Abstract

The use of wavelength convertors in multiwavelength optical networks can enhance network flexibility. Cross-phase saturation effects in semiconductor optical amplifiers (SOAs) have been used in interferometric arrangements to acWeve noninverted conversion with chirp compression and high extinction ratios.¹ However, successful operation of such devices requires careful control of the drive conditions. Furthermore, their high-speed low-chirp operation, requiring large signal and cw powers, must avoid gain saturation, which counteracts the noninverted interferometric conversion. The cross-gain-saturation effect in SOAs, on the other hand, has been shown to enable robust high-speed wavelength conversion. Under strong electrical and optical pumping, conversion speeds in excess of 20 Gbit/s have been illustrated.² However, the effect of chirp on transmission distance at such ultrahigh bit rates has not been studied theoretically in detail. This paper considers the chirp introduced on conversion, employing crossgain saturation, and studies its dependence on amplifier drive current and signal power. It further shows how an increase in injected cw optical power can reduce chirp while improving conversion speed.

© 1996 Optical Society of America