@article{5999,
  author = {Jun Ye and L.-S. Ma and John Hall},
  title = {Sub-Doppler optical frequency reference at 1064 μm by means of ultrasensitive cavity-enhanced frequency modulation spectroscopy of a C_2HD overtone transition},
  abstract = {Using our cavity-enhanced frequency modulation technique, we obtained the saturated signal of the weakly absorbing gas C2HD for the P(5) line of the (ν2 + 3ν3) overtone band at 1.064 μm. An absorption sensitivity of 1.2 × 10−10 (1.8 × 10−12/cm) has been obtained. The absolute frequency of the line center is established (within ±2.6 kHz) with respect to a doubled Nd:YAG laser/I2 frequency reference. The short-term stability, limited by the available signal-to-noise ratio, currently is 1 × 10−11 at 1 s, improving to 5 × 10−13 at 1000 s. The measured pressure-broadening rate is 34.7(0.8) kHz/mTorr (260 ± 6.1 kHz/Pa). Selection of slow molecules gave a linewidth four times narrower than the room-temperature transit-time limit.

© 1996 Optical Society of America},
  year = {1996},
  journal = {Optics Letters},
  volume = {21},
  pages = {1000},
  month = {1996-07},
  issn = {0146-9592},
  doi = {10.1364/OL.21.001000},
}