A BURIED ELECTRODE MACH ZEHNDER WAVEGUIDE INTENSITY MODULATOR WITH OPERATION SPEEDS IN EXCESS OF 100 GHZ

THIS PROPOSAL DESCRIBES AN APA OPTICS PROGRAM TO DEVELOP A HIGH SPEED (100GHZ) GAAS WAVEGUIDE BASED MACH ZEHNDER MODULATOR. OUR APPROACH CENTERS ON THE USE OF A BURIED ELECTRODE CONFIGURATION TO ACHIEVE VELOCITY MATCHING OF THE RF AND OPTICAL SIGNALS. THIS WE FEEL WILL RESULT IN A DEVICE WITH A BROADBAND RESPONSE FROM DC TO 100GHZ. WE WILL WORK IN CONJUNCTION WITH THE ULTRFAST SCIENCE LAB AT THE UNIVERSITY OF MICHIGAN WHICH WAS THE FIRST GROUP TO PROPOSE THE USE OF SUCH SUPERSTATE CONCEPT FOR VELOCITY MATCHING. THE GOAL OF OUR PHASE I PROGRAM WILL BE TO DEMONSTATE THE VALIDITY OF OUR TECHNICAL APPROACH. WE WILL USE AN INHOUSE MBE SYSTEM TO FABRICATE THE OPTICAL WAVEGUIDE STRUCTURES. THESE WILL BE METAL (TUNGSTEN, TITANIUM ETC.) COATED AND THEN COVERED WITH THE GAAS SUPERSTRATE BY SUING A MBE PROCESS. THE RF AND OPTICAL VELOCITIES IN THESE STRUCTURES WILL THEN BE MEASURED TO SHOW IF THE NECESSARY SLOWDOWN OCCURRED. THE PHASE I PROGRAM WILL ALSO INCLUDE DEVELOPMENT OF PROCESSING SEQUENCY FOR THE FABRICATION OF THE MACH ZEHNDER DEVICES UNDER A PHASE II PROGRAM. WITH OUR EXPERTISE IN FABRICATING GAAS BASED MACH ZEHNDER MODULATORS FOR A COMMERCIAL PRODUCT (FLAT RESPONSE FROM DC TO 3 GHZ, TOTAL OPTICAL LOSSESS 8 DLB) AND AN ONGOING SDI SUPPORTED PROGRAM FOR HIGH SPEED COUPLER DEVICES, WE ARE IN AN EXCELLENT POSITION TO CARRY OUT THE PROPOSED WORK.