Analysis on Planar-Type Long-Period Gratings for Wavelength Tuning Filters

摘要

This paper reports numerically analyzed results on temperature dependent performances of planar-type long period waveguide gratings (LPWGs) for thermally tunable wavelength filter applications. The thermally tunable characteristics of the LPWG with a four-layer geometry have been evaluated. The calculated results show that the tuning characteristics depend significantly on the temperature dependent refractive index change rate of the core and clad waveguide materials compared to their thermal expansion coefficient.