Development and study of a 1.5 μm optical frequency standard referenced to the P(16) saturated absorption line in the (v_(1)+v_(3)) overtone band of ~(13)C_(2)H_(2)

摘要

We describe a recently developed saturated absorption spectrometer realizing an optical frequency standard based on the P(16) transition of the (v_(1)+v_(3)) band of ~(13)C_(2)H_(2). Studies of stability, reproducibility and sensitivity to various parameters were performed. The current stability of the system has been measured to reach 4×10~(-13) for an averaging time of 100 s. To our knowledge, we report the first results on the parameter shifts of the Doppler-free P(16) line. A modulation amplitude shift of 4700±300 Hz/MHz_(pp), an intracavity power shift of -11.4±0.6 Hz/mW, and a pressure shift of -230±20 Hz/mTorr were measured for standard operating conditions of: 1.0 MHz_(pp) modulation excursion, 120 mW intracavity power, and 20 mTorr gas pressure. Control of these parameters should allow kilohertz reproducibilities of this device in the long term.