Temperature dependence of the second harmonic distortion of buried heterostructure distributed feedback lasers

The measurements of second harmonic distortion at different temperatures for 1.3 mu m buried heterostructure distributed feedback lasers are reported. The results show that under low frequency modulation the lasers generate different levels of harmonic distortion at different temperatures and the bias level for the null point may increase with the operating temperature. This temperature dependence of the second harmonic distortion can be associated with the laser´s leakage current. On the other hand, under high frequency modulation, the magnitude of harmonic distortion is not sensitive to temperature change.