Study On Multi-Channel Grating Spectrometer Of SD-OCT

The paper studies on spectrometer,the important part of SD-OCT.In order to improve the resolution ratio and reduce the cost of SD-OCT system,the paper proposes a new design of Multi-Channel grating spectrometer.Then design the structure of the spectrometer in the non-sequential mode of Zemax and optimize the image of the spectrometer in the sequential mode of Zemax.Choose FPGA to drive array CCD.Deign the software of the spectrometer based on LabVIEW.The main contents of this paper were as follows:(1)In order to make sure the array CCD can receive all spectrum signals,this paper designs the structure of the multi-channel grating spectrometer.In the non-sequencial mode of the Zemax,we set different channels in right positions.Although,in the mode of sequencial,we optimize the quality of the image of the system,to make sure different spectrum signal of different wavelenths received by single pixel of the array CCD.(2)Choose array CCD TH7888 A of the company of Atmel as the sensor of receiving spectrum signals.To drive the CCD,we use FPGA chip based on hardware description language Verilog on the platform of ISE 14.0 to design the driving circuit.As a result,we get the right driver of the array CCD.In addition,the output frequency of the CCD is 20 MHz.(3)Design the software of multi-channel spectrometer based on the platform of LabVIEW.The software has the function of data acquisition,data storage and data processing,etc.we can use it to measure the wave length or the thickness of objects.Using the function of measuring wavelength,we can get two important parameters of SD-OCT,the wavelength and the FWHM.By the function of measuring objects,we can get the thickness.Those functions of the software all have been test.