Abstract
We report the first experimental observations of enhancement of nearly degenerate four wave mixing (NDFWM) in a distributed, feedback (DFB) semiconductor laser amplifier rising a method recently proposed theoretically by McCall.1 The NDFWM interaction has received recent attention due to its possible uses for rapid (ns), low power (µW) phase conjugation, THa frequency conversion, and as a diagnostic tool for probing device characteristics.2 Furthermore, in telecommunication systems, the phenomenon may represent a source of cross-talk in travelling wave amplifiers for channel spacings less than a few Ghz3, which should ideally be minimized. A common collinear interaction geometry (also used in our experiments) consists of injecting an optical amplifier with a large pump signal and a weaker, frequency- shifted probe signal. The nonlinear mixing generates a "frequency-flipped" phase conjugate of the probe. A typical spectrum is shown in Fig. 1(a). The mechanism of NDFWM has been theoretically modelled by Agrawal1 and is based on carrier density population pulsations due to optical beats between injected signals. The enhancement technique employed in this experiment involved modulating the DFB amplifier drive current also at the beat frequency.
© 1993 Optical Society of America
PDF ArticleMore Like This
Takaaki Mukai and Tadashi Saitoh
WD1 International Quantum Electronics Conference (IQEC) 1988
Larry A. Rahn
TuB1 High Resolution Spectroscopy (HRS) 1993
François Girardin, Georg Guekos, and Antonio Mecozzi
CThH18 The European Conference on Lasers and Electro-Optics (CLEO/Europe) 1998