Development of an acetylene optical frequency standard at 1.5 μm and its applications

We report the recent progress of our work on the development of an optical frequency standard in the 1.5 mum region based on a Doppler-free acetylene absorption. We have developed compact and portable acetylene-stabilized diode lasers for practical use. We have realized the frequency stability and reproducibility of about 2 x 10(-13) and 2 x 10(-11) respectively using a third-harmonic signal detection. We have measured the absolute frequency of the acetylene transition with an uncertainty of about 10(-10) using a frequency chain based on a two-color mode-locked fiber laser. One of the important applications of the acetylene optical frequency standard is the WDM optical communication system, which requires precise absolute frequency references for a hundred of channel frequencies in the wavelength region of 1530 - 1565 nm. We have developed a wide-range heterodyne optical phase-locked diode laser using the acetylene-stabilized laser as a master in order to realize the WDM channel frequency standards.