Frequency Conversion by Four-Wave-Mixing in Semiconductor Laser Amplifiers: How to relax the filter problem?

Abstract

In /1/ an all optical frequency conversion method was reported, which is based on nearly de generate four-wave mixing (NDFWM) and homogeneous gain saturation in semiconductor laser amplifiers (SLA). This method promises a frequency conversion range up to about 10 THz (de pending on the gain bandwidth of the SLA), a conversion efficiency η of more than 0 dB, the frequency conversion of a given data signal simultaneously to several frequencies and finally data transparency. However, it restricts the bit rate to ≤ 1 Gbit/s. in two experiments a successful operation of this method was demonstrated /2, 3/. A disadvantage of the frequency conversion method are the severe requirements on the resolution of the optical filter, which is necessary to select the converted data signal out of a multicomponent spectrum generated at the output of the SLA. In this paper we investigate how to relax the requirements on the selectivity of the optical filter.