MEMS Optical SwitchesIntroductionOptical switchesSlide 42D MEMS Switches3D MEMS Switches3D switch examplesHow to fabricateHow to designActuating Mechanism (I)Actuating Mechanism (II)Slide 12Actuating Mechanism ComparisonPerformance and ChallengesConclusionMEMS Optical SwitchesXiaobo HouECEE 641March. 13, 2003Introduction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 rangeOptical switchesWhat are the options(From Tellium Inc)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-chip2D MEMS SwitchesMirrors have only 2 positions (cross or bar)Crossbar configurationN2 mirrors3D MEMS SwitchesMirrors can be tilted to any anglesN or 2N mirrors accomplishing non-block switchingGood scalability3D switch examplesLucent WaveStar LambdaRouter, 1999Nortel X-10002000How to fabricateMEMS processHow to designParaxial Gaussian beam model Optimize beam size W0, Given separation between mirror arrays0wZR2002011)(wzwzzwzwR21)(0zwoptActuating Mechanism (I)Electrostatic–mirrors are tilted by electrostatic force between opposite charged platesActuating Mechanism (II)Electromagneticattraction between electromagnets with different polarityActuating Mechanism (II)Scratch Drive Actuators (SDAs)mecromachining schemeActuating Mechanism ComparisonActuating Mechanisms Advantages Disadvantages Electrostatic Well understood Good repeatability Nonlinearity in force-voltage relationship, High driving voltages. Electromagnetic Large force High linearity Low driving voltages Shielding magnetic devices Reliability to be proved Scratch Drive Actuator(SDA) No holdup voltage required Movement in small steps (10nm) (N/A)Performance and ChallengesSwitching speedsubmicrosecondScalability512  512Insertion Loss3-7 dBPower dissipationless than electrical switch core?Controllability?Reliability?Manufactuability?Serviceability?standardizationConclusionMEMS optical switches are currently dominant and promising in the futureOpen question to switch speed:what is the ultimate requirement?ALL-optical?Not