Modulation system and modulation characteristics of high power semiconductor laser

In this paper, we studied the factors that affect the high frequency modulation performance of semiconductor laser in the process of direct modulation. The equivalent circuit model of LD is derived from the rate equation of semiconductor laser, which was established by using PSpice. We analyzed the effects of the parasitic parameters, the DC bias and the current modulation intensity on modulation characteristics of the laser, and put forward the corresponding methods to improve the performance of modulation. We designed a direct modulation system of semiconductor laser and simulated the system by OrCAD/PSpice. This system can output modulation semiconductor laser with frequency of 1 MHz and average power of 1.1 W.