Photonic Time-stretch for high-speed analog-to-digital conversion and imaging
Nov 17, 2011
from 12:00 PM to 02:00 PM
|Contact Name||Ali M. Fard|
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Advisor: Prof. Bahram Jalali
Thursday, November 17, 2011 at 12:00PM
Engineering IV, Faraday Room 67-124
Real-time instrumentation is an underlying platform for a broad range of industrial, scientific, and medical applications. The demand for such instruments capable of detection and diagnostics in a very short time scale is rapidly growing. While alternative approaches based on strobe light effect (i.e., stroboscopic) provide valuable information about an event, capture of transient and rare-occurring events will require true real-time instruments with fine time resolution and long record length. In the context of optics, these instruments are needed to capture and quantify fast transient errors in optical communication systems and metastatic cancer cells in biological imaging systems. The photonic time-stretch is a novel technique that can slow down, amplify, and capture fast events. It provides a versatile tool for analog-to-digital conversion, imaging, and spectroscopy. This seminar focuses on the concept of photonic time-stretch technique and its applications to real-time high-speed instrumentation. It will be discussed how photonics can be helpful in achieving wideband signal digitization and characterization with high dynamic range and resolution. Novel architectures employing the photonic time-stretch pre-processor enabling rapid optical performance monitoring for future self-managed and reconfigurable optical networks will be described. Furthermore, a new approach called all-optical time-stretch oscilloscope, for real-time capture of ultrafast optical signals without the need for optical-to-electrical (O/E) and electrical-to-optical (E/O) conversions will be introduced. This new approach suggests a path to capture high-speed complex (phase- and amplitude-modulated) optical signals.
In this presentation, the photonic time-stretch technique will also be demonstrated as an enabling technology for high-speed optical imaging. A new imaging modality based on photonic time-stretch technique and spectrally-encoded imaging for high-speed high-contrast imaging of unstained transparent media will be introduced. This imaging modality, called Nomarski serial time-encoded amplified microscopy, holds great promise for high-throughput imaging and screening of biological cells.
Ali M. Fard is currently a PhD candidate in the Photonics Laboratory at University of California Los Angeles. He received his B.Sc. degree in Electrical Engineering from University of Tehran in 2007 and his M.Sc. degree from University of California Los Angeles in 2009. His research interests include biomedical optics, microwave photonics, and ultrafast data conversion. He has published over 25 journal and conference proceedings. He is also a co-inventor of 3 pending patents (US and international).
Ali Fard received the 2011 SPIE Scholarship award in Optics and Photonics, and is the recipient of 2011 L.M.K. Boelter award (Funded by Dimitris N. Chorafas Foundation). He is a member of Optical Society of America (OSA), International Society of Optical Engineers (SPIE), and Institute of Electrical and Electronics Engineers (IEEE). He is also the founding president of OSA Student Chapter, and the founding vice-president of SPIE Student Chapter at UCLA.