A simple and low-cost setup for part per billion level frequency stabilization and characterization of red He-Ne laser

This work describes the frequency stabilization of a dual longitudinal mode, red (632.8 nm) He-Ne laser, implemented using a low-cost microcontroller and its performance characterization using a simple interferometric method. Our studies demonstrate that frequency stability up to 0.42 MHz (3$\sigma$, 17 hours) can be achieved using this set up. This simple and low-cost system can serve as an excellent part per billion level frequency reference for several high resolution spectroscopy based applications.