Tunable wavelength filters using polymer long-period waveguide gratings based on metal-cladding directly defined technique
Wang Ji-Hou, Chen Chang-Ming, Zheng Yang, Wang Xi-Bin, Yi Yun-Ji, Sun Xiao-Qiang, Wang Fei, Zhang Da-Ming
       

(color online) (a) Schematic configuration of metal-cladding LPWG filter with self-electrode heaters; (b) cross-sectional structure of the metal-cladding defined waveguide and mode distribution calculated based on effective index method.