Scalable Micro Mechanical Optical Crossconnects
01 January 2000
Optical crossconnect switches with large port counts are the key components for the management of upcoming optical networks. Most technologies proposed for optical switches are essentially planar in geometry, which leads to switch dimensions scaling with the square of the port number. Planar technologies will not scale beyond 64x64 ports. To achieve larger (256x256, 1296x1296) switches, a three dimensional switch geometry is required. Micro electromechanical system (MEMS) are the key technology to implement array of small two tilt axis beam steering mirrors. The presented systems consist of 2D arrays of MEMS mirrors and 2D fiber a arrays each with a collimating microlens array. A cross connect path consist of light leaving one fiber and being collimated and projected onto a MEMS micro-mirror by a microlens. The first micro-mirror tilts so as to direct the beam onto a second micro-mirror, and the second micro-mirror tilts so as to direct the light towards a microlens where it is coupled into the output fiber. In this configuation the length of the switch scales linearly with number of ports, and the maximum port number is determined by used the micro mirror technology. Two switches are presented; the first with 256 port and a mean insertion loss of 7dB and the second with 1296 ports and an insertion loss of 5.1 dB. Both switch show a crosstalk smaller than -50dB. The optical performance has been verified with input optical signals ranging from 40 DWDM 40 Gb/s and 320Gb/s TDM data. On the switch with 1296 ports a potential aggregate switch capacity of 2.08 Petabit/s has been demonstrated.