Analysis and Design of 2×4 90° Crystal Space Optical Hybrid for Coherent Optical Communication
American Journal of Optics and Photonics
Volume 8, Issue 2, June 2020, Pages: 33-39
Received: Mar. 6, 2020; Accepted: Mar. 24, 2020; Published: Apr. 23, 2020
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Xizheng Ke, School of Automation and Information Engineering, Xi'an University of Technology, Xi’an, China; Shaanxi Civil-Military Integration Key Laboratory of Intelligence Collaborative Networks, Xi’an, China
Jianlu Han, School of Automation and Information Engineering, Xi'an University of Technology, Xi’an, China
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Based on the principles of crystal birefringence, wave plate phase delay and polarization transformation, a 2×4 90 degree crystal optical hybrid is presented. The beam splitting and coupling between signal and local oscillator lights of the hybrid is realized by two birefringent crystals and two half wave plates, and the required phase shift is produced by a quarter wave plate. Combined with the actual situation, the schemes of phase compensation and power ratio adjustment are given to optimize the performance of the device. And the feasibility of phase compensation and splitter ratio adjustment scheme is simulated and analysed through the establishment of mathematical model according to Jones matrix. The results show that the phase difference and splitter ratio can be set simply and accurately by the scheme of phase compensation and splitter ratio adjustment. Meanwhile, compared with the previous crystal spatial optical hybrid, this hybrid can improve the coupling effect of signal beam and local oscillator beam, and reduce the influence of crystal processing error between in-phase and quadrature branch. It has the advantages of simple and compact structure and good performance, and can be used in free-space optical coherent optical communication system.
Coherent Optical Communication, Optical Hybrid, Birefringence Effect, Phase Compensation
To cite this article
Xizheng Ke, Jianlu Han, Analysis and Design of 2×4 90° Crystal Space Optical Hybrid for Coherent Optical Communication, American Journal of Optics and Photonics. Vol. 8, No. 2, 2020, pp. 33-39. doi: 10.11648/j.ajop.20200802.11
Copyright © 2020 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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