1. MEMS Optical Switches Xiaobo Hou ECEE 641 March. 13, 2003

2. Introduction  Why optical switches –Explosive network traffic –Rapidly growing data rate and port count –Bottleneck due to conventional OEO switches (bandwidth, bit error rate and capacity mismatch) –Cost effective Competition is in the high date rate range

3. Optical switches  What are the options (From Tellium Inc)

4. MEMS Optical Switches  What is MEMS –Micro-Electro-Mechanical System  What is MEMS optical switches –Steerable micromirror array to direct optical light from input port to its destination port. –System-in-a-chip

5. 2D MEMS Switches  Mirrors have only 2 positions (cross or bar)  Crossbar configuration  N 2 mirrors

6. 3D MEMS Switches  Mirrors can be tilted to any angles  N or 2N mirrors accomplishing non-block switching  Good scalability

7. 3D switch examples  Lucent WaveStar LambdaRouter, 1999  Nortel X-1000 2000

8. How to fabricate  MEMS process

9. How to design  Paraxial Gaussian beam model  Optimize beam size W 0, Given separation between mirror arrays

10. Actuating Mechanism (I)  Electrostatic –mirrors are tilted by electrostatic force between opposite charged plates

11. Actuating Mechanism (II)  Electromagnetic attraction between electromagnets with different polarity

12. Actuating Mechanism (II)  Scratch Drive Actuators (SDAs) mecromachining scheme

13. Actuating Mechanism Comparison

14. Performance and Challenges  Switching speed submicrosecond  Scalability 512  512  Insertion Loss 3-7 dB  Power dissipation less than electrical switch core ? Controllability ? Reliability ? Manufactuability ? Serviceability ? standardization

15. Conclusion  MEMS optical switches are currently dominant and promising in the future  Open question to switch speed: what is the ultimate requirement?  ALL-optical? Not yet.