Abstract
We have developed optical frequency standards for wavelength-division-multiplexing (WDM) optical communication systems based on absorption lines of acetylene molecules in the 1.5 μm region. We developed acetylene-stabilized diode lasers using a Doppler-free saturation absorption of acetylene as a frequency reference. We also developed an accurate frequency measurement sysytem in the 1.5 μm region and the absolute optical frequency of an acetylene line was measured with an uncertainty of 12 kHz. As a result, the acetylene optical frequency standard can be used as an accurate absolute frequency reference for the calibration of optical instruments used in the WDM systems.
