共查询到20条相似文献,搜索用时 171 毫秒
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在物理实验中,有许多实验需要用到激光器,尤其是光学实验用处更为广泛。比如:光的干涉、光的衍射、光的偏振、全息照相等实验都需要用到激光器。在我们的物理实验中最常用的就是氦氖激光器。它具有单色性好、亮度高、发散角小、方向性强等特点。在实验中可以作为点光源或自然光源。它在物理实验中一直起着积极的作用。多年以来,我们一直在实验中采用氦氖激光器,但由于氦氖激光器膜口封接不过关、实验室的温度、湿度不合适,再加之学生使用方法不当,使氦氖激光器寿命大大减少,而半米以上的氦氖激光器管腔调节平衡比较繁琐,调节不好功率上不去,功率也不很稳定,所以每次使用前都要经过一段时间的调节,才能使激光器的功率达到实验要求。 相似文献
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线宽压窄和频率锁定是提高激光器(特别是半导体激光器)性能的重要手段。在理论分析光反馈时的半导体激光器线宽压窄和频率锁定机理的基础上,建立了一套基于高品质V型光学谐振腔的半导体激光器线宽压窄实验系统,并利用该系统开展了初步实验研究。通过对比无有光反馈情况下的V型腔的透射光扫描线形,初步验证了V型腔用于半导体激光器线宽压窄和频率锁定的可行性,为后续研究奠定了基础。 相似文献
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本文研究了全息存储实验中以波长532 nm的半导体激光器作为记录和读出光源,碱性品红作为光敏剂的丙烯酰胺基光致聚合物薄膜的光致光衍射现 象.它可以考虑为透过全息干涉条纹的原始入射光和反射光,与来自光聚物中未曝光的不均匀表面和内部的散射光四波混频的结果.根据简并四波混频理论中的位相匹配条件对双光束全息写入时产生的衍射光锥,以及单光束辐照复现时产生的衍射光锥现象分别做出了理论解释;并且利用全息散射理论结合三角学知识对入射光的入射角与衍射光锥的锥角的依赖关系进行了深入讨论.
关键词:
全息
光致聚合物
衍射光锥
碱性品红 相似文献
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基于法布里-珀罗半导体激光器实现高重复频率光脉冲的时钟分频 总被引:1,自引:1,他引:0
实验研究了重复速率为6.32 GHz的光脉冲注人法布里-珀罗(Fabry-Perot)半导体激光器实现3.16 GHz光脉冲输出的时钟分频现象,讨论了 Fabry-Perot半导体激光器的偏置电流、注入光功率、注入光光谱以及光谱线宽等因素对时钟分频的影响.利用光注入半导体激光器产生的周期二振荡非线性动力学特性.实现了高重复速率光脉冲的时钟分频.研究表明,当注入光的光谱较窄且锁定Fabry-Perot半导体激光器某一纵模时,在较低的偏置电流和一定的注入光功率时,时钟分频才能发生.采用半导体激光器的速率方程.通过数值模拟,研究了半导体激光器的偏置电流和线宽增强因子以及注入光功率对时钟分频的影响,所得结果与实验结果相吻合. 相似文献
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In this paper, we investigate modulation transfer in an injection-locked diode laser when the master laser frequency or intensity is modulated. The modulation transfer properties of injection-locked diode lasers are shown to depend on frequency detuning between the master and slave lasers. This observation is of practical importance, since the laser frequencies are typically prone to ambient conditions. Also conversion of the master laser frequency modulation to slave laser intensity modulation is shown to be of importance if large frequency modulation amplitudes and small intensity modulation amplitudes of the master laser are used. On the other hand, the injection-locking technique is proved to be an effective way to suppress spurious intensity modulation in certain operational conditions. 相似文献
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We are building a long-range FM/cw nonscanning imaging lidar breadboard. This lidar system achieves ranging based on a frequency
modulation/continuous wave (FM/cw) technique, implemented by an amplitude modulated mid-IR diode laser transmitter with a
linear frequency modulation (LFM) of the subcarrier. Firstly, various schemes of light beam modulation are analyzed. Secondly,
we put forward a laser modulation scheme whose core was formed by a 1.55 μm electro-absorption modulated laser diode (EML) and an erbium-doped optical fiber amplifier (EDFA), then a corresponding
experimental system architecture and components for light beam modulation and detection are established. Finally, a corresponding
experiment of laser beam modulation is completed for the first time. In our experiment, the EML amplitude is modulated by
a 200 MHz to 800 MHz LFM signal, whose amplitude value is 2.05 V. The average output power of the modulated laser obtained
in the experiment is 10 W, peak power is 16.4 W, and the average modulation depth is 78%. The results of tests predict that
this laser modulation scheme is likely to improve the imaging range of the FM/cw lidar. 相似文献
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《应用光谱学评论》2013,48(4):395-432
Abstract The need for higher sensitive detection technology for trace gas samples, either in the laboratory setup or in the atmospheric remote sensing has been a goal for several decades. The development of the tunable diode laser has propelled the progress of trace detection technology, and modulation technology enables the improvement of the detection sensitivity. As a result, the detection of 10?7 or 10?8 absorbance is possible for some applications, and modulation technology has been applied to the ultraviolet as well as mid-infra red wavelength range. In this review, recent progress of tunable diode lasers and diode laser-based modulation technologies are presented. Wavelength modulation, frequency modulation, and two-tone frequency modulation techniques are mainly described along with the actual application of the techniques. In addition, the state-of-the-art of diode laser development which can be adopted for the trace detection is presented. 相似文献
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An improved electrical equivalent model for multimode laser diode incorporating thermal effects and spectral behavior is developed from the multi mode rate equations. The temperature dependent optical power, wavelength shift, spectral widths are determined in the dc sweep simulations. The output power, frequency chirp and temperature rise are evaluated under pulse modulation conditions. Further, the laser diode bandwidth dependence on temperature is also evaluated. Analysis is carried out in the temperature range of 283–343 K, by simulating the equivalent circuit, using PSpice circuit simulator. 相似文献
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Two methods for recovery of gas absorption line profiles are presented in this paper using photoacoustic spectroscopy and tunable diode laser spectroscopy (TDLS) with wavelength modulation (WM). A theoretical analysis based on Fourier coefficients is given in order to describe the various components that arise under simultaneous intensity and frequency modulation. The first method makes use of the residual amplitude modulation (RAM) signal which is always present in current modulation of distributed feedback (DFB) tunable diode lasers. The second method involves integration of a near-pure first harmonic derivative signal, separated from other distorting components by appropriate choice of the lock-in detection phase in the case of low modulation index. Good agreement is obtained with both methods between the experimental results and the theoretical simulation for the P17 absorption line of acetylene at 1535.39 nm but the second method gives a much improved accuracy and signal-to-noise ratio in lineshape recovery with photoacoustic spectroscopy. 相似文献
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电光晶体调谐的外腔反馈半导体激光器 总被引:1,自引:0,他引:1
报道一种用电光晶体实现快速调谐和凋制激光频率的方法.在Littrow型外腔反馈半导体激光中插入LiNbO3晶体,利用LiNbO3晶体的电光效应,通过改变晶体电压来调节激光器的有效腔长,可以对激光频率进行快速的调谐和调制.采用该方法,自制外腔反馈半导体激光器的调谐频率可达到2 kHz,它的调谐范围为350 MHz,激光频率调谐系数约为1.06 MHz/V,用饱和吸收光谱观测频率调谐的效果.快速激光频率调制可以应用在稳频技术上,将外腔反馈半导体激光器调制在5~100 kHz频率下,均获得了87Rb原子D2线的饱和吸收光谱的色散信号,并实现了激光频率在饱和吸收峰上的长期稳定. 相似文献
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We improved the thermal equivalent-circuit model of the laser diode module(LDM) to evaluate its thermal dynamic properties and calculate the junction temperature of the laser diode with a high accuracy.The thermal parameters and the transient junction temperature of the LDM are modeled and obtained according to the temperature of the thermistor integrated in the module.Our improved thermal model is verified indirectly by monitoring the emission wavelength of the laser diode against gas absorption lines,and several thermal parameters are obtained with the temperature uncertainty of 0.01 K in the thermal dynamic process. 相似文献
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An active phase-shifting interferometer using current modulation of a laser diode is proposed. Fringe movement in the instrument is detected by a spatial filtering detector whose output is fed back to the injection current of the laser diode to lock the fringes and shift them correctly for phase shifting analysis. Frequency modulation characteristics of the laser diode and frequency response of the feedback system are first investigated. We constructed a portable interferometer head set apart from a mirror under test then measured the shape of a spherical mirror 130 mm in diameter, which was placed on a wooden table subject to vibration. Measurement repeatability of λ/35 was achieved. 相似文献