Open AccessSecond-order all-fiber comb filter based on polarization-diversity loop configuration
Author(s) -
Yong Wook Lee,
Hyun-Tak Kim,
Yong Wan Lee
Publication year - 2008
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.003871
Subject(s) - optics , comb filter , birefringence , passband , polarization (electrochemistry) , beam splitter , materials science , physics , filter (signal processing) , band pass filter , bandwidth (computing) , telecommunications , computer science , laser , chemistry , computer vision
By concatenating three birefringence loops in series, a second-order all-fiber comb filter based on a polarization-diversity loop configuration is newly proposed. The proposed filter consists of one polarization beam splitter, polarization-maintaining fibers, and two halfwave plates. The effect of a second-order structure of polarization-maintaining fiber loops on a bandwidth of the filter passband was theoretically analyzed and experimentally demonstrated. Transmission output of the second-order filter (flat-top and narrow-band transmission spectra) could be obtained by adjusting two half-wave plates. 1 and 3 dB bandwidths of the proposed filter in flat-top and narrow-band operations were greater by approximately 102.9 and 44.3 % and smaller by approximately 47.9 and 47.1 % than those of a conventional Sagnac birefringence filter, respectively.