Linewidth broadening and mode splitting due to weak feedback in single-frequency 1.5 μm lasers

Abstract

Measurements of the effect of weak feedback on single-frequency 1.5 μm lasers are reported. The results are found to agree well with published theoretical analyses. Sensitivity to feedback is found to be the same for DFB, C3 and Fabry-Perot lasers. These results indicate that coherent systems using DFB lasers may require greater than 50 dB isolation.