Sub-Doppler Optical Frequency Reference at 1.064 υm Via Ultrasensitve Cavity-Enhanced FM Spectroscopy of C2HD Overtone Transition

Published

December 1, 1996

Author(s)

J Ye, L -. Ma, John L. Hall

Abstract

Using our newly-developed frequency modulation technique with a high finesse cavity, we have obtained the saturated signal of the weakly-absorbing gas of C₂HD for the P(5) line of υ₂+3υ₃) overtone band at 1.064 υm. An integrated absoption sensitivity of 1.2X10^-10(1.8X10^-12/cm) has been obtained. The absolute frequency of the line center is established (within +or-}2.6 kHz) with respect to a doubled Nd:YAG laser/I₂ frequency reference. The short term stability, limited by the avaliable signal-to-noise ratio, is currently at 1x10^-11 at 1 second, improving to 5x10^-13 at 1000 sec. Pressure broadening coefficient is measured to be 34.7(0.5) kHz/mTorr (260 +or-}3.8kHz/Pa). An observed line width of four times narrower than that dictated by the room temperature transmit time limit has been obtained by selsecting slow molecules at the pressure of 2 mTorr.

Citation

Optics Letters

Volume

Vo. 21

Issue

No. 13

Pub Type

Journals

Keywords

absoption sensitivity, molecular overtone transition, Nd, optical frequency reference, pressure broadening, slow molecules, YAG laser(NPRO)

Citation

Ye, J. , Ma, L. and Hall, J. (1996), Sub-Doppler Optical Frequency Reference at 1.064 υm Via Ultrasensitve Cavity-Enhanced FM Spectroscopy of C₂HD Overtone Transition, Optics Letters (Accessed October 11, 2025)