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Incoherent radiation of amplifying random media

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Frontiers of Optoelectronics 2008年第Z1期1卷 95-100页

作者： Yunxia YE dianyuan fan College of Mechanical Engineering Jiangsu University Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences

Incoherent radiation of amplifying random media was investigated using Monte Carlo simulation and the characteristics of random laser were *** entire emission spectra of the random media would become narrow abruptly when pumping energies exceeded certain threshold values, and as the pumping energies further increased, distinct sharp peaks would emerge on the spectrum background. The intensity of a certain spatial point within the scattering media was contributed from emissions of many frequencies. The intensity of a single frequency of the entire spectrum was contributed with emissions from wide spatial location and angle ranges. It has been pointed out that the incoherent radiation of amplifying random media is essentially different from amplified spontaneous emission without any feedback as well as conventional resonant-feedback laser. The explanation on distinct sharp peaks is that rare photons have experienced rather more scattering events and walked longer paths in amplifying random media, which accumulates more gain for these photons.

关键词： random laser incoherent radiation Monte Carlo scatter

A CW seeded femtosecond optical parametric amplifier

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Science China(Physics,Mechanics & Astronomy) 2004年第6期47卷 767-772页

作者： ZHU Heyuan XU Guang WANG Tao QIAN Liejia fan dianyuan State Key Laboratory for Advanced Photonic Materials & Devices Department of Optical Science and Engineering Fudan University Shanghai 200433 China

A CW seeded femtosecond optical parametric amplifier, a compromise between OPG/OPA and strongly seeded OPA configurations, has been demonstrated. An independent CW Nd︰YAG laser with sub-watt power decreases the pump threshold of the OPA and improves the stability of the output pulses considerably. Output signal energies as high as 30 μJ with pulse durations less than 250 fs near 1 μm are reported from this two-stage device.

关键词： femtosecond CW seeded optical parametric amplification.

A terawatt Nd:glass chirped pulse amplification laser system seeded by two order optical parametric amplification

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Science China(Physics,Mechanics & Astronomy) 2012年第5期55卷 776-780页

作者： ZHANG LiFu FU XiQuan DENG JianQin ZHANG Jin WEN ShuangChun fan dianyuan Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education and College of Information Science and Engineering Hunan University Changsha 410082 China College of Electrical Engineering Anhui Polytechnic University Wuhu 241000 China

We present the performance of a high-power Nd:glass laser system,which produces a 1.1 J,250 fs,7.3 nm broadband laser pulse based on the combination of optical parametric amplification(OPA) and chirped pulse amplification(CPA).The two-stage OPA provides broadband seed pulses for the three-stage Nd:glass amplifiers based on the technology of *** to the conventional oscillator seed source,the most important advantage of such a seed source supplied by the two-stage OPA is that it possesses the capacities of broad bandwidth and high energy.

关键词： broadband laser pulse optical parametric amplification (OPA) chirped pulse amplification (CPA)

Cylindrical vector beam multiplexer/demultiplexer using off-axis polarization control

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Light(Science & Applications) 2021年第12期10卷 2360-2368页

作者： Shuqing Chen Zhiqiang Xie Huapeng Ye Xinrou Wang Zhenghao Guo Yanliang He Ying Li Xiaocong Yuan dianyuan fan Institute of Microscale Optoelectronics Shenzhen University518060 ShenzhenChina Guangdong Provincial Key Laboratory of Optical Information Materials and Technology&Institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal University510006 GuangzhouChina

The emergence of cylindrical vector beam(CVB)multiplexing has opened new avenues for high-capacity optical *** several configurations have been developed to couple/separate CVBs,the CVB multiplexer/demultiplexer remains elusive due to lack of effective off-axis polarization control *** we report a straightforward approach to realize off-axis polarization control for CVB multiplexing/demultiplexing based on a metal–dielectric–metal *** show that the left-and right-handed circularly polarized(LHCP/RHCP)components of CVBs are independently modulated via spin-to-orbit interactions by the properly designed metasurface,and then simultaneously multiplexed and demultiplexed due to the reversibility of light path and the conservation of vector *** also show that the proposed multiplexers/demultiplexers are broadband(from 1310 to 1625 nm)and compatible with *** a proof of concept,we successfully demonstrate a four-channel CVB multiplexing communication,combining wavelength-division-multiplexing and polarization-division-multiplexing with a transmission rate of 1.56 Tbit/s and a bit-error-rate of 10^(−6) at the receive power of−21.6 *** study paves the way for CVB multiplexing/demultiplexing and may benefit high-capacity CVB communication.

关键词： polarization beam properly

Generation of ultrafast radially polarized pulses through chirp-assisted femtosecond optical parametric amplification

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Science China(Physics,Mechanics & Astronomy) 2022年第5期65卷 51-57页

作者： SaiSai Hu JieFeng Huang XinHao Ren ChangWen Xu ShiXiang Xu dianyuan fan HaiZhe Zhong International Collaborative Laboratory of 2D Materials for Optoelectronic Science&Technology of Ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Micro-Nano Photonic Information Technology College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China

Radially polarized beams characterized by an axially symmetric polarization distribution can be sharply focused to produce strong longitudinal fields in the *** applications of these beams will be facilitated by the availability of higher powers and shorter ***,the ultrafast radially polarized pulse is typically generated via wavefront reconstruction from conventional linearly polarized *** pulse duration and intensity limits are strictly dependent on extra-cavity ***,a chirp-assisted near-degenerate type-II parametric process is presented as a pulse-energy-scalable method of accessing ultrafast radially polarized *** a proof-of-principle experiment,the broadband gain balance between the orthogonally polarized signal components was realized via controlling the chirp of the pump *** an analogous pulseduration transfer effect,the radially polarized signal inherited the temporal and spectral characteristics of the pump pulse and maintained the radial polarization state of each frequency component of the *** a shorter pump pulse,the generation of few-cycle radially polarized pulses should be achievable,which may facilitate a wide range of ultrafast applications such as vacuum electron acceleration and high-harmonic generation.

关键词： radially polarized beam optical parametric amplifier ultrafast lasers spectral broadening optical parametric phase

Giant photonic spin Hall effect in momentum space in a structured metamaterial with spatially varying birefringence

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Light(Science & Applications) 2015年第1期4卷 354-359页

作者： Xiaohui Ling Xinxing Zhou Xunong Yi Weixing Shu Yachao Liu Shizhen Chen Hailu Luo Shuangchun Wen dianyuan fan Laboratory for Spin Photonics School of Physics and ElectronicsHunan UniversityChangsha 410082China Department of Physics and Electronic Information Science Hengyang Normal UniversityHengyang 421002China SZU-NUS Collaborative Innovation Center for Optoelectronic Science&Technology and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceShenzhen UniversityShenzhen 518060China

The photonic spin Hall effect(SHE)in the reflection and refraction at an interface is very weak because of the weak spin-orbit ***,we report the observation of a giant photonic SHE in a dielectric-based *** metamaterial is structured to create a coordinate-dependent,geometric Pancharatnam–Berry phase that results in an SHE with a spin-dependent splitting in momentum *** is unlike the SHE that occurs in real space in the reflection and refraction at an interface,which results from the momentum-dependent gradient of the geometric Rytov–Vladimirskii–Berry *** theorize a unified description of the photonic SHE based on the two types of geometric phase gradient,and we experimentally measure the giant spin-dependent shift of the beam centroid produced by the metamaterial at a visible *** results suggest that the structured metamaterial offers a potential method of manipulating spin-polarized photons and the orbital angular momentum of light and thus enables applications in spin-controlled nanophotonics.

关键词： geometric phase metamaterial photonic spin Hall effect

Mode Multiplication of Cylindrical Vector Beam Using Raytracing Control

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Chinese Physics Letters 2024年第9期41卷 40-51页

作者： Jing Wang Qingji Zeng Haisheng Wu Chuangxin Xie Huapeng Ye Ze Dong dianyuan fan Shuqing Chen Institute of Microscale Optoelectronics Shenzhen UniversityShenzhen 518060China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology and Institute of Electronic Paper DisplaysSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

Cylindrical vector beams(CVBs)hold significant promise in mode division multiplexing communication owing to their inherent vector mode ***,existing studies for facilitating CVB channel processing are confined to mode shift conversions due to their reliance on spin-dependent helical modulations,overlooking the pursuit of mode multiplication *** challenge lies in the multiplicative operation upon inhomogeneous vector mode manipulation,which is expected to advance versatile CVB channel switching and ***,we tackle this gap by introducing a raytracing control strategy that conformally maps the light rays of CVB from the whole annulus distribution to an annular sector *** with the multifold conformal annulus-sector mappings and polarization-insensitive phase modulations,this approach facilitates the parallel transformation of input CVB into multiple complementary components,enabling the mode multiplication conversion with protected vector *** as a demonstration,we experimentally implemented the multiplicative operation of four CVB modes with the multiplier factors of N=+2 and N=−3,achieving the converted mode purities over 94.24%and 88.37%.Subsequently,200 Gbit/s quadrature phase shift keying signals were successfully transmitted upon multiplicative switching of four CVB channels,with the bit-error-rate approaching 1×10^(−6).These results underscore our strategy’s efficacy in CVB mode multiplication,which may open promising prospects for its advanced applications.

关键词： structure multiplicative approaching

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高功率激光放大器能流分布的模拟

中国激光 2000年第4期27卷 337-342页

作者：王韬范滇元中国科学院上海光机所高功率激光物理国家实验室上海201800

基于高功率激光放大器工作的动力学模型 ,开发了放大器能流分布的模拟软件 ,实现了对放大器主要性能的计算机模拟。软件采用了面向对象的程序设计方法 ,具有灵活构建光路的能力。通过与国外同类软件及“神光 - ”装置的实验结果比较。

关键词：高功率激光能流密度模拟激光放大器

Harpoon-shaped topological photonic crystal for on-chip beam splitter

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 91-98页

作者： Zhiwei Guan Ruixue Dou Chuangxin Xie Tianyimei Zuo Liyu Huang Keyin Wen Chaofeng Wang Huapeng Ye Junmin Liu Ze Dong dianyuan fan Shuqing Chen Institute of Microscale Optoelectronics Shenzhen UniversityShenzhen 518060China College of Physics and Engineering Technology Minzu Normal University of XingyiXingyi 562400China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology and Institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China College of New Materials and New Energies Shenzhen Technology UniversityShenzhen 518118China School of information and Electronics Beijing Institute of TechnologyBeijing 100081China

The advancement of integrated optical communication networks necessitates the deployment of on-chip beam splitters for efficient signal interconnections at network ***,the pursuit of micron-scale beam splitting with large corners and reducing the device footprint to boost connection flexibility often results in phase *** mismatches,which stem from radiation modes and backward scattering,pose significant obstacles in creating highly integrated and interference-resistant *** address this,we introduce a solution based on the topological valley-contrasting state generated by photonic crystals with opposing valley Chern numbers,manifested in a harpoon-shaped structure designed to steer the splitting *** approach enables adiabatic mode field evolution over large corners,capitalizing on the robust phase modulation capabilities and topological protection provided by the subwavelength-scale valley-contrasting *** demonstration reveals that beam splitters with large corners of 60°,90°,and 120°exhibit insertion loss fluctuations below 2.7 dB while maintaining a minimal footprint of 8.8μm×8.8μ*** a practical demonstration,these devices facilitate three-channel signal connections,successfully transmitting quadrature phase shift keying signals at 3.66 Tbit/s with bit error rates below the forward error correction threshold,demonstrating performance comparable to that in defects *** harnessing the unidirectional excitation feature,we anticipate significant enhancements in the capabilities of signal distribution and connection networks through a daisy chain configuration.

关键词： channel interconnection on-chip beam splitter topological valley-contrasting state