基于现场可编程门阵列技术(Field-Programmable Gate Array, FPGA),我们开发了采样速率、数据处理长度等多参数可调的快速傅立叶变换功能模块,用于灵活匹配实验测量中所要求的带宽和谱分辨率等参数要求。通过磁光法拉第自旋噪声谱在半导体的对比测量,我们验证了FPGA技术的数据处理速率是商业谱分析仪的600倍左右。

We have developed real-time fast Fourier transformation (FFT) of a tunable sampling rate and data length using a field-programmable gate array (FPGA), respectively, for a best match of the spectral bandwidth and spectral resolution required in a specific measurement. By performing spin noise measurements of Faraday rotation in n-GaAs, we have demonstrated that the rate of processing data by the developed FPGA-based FFT is higher by a factor of ～600 than that by a commercial spectrum analyzer.