necessity to continue to grow the 100 Gigabit Ethernet market
The CFP4 was always scheduled to follow quickly the launch of the CFP2, says Ward. But the availability of the CFP4 will be important for the MSA. Data centre switch vendor Arista Networks has said that the CFP2 was late to market, while Cisco Systems has developed the CPAK, its own CFP2 alternative. "We see it [the CFP4] as a necessity to continue to grow the 100 Gigabit Ethernet market," says Ward.
Other 100 Gigabit Ethernet (GbE) variants will follow in the CFP4 form factor such as the LR4 and SR10 and the 10x10GbE breakout variant. This raises the interesting prospect of requiring an “inverse gearbox” chip that will translate between the CFP4's four electrical channels and the SR10's 10 optical channels. "We are going to see a lot of design activity around CFP4 in 2014," says Ward.
Meanwhile, Acacia Communications unveiled the AC-100, the first 100 Gig coherent CFP module for metro and regional networks, that includes a digital signal processor (DSP) system-on-chip.
"The DSP can be programmed for different performance and power levels to achieve a range of distances," says Daryl Inniss, vice president and practice leader components at market research firm, Ovum.
Acacia Communications says a CFP-based coherent design provides carriers and content providers with a 100 Gig metro solution that is more economical than 10 Gig.
Oplink Communications announced a direct detection 100 Gig metro CFP at ECOC. The 4x28Gbps CFP uses MultiPhy's maximum likelihood sequence estimation (MLSE) algorithm implemented using its MP1100Q and MP1101Q ICs. The devices enhance the reach of the module and allows 10 Gig optical components to be used for the receive and transmit paths. "Oplink’s CFP is the first module to come to market with our devices inside," says Neal Neslusan, vice president of marketing and sales at MultiPhy.
There are now at least three vendors selling direct-detection 100Gbps modules, says Neslusan, with Oplink and Menara Networks, which has also announced a CFP product, joining Finisar.
MultiPhy is working with several additional companies and that one system vendor will come to market with a product using the company's chips in the coming months. The company is also working on a second-generation direct detection IC design. "We believe there is a compelling roadmap story for direct detection," says Neslusan.
Oclaro announced it is now shipping in volume its 10km 100GBASE-LR4 CFP2 supporting 100GbE and OTU4 (OTN) rates. Oclaro has demonstrated the CFP2 working with a Xilinx Virtex 7 FPGA. "If customers choose that combination of technology, we have already tested it for them and they can rely on those rates [100GbE and OTU4] working," says Per Hansen, vice president of product marketing, optical networks solutions at Oclaro.
JDSU also said that its CFP2 LR4 is nearing completion. "We are getting pretty close to releasing it," says Brandon Collings, chief technology officer, communications and commercial optical products at JDSU.
Ed Murphy, JDSU
The integrated transmit and receive optical sub-assembly (TOSA/ ROSA) designs for the CFP2 LR4 use hybrid integration.
"In this case it is not monolithic integration as it is in the case of the indium phosphide line side modules but hybrid integration taking advantage of our PLC (planar lightwave circuit) technology in combination with arrays of photo detectors or high speed EMLs (externally modulated lasers)," says Murphy.
JDSU has based its module roadmap on the CFP2 TOSA and ROSA designs. The designs are sufficiently integrated to also fit within the QSFP28 and CFP4 modules.
There may be tweaks to the chips to lower the power dissipation, says Murphy, but these will be minor variants on existing parts.
Coherent components
Several component makers discussed their latest compact designs for next-generation coherent transmission line cards and modules.
NeoPhotonics detailed its micro-ITLA narrow linewidth tunable laser (micro-ITLA) that occupies less than a third of the area of the existing ITLA design. The company also announced a small form factor intradyne coherent receiver (SFF-ICR), less than half the size of existing integrated coherent receivers (ICRs).
NeoPhotonics supplies components to module and system vendors, and says customer interest in the second-generation coherent components is for higher port count line cards. "Instead of 100 Gig on a line card, you can have 200 or 400 Gigabit on a line card," says Ferris Lipscomb, vice president of marketing at NeoPhotonics. Moving to pluggable module designs will be a follow-on development, but for now, the market is not quite ready, he says.
An integrated coherent transmitter for metro, combining a tunable laser and integrated indium phosphide modulator in a compact package is also offered by NeoPhotonics.
The laser has two outputs - one output is modulated for the transmission while the second output is a local oscillator source feeding the coherent receiver. About half of all 100Gbps designs use such a split laser source, says Lipscomb, rather than two separate lasers, one each for the transmitter and the receiver. "That means that one transponder can only transmit and receive the same wavelength and is a little less flexible but for cost reduction that is what people are doing," says Lipscomb.
Oclaro is now sampling to customers its next-generation indium phosphide-based coherent components. The company, also a supplier of coherent modules, says the components will enable CFP and CFP2 pluggable coherent transceivers. The pluggable modules are suited for use in metro and metro regional networks.
Oclaro's components include an integrated transmitter comprising an indium phosphide laser and modulator, and the SFF-ICR. Oclaro's micro-ITLA is in volume production and has an output power high enough to perform both the transmit and the local oscillator functions. The micro-ITLA is used for line cards, 5x7-inch and 4x5-inch MSAs module and CFP designs.
u2t Photonics is another company that is developing a SFF-ICR. The company gave a private demonstration at ECOC to its customers of its indium phosphide modulator for use with CFP and CFP2 modules. "We demonstrated technical feasibility; it is a prototype which shows the capability of indium phosphide technology," says Jens Fiedler, executive vice president sales and marketing at u2t Photonics.
u2t Photonics and Finisar both licensed 100Gbps coherent indium phosphide modulator technology developed at the Fraunhofer Heinrich-Hertz-Institute.
There are new coherent DSP chips coming out early next year
Also showcased was u2t's gallium arsenide modulator technology implementing 16-QAM (quadrature amplitude modulation) at ECOC, but the company has yet to announce a product.
JDSU also gave an update on its line side coherent components. It is developing an integrated transmitter - a laser with nested modulators - for coherent applications. "This work is underway as a technology for line side CFP and CFP2 modules," says Ed Murphy, senior director, communications and commercial optical products at JDSU.
The difference between the CFP and CFP2 coherent modules is that the DSP system-on-chip is integrated within the CFP. Acacia's AC-100 CFP is the first example of such a product. For the smaller CFP2, the DSP will reside on the line card.
"There are new DSP [chips] coming out early next year," says Robert Blum, director of product marketing for Oclaro's photonic components. The DSPs will require a power consumption no greater than 20W if the complete design - the DSP and optics - is to comply with the CFP's maximum power rating of 32W.
Pluggable coherent modules promise greater port densities per line card. The modules can also be deployed with traffic demand and, in the case of a fault, can be individually swapped rather than having to replace the line card, says Blum.
JDSU says two factors are driving the metro coherent market. One is the need for lower cost designs to meet metro's cost-sensitive requirements. The second is that the metro distances can use essentially the same devices for 16-QAM to support 200Gbps links as well as 100Gbps. "It is the same modulator structure; maybe a few of the specs are a bit tighter but you can think of it as the same device," says Murphy.
System vendors have trialled 200Gbps links but deployments are expected to start from 2014. The deployments will likely use lithium niobate modulators, says Murphy, but will be followed quickly by indium phosphide designs.
NeoPhotonics used ECOC to declare that it has now integrated the semiconductor optical component arm of Lapis Semiconductor which it acquired for $35.2 million in March 2013.
Ferris Lipscomb
The unit, known as NeoPhotonics Semiconductor GK, makes drivers and externally modulated lasers. "These are key technologies for high-speed 100 Gig and 400 Gig transmissions, both on the line side and on the client side," says Lipscomb.
NeoPhotonics, previously a customer of Lapis, decided to acquire the unit and benefit from vertical integration as it expands its 100 Gig and higher-speed coherent portfolio.
Owning the technology has cost and optical performance benefits, says Lipscomb. It enables the integration of a design on one chip, thereby avoiding interfacing issues.
Further reading:
Part 2, click here
u2t Photonics pushes balanced detectors to 70GHz
- u2t's 70GHz balanced detector supports 64Gbaud for test and measurement and R&D
- The company's gallium arsenide modulator and next-generation receiver will enable 100 Gigabit long-haul in a CFP2
"The performance [of gallium arsenide] is very similar to the lithium niobate modulator"
Jens Fiedler, u2t Photonics
u2t Photonics has announced a balanced detector that operates at 70GHz. Such a bandwidth supports 64 Gigabaud (Gbaud), twice the symbol rate of existing 100 Gigabit coherent optical transmission systems.
The German company announced a coherent photo-detector capable of 64Gbaud in 2012 but that had an operating bandwidth of 40GHz. The latest product uses two 70GHz photo-detectors and different packaging to meet the higher bandwidth requirements.
"The achieved performance is a result of R&D work using our experience with 100GHz single photo-detectors and balanced detector technology at a lower speed,” says Jens Fiedler, executive vice president sales and marketing at u2t Photonics.
The monolithically-integrated balanced detector has been sampling since March. The markets for the device are test and measurement systems and research and development (R&D). "It will enable engineers to work on higher-speed interface rates for system development," says Fiedler.
The balanced detector could be used in next-generation transmission systems operating at 64 Gbaud, doubling the current 100 Gigabit-per-second (Gbps) data rate while using the same dual-polarisation, quadrature phase-shift keying (DP-QPSK) architecture.
A 64Gbaud DP-QPSK coherent system would halve the number of super-channels needed for 400Gbps and 1 Terabit transmissions. In turn, using 16-QAM instead of QPSK would further halve the channel count - a single dual-polarisation, 16-QAM at 64Gbaud would deliver 400Gbps, while three channels would deliver 1.2Tbps.
However, for such a system to be deployed commercially the remaining components - the modulator, device drivers and the DSP-ASIC - would need to be able to operate at twice the 32Gbaud rate; something that is still several years out. That said, Fiedler points out that the industry is also investigating baud rates in between 32 Gig and 64 Gig.
Gallium arsenide modulator
u2t acquired gallium arsenide modulator technology in June 2009, enabling the company to offer coherent transmitter as well as receiver components.
At OFC/NFOEC 2013, u2t Photonics published a paper on its high-speed gallium arsenide coherent modulator. The company's design is based on the Mach-Zehnder modulator specification of the Optical Internetworking Forum (OIF) for 100 Gigabit DP-QPSK applications.
The DP-QPSK optical modulation includes a rotator on one arm and a polarisation beam combiner at the output. u2t has decided to support an OIF compatible design with a passive polarisation rotator and combiner which could also be integrated on chip. The resulting coherent modulator is now being tested before being integrated with the free space optics to create a working design.
"The performance [of gallium arsenide] is very similar to the lithium niobate modulator," says Fiedler. "Major system vendors have considered the technology for their use and that is still ongoing."
The gallium arsenide modulator is considerably smaller than the equivalent lithium niobate design. Indeed u2t expects the technology's power and size requirements, along with the company's coherent receiver, to fit within the CFP2 optical module. Such a pluggable 100 Gigabit coherent module would meet long-haul requirements, says Fiedler.
The gallium arsenide modulator can also be used within the existing line-side 100 Gigabit 5x7-inch MSA coherent transponder. Fiedler points out that by meeting the OIF specification, there is no space saving benefit using gallium arsenide since both modulator technologies fit within the same dimensioned package. However, the more integrated gallium arsenide modulator may deliver a cost advantage, he says.
Another benefit of using a gallium arsenide modulator is its optical performance stability with temperature. "It requires some [temperature] control but it is stable," says Fiedler.
Coherent receiver
u2t's current 100Gbps coherent receiver product uses two chips, each comprising the 90-degree hybrid and a balanced detector. "That is our current design and it is selling in volume," says Fiedler. "We are now working on the next version, according to the OIF specification, which is size-reduced."
The resulting single-chip design will cost less and fit within a CFP2 pluggable module.
The receiver might be small enough to fit within the even smaller CFP4 module, concludes Fiedler.
Hybrid integration specialist Kaiam acquires Gemfire
Kaiam Corp. has secured US $16M in C-round funding and completed the acquisition of Gemfire.
"We have a micro-machine technology that allows us to use standard pick-and-place electronic assembly tools, and with our micro-machine, we achieve sub-micron alignment tolerances suitable for single-mode applications"
Byron Trop, Kaiam
With the acquisition, Kaiam gains planar lightwave circuit (PLC) technology and Gemfire's 8-inch wafer fab in Scotland. This is important for the start-up given there are few remaining independent suppliers of PLC technology.
Working with Oplink Communications, Kaiam has also demonstrated recently a 100 Gigabit 10x10 MSA 40km CFP module.
Hybrid integration technology
Kaiam has developed hybrid integration technology that achieves sub-micron alignment yet only requires standard electronic assembly tools.
"With single-mode optics, it is very, very difficult to couple light between components," says Byron Trop, vice president of marketing and sales at Kaiam. "Most of the cost in our industry is associated with aligning components, testing them and making sure everything works."
The company has developed a micro-machine-operated lens that is used to couple optical components. The position of the lens is adjustable such that standard 'pick-and-place' manufacturing equipment with a placement accuracy of 20 microns can be used. "If you set everything [optical components] up in a transceiver with a 20-micron accuracy, nothing would work," says Trop.
Components are added to a silicon breadboard and the micro-machine enables the lens to be moved in three dimensions to achieve sub-micron alignment. "We have the ability to use coarse tools to manipulate the machine, and at the far end of that machine we have a lens that is positioned to sub-micron levels," says Trop. Photo-diodes on a PLC provide the feedback during the active alignment.
Another advantage of the technique is that any movement when soldering the micro-machine in position has little impact on the lens alignment. "Any movement that happens following soldering is dampened over the distance to the lens," says Trop. "Therefore, movement during the soldering process has negligible impact on the lens position."
Kaiam buys its lasers and photo-detector components, while a fab make its micro-machine. Hybrid integration is used to combine the components for its transmitter optical sub-assembly (TOSA) and receiver optical sub-assembly (ROSA) designs, and these are made by contract manufacturers. Kaiam has a strategic partnership with contract manufacturer, Sanmina-SCI.
The company believes that by simplifying alignment, module and systems companies have greater freedom in the channel count designs they can adopt. "Hybrid integration, this micro-alignment of optical components, is no longer a big deal," says Trop. "You can start thinking differently."
"We will also do more custom optical modules where somebody is trying to solve a particular problem; maybe they want 16 or 20 lanes of traffic"
For 100 Gigabit modules, companies have adopted 10x10 Gigabit-per-second (Gbps) and 4x28Gbps designs. The QSFP28 module, for example, has enabled vendors to revert back to four channels because of the difficulties in assembly.
"Our message is not more lanes is better," says Trop. "Rather, what is the application and don't consider yourself limited because the alignment of sub-components is a challenge."
With the Gemfire acquisition, Kaiam has its own PLC technology for multiplexing and de-multiplexing multiple 10Gbps and, in future, 25Gbps lanes. "Our belief is that PLC is the best way to go and allows you to expand into larger lane counts," says Trop.
Gemfire also owned intellectual property in the areas of polymer waveguides and semiconductor optical amplifiers.
Products and roadmap
Kaiam sells 40Gbps QSFP TOSAs and ROSAs for 2km, 10km and 40km reaches. The company is now selling its 40km 10x10 MSA TOSA and ROSA demonstrated at the recent OFC/NFOEC show. Trop says that the 40km 10x10 CFP MSA module is of great interest to Internet exchange operators that want low cost, point-to-point links.
"Low cost, highly efficient optical interconnect is going to be important and it is not all at 40km reaches," says Trop. "Much of it is much shorter distances and we believe we have a technology that will enable that."
The company is looking to apply its technology to next-generation optical modules such as the CFP2, CFP4 and QSFP28. "We will also do more custom optical modules where somebody is trying to solve a particular problem; maybe they want 16 or 20 lanes of traffic," says Trop.
