Polarization diversity circuit based on silica waveguides and photonic crystal waveplates for a 4×4 silicon optical switch

Abstract

We propose a compact polarization diversity circuit for a silicon waveguide device. It consists of silica waveguides and photonic crystal waveplates, and can convert input light with various polarization states into two output light signals with the same polarization. Setting these circuits at the front and rear of two silicon optical switches, the polarization dependence in the switch can be dramatically suppressed. We fabricated polarization diversity circuits for a 4×4 silicon optical switch and realized a polarization insensitive 4×4 optical switch. The polarization dependent loss was reduced to 1.1 dB and the polarization dependent crosstalk was less than −17 dB.

Polarization rotator with large bandwidth and low insert loss based on lemon core photonic crystal fiber

“…PRs have been widely employed in polarization multiplexing/demultiplexing systems, 7 coherent light transceivers, 8 and polarization diversity loops. 9 To date, various PRs have been developed and are mainly classified into two types: on-chip photonic integrated 10,11 and photonic crystal fiber (PCF). 12,13 On-chip PRs are primarily fabricated using platforms such as SOI, Si 3 N 4 , and InP, 11,14,15 which are known for their compactness and suitability for large-scale photonic integration.…”

“…The polarization rotator (PR) is a pivotal device in polarization control, capable of rotating the polarization direction of transverse electric (TE) or transverse magnetic (TM) modes by 90 deg, thus enabling mutual conversion between them. PRs have been widely employed in polarization multiplexing/demultiplexing systems, 7 coherent light transceivers, 8 and polarization diversity loops 9 . To date, various PRs have been developed and are mainly classified into two types: on-chip photonic integrated 10 , 11 and photonic crystal fiber (PCF) 12 , 13 .…”