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



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


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.
Optics Letters
Vo. 21
No. 13


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


Ye, J. , Ma, L. and Hall, J. (1996), Sub-Doppler Optical Frequency Reference at 1.064 &#965;m Via Ultrasensitve Cavity-Enhanced FM Spectroscopy of C<sub>2</sub>HD Overtone Transition, Optics Letters (Accessed February 25, 2024)
Created November 30, 1996, Updated October 12, 2021