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Intrinsic polarization conversion and avoided-mode crossing in X-cut lithium niobate microrings

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Chinese Physics B 2024年第6期33卷 398-403页

作者：谭泽林张检发朱志宏陈伟邵铮铮刘肯秦石乔 College of Advanced Interdisciplinary Studies&Hunan Provincial Key Laboratory of Novel Nano Optoelectronic Information Materials and Devices National University of Defense TechnologyChangsha 410073China Nanhu Laser Laboratory National University of Defense TechnologyChangsha 410073China College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China School of Physics Central South UniversityChangsha 410083China

Compared with well-developed free space polarization converters, polarization conversion between TE and TM modes in the waveguide is generally considered to be caused by shape birefringence, like curvature, morphology of waveguide cross section and scattering. Here, we study the polarization conversion mechanism in 1-THz-FSR X-cut lithium niobate microrings with multiple-resonance condition, that is the conversion can be implemented by birefringence of waveguides,which will also introduce an avoided-mode crossing. In the experiment, we find that this mode crossing results in severe suppression of one sideband in local nondegenerate four-wave mixing and disrupts the cascaded four-wave mixing on this side. Simultaneously, we propose one two-dimensional method to simulate the eigenmodes(TE and TM) in X-cut microrings, and the mode crossing point. This work will provide one approach to the design of polarization converters and simulation for monolithic photonics integrated circuits, and may be helpful to the studies of missed temporal dissipative soliton formation in X-cut lithium niobate rings.

关键词： polarization conversion birefringence nondegenerate four-wave mixing

Polymerization enabled reduction of the electrically induced birefringence change in nematic liquid crystals

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Chinese Optics Letters 2022年第2期20卷 172-176页

作者：陈佳浩李超逸孙路瑶马玲玲李炳祥陆延青 College of Electronic and Optical Engineering and College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210023China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures&College of Engineering and Applied Sciences Nanjing UniversityNanjing 210093China Advanced Materials and Liquid Crystal Institute Kent State UniversityKentOH 44242USA

Electric fields modify the optical properties of nematic liquid crystals(NLCs) by changing the nematic molecular orientation or order parameters, which enables electro-optic applications of NLCs. However, the field-induced optic change is undesirable in some cases. Here, we experimentally demonstrate that polymer stabilization weakens the birefringence change of NLCs caused by the nanosecond electrically modified order parameter effect. The birefringence change is reduced by 65% in the NLC doped with 25% reactive monomer, which is polymerized close to the nematic-to-isotropic phase transition. This technique could be used in liquid crystal devices where the birefringence change is unfavored.

关键词： liquid crystal electro-optical response birefringence polymerization

Evaluating refractive index and birefringence of nonlinear optical crystals:Classical methods and new developments

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Chinese Journal of Structural Chemistry 2023年第1期42卷 46-63页

作者： Qi Shi Lingyun Dong Ying Wang College of Chemistry and Materials Science Hebei UniversityBaoding071002China College of Biochemistry and Environmental Engineering Baoding UniversityBaoding071002China

Nonlinear optical(NLO)materials play an increasingly important role in laser technology.birefringence is one of the most important parameters for NLO materials to realize angle phase-matching conditions.In comparison with other desirable optical properties,the availability of birefringence and refractive index dispersion is especially problematic owing to the strict requirements for single crystals.In this review,we described how to obtain the refractive index and birefringence of NLO materials from crystals sub-millimeters to centimeters in size.Espe-cially,recently developed methods including the minimum deflection angle method,auto-collimation method,prism coupling method,oil immersion technique,interference color method,and theoretical calculation(DFT)for rapid assessment of birefringence are summarized,the contents of which are mainly focused on the principles and typical applications,together with the advantages and drawbacks.In addition,representative examples of bire-fringent measurements were presented.The purpose of this work is to provide a useful perspective on the characterization of birefringence for NLO materials.It is hoped that this review can give a clear description of the birefringence measurements and accelerate the discovery of new NLO crystals.

关键词： Nonlinear optical crystals Refractive index birefringence DFT calculation Phase-matching

Deep-ultraviolet nonlinear-optical crystal BaNa_(2)[PO_(3)(OH)]_(2) with large birefringence and strong second-harmonic-generation response

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Chinese Journal of Structural Chemistry 2023年第1期42卷 9-14页

作者： Yuanyu Yang Yao Guo Yi-Gang Chen Chengbo Li Xian-Ming Zhang Key Laboratory of Magnetic Molecules and Magnetic Information of Ministry of Education School of Chemistry and Material ScienceShanxi Normal UniversityTaiyuan030006China Henan Joint International Research Laboratory of Nanocomposite Sensing Materials School of Materials Science and EngineeringAnyang Institute of TechnologyAnyang455000China College of Chemistry&Chemical Engineering Key Laboratory of Interface Science and Engineering in Advanced MaterialMinistry of EducationTaiyuan University of TechnologyYingze WestTaiyuan030024China

Deep-ultraviolet(DUV,λ<200 nm)nonlinear-optical(NLO)crystals play a pivotal role in modern laser science and technology.Metal phosphates have been considered as fascinating candidates for DUV NLO crystal material.How... 详细信息

Deep-ultraviolet(DUV,λbirefringence for promising DUV NLO metal phosphates is a long-standing issue.Herein,a new DUV NLO metal phosphate,BaNa_(2)[PO_(3)(OH)]_(2),was successfully synthesized,which features a two-dimensional[NaPO_(3)(OH)]_(∞)alveolate layer alternately connected by highly asymmetric[PO_(3)(OH)]groups and NaO5 triangular bipyramids.BaNa_(2)[PO_(3)(OH)]_(2)can realize a good balance of DUV nonlinear properties covering short UV absorption edge less than 190 nm,strong SHG response with the magnitude of~1.2×benchmark KH_(2)PO_(4)(KDP),and the largest birefringence with the experimental value of 0.064@590±3 nm in reported alkaline/alkaline-earth metal phosphates,producing the shortest phase-matching output down to the wavelength of 164 nm.These research results show that BaNa_(2)[PO_(3)(OH)]_(2)crystal is a potential DUV NLO crystal material.

关键词： Nonlinear-optical birefringence Structure Phosphates Optical properties

birefringence via Doppler broadening and prevention of information hacking

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Chinese Physics B 2018年第1期27卷 365-370页

作者： Humayun Khan Muhammad Haneef Bakhtawar Laborotary of Theoretical Physics Department of Physics Hazara University

We propose a new scheme for the coherent control of birefringent light pulses propagation in a four-level atomic medium. We modify the splitting of a light pulse by controlling the electric and magnetic responses. The Doppler broad- ening effect is also noted on the propagation of the birefringent pulses. The dispersions of the birefringence beams are oppositely manipulated for delay and advancement of time at a Doppler width of 10Y. A time gap is created between the birefringence beams, which protects from hacking of information. The time gap is then closed to restore the pulse into the original form by a reverse manipulation of the dispersion of the birefringence beams, i.e., introducing another medium whose transfer function is the complex conjugate of that of the original medium. The results are useful for secure communication technology.

关键词： birefringence Doppler broadening time gap hacking

birefringence of (Al)GaAs/AlGaAs multiplequantum well optical waveguides

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Chinese Journal of Lasers 1994年第4期3卷 331-337页

作者： MA Chunsheng(Department of Electronic Engineering, National Integrated Optoelectronics Laboratory,Jinn University, Changchon 130023, China) Jilin Univ Changchun China

Ｂｉｒｅｆｒｉｎｇｅｎｃｅｏｆ（Ａｌ）ＧａＡｓ／ＡｌＧａＡｓｍｕｌｔｉｐｌｅｑｕａｎｔｕｍｗｅｌｌｏｐｔｉｃａｌｗａｖｅｇｕｉｄｅｓ￥ＭＡＣｈｕｎｓｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＥｌｅｃｔｒｏｎｉｃＥｎｇｉｎｅｅ... 详细信息

Ｂｉｒｅｆｒｉｎｇｅｎｃｅｏｆ（Ａｌ）ＧａＡｓ／ＡｌＧａＡｓｍｕｌｔｉｐｌｅｑｕａｎｔｕｍｗｅｌｌｏｐｔｉｃａｌｗａｖｅｇｕｉｄｅｓ￥ＭＡＣｈｕｎｓｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＥｌｅｃｔｒｏｎｉｃＥｎｇｉｎｅｅｒｉｎｇ，ＮａｔｉｏｎａｌＩｎｔｅ...

关键词： multiple quantum well optical wavesuide birefringence

ANSYS-Based birefringence Property Analysis of Side-Hole Fiber Induced by Pressure and Temperature

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Photonic Sensors 2018年第1期8卷 13-21页

作者： Xinbang ZHOU Zhenfeng GONG School of Ocean Science and Technology Dalian University of Technology. Panjin Panjin 124000 China College of Physics and Optoelectronics Engineering Dalian University of Technology Dalian 116024 China

在这份报纸，我们理论上用有限元素分析方法与洞的不同形状在方面洞纤维的 birefringence 性质上调查压力和温度的影响。方面洞纤维的 birefringence 的物理机制与不同外部压力和温度的存在被讨论。圆形核心、矩形核心、三角形核心的方... 详细信息

在这份报纸，我们理论上用有限元素分析方法与洞的不同形状在方面洞纤维的 birefringence 性质上调查压力和温度的影响。方面洞纤维的 birefringence 的物理机制与不同外部压力和温度的存在被讨论。圆形核心、矩形核心、三角形核心的方面洞纤维的紧张领域分发和 birefringence 价值被介绍。我们的分析证明三角形核心的方面洞纤维有削弱温度和紧张的生气敏感的低温度敏感。另外，方面洞纤维的一个优化结构图案被介绍它能被用于察觉到的申请。

关键词： Fiber optics birefringence pressure measurement temperature

Lensless polarimetric coded ptychography for high-resolution,high-throughput gigapixel birefringence imaging on a chip

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Photonics Research 2023年第12期11卷 2242-2255页

作者： LIMING YANG RUIHAI WANG QIANHAO ZHAO PENGMING SONG SHAOWEI JIANG TIANBO WANG XIAOPENG SHAO CHENGFEI GUO RISHIKESH PANDEY GUOAN ZHENG School of Optoelectronic Engineering Xidian UniversityXi’an 710071China Department of Biomedical Engineering University of ConnecticutStorrsConnecticut 06269USA

Polarimetric imaging provides valuable insights into the polarization state of light interacting with a sample.It can infer crucial birefringence properties of specimens without using labels,thereby facilitating the diagnosis of diseases such as cancer and osteoarthritis.In this study,we present a novel polarimetric coded ptychography(pol-CP)approach that enables high-resolution,high-throughput gigapixel birefringence imaging on a chip.Our platform deviates from traditional lens-based systems by employing an integrated polarimetric coded sensor for lensless coherent diffraction imaging.Utilizing Jones calculus,we quantitatively determine the birefringence retardance and orientation information of biospecimens from the recovered images.Our portable pol-CP prototype can resolve the 435 nm linewidth on the resolution target,and the imaging field of view for a single acquisition is limited only by the detector size of 41 mm2.The prototype allows for the acquisition of gigapixel birefringence images with a 180 mm^(2) field of view in~3.5 min,a performance that rivals high-end whole slide scanner but at a small fraction of the cost.To demonstrate its biomedical applications,we perform high-throughput imaging of malaria-infected blood smears,locating parasites using birefringence contrast.We also generate birefringence maps of label-free thyroid smears to identify thyroid follicles.Notably,the recovered birefringence maps emphasize the same regions as autofluorescence images,underscoring the potential for rapid on-site evaluation of label-free biopsies.Our approach provides a turnkey and portable solution for lensless polarimetric analysis on a chip,with promising applications in disease diagnosis,crystal screening,and label-free chemical imaging,particularly in resource-constrained environments.

关键词： polarization birefringence resolution

Design and analysis of high birefringence and nonlinearity with small confinement loss photonic crystal fiber

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Frontiers of Optoelectronics 2019年第2期12卷 165-173页

作者： Rekha SAHA Md.Mahbub HOSSAIN Md. Ekhlasur RAHAMAN Himadri Shekhar MONDAL Electronics and Communication Engineering Discipline Khulna UniversityKhulna 9208Bangladesh

High birefringence with low confinement loss photonic crystal fiber (PCF) has significant advantages in the field of sensing, dispersion compensation devices, nonlinear applications, and polarization filter. In this report, two different models of PCFs are presented and compared. Both the models contain five air holes rings with combination of circular and elliptical air holes arrangement. Moreover, the elliptical shaped air holes polarization and the third ring air holes rotational angle are varied. To examine different guiding characteristics, finite element method (FEM) with perfectly matched layer (PML) absorbing boundary condition is applied from 1.2 to 1.8 |im wavelength range. High birefringence, low confinement loss, high nonlinearity, and moderate disper-sion values are successfully achieved in both the PCFs models. Numeric analysis shows that model-1 gives higher birefringence (2.75 ×10^-2) and negative dispersion (-540.67 ps/(nm ·km)) at 1.55 |im wavelength. However, model-2 gives more small confinement loss than model-1 at the same wavelength. In addition, the proposed design demonstrates the variation of rotation angle has great impact to enhance guiding properties especially the birefringence.

关键词： birefringence dispersion polarization main-taining photonic crystal fiber (PCF) polarization-selective devices polarization