| Title |
Lyot-Type High-Order Fiber Comb Filter Based on Polarization-Diversity Loop Structure |
| Authors |
Song-Hyun Jo ; Young-Ho Kim ; Yong-Wook Lee |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2013.27.12.010 |
| Keywords |
Polarization-Maintaining Fiber ; Birefringence ; Lyot Filter ; Comb Filter |
| Abstract |
In this paper, we propose a Lyot-type optical fiber comb filter based on a polarization-diversity loop structure (PDLS), which has flat-top pass bands and multiwavelength switching capability. Generally, the PDLS can remove the dependency of the filter on input polarization. The proposed filter is composed of a polarization beam splitter, two half-wave plates (HWPs), and two polarization-maintaining fiber loops concatenated with a 60° offset between their principal axes. By controlling two HWPs, it can operate in a flat-top band mode or a lossy flat-top band mode with an inherent insertion loss of ∼3.49dB. In particular, flat-top bands can be interleaved in both modes, which cannot be realized in a Lyot-Sagnac comb filter based on a fiber coupler. Compared with Solc-type high-order comb filters with the same order, the proposed filter shows sharper transition between pass and stop bands. |