Temperature-insensitive reflective arrayed-waveguide grating multiplexers

We present a new approach to temperature compensation of silica-based arrayed-waveguide grating multiplexers. An external mirror rotating with temperature at a constant rate, in combination with a reflective multiplexer, is used to compensate for the temperature-induced change of the refractive index, and the resulting wavelength shift of individual channels, making the device athermal. A wavelength-temperature slope of less than 3.2/spl times/10/sup -4/nm//spl deg/C was obtained in the temperature range 5/spl deg/C-70/spl deg/C, without noticeable degradation in the device performance.