Application Note: A fully stabilized 400 MHz comb using convenient digital locking electronics
Summary: In just a few hours, we built a fully stabilized optical frequency comb system using the Octave Photonics Digital Offset Phase Locker (DOPLR) and the MENHIR-1550 400 MHz mode-locked laser from Menhir Photonics. The DOPLR features two high-bandwidth (>2 MHz) locking channels and locks both the carrier-envelope-offset (CEO) and the repetition rate of the comb using an optical lock to a CW laser. The Octave Photonics Comb-Offset Stabilization Module (COSMO) detects the CEO with an exceptionally high signal-to-noise ratio of 67 dB. We demonstrate in-loop integrated phase noise of 165 mrad (CEO) and 108 mrad (optical), confirming the utility of this system for precision measurements.
Figure: Very high signal-to-noise ratio is achieved for both the fceo and optical heterodyne beats. In both cases, the locked beats exhibit integrated RMS phase noise less than 0.2 rad.
Read more in our Application Note.