Abstract

The wavelength conversion using the four-wave mixing (FWM) effect in a semiconductor optical amplifier (SOA) can provide the needed functions for optical networks,¹ but it suffers from poor conversion efficiency. Significant improvement on the conversion efficiency and noise figure is required for practical applications. The FWM conversion efficiency increases approximately with G₀P²_s, where G₀ is the unsaturated gain and P_s is the saturation intensity of the SOA.¹ Therefore, increasing the gain and/or saturation power of a SOA is the key to improve conversion efficiency. The saturation intensity is inversely proportional to the carrier lifetime. The carrier recovery rate can be enhanced by injecting a holding light of which the wavelength is in the gain region of the SOA.² This method raises the saturation intensity but decreases the amplifier gain. Dupertuis et al. proposed to use an assisted beam at transparency to speed up a SOA.³ This technique can increase the saturation intensity without sacrificing the gain. In this paper, we will demonstrate that using an assisted beam can improve the efficiency and signal-to-noise ratio of FWM wavelength conversion.

© 2002 Optical Society of America