Stability Control of Intermediate Frequency for A Double Cavity HCN Laser

As the light source of the interferometer, the HCN laser's frequency stability is particularly important. This paper analyzes the significance of a frequency stabilization system and the principle of intermediate frequencies signal generation. We design a system which employs a two-cavity HCN laser to obtain a stable intermediate frequency (IF) output. The system is based on ARM embedded system with the principle of intermediate frequency acquisition. PID is the core algorithm of the system.