ATHERMAL NARROW-BAND OPTICAL FILTER AT 1.55 MU-M WAVELENGTH BY SILICA-BASED ATHERMAL WAVE-GUIDE

The temperature dependence of central wavelength of optical filters is a serious problem for the dense WDM systems. This dependence is owing to the temperature dependence of optical path-length of the waveguide . In this study, we realized a temperature independent silica-based op tical filter at 1.55 mu m wavelength using an athermal waveguide, in w hich optical pathlength is independent of temperature. First, we desig ned a silica-based athermal waveguide, and next we designed and fabric ated a ring resonator using the athermal waveguide. As a result, we su ccessfully decreased the temperature dependence of central wavelength to less than 4 x 10(-4) nm/K, which is 3% and 0.3% of corresponding va lues of conventional silica-based and semiconductor waveguide filters, respectively.