The Digital Offset Phase Locker (DOPLR) is an easy-to-use benchtop instrument for stabilizing voltage-tunable RF signals. The DOPLR has been designed specifically for the phase locking of laser heterodyne beat signals, though other electronic signals such as those from voltage-controlled oscillators (VCOs) can also be used.

DOPLR provides the benefits of all-digital locking capabilities in a user-friendly laboratory instrument form factor. Noisy signal? No problem! Simply power up and use the convenient knobs and buttons to optimize your loop filter settings.

A common use case is locking the fceo beat frequency obtained from an Octave Photonics COSMO module. Read more about full fceo and frep comb stabilization in our Application Note.

Link to download latest firmware: v1.0.16 [February 2026]