title: Surface relief apodized grating tunable filters produced by using a shadow mask.
abstract: To produce a compact low-cost tunable filter required for WDM optical communications, a polymeric Bragg reflection filter with an apodized grating structure is proposed. A high-contrast polymeric waveguide is incorporated in order to obtain high reflectivity from a short Bragg grating. To overcome the bandwidth broadening, an apodized grating with a gradually changing depth of surface relief grating along the propagation direction is fabricated through the dry etching with a shadow mask. The apodized polymer grating exhibits 3-dB, 20-dB bandwidths of 0.36 nm, and 0.72 nm, respectively with a 95% reflection. The reflection wavelength is tunable over 14 nm for an applied thermal power of 500 mW.
authors.forename: Guanghao
authors.initials: G
authors.lastname: Huang
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Shin
authors.forename: Won-Joon
authors.initials: WJ
authors.lastname: Lee
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Park
authors.forename: Woo-Sung
authors.initials: WS
authors.lastname: Chu
authors.forename: Min-Cheol
authors.initials: MC
authors.lastname: Oh