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Presenter: Dr. Lukas Chrostowski - Assistant Professor, Electrical and Computer Engineering, Faculty of Applied Science, University of British Columbia
Supervisor:

Date: Fri, May 6, 2005
Time: 14:30:00 - 15:30:00
Place: EOW 430

ABSTRACT

Abstract

Semiconductor diode lasers have been widely deployed for optical communications for 30 years. Recently, however, the highest-performance links (ex. DWDM, > 10 Gb/s) have had to resort to bulky and expensive external modulators, instead of using the more simple direct modulation approach. A large optical chirp, a low frequency response, and high signal distortion are the main reasons for the unsuitability of directly modulated lasers for both digital and analog fiber communication.

In this talk, I will review experimental results showing tremendous improvements in the performance of directly modulated 1.55 um Vertical Cavity Surface Emitting Lasers. These were obtained by using the optical injection locking technique. Optical injection locking uses a second laser to inject photons at a similar wavelength into the transmitter laser. The transmitter laser is thus locked (in wavelength and phase) to the master due to the coherent non-linear interaction in the cavity. The dynamic properties of the laser are significantly enhanced, including: a) the resonance frequency can increase from 5 GHz to over 50 GHz, b) optical chirp is reduced 3X, c) signal distortion is reduced by 10 to 20 dB Hz 2/3, and d) laser relative intensity noise is decreased by 10 dB.

Biography

Lukas Chrostowski received the degrees of B. Eng. in Electrical Engineering at McGill University in 1998, and PhD at the University of California, Berkeley, in 2004. His thesis was on "Optical Injection Locking of Vertical Cavity Surface Emitting Lasers." His research interests are in the areas of nanophotonics, high-speed modulation of semiconductor lasers, optical communications, fabrication of vertical cavity lasers, and bio-medical applications. He is currently an assistant professor in the Electrical and Computer Engineering department at the University of British Columbia. He received the 2004 Demetri Angelakos Memorial Award at Berkeley which is given to a graduate student who both excels in his/her work and generously helps other students. Lukas has climbed several mountains, including Denali (also known as McKinley), which at 6194 meters is the highest peak in North America.