Open AccessSurface relief apodized grating tunable filters produced by using a shadow mask
Author(s) -
Guanghao Huang,
Joon-Ho Shin,
Won Joon Lee,
Taehyun Park,
Woo-Sung Chu,
MinCheol Oh
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.021090
Subject(s) - apodization , grating , optics , materials science , blazed grating , reflection (computer programming) , wavelength , fiber bragg grating , diffraction grating , holographic grating , optical filter , optoelectronics , physics , computer science , programming language
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.