Improvement on frequency stabilization servo system of the external cavity semiconductor laser

In this paper, the technology of molecule saturation absorption frequency stabilization of the external cavity laser diodes (ECLD) on 1.5 mu m which is recently researched is discussed, and it can obtain high ratio of precision. The improved scheme of the servo circuit system of the ECLD's molecule saturation absorption frequency stabilization is investigated in the paper. The peripheral loop servo circuit system is the key of the frequency stabilization control. The original servo system uses a lot of discrete components. Its structure is intricate and the performance is not stable enough. In the paper, the parts of the peripheral closed loop servo are conformed in an FPGA slug. This module can realize the closed loop control functions which are necessary for the frequency stabilization. So, the whole system is not only integrated and minityped, but also can be intelligent controlled; the stabilization is greatly increased, and it enables the accuracy to reach 10(-8)rad.