An acetylene (¹³ C₂H₂) stabilized single‐polarization fiber laser

In this paper, we report on a nonmodulated output‐type frequency stabilized fiber laser that uses an absorption line of the acetylene molecule. First, in this fiber laser, a single‐frequency oscillation was formed by inserting into the resonator a 3.7‐GHz super‐narrow‐band optical filter that uses a fiber Bragg grating (FBG). Next, fully 2‐GHz continuous tuning of the oscillation frequency was achieved by tuning while synchronizing the central frequency of the FBG and the laser resonance frequency. We succeeded in stabilizing the oscillation frequency of this laser at a linear absorption line of the molecule (line width approximately 700 MHz) of an acetylene absorption cell set up externally. The stability of the optical frequency estimated from the error signal (Allan variance) was highly stable, namely, 1.7×10 −10 for an integration time of 1 s and 1.7×10 −11 for 10 2 s. Its oscillation linewidth was approximately 6 kHz, and thus a narrow‐linewidth single‐polarization frequency‐stabilized laser was realized.