Temperature dependence of polarization characteristics in buried facet semiconductor laser amplifiers

The temperature dependence of gain and amplified spontaneous power for both TE and TM modes in semiconductor laser amplifiers are measured. Experiments are performed on three selected amplifier types, with higher TE, higher TM, and equal TE-TM gains, respectively. The gain differences are significantly reduced at higher temperature for the TE-dominant and TM-dominant amplifiers. For amplifiers with equal TE-TM gains, the TE and TM gains remain equal at high temperature. The measurements of the amplified spontaneous power show similar similar characteristics. More importantly, less polarization-sensitive gain characteristics can be obtained with some decrease in maximum gain by raising the operating temperature. The experimental results are explained by using the gain equations of the semiconductor laser amplifier