HIGH MODUALATION RATE WAVEGUIDE PHOTODIODES

AT FREQUENCIES ABOVE 10 GHZ, CONVENTIONAL PHOTODIODES MUST SACRIFICE QUANTUM EFFICIENCY FOR SPEED SINCE THE THIN ACTIVE LAYERS REQUIRED DO NOT ABSORB ALL OF THE LIGHT PASSING THROUGH THEM. A WAVEGUIDE PHOTODIODE STRUCTURE ALLOWS ABSORPTION OVER A MUCH GREATER LENGTH ALONG THE ACTIVE LAYER THUS PROMISING BOTH SPEED AND EFFICIENCY. SUCH A PHOTODIODE REQUIRES A MORE SOPHISTICATED APPROACH FOR EFFICIENT COUPLING TO AN OPTICAL FIBER. WE PROPOSE TO DEMONSTRATE A FIBER-COUPLED PACKAGED WAVEGUIDE PHOTODIODE WITH AN EFFICIENCY OF >80% AND A 3 DB FLAT RESPONSE TO >20 GHZ.