The Californian-based start-up has as been selling its FC 320, a 320-port 3D MEMS-based switch, since 2006. The optical switch is used by Verizon and AT&T at submarine cable landing sites, and by Government agencies.

Now Calient has raised US $19.4 million (€13.77M) in its latest funding round to complete the development and manufacturing of a more compact, power efficient version of its optical switch.

The company has upgraded the electronics and software of its MEMS-based optical switch module. This, says Gregory Koss, Calient's senior vice president for products and partners, reduces the power consumption to 20W, a 90% reduction compared to its existing design.

The new switch module is also more compact. Using the module in a new 320-port switch platform more than halves the size: from 17 to 7 rack units.

The 3D MEMS optics has not been changed. The MEMS design uses mirrors to form a free-space connection between an fibre input port and any of the 320 output ports. A control system then adjusts the mirrors to maximise the output signal. In all the years Calient has been selling its systems, there has not been a single MEMS failure, says the company.

Calient is also changing its strategy by selling the switch as a module to system vendors. The switch module can be incorporated on a line card, while Calient will work with system vendor partners that want to integrate the module within their own platform designs.

"[Data centre] operators want a future-proofed network. They don't want to rebuild when links are upgraded from 10 to 40 and then 100 Gig."

Gregory Koss, Calient Technologies

Data centre and cloud

Calient's MEMS-based switch will be used to connect large server clusters in content service providers' 'mega' data centres.

According to Koss, content service providers are interested in using an optical switch to link their server clusters. In a typical configuration, 48 servers are connected to a top-of-rack switch. This top-of-rack switch, via a 10 Gigabit Ethernet link, would be one input to the 320-port optical switch.

"[Data centre] operators want a future-proofed network," says Koss. "They don't want to rebuild when links are upgraded from 10 to 40 and then 100 Gig."

Common cabling used in the data centre include copper and multi-mode fibre while Calient's design uses single-mode fibre. According to Koss, data centre managers are installing more single-mode fibre: "It is it not so much for reach but for bandwidth and for scaling.”

The switch can also be used for what Calient calls cloud networking, to monitor and manage an enterprise's fibres as it enters the data centre.

ROADMs

The switch will also address agile optical networking, to enable colourless, directionless and contentionless ROADMs.

The optical module will be used for the add/ drop, alongside rather than replacing 1x9 or 1x20 WSSs which are used for the pass-through lambdas.

Koss says that the company's main focus in 2012 is addressing the data centre market opportunity but that the switch is of interest to ROADM system vendors. Such a 3D MEMS-based ROADM design will take longer to bring to market.