Simultaneous measurement of the linewidth, linewidth enhancement factor /spl alpha/, and FM and AM response of a semiconductor laser

Using a commercially available computer controlled spectrum analyser with tracking generator, optical input section, and optical delay line it is possible to measure the linewidth, linewidth enhancement factor /spl alpha/, and FM and AM response of a semiconductor laser in one process. The determination of the linewidth yields also information about the frequency noise density and the determination of a delivers information about the nonlinear gain. Assuming an optical input power of 0 dBm, a laser linewidth <50 MHz and a modulation response of the laser without cut-off, AM indices m>0.01% and FM deviations of about >10 MHz up to 20 GHz can be detected.<
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