Astarte Demonstrates Optical Cross-Connect with MEMS Switch

Using optical switching technology from Texas Instruments Inc. (TI, Dallas, TX), Astarte Fiber Networks Inc. (Boulder, CO) has demonstrated a single-stage optical cross-connect platform with hundreds of fiber ports that it says will scale to handle thousands of ports.

Single-stage switching produces low loss, even for optical switches with very large port counts, Astarte explains, asserting that other technologies require multiple switch stages to achieve port counts beyond 16x16 because losses become too great. Larger switches can be built from these smaller blocks, but amplification and interconnection difficulties make these technologies impractical today, Astarte says.

The switch actuating mechanism grew out of TI's production of Digital Micromirror Device (DMD) microchips, used in projection displays and hardcopy applications. The switch actuating mechanism includes silicon micromirrors based on microelectomechanical systems (MEMS). The hermetically packaged mirrors are electromagnetically controlled. Astarte tested the mirror for hundreds of millions of switching operations.

Each module in Astarte's cross-connect contains transmit and receive fibers ports and associated optical and electronic components. Removable modules allow technicians to perform in-service expansion of the switch and module-level repairs.

Redundant system processors download connection commands received by the cross-connect to the individual modules. Each module then autonomously performs the commanded connection, concurrently with switch connection commands.

Non-blocking connectivity through the cross-connect allows connections between any pair of input and output fibers to co-exist. Establishment or termination of any optical connection has no effect on existing connections within the cross-connect, which can fully reconfigure and implement a new connection table in less than 10 milliseconds.

The cross-connect transparently handles optical signals in the range of 1250 nm to 1650 nm. Data rate transparency allows carriers to upgrade their fiber networks without changing the cross-connect.

Insertion loss (input fiber to output fiber) is less than 6 dB over the entire transmission window, and polarization-dependent loss is less then 0.5 dB.