Title :
Proposal for Compact Polarization Splitter Using Asymmetrical Three-Guide Directional Coupler
Author :
Yin Xu ; Jinbiao Xiao ; Xiaohan Sun
Author_Institution :
Nat. Res. Center for Opt. Sensing, Southeast Univ., Nanjing, China
Abstract :
A compact silicon-based polarization splitter (PS) is proposed using a three-guide directional coupler composed of a silicon nanowire in the center and two horizontal/vertical hybrid-plasmonic waveguides (HPWs) at outer sides. Utilizing the evanescent coupling, the injected TE/TM modes in the central silicon nanowire can be only coupled to the horizontal/vertical HPWs, leading to the separation of input polarizations. Moreover, to improve the extinction ratio (ER), an S-bend connecting with the vertical HPW is employed. Results show that a coupling length of 6.5 (4.5) μm is achieved at the wavelength of 1.55 μm with ER and insertion loss of ~18.9 (15.2) dB and ~0.44 (0.89) dB for TE (TM) mode, and the bandwidths can cover the entire C-band for both polarizations. In addition, fabrication tolerances to the structural parameters are presented and field evolution through the designed PS is also demonstrated.
Keywords :
elemental semiconductors; integrated optoelectronics; light polarisation; nanophotonics; nanowires; optical beam splitters; optical design techniques; optical directional couplers; optical fabrication; optical losses; optical waveguides; plasmonics; silicon; S-bend; Si; asymmetrical three-guide directional coupler; compact silicon-based polarization splitter; coupling length; evanescent coupling; extinction ratio; fabrication tolerances; horizontal-vertical hybrid-plasmonic waveguides; injected TE-TM modes; insertion loss; silicon nanowire; structural parameters; wavelength 1.55 mum; Couplings; Erbium; Fabrication; Optical waveguides; Optimized production technology; Silicon; Integrated optical devices; polarization splitters; silicon photonics;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2015.2389815
