Polarization-based optical communications are attracting more attention recently, where the crucial points are polarization features and their measurements. Based on the Müller matrix method, we obtain measurable...Polarization-based optical communications are attracting more attention recently, where the crucial points are polarization features and their measurements. Based on the Müller matrix method, we obtain measurable expressions for the polarization-dependent gain（PDG） and the loss of polarization orthogonality（LPO）, while give the boundary of the LPO for any PDG devices. We experimentally demonstrate that non-linear LPO can be created in a semiconductor optical amplifier and find that the LPO will slightly skim over the boundary near the threshold of the injected current. Furthermore, an empirical formula is achieved to gauge the LPO-induced power penalty, which is proven to be valid in differential polarization shift-keying transmission by executing a bit error rate measurement. Our conclusions are applicable to non-orthogonal polarization cases and valuable to polarization-related communications, even orbital angular momentum multiplexing.展开更多
We report a waveguide crossing based on a multimode-interference （MMI） structure for metal-insulator-metal （MIM） waveguides. The MMI-based crossing comprises two orthogonal intersecting MMI waveguides that are con...We report a waveguide crossing based on a multimode-interference （MMI） structure for metal-insulator-metal （MIM） waveguides. The MMI-based crossing comprises two orthogonal intersecting MMI waveguides that are connected to the single-mode input/output waveguide symmetrically. Single self-images are formed at the cross- ing center and output plane of the MMI waveguide, thereby mitigating the crosstalk and improving the through- put. The characteristics of the proposed MMI-based crossing are investigated with the finite element method of Comsol Multiphysics. The results show that the throughput reaches -1.8 dB and the crosstalk is less than -46 dB at the wavelength of 1550 nm.展开更多
基金supported by the National Natural Science Foundation of China (Nos.11274037 and 11574026)the Program for New Century Excellent Talents in University, MOE of China (No.NCET-120765)the Foundation for the Author of National Excellent Doctoral Dissertation, China (No.201236)
文摘Polarization-based optical communications are attracting more attention recently, where the crucial points are polarization features and their measurements. Based on the Müller matrix method, we obtain measurable expressions for the polarization-dependent gain（PDG） and the loss of polarization orthogonality（LPO）, while give the boundary of the LPO for any PDG devices. We experimentally demonstrate that non-linear LPO can be created in a semiconductor optical amplifier and find that the LPO will slightly skim over the boundary near the threshold of the injected current. Furthermore, an empirical formula is achieved to gauge the LPO-induced power penalty, which is proven to be valid in differential polarization shift-keying transmission by executing a bit error rate measurement. Our conclusions are applicable to non-orthogonal polarization cases and valuable to polarization-related communications, even orbital angular momentum multiplexing.
基金supported by the National Natural Science Foundation of China(Nos.11374041 and11574035)the Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications),China
文摘We report a waveguide crossing based on a multimode-interference （MMI） structure for metal-insulator-metal （MIM） waveguides. The MMI-based crossing comprises two orthogonal intersecting MMI waveguides that are connected to the single-mode input/output waveguide symmetrically. Single self-images are formed at the cross- ing center and output plane of the MMI waveguide, thereby mitigating the crosstalk and improving the through- put. The characteristics of the proposed MMI-based crossing are investigated with the finite element method of Comsol Multiphysics. The results show that the throughput reaches -1.8 dB and the crosstalk is less than -46 dB at the wavelength of 1550 nm.
