Three-dimensional athermal waveguide at 1.3 μm wavelength for temperature independent lightwave devices

Abstract

To eliminate the temperature dependence of narrow-band filter, a three-dimensional athermal waveguide of which optical path length is independent of temperature was developed at 1.3 μm wavelength. The temperature coefficient of the refractive index of films made of glass materials was measured at this wavelength, and a strip-loaded athermal waveguide was designed using a scalar finite element method. The temperature coefficient of optical path length was successfully decreased to 9.65X10-9[/K] (0.1% of the conventional waveguide).