Polymeric wavelength filters fabricated using holographic surface relief gratings on azobenzene-containing polymer films

Polymeric wavelength filters with Bragg gratings have been fabricated using holographic surface relief gratings on azobenzene polymer films. In order to fabricate Bragg gratings on polymer waveguides, we used holographic surface relief gratings on the azobenzene polymer film as an etch mask and the grating patterns were transferred to the polymer waveguides by O2 reactive ion etching. The grating period was ∼500 nm and the depth was ∼30 nm with a 10-mm-long Bragg grating length. A transmission dip of −15 dB at the Bragg wavelength and a 3-dB-transmission bandwidth of ∼0.2 nm were obtained from the device.