Jennifer A. Taylor+*, Frank Quinlan*, Archita Hati*, Craig Nelson*, Scott A. Diddams*
+Dept. of Physics, University of Colorado Boulder, CO, USA
*Time and Frequency Division National Institute of Standards and Technology Boulder, CO, USA
Shubhashish Datta, Abhay Joshi
Discovery Semiconductors, Inc.
119 Silvia Street
Ewing, NJ 08628, USA
Tel: 609-434-1311, Fax: 609-434-1317
Femtosecond laser frequency combs provide an effective and efficient way to take an ultra-stable optical frequency reference and divide the signal down into the microwave region. In order to convert optical pulses into a usable rf signal, one must use high-speed photodetection; unfortunately, excess phase noise from both technical and fundamental sources can arise in the photodetection process. In order to ultimately minimize the noise effects of the photodetector, must first characterize some of the known sources for noise arising in these devices. In this paper, we will study two sources of excess noise in high-speed photodiodes power-to-phase conversion and shot noise. The noise performance of each device will give us clues as to the nature of the sources, their effect on the output signal, and what design features of the photodiode minimize these noise effects.
* Proc. 2010 IEEE Intl. Freq. Cont. Symp., pp. 684 - 688, Newport Beach, CA, June 1-4, 2010