TEMPERATURE-INDEPENDENT NARROW-BAND OPTICAL FILTER BY AN ATHERMAL WAVE-GUIDE

The temperature dependence of the central wavelength of narrow-band fi lters is a serious problem for the dense WDM systems. In this study, w e realized a temperature independent narrow-band filter at 1.3 mu m wa velength. First, we designed an athermal waveguide in which optical pa th length is independent of temperature by using a finite element meth od. Using this athermal waveguide, we designed and fabricated a ring r esonator. As a result, we successfully decreased the temperature coeff icient of central wavelength to 7 x 10(-4) nm/K, which is 7 % of conve ntional SiO2 waveguide filters and 0.7 % of conventional semiconductor waveguide filters.