A spin noise spectrometer based on FPGA

摘要

Spin noise spectroscopy is an important tool to measure the electron spin dynamics. In this paper, an ultra fast spin noise spectrometer is designed based on FPGA(Field Programmable Gate Array). The spin noise signal is acquired using a 1 GSPS ADC(Analog-to-digital converter) and transferred to the frequency domain through a 128K points FFT(Fast Fourier Transform). In order to increase the SNR (signal to noise ration), accumulation is carried out in the FPGA in real time. The accumulation times can be configured from 1 to 128K. All this processing is implemented in a single FPGA. In order to decrease the resource cost, MDF(multiple-path delay feedback) pipelined FFT processor is designed. Compared to the existing system, the FFT points is increased with a higher spectrum resolution. The spectrometer is tested and verified with the input signal from wave generator and in the spin noise measurement.