Phase-locking of octave-spanning optical frequency comb based on Kerr-lens mode-locked Yb:KYW laser to reference laser

• Published in: Japanese Journal of Applied Physics Vol. 60; no. 2; pp. 22003 - 22008
• Main Authors: Mitaki, Masatoshi, Sugiyama, Kazuhiko
• Format: Journal Article
• Language: English
• Published: Tokyo IOP Publishing 01.02.2021; Japanese Journal of Applied Physics
• Subjects: Carrier density; Damping; Laser mode locking; Lasers; Lenses; Locking; Optical frequency; Piezoelectricity; Semiconductor lasers
• ISSN: 0021-4922; 1347-4065
• DOI: 10.35848/1347-4065/abd86c

We phase locked an octave-spanning optical frequency comb based on a laser-diode-pumped Kerr-lens mode-locked Yb:KYW laser to a reference laser. We controlled the cavity length of the mode-locked laser to phase lock the mode frequency of the comb to the reference laser. This was conducted using a fast piezoelectric-actuated mirror on a lead-filled mount, which was aimed at damping the mechanical resonances. We achieved a servo bandwidth of 200 kHz, a residual phase noise of 0.47 rad, and a power concentration to a carrier of 91%. To extend the locking duration of the carrier-envelope offset frequency, we compensated its slow drift using the position of the Yb:KYW crystal while the pump-laser power was controlled to achieve its phase locking. We continuously maintained the full phase locking of the comb for 3 h until the reference lasers were out of lock.