A Design Approach For A High Performance Optical Spectrum Analyzer

This paper introduces a design approach of a high performance optical spectrum analyzer. First, it analyses inland demand for the analyzer, then points out the gap between the fields national and abroad. And in succession, it introduces the rationale of the optical spectrum analyzer, and puts forward three schemes to carry out the project: diffraction raster type, Fabry-Perot interferometer type and Michelson interferometer type.The optical spectrum analyzer of diffraction raster type can test the spectrum of all kinds of LDs and LEDs. The resolution bandwidth of the spectrum can be changed as wish. And this scheme has the advantages such as broad wavelength span, high sensitivity, wide dynamic range and so on. So, this project adopts the realization scheme of double-pass raster monochromator plus direct drive and direct reading of the raster's angle position to control.Utilization of double-pass raster monochromator can obtain the high sensitivity of a single raster monochromator and the wide dynamic range of a double raster monochromator simultaneously. The elaborate cuneiform-delay board inserted in the optical path can provide excellent insensitive polarization characteristics. Collimation and focus system choose high-quality paraboloid reflector to reduce the size of monochromator, so as to decrease the cubage of the analyzer to the minimum limit. At the same time because the reflective system has no chromatic aberration, the system conduces to improve the analyzer's resolution. The control system of high resolution, direct drive and direct reading of diffraction raster's angle position can not only eliminates the diverse inherent errors of the traditional gear decelerating mechanism, but also greatly improve the scan speed of the raster.The paper then analyzes hardware scheme, software scheme and structure scheme to carry out the project and analyzes key technologies and their realization method directly related to the project. It whereafter provides the main technicalspecifications' test methods and test results. In the end it compares the product with oversea up-to-date optical spectrum analyzer and proves that the technical level completely reaches the highest level in this field overseas.