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Efficient single-pixel imaging encrypted transmission based on 3D Arnold transformation

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Chinese Physics B 2024年第3期33卷 378-386页

作者：梁振宇王朝瑾王阳阳高皓琪朱东涛许颢砾杨星 State key laboratory of Pulsed Power laser technology National University of Defense TechnologyHefei 230001China Advanced laser technology laboratory of Anhui Province Hefei 230001China

Single-pixel imaging(SPI)can transform 2D or 3D image data into 1D light signals,which offers promising prospects for image compression and transmission.However,during data communication these light signals in public channels will easily draw the attention of eavesdroppers.Here,we introduce an efficient encryption method for SPI data transmission that uses the 3D Arnold transformation to directly disrupt 1D single-pixel light signals and utilizes the elliptic curve encryption algorithm for key transmission.This encryption scheme immediately employs Hadamard patterns to illuminate the scene and then utilizes the 3D Arnold transformation to permutate the 1D light signal of single-pixel detection.Then the transformation parameters serve as the secret key,while the security of key exchange is guaranteed by an elliptic curve-based key exchange mechanism.Compared with existing encryption schemes,both computer simulations and optical experiments have been conducted to demonstrate that the proposed technique not only enhances the security of encryption but also eliminates the need for complicated pattern scrambling rules.Additionally,this approach solves the problem of secure key transmission,thus ensuring the security of information and the quality of the decrypted images.

关键词： single-pixel imaging 3D Arnold transformation elliptic curve encryption image encryption

High power tunable Raman fiber laser at 1.2μm waveband

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Frontiers of Optoelectronics 2024年第1期17卷 1-8页

作者： Yang Zhang Jiangming Xu Junrui Liang Jun Ye Sicheng Li Xiaoya Ma Zhiyong Pan Jinyong Leng Pu Zhou College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Nanhu laser laboratory National University of Defense TechnologyChangsha 410073China Hunan Provincial key laboratory of High Energy laser technology National University of Defense TechnologyChangsha 410073China

Development of a high power fiber laser at special waveband,which is difficult to achieve by conventional rare-earth-doped fibers,is a significant challenge.One of the most common methods for achieving lasing at special wavelength is Raman conversion.Phosphorus-doped fiber(PDF),due to the phosphorus-related large frequency shift Raman peak at 40 THz,is a great choice for large frequency shift Raman conversion.Here,by adopting 150 m large mode area triple-clad PDF as Raman gain medium,and a novel wavelength-selective feedback mechanism to suppress the silica-related Raman emission,we build a high power cladding-pumped Raman fiber laser at 1.2μm waveband.A Raman signal with power up to 735.8 W at 1252.7 nm is obtained.To the best of our knowledge,this is the highest output power ever reported for fiber lasers at 1.2μm waveband.Moreover,by tuning the wavelength of the pump source,a tunable Raman output of more than 450 W over a wavelength range of 1240.6–1252.7 nm is demonstrated.This work proves PDF’s advantage in high power large frequency shift Raman conversion with a cladding pump scheme,thus providing a good solution for a high power laser source at special waveband.

关键词： Phosphosilicate fiber Raman fiber laser 1.2μm waveband Wavelength tunable

Integrated Fabry–Perot interferometer based on Er/Yb co-doped fiber for all-optical phase modulation

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Chinese Optics Letters 2024年第4期22卷 95-100页

作者：汪凡林思雨曲彦臣韩晓鹏掌蕴东 National key laboratory of Tunable laser technology.Institute of Opto-Electronics Harbin Institute of TechnologyHarbin 150080China

Fast and stable phase control is essential for many applications in optics. Here, we propose an all-fiber all-optical phase modulation scheme based on a Fabry–Perot interferometer(FPI) and an Er/Yb co-doped fiber(EYDF). By using the EYDF as an F-P cavity via rational design, a phase shift with a modulation sensitivity of 0.0312π/mW is introduced to the modulator.The phase shifts in the EYDF consist of a thermal phase shift and a nonlinear phase shift with a ratio of 19:1, and the corresponding temporal responses of the modulation are 204 ms and 2.5 ms, respectively. In addition, the compact FPI is encapsulated to provide excellent stability for the modulator.

关键词： in-line Fabry-Perot interferometer nonlinear phase shift all-optical phase modulation

Intermediate phase-assisted growth of CsPbBr3 for high performance of carbon-based perovskite solar cells

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Rare Metals 2024年第5期43卷 2222-2229页

作者： Bo-Yan Liu He-Ming Yang Yu-Dong Zuo Zhi-Hao Tao Jun-Chun Li Ya-Jing Chang Guo-Qing Tong Yang Jiang School of Materials Science and Engineering Hefei University of Technology State key laboratory of Pulsed Power laser technology National University of Defense Technology

CsPbBr3inorganic perovskites have been regarded as the promising materials in the field of photovoltaics because of the high tolerance against environment The high energy barrier of phase transition from lead bromide （PbBr2） to CsPbBr3perovskite and low solubility of perovskite in organic solvent impede the further improvement of device performance in terms of CsPbBr3solar cells.Herein,an intermediate phase-assisted growth of CsPbBr3perovskite was proposed by introducing tetraphenylphosphonium bromide （TPPB） as additive.The TPPB is expected to react with PbBr2in organic solvent to form an intermediate phase of[TPPB·DMF]·PbBr2,which not only effectively improves the crystallinity of PbBr2crystals,but also greatly reduces the phase transition energy barrier,leading to uniform and compact CsPbBr3perovskite films with large grain size and high crystallinity In combination with carbon electrode,the CsPbBr3solar cells yield a champion device performance of 9.57%in comparison of pristine CsPbBr3solar cells showing a low efficiency of 8.17%.Furthermore,the intermediate phaseassisted growth of CsPbBr3-based solar cells displays an outstanding storage over 720 h.

关键词： CsPbBr 3 Perovskite solar cells Carbon electrode Hole transport layer free Intermediate phase

Femtosecond laser-induced periodic surface structures on hard and brittle materials

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Science China(Technological Sciences) 2024年第1期67卷 19-36页

作者： ZHAO GuoXu WANG Gong LI YunFei WANG Lei LIAN YuDong YU Yu ZHAO Hui WANG YuLei LU ZhiWei Center for Advanced laser technology Hebei University of TechnologyTianjin 300401China Hebei key laboratory of Advanced laser technology and Equipment Tianjin 300401China State key laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China School of Information and Electrical Engineering Hebei University of EngineeringHandan 056038China

Hard and brittle materials have high hardness,excellent optical stability,chemical stability,and high thermal stability.Hence,they have huge application potential in various fields,such as optical components,substrate materials,and quantum information,especially under harsh conditions,such as high temperatures and high pressures.Femtosecond laser direct writing technology has greatly promoted the development of femtosecond laser-induced periodic surface structure(Fs-LIPSS or LIPSS by a femtosecond laser)applications of hard and brittle materials due to its high precision,controllability,and three-dimensional processing ability.Thus far,LIPSSs have been widely used in material surface treatment,optoelectronic devices,and micromechanics.However,a consensus has not been reached regarding the formation mechanism of LIPSSs on hard and brittle materials.In this paper,three widely accepted LIPSS formation mechanisms are introduced,and the characteristics and applications of LIPSSs on diamonds,silicon,silicon carbide,and fused silica surfaces in recent years are summarized.In addition,the application prospects and challenges of LIPSSs on hard and brittle materials by a femtosecond laser are discussed.

关键词： laser-induced periodic surface structures hard and brittle materials femtosecond laser

5 kW-level single-mode fiber amplifier based on low-numerical-aperture fiber

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Chinese Optics Letters 2024年第4期22卷 71-76页

作者：陈益沙叶云黄良金杨欢吴函烁闫志平潘志勇王小林王泽锋周朴 College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Nanhu laser laboratory National University of Defense TechnologyChangsha 410073China Hunan Provincial key laboratory of High Energy laser technology National University of Defense TechnologyChangsha 410073China

A low-numerical-aperture(NA)concept enables large-mode-area fiber with better single-mode operation ability,which is beneficial for transverse mode instability and nonlinear effects suppression.In this contribution,we reported a high-power fiber amplifier based on a piece of self-developed large-mode-area low-NA fiber with a core NA of 0.049 and a core/inner cladding diameter of 25/400μm.The influence of the pump wavelength and fiber length on the power scaling potential of the fiber amplifier is systematically investigated.As a result,an output of 4.80 kW and a beam quality factor of~1.33 were finally obtained,which is the highest output power ever reported in a fiber amplifier exploiting the low-NA fiber.The results reveal that low-NA fibers have superiority in power scaling and beam quality maintenance at high power levels.

关键词： high power fiber lasers ytterbium-doped fiber low-numerical-aperture fiber mode instability

High-power mode-programmable orbital angular momentum beam emitter with an internally sensed optical phased array

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Chinese Optics Letters 2024年第2期22卷 120-127页

作者：龙金虎邓宇高志强常洪祥常琦马阎星吴坚粟荣涛马鹏飞周朴 College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Nanhu laser laboratory National University of Defense TechnologyChangsha 410073China Hunan Provincial key laboratory of High Energy laser technology National University of Defense TechnologyChangsha 410073China

The high-power mode-programmable orbital angular momentum(OAM)beam has attracted significant attention in a wide range of applications,such as long-distance optical communication,nonlinear frequency conversion,and beam shaping.Coherent beam combining(CBC)of an optical phased array(OPA)can offer a promising solution for both generating the high-power OAM beam and rapidly switching the OAM modes.However,achieving real-time phase noise locking and formation of desired phase structures in a high-power CBC system faces significant challenges.Here,an internal phase-sensing technique was utilized to generate the high-power OAM beam,which effectively mitigated thermal effects and eliminated the need for large optical devices.An OPA with six elements was employed for experimental demonstration.The first effective generation of over 1.5 kW mode-programmable OAM beam in a continuous-wave domain was presented.Moreover,the results demonstrated that the generated OAM beam could be modulated with multiple dimensions.The topological charge can be switched in real time from-1 to-2.Notably,this OAM beam emitter could function as an OAM beam copier by easily transforming a single OAM beam into an OAM beam array.More importantly,a comprehensive analysis was conducted on power scaling,mode switching speed,and expansion of OAM modes.Additionally,the system’s compact design enabled it to function as a packageable OAM beam emitter.Owing to the advantages of having high power and programmable modes with multiple dimension modulation in phase structures and intensity distribution,this work can pave the way for producing high-power structured light beams and advancing their applications.

关键词： orbital angular momentum optical vortex optical phased array coherent beam combining

Generation and regulation of electromagnetic pulses generated by femtosecond lasers interacting with multitargets

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Nuclear Science and Techniques 2024年第1期35卷 96-107页

作者： Ya-Dong Xia De-Feng Kong Qiang-You He Zhen Guo Dong-Jun Zhang Tong Yang Hao Cheng Yu-Ze Li Yang Yan Xiao Liang Ping Zhu Xing-Long Xie Jian-Qiang Zhu Ting-Shuai Li Chen Lin Wen-Jun Ma Xue-Qing Yan State key laboratory of Nuclear Physics and technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China Beijing laser Acceleration Innovation Center Beijing 101407China Institute of Guangdong laser Plasma technology Guangzhou 510540China National laboratory on High Power laser and Physics Shanghai Institute of Optics and FineChinese Academy of SciencesShanghai 201800China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Ultrashort and powerful laser interactions with a target generate intense wideband electromagnetic pulses(EMPs).In this study,we report EMPs generated by the interactions between petawatt(30 fs,1.4×10^(20) W/cm^(2))femtosecond(fs)lasers with metal flat,plastic flat,and plastic nanowire-array(NWA)targets.Detailed analyses are conducted on the EMPs in terms of their spatial distribution,time and frequency domains,radiation energy,and protection.The results indicate that EMPs from metal targets exhibit larger amplitudes at varying angles than those generated by other types of targets and are enhanced significantly for NWA targets.Using a plastic target holder and increasing the laser focal spot can significantly decrease the radiation energy of the EMPs.Moreover,the composite shielding materials indicate an effective shielding effect against EMPs.The simulation results show that the NWA targets exert a collimating effect on thermal electrons,which directly affects the distribution of EMPs.This study provides guidance for regulating EMPs by controlling the laser focal spot,target parameters,and target rod material and is beneficial for electromagnetic-shielding design.

关键词： Electromagnetic pulses laser plasma interaction Electromagnetic shielding Electron distribution

Compositional and Hollow Engineering of Silicon Carbide/Carbon Microspheres as High-Performance Microwave Absorbing Materials with Good Environmental Tolerance

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Nano-Micro Letters 2024年第9期16卷 128-146页

作者： Lixue Gai Yahui Wang Pan Wan Shuping Yu Yongzheng Chen Xijiang Han Ping Xu Yunchen Du MIIT key laboratory of Critical Materials technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001People’s Republic of China Anhui Provincial laboratory of Advanced laser technology College of Electronic EngineeringNational University of Defense TechnologyHefei 230037People’s Republic of China

Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable MAMs under some rigorous conditions,while their composites still fail to produce satisfactory microwave absorption performance regardless of the improvements as compared with the individuals.Herein,we have successfully implemented compositional and structural engineering to fabricate hollow SiC/C microspheres with controllable composition.The simultaneous modulation on dielectric properties and impedance matching can be easily achieved as the change in the composition of these composites.The formation of hollow structure not only favors lightweight feature,but also generates considerable contribution to microwave attenuation capacity.With the synergistic effect of composition and structure,the optimized SiC/C composite exhibits excellent performance,whose the strongest reflection loss intensity and broadest effective absorption reach−60.8 dB and 5.1 GHz,respectively,and its microwave absorption properties are actually superior to those of most SiC/C composites in previous studies.In addition,the stability tests of microwave absorption capacity after exposure to harsh conditions and Radar Cross Section simulation data demonstrate that hollow SiC/C microspheres from compositional and structural optimization have a bright prospect in practical applications.

关键词： SiC/C composites Compositional engineering Hollow engineering Microwave absorption Environmental tolerance