Open AccessTunable channel drop filters consisting of a tilted Bragg grating and a mode sorting polymer waveguide
Author(s) -
Taehyun Park,
Joon-Ho Shin,
Guanghao Huang,
Woo-Sung Chu,
MinCheol Oh
Publication year - 2016
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.24.005709
Subject(s) - optics , fiber bragg grating , materials science , distributed bragg reflector , grating , coupled mode theory , waveguide , wavelength division multiplexing , bragg's law , wavelength , radiation mode , optical filter , optoelectronics , refractive index , single mode optical fiber , diffraction , physics , optical fiber
Optical wavelength filters with large tuning range and narrow bandwidth are crucial for enhancing the capability of WDM communication systems. A polymeric tunable filter for C-band, comprising a tilted Bragg grating and a mode sorting waveguide junction is proposed in this work. For dropping a certain wavelength signal, the tilted Bragg grating reflects an odd mode into an even mode and then the reflected even mode propagates towards an output port of the asymmetric Y-junction due to the mode sorting. Consequently, the output port is separated from the input port, which is not possible in an ordinary Bragg reflector. The tilted Bragg reflector with an odd-even mode coupling efficiency of 61% exhibited a maximum reflectivity of 95% for a grating of 6 mm. A linear wavelength tuning of over 10 nm was achieved for an applied thermal power of 312 mW.