Abhay Joshi1, Shubhashish Datta1, Jim Rue1, Jeffrey Livas2, Robert Silverberg2, and Felipe Guzman Cervantes3
1 Discovery Semiconductors, Inc. 119 Silvia Street, Ewing, NJ 08628, USA, Tel: 609-434-1311, Fax: 609-434-1317; 2 National Aeronautics and Space Administration Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA; 3 Albert-Einstein-Instut Hannover, Callinstrasse 38, Hannover 30167, Germany
Quad photoreceivers, namely a 2 x 2 array of p-i-n photodiodes followed by a transimpedance amplifier (TIA) per diode, are required as the front-end photonic sensors in several applications relying on free-space propagation with position and direction sensing capability, such as long baseline interferometry, free-space optical communication, and biomedical imaging. It is desirable to increase the active area of quad photoreceivers (and photodiodes) to enhance the link gain, and therefore sensitivity, of the system. However, the resulting increase in the photodiode capacitance reduces the photoreceiver's bandwidth and adds to the excess system noise. As a result, the noise performance of the front-end quad photoreceiver has a direct impact on the sensitivity of the overall system. One such particularly challenging application is the space-based detection of gravitational waves by measuring distance at 1064 nm wavelength with ~ 10 pm/√Hz accuracy over a baseline of millions of kilometers.
* Proc. of SPIE Vol. 8453 84532G-1