Self-reference shot-noise-limited phase demodulator with 1530 nm acetylene absorption line

Abstract

We report results on characterization of the self-reference interferometric configuration based on quantum memory of the acetylene (12C2H2) molecules at the wavelength of 1530.37 nm of the vibrational–rotational P9 absorption line. The demodulator under consideration is robust, simple, operates at room temperature with the wavefronts of high etendue of the sub-mW power scale, and needs neither phase, no frequency locking loops. Proposed original balance detection schemes enable effective suppression of the semiconductor laser phase noise, and the shot-noise-limited demodulation resolution at frequencies higher than the high-pass configuration cut-off frequency ≈0.25 GHz.

Keywords

• Self-reference interferometry
• Detection of phase modulation
• Spectroscopy of acetylene