Photonic time-stretch analog-to-digital conversion for high resolution and real-time burst sampling of ultra-wideband signals

Shalabh Gupta
Advisor: Bahram Jalali

Friday, May 29, 2009 at 11:00am-1:00pm
Engr IV Room 67-124

Abstract:
To satisfy the ever growing bandwidth demand created by evolution of the internet, future optical transmission systems are expected to achieve 100-Gbps and higher data rates per wavelength channel. To enable these data rates, optical links with bandwidth efficient modulation formats are being developed. The receivers for such links need to remove channel impairments using complex signal processing, which can now be performed digitally thanks to advancements in CMOS technology. However, analog-to-digital converter (ADC) remains a crucial bottleneck in digitizing these signals. In this talk, techniques developed for achieving high-resolution photonic time-stretch analog-to-digital conversion of ultra-wideband signals will be presented, as a step towards overcoming this bottleneck.

High-speed ADCs are also crucial for test and measurement equipment. To improve capture speeds and real-time bandwidths, new sampling techniques are required, for which, real-time burst sampling (RBS) using the time-stretch ADC is introduced in this work. This technique combines real-time captures with large bandwidth capabilities, to create the world's first and fastest hybrid sampling oscilloscope. In this talk, I will also show how this system can be used to revolutionize high-speed test and measurement equipment.

Biography:
Shalabh Gupta received B.Tech degree in Electrical Engineering from Indian Institute of Technology Kanpur, India, in 2001 and M.S. degree in Electrical Engineering from University of California Los Angeles (UCLA) in 2004. He is currently a Ph.D. candidate in the EE department at UCLA.

From August 2003 to March 2006 he worked at Chrontel Inc., San Jose, CA and Skyworks Solutions Inc., Irvine, CA, designing analog and RF ICs for high speed serial links and GSM/EDGE transceiver chipsets. During summer 2008, he was with NEC Labs, Princeton, NJ, where he was involved in solving problems related to next generation (100-Gbps) optical communications systems. His research interests include photonic analog-to-digital conversion, ultrafast optical signal processing, high-speed optical communications systems, biophotonics, and high-speed analog/RF integrated circuits.