自旋激光器的动力学特性及应用研究进展

在半导体激光器中引入自旋极化载流子是实现室温自旋电子应用的新途径,其超越了常规的磁阻效应。自旋极化载流子的注入导致自旋激光器具有丰富的动力学行为并展示出包括高频偏振振荡和偏振混沌动力学等特性,使其在保密光通信、量子计算、光信息处理和数据存储、可重构光互联以及生物医学传感等领域具有巨大的应用潜力。梳理了近年来自旋激光器的动力学特性及其应用研究进展。介绍了自旋激光器丰富的动力学行为及混沌演变机制;随后分析了自旋激光器的高频振荡特性;归纳了基于自旋激光器动力学特性的最新应用研究进展。在此基础上,展望了自旋激光器的发展趋势和面临的挑战,为相关领域的研究和工程应用提供参考。     

Frequency-comb-referenced mid-IR sources for next-generation environmental sensors

We report on recent development of IR spectrometers based on non-linear optical generation and quantum-cascade lasers. Frequency stabilization and referencing to optical frequency-comb synthesizers is described. Their characteristics for spectroscopic as well as metrological applications are pointed out. The potential of the combination of mid-IR sources with enhancement cavities for high-resolution and sensitive measurements of gas spectra is illustrated. Finally, we describe wave-front engineering of long wavelength beams for spatial control and imaging applications.     

The waveguide laser: A review

The present article reviews the fundamental physical principles essential to an understanding of waveguide gas and liquid lasers, and the current technological state of these devices. At the present time, waveguide laser transitions span the visible through submillimeter regions of the wavelength spectrum. The introduction discusses the many applications of waveguide lasers and the wide variety of laser configurations that are possible. Section 1 summarizes the properties of modes in hollow dielectric waveguides of circular, rectangular, and planar cross section. Section 2 considers various approaches to optical feedback including internal and external mirror Fabry-Perot type resonators, hollow waveguide distributed feedback structures, and ring-resonant configurations. Section 3 discusses those aspects of molecular kinetic and laser theory pertinent to the design and optimization of waveguide gas lasers such as the scaling laws for discharge-excited gas lasers, molecular models useful in maximizing the oscillation bandwidth, the effects of gas flow rate, and the physics of optically-pumped far-infrared lasers. Finally, a review of the waveguide gas and liquid lasers reported to date is given in Section 4.     

Excimers and excimer lasers

The development of excimers and excimer lasers are reviewed. The excimers of the noble gases (Xe ₂ ^* , Kr ₂ ^* , Ar ₂ ^* ) and of the noble gas halides (e.g. KrF, XeCl) which, respectively, radiate in the vacuum ultra-violet and ultra-violet regions of the spectrum are described in terms of their structure, spectroscopy and formation kinetics and the methods of pumping, operational characteristics and applications of the lasers are discussed.     

The use of low power air-cooled lasers in conjunction with an intensified diode array for Raman spectroscopy

A range of air-cooled lasers operating with a single phase electricity supply has been evaluated for use in laser-Raman spectroscopy. Three main types of laser are available — helium-neon, argon, and helium-cadmium. Such lasers should prove valuable for applications such as on-line sampling in hostile environments, where their robust nature and low cost give distinct advantages over conventional water-cooled gas ion lasers.     

On the history of far-infrared (FIR) gas lasers: Thirty-five years of research and application

Milestones in research and important applications of FIR molecular gas lasers in the three and a half decades since their discovery are briefly recalled.     

新型二维材料在固体激光器中的应用研究进展

本文主要介绍了二维可饱和吸收体材料在固体激光器中的应用与研究进展。简要介绍了新型二维材料的性质和优点。以石墨烯、拓扑绝缘体、过渡金属硫化物和黑磷等新型二维材料为例分析了它们在固体激光器中实现调Q或锁模的过程,展示了二维材料在脉冲固体激光研究中的重要应用前景。二维材料与固体激光器的结合,可进一步推进二维材料的研究,有望开发出大量新型固体激光器件并且作为基础光源应用于多个领域,推动相关领域的发展。     

Review on diode-pumped alkali vapor laser

Diode-pumped alkali vapor lasers (DPAL) are attracted much attention during recent years for its numerous potential applications. Development of DPAL is reviewed in this paper. The key techniques of DPAL are summarized and analyzed in detail, including the interactions between buffer gas and alkali vapor, pumping structure and power scaling magnification. Novel techniques used in DPAL are discussed, such as hydrocarbon-free DPAL and unstable cavity with transverse pumping. Blue-violet lasers by frequency doubling of DPAL are also introduced specifically. In addition, potential applications and the prospects of DPAL are concluded briefly.     

Frequency-tunable semiconductor lasers

Recent advances in frequency-tunable semiconductor lasers are reviewed. They are classified into hybrid and monolithic tunable lasers. Monolithic tunable lasers based on distributed Bragg reflector or distributed feedback laser structures are most attractive for practical applications. The device structures and the tuning characteristics are described, with emphasis on the tuning range, spectral linewidth and frequency-switching time. Recent system experiments using monolithic tunable lasers in an optical communication area are also described.An Invited Paper     

Lasers for chemical applications

The characteristics of lamps and lasers are contrasted from the viewpoint of a photochemist. The number of potential photochemical applications of lasers is shown to be vastly greater than that using conventional lamps. Several examples are given, which are only made feasible by the special properties of laser light.     

Diode laser based light sources for biomedical applications

Diode lasers are by far the most efficient lasers currently available. With the ever‐continuing improvement in diode laser technology, this type of laser has become increasingly attractive for a wide range of biomedical applications. Compared to the characteristics of competing laser systems, diode lasers simultaneously offer tunability, high‐power emission and compact size at fairly low cost. Therefore, diode lasers are increasingly preferred in important applications, such as photocoagulation, optical coherence tomography, diffuse optical imaging, fluorescence lifetime imaging, and terahertz imaging. This review provides an overview of the latest development of diode laser technology and systems and their use within selected biomedical applications. 670 nm external cavity diode laser for Raman spectroscopy built on a 13 × 4 mm² microbench (Copyright FBH/Schurian.com ).     

High Resolution Linear Laser Absorption Spectroscopy-Review

Throughout the optical spectral region from the visible to the far infrared, lasers have in recent years become increasingly important for high resolution spectroscopy in both laboratory measurements and practical applications. In general, laser sources can be classified into broadly tunable and discretely tunable types with the gas laser belonging to the latter. While gas lasers oscillate in narrow lines scattered throughout the optical spectral region, broadly tunable laser emissions cover a range of wide spectral region depending on the lasing media and operating characteristics. For example, the Pb-salt diode laser covers the spectral region from about 2.6 to 30 μm, the dye laser from 400 to 700 nm, the color center laser from 0.8 to 3.3 μm, the difference frequency spectrometer from 2.2 to 4.2 μm and the spin-flip Raman laser from 5.2 to 6.0 μm. The very limited tunability of the gas laser can sometimes be extended to many times the Doppler width by Zeeman tuning the gain medium or pressure broadening the gain profile or electrooptically modulating the laser output frequency with a tunable microwave source.     

DFB激光二极管电流-温度调谐特性的解析模型

从DFB型激光二极管调谐机理出发,提出了电流-温度调谐特性的解析模型,通过实验测量结果辨识出模型参数,将模型应用于四个不同厂家的DFB型二极管激光器,得到激光器电流-温度调谐的解析模型;将模型预测值与实验测量值比较,相关系数均在0.9999以上.同时,利用CO₂气体的多个吸收谱线测量激光的波长,验证了解析模型的预测波长值,与HITRAN谱库中CO₂气体吸收波长的误差在3 pm内.解析模型能够精确预测激光器在快速调谐过程中的瞬态输出波长,其精度能够满足光谱分析、光 关键词： DFB激光二极管 调谐机理 解析模型 电流调谐和温度调谐     

Novel diode laser-based sensors for gas sensing applications

The development of compact spectroscopic gas sensors and their applications to environmental sensing will be described. These sensors employ mid-infrared difference-frequency generation (DFG) in periodically poled lithium niobate (PPLN) crystals pumped by two single-frequency solid state lasers such as diode lasers, diode-pumped solid state, and fiber lasers. Ultrasensitive, highly selective, and real-time measurements of several important atmospheric trace gases, including carbon monoxide, nitrous oxide, carbon dioxide, formaldehyde [correction of formaldehye], and methane, have been demonstrated.     

Performance studies of a novel design atmospheric pressure pulsed HF/DF laser

Intense multi and single line laser operation is reported from TEA semiconductively preionised HF/DF lasers employing various discrete components or flat plate excitation circuits. The performance, the spectral and the beam characteristics of these lasers are given and are compared to the characteristics of previously described HF/DF lasers. Their improved performance parameters are explained in terms of the preionizing action of the semiconductors, the low inductance of the circuits employed and the good matching of the voltage and current waveforms of the excitation circuitry to their excitation. Finally, their potential in specific applications, like infrared vitreous surgery (HF) or atmospheric laser beam propagation (DF), is stressed.     

High power lasers for processing of materials - a comparison of available systems

Lasers are being used increasingly for specialized engineering applications such as the drilling and scribing of ceramics, and the profile cutting, welding and surface heat-treatment (hardening, alloying and splat-quenching) of metals. The most important characteristics of lasers used for these materials- processing applications (in particular argon-ion, Nd-YAG, and CO₂) are reviewed, with special emphasis on the importance of the electrical efficiency of such systems. The article concludes with a summary of the current status of industrial multi-kilowatt CO₂ lasers, which are of particular interest for metal-working applications.     

Lasers operating on cascade transitions of triatomic molecules

The general conditions necessary for the operation of gas lasers based on cascade vibrational-rotational transitions of molecules in the pulse-periodic regime are formulated. The features of such triatomic-molecule lasers with arbitrary excitation are discussed. A computation model is proposed for determining the energy characteristics (maximum attainable efficiency, average and relative lasing power, specific energy output) of free-flow cascade lasers. Systems are analyzed with various excitation methods: gasdynamic (including those with optical feedback), electric-discharge, and chemical (with the DF-CO₂ laser as the example). Practical recommendations with respect to the choice of mixture composition, optimum cavity lengths along the gas stream, and Q-switching frequency are made for the cascade lasers. A molecular gasdynamic laser emitting three wavelengths simultaneously is proposed.Quantum Radiophysics and Optics Division, Lebedev Physics Institute. Translated from Preprint No. 177 of the Lebedev Physics Institute, Academy of Sciences of the USSR, Moscow, 1989     

LD泵浦Nd:YAG微片激光器

ＬＤ泵浦Ｎｄ：ＹＡＧ微片激光器结构简单紧凑，与半导体激光器相比，前者具有激光线宽窄、光束质量好、相干长度长等优点，因此在一些测量领域有着较好的应用前景。目前对ＬＤ泵浦Ｎｄ：ＹＡＧ微片激光器的实验工作主要是获得单频、单模连续输出和线性频率调制特性研究。本文综述了近几年来ＬＤ泵浦Ｎｄ：ＹＡＧ微片激光器的研究方向、成果及应用，主要介绍了各国对ＬＤ泵浦Ｎｄ：ＹＡＧ微片激光器的调频特性的研究状况     

Low‐wavelength emission of Nd‐doped lasers

This paper gives an overview of the results obtained with diode‐pumped Neodymium‐doped crystals operating below 900 nm. Operation at such low wavelengths requires considering the strong thermal population of the lower level of the laser transition. Based on a theoretical study and simulations, the paper presents the challenges related to the design of these three‐level lasers. Experimental results are given with Nd:YAG and Nd:vanadate crystals. It is explained how to deal with the line competition with emission at 946 nm or 912 nm. Finally, intracavity second‐harmonic generation is presented. The output powers reach a few hundred mW at wavelengths below 450 nm. Hence, the paper demonstrates the potential of Nd‐doped diode‐pumped solid‐state lasers for applications in the blue range, in replacement of gas lasers such as helium‐cadmium lasers.