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) Transmission spectra measure actually for the TM polarization with different electric powers applied to the electrode and (b) TO switching response by applying square-wave voltage at a frequency of 70 Hz.