Temperature sensitivity of a long-period waveguide grating in a channel waveguide

We present a simulation of the temperature sensitivity of the resonance wavelength of a long-period waveguide grating (LPWG). We find that the temperature sensitivity of an LPWG in a channel waveguide is proportional to a modal dispersion factor that depends sensitively on the size of the core of the waveguide. Measurements with experimental polymer LPWGs agree well with the simulation results. The dimension of the waveguide core is an effective parameter for the control of the thermal characteristics of an LPWG in a channel waveguide.