All-fiber acetylene-referenced optical frequency comb

Abstract

We demonstrated an all-fiber compact Erbium-doped optical frequency comb based on optical reference. Compared with the traditional RF reference, the whole system adopts the all-fiber design of optical reference. Comb stabilization is achieved by simultaneously locking the repetition rate (fr) to an RF reference and an optical comb tooth to a CW reference. The standard deviation of the fr frequency in 4.5 hours was recorded as 0.37 mHz, leading to a fraction instability of 4.3 ×10−12 at 1 s gate time and 2.8 ×10−13 at 10 s gate time. The locking of single comb tooth is achieved by locking the optical comb and the beat note of the CW laser. We used the P(16) overtone transition line of 13C2H2 as the CW reference and optimized the stabilization by choosing appropriate lock point on the Doppler-limited absorption transition. The comb was able to achieve stable locking for almost five hours. The short-term fraction instability of the optical frequency was measured to be 6.56 ×10−10 at 1 s gate time, which is mostly from the CW reference. Our approach of acetylene-stabilized fiber comb offers a feasible solution to help fiber combs move from laboratory to outdoors applications based on fiber sensing, laser stabilization and spectrum analysis.