Device for Measurement of the Stability of Laser Emission Power

An automated device for determining the stability of the power of continuous laser emission created in accordance with the requirements of the ISO 11554 international standard is considered. The mean value of the measured emission intensity and root-mean-square deviation from this mean value, the maximum and minimum values of the intensity and stability of the emissive power are calculated on the basis of a measurement of the intensity of laser emission expressed in terms of relative units. The measurements are performed for medium-term (1 min) and long-term (60 min) intervals.     

高稳定度高功率密度主被动锁模YAG激光器

从理论上和实验上，将一声光驻波调制器插入纯被动锁模ＹＡＧ激光谐振腔内，使其特性显著地改进，即锁模几率达到百分之百，锁模阈值明显地降低，锁模脉冲列的稳定性显然提高。并用雪崩晶体管串供Ｐｏｃｋｅｌ盒选取单脉冲用的高压方波。在此基础上，再经两级激光放大及二、三倍频谐波发生器，研制出一台高稳定度高功率密度主被动锁模ＹＡＧ激光器的超短激光脉冲光源     

智能化感光材料高分辨率测定仪研制

这篇文章对计算机控制的智能化感光材料分辨率测定仪的系统结构,控制过程做了详细介绍了,该仪器具有光学分辨率高,检测速度快,微控制自动化程度的优点,此外,测定仪与微接简单,控制程序界面友好,用户操作方便,在实际测量中达到连续拍摄５层焦面共３５个标板图案理想效果,表明测定仪操作稳定可靠,而且测定重复性好。     

脉冲激光峰值／平均功率测试方法研究

为解决生产过程中所用脉冲激光光源输出峰值/平均功率测试的量值准确一致及其量值溯源问题,确保生产过程受控。文章以激光能量计作为量值传递标准,采用脉冲激光能量法实现脉冲激光峰值功率量值溯源;并运用波形半宽度分析法进行有效测试。     

Laser with a nonlinear mirror: application for improving the output power stability of a cw laser

We put forward a new method for improving the output power stability of a cw laser. The basic idea is to replace the output mirror of a laser with a nonlinear mirror that is formed by a dispersive nonlinear Fabry-Perot étalon. Based on the semiclassical dynamic model for this system, first we derive the static conditions for this laser operating with stabilized output power, then we study the dynamic responses of output power to gain fluctuations. Both static and dynamic results show that, compared with normal lasers, the output power stability of our laser can be improved significantly when the output power fluctuations are caused by the fluctuations of the gain. The improvement of the output power can be explained by the fact that there exists an optical servoloop in this laser that is produced by the nonlinear mirror.     

半导体激光器输出功率影响因素的研究进展

大功率半导体激光器是现代激光加工设备、激光再制造设备、激光医疗、激光显示以及国防设备中重要的关键基础元器件和核心组件,在工业和国防等领域有着广泛的应用.提高半导体激光器的输出功率首先需要确定影响功率输出的因素,然后通过优化外延材料、芯片结构和制备工艺来解决这些问题.因此,对大功率半导体激光器输出功率影响因素的研究具有重...     

Stability analysis of a diode-pumped,thermal birefringence-compensated two-rod Nd:YAG laser with 770-W output power

Using a ray matrix method, we analyze theoretically how the r and theta polarizations affect the resonator stability condition of two laser heads with or without thermal birefringence compensation. The resonator stability condition is analyzed graphically for a plane-parallel and a concave-concave resonator. The maximum range of stable region is found for both the short and the long cavity. The characteristics of the laser output power are confirmed experimentally in association with the resonator stability condition. The laser output power of 776 W is obtained with the optical-to-optical efficiency of 45% for a plane-parallel resonator with a short crystal separation.     

Optothermal Frequency and Power Modulation of Laser Diodes

Abstract

A practical technique is demonstrated for the optothermal modulation of laser diodes, with supporting theory. Thermal power is produced optically by focusing the output of another laser onto the diode output facet. The relative magnitudes of the frequency and power modulation are shown to be sensitive to the position of the heated region, and under appropriate conditions useful frequency modulation amplitudes can be achieved (? GHz) with negligible power modulation.     

Consideration of the Effect of Instability of the Laser Emission Power on the Final Result of the Reproduction of the Unit of Mean Laser Emission Power and the Transmission of Its Dimensions

An algorithm for reconstructing the form of continuous laser emission at the input of a system for measuring the standard of the unit of mean laser power is presented. The power can also be calculated using this algorithm.     

The Effect of Laser Power,Traverse Velocity and Spot Size on the Peel Resistance of a Polypropylene/Adhesive Bond

The mean peel resistance force achieved with respect to variation in the laser power, incident spot traverse velocity and incident spot diameter between linear low density polyethylene film backed by a thin commercial adhesive coating that were bonded to a polypropylene (PP) substrate via thermal activation provided by a 27W CO₂ laser is discussed in this work. The results gathered for this work have been used to generate a novel empirical tool that predicts the CO₂ laser power required to achieve a viable adhesive bond for this material combination. This predictive tool will enable the packaging industry to achieve markedly increased financial yield, process efficiency, reduced material waste and process flexibility. A laser spot size‐dependent linear increase in laser line energy was necessary for this material combination, suggesting the minimal impact of thermal strain rate. Moreover, a high level of repeatability around this threshold laser line energy was indicated, suggesting that laser‐activated adhesive bonding of such polymer films is viable. The adhesion between the material combination trialled here responded linearly to thermal load. In particular, when using the smallest diameter laser spot, it is proposed that the resulting high irradiance caused film or adhesive material damage, thus resulting in reduced peel resistance force. The experimental work conducted indicated that the processing window of an incident CO₂ laser spot increases with respect to spot diameter, simultaneously yielding greater bond stability in the face of short‐term laser variance. © 2015 The Authors. Packaging Technology and Science published by John Wiley & Sons Ltd.     

采用液晶光阀的氦氖激光准直控制

激光光束的漂移,功率稳定性和激光光斑的强度分布对称性是影响准直精度的主要参数。通过分析液晶光阀的特性,提出了一种智能型光束准直控制方法,可同时控制激光功率的稳定性和光斑的强度分布对称性。利用热平衡技术,设计了一套温度实时反馈控制的准直装置。实验结果证实了该方法的可行性和有效性。     

神光III强激光能源模块参数设计与保护策略

介绍了神光III预研计划能源模块电路设计方法及参数选择原则 ,详细分析了电源系统可能存在的各种故障情况 ,在此基础上提出了电源系统故障保护的方法和对策 ,这对于电源系统的设计和安全运行具有十分重要的意义。实验结果表明 ,所研制的脉冲电源满足系统要求。     

新型高功率因体激光器电源

用旋转磁通压缩脉冲发电机作为高功率固体激光器电源是一条新的技术路线,该类电源具有小型、机动、灵活、可靠、寿命长等特点。本文通过比较了各种类型脉冲电源的性能指标,解释了旋转磁通压缩、串级、自激、偏极与双机同壳等原理,给出电机的设计公式和一１０ＭＷ串级主动旋转磁通压缩脉冲发电机的设计与实验结果。     

用集成功放组成的精密功率放大器

介绍了一种用厚膜集成功放加上稳幅电路组成的精密功率放大器,其稳定度、频率响应和波形失真都达到了很高的指标。     

开关型小功率激光电源

抛弃了传统Ｈｅ──Ｎｅ激光电源的升压方法，采用８０９８单片机的ＰＷＭ输出信号驱动逆变器，并对系统进行全面控制。给出了系统的硬件结构及软件设计。实际应用表明，此电源具有体积小、重量轻、恒流特性好、调节范围宽等特点，极易实现激光电源电路和测量仪器电路的一体化。     

Three-longitudinal-mode He-Ne laser frequency stabilized at 633 nm by thermal phase locking of the secondary beat frequency

We present a simple scheme for thermal frequency stabilization of a three-longitudinal-mode He-Ne laser at 633 nm with improved short-term (5 x 10(-11) at 1-s average time) and long-term (124-kHz standard deviation for 10 h) frequency stability. A stabilized output power of 3 mW was readily obtained from the central mode by polarization-mode selection. The optical frequency of the central mode could be precisely tuned by an external frequency reference over 160 MHz with high precision or could be optically phase locked to a reference laser by use of a thermal frequency-stabilization circuit and an external acousto-optic modulator. The laser will be useful in various applications for which a laser source with high power and frequency stability is necessary.     

激光淬火功率对45~#钢抗植物磨料磨损性能的影响

本文以苜蓿草粉为典型植物磨料,系统研究了激光淬火功率对45~#钢抗植物磨料磨损性能的影响。试验结果表明:在实验条件下,材料表面硬度最大值可达679HV,材料硬度最大值在距表面0.2~0.4mm之间;激光淬火后的45~#钢抗植物磨料磨损性能远高于未经激光处理的试件。激光功率对材料硬度和耐磨性的影响趋势并不完全一致,耐磨性最好的试件硬度并非最高;植物磨料对激光淬火后的45~#钢的磨损机理主要为显微切削,与未经激光淬火的试件相比,激光淬火后的45~#钢表面犁削深度明显浅而窄,但当激光功率降至1750W时,塑变疲劳和碳化物剥落明显增加。研究结论可为农业机械金属材料的耐磨性设计提供依据。     

International Intercomparison of Laser Power Measurements in the Visible Region

In this paper we describe results of the international intercomparison of He-Ne and Ar-ion laser power measurements. The intercomparison measurements were of He-Ne laser power of 3 mW at the wavelength of 633 nm and Ar-ion laser power of 200 mW at 488 nm and 515 nm. The participating laboratories coincided within deviation from the average of 0.6 percent at 633 nm, 0.8 percent at 488 nm, and 0.9 percent at 515 nm.     

Four watt long-term stable intracavity frequency-doubling Nd:YVO(4) laser of single-frequency operation pumped by a fiber-coupled laser diode

The longitudinal-mode stability of a single-frequency intracavity frequency-doubling laser can be enhanced by increasing the ratio between the nonlinear spectral bandwidth and the gain bandwidth of the laser. A 4 W long-term stable cw single-frequency green laser is obtained using an etalon inside the laser cavity as a spectral filter. No mode hopping is observed when the laser operates for 6 h and the power fluctuation is less than +/-1.2%. In contrast, in the situation of no etalon inside the laser cavity, mode hopping can be observed at irregular intervals and the power fluctuation is +/-3.8% when the laser operates for 4 h.     

一种测量氦氖激光器功率的新方法

介绍利用照度计测量氦氖激光器功率的新方法。