Standalone optical frequency-offset locking electronics for atomic physics

We present a standalone frequency-offset locking system for controlling narrow-linewidth lasers using off-the-shelf electronic components. We lock two frequency-doubled 1560 nm lasers to a stable primary laser operating at 780 nm via their optical beat note. This radio frequency beat note is fed through a broadband variable divider, a frequency-to-voltage converter, and a proportional-integral controller to lock each follower laser to a tunable offset frequency relative to the primary. This arch