一种基于FPGA的高速光谱反演系统

High-speed Spectrum Inversion System Based on FPGA

为了高速采集并反演光谱数据,采用FPGA设计了一种高速光谱反演系统。由FPGA控制CCD驱动模块,使CCD高速采集干涉条纹数据并传输给FPGA处理模块。设计了高速数据采集与处理的FPGA硬件结构,通过仿真数据分析了采集模块与处理模块的时序逻辑关系。为了同时满足系统光谱反演精度与速度的要求,对比了8bit、10bit和12bit数据位深条件下的频谱分布,实验结果显示,位深越小速度越快,但其会降低光谱反演的对比度;而位深越大光谱反演的对比度越好,但处理速度越慢,综合考虑本系统采用10bit位深结构。实验针对中心波长为975nm的激光进行光谱反演,并与MATLAB反演数据进行对比分析。结果显示本系统检测精度符合要求,且速度更快。

To acquire and invert spectral data at high speed, a high-speed spectral inversion system was designed using a field programmable gate array (FPGA). A charge-coupled device (CCD) driver module is controlled by the FPGA to enable the CCD to acquire interference fringe data at high speed, and then transmit it to the FPGA processing module. In this study, the FPGA hardware structure of high-speed data acquisition and processing was designed. Through simulation data, the temporal logic relationship between the acquisition and processing modules was analyzed. To meet the requirements of system spectral inversion accuracy and speed simultaneously, we compared the spectrum distribution under 8-, 10-, and 12-bit data depth conditions. The experimental results showed that the smaller the bit depth, the faster the speed, but the contrast of spectral inversion is reduced. By contrast, the larger the bit depth, the better the spectral inversion contrast, but the slower the processing speed. Considered comprehensively, this system adopts a 10-bit deep structure. Experiments were performed on the spectral inversion of a laser with a central wavelength of 975 nm, and the results were compared with MATLAB inversion data. The results show that the detection accuracy of this system meets the requirements, and the speed is faster.