3-DIMENSIONAL ATHERMAL WAVE-GUIDE AT 1.3 MU-M WAVELENGTH FOR TEMPERATURE INDEPENDENT LIGHTWAVE DEVICES

To eliminate the temperature dependence of narrow-band filter, a three -dimensional athermal waveguide of which optical path length is indepe ndent of temperature was developed at 1.3 mu m wavelength. The tempera ture coefficient of the refractive index of films made of glass materi als was measured at this wavelength, and a strip-loaded athermal waveg uide was designed using a scalar finite element method. The temperatur e coefficient of optical path length was successfully decreased to 9.6 5x10(-9)[/K] (0.1% of the conventional waveguide).