High-performance data acquisition and processing system based on SOM-FPGA and its application in optical instruments

An ideal data acquisition and processing system has the characteristics of high integration, low latency, wide applicability, and scalability. Its development plays a vital role in the advancement of optical instruments. Most of the data acquisition and processing systems currently used are based on digital signal processing (DSP) or system-on-chip (SoC) architectures, which are limited in processor performance, number of interfaces, and edge computing capabilities. In this presentation, we report a data acquisition system (SOM-FPGA lock-in, SFLI) based on modular system-on-module (SOM) and field-programmable gate array (FPGA) architecture. The SFLI system integrates high-speed signal acquisition and processing, digital lock-in amplifier (DLIA), and edge data storage functions, improves the edge computing capability of the system, and has the advantages of high performance, multiple interfaces, and low cost. The system can simultaneously achieve four-channel high-speed acquisition (sampling rate up to 65 MSPS) and digital phase sensitive detector (demodulation frequency from DC to 5 MHz). When the modulation frequency is 20 kHz and the input voltage range is 1 V, the input voltage noise of the SFLI system is about 41 nV/√Hz. The performance of the SFLI system is compared with that of a commercial lock-in amplifier, showing good consistency. The SFLI has been applied to cavity-enhanced spectroscopy technology, providing a new solution for the miniaturization of optical instruments and edge computing in practical applications.