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1.
L. Aubrecht 《Czechoslovak Journal of Physics》1972,22(12):1211-1219
The problem of dielectric modulation of the single mode laser by acoustic wave is considered. The basic equations for creation and annihilation operators are solved. Expectation values for the number of quanta in the mode obtained from given solution are calculated and discussed.Technická 2, Praha 6, Czechoslovakia. 相似文献
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Hisham Kadhum Hisham Ahmad Fauzi Abas Ghafour Amouzad Mahdiraji Mohd Adzir Mahdi Ahmad Shukri Muhammad Noor 《Optical Review》2012,19(2):64-70
A comprehensive study on the small-signal intensity modulation (IM) characteristics of a fiber grating Fabry-Perot (FGFP)
laser is numerically investigated. The effect of external optical feedback (OFB), temperature, injection current, cavity volume,
nonlinear gain compression factor, and fiber grating (FG) parameters on IM characteristics are presented. The temperature
dependence (TD) of IM is calculated according to the TD of laser cavity parameters instead of using the well-known Parkove
relationship. It has been shown that the optimum external fiber length (L
ext) is 3.1 cm. The optimum range of working temperature for FGFP laser is between 23 to 27 °C. We also show that by increasing
the laser injection current from 10 to 60 mA, the IM peak amplitude decreased from 6.3 to 0.2 dB and the relaxation-oscillation
frequency (ROF) is shifted from 1.2 GHz towards higher frequency of 5.48 GHz. In addition, the AR coating reflectivity and
gain compression factor have no significant effect on the IM. The study indicates that a stable operation and excellent modulation
characteristic can be obtained after optimization process. 相似文献
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Amir Fardad 《Optics Communications》2006,259(2):631-635
A novel pump-sharing module for multi-channel amplifiers based on integration of high-power multimode semiconductor lasers and planar waveguide circuits is proposed. The feedback-free modules are designed for optimum coupling, throughput and power uniformity on silicon using BPM method and fabricated via the sol-gel process of photo patternable precursors. Modal properties of the multimode lasers are considered by studying spectrum and spatial distribution of laser output power at different temperatures. Employing an 1500 mW 980 nm multimode laser (TE polarized), via lens and Butt coupling up to 1250 mW of laser output is coupled into the multimode channel waveguides, which are tapered and branched to four single mode waveguides. The measured pump power from splitter outputs, randomly polarized, exceeds 600 mW. At constant temperatures ranging from 22 °C to 30 °C, the pump-sharing modules exhibit good stability with a power uniformity of <0.5 dB over hours. 相似文献
6.
《中国光学快报(英文版)》2016,(7)
Based on the modified ramp and fire technique, a novel injection seeding approach with real-time resonance tracking is successfully demonstrated in a single-frequency Nd:YAG pulsed laser. Appling a high-frequency sinusoidal modulation voltage to one piezo actuator and an adjustable DC voltage to another piezo actuator for active feedback, single-mode laser output with high-frequency stability is obtained, and the effect of the piezo hysteresis on the frequency stability can be eliminated for a laser diode pumped Q-switched Nd:YAG laser at a repetition rate of 400 Hz. 相似文献
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在色噪声间的关联程度受时间周期调制的激光系统中,研究噪声受信号调制情况下的随机共振.用线性化近似的方法计算了光强关联函数及信噪比.具体讨论信噪比随噪声强度、噪声自关联时间、信号频率以及时间周期调制频率的变化关系.发现一种新的随机共振:信噪比随时间周期调制频率的变化出现周期振荡型随机共振;发现广义随机共振:信噪比随抽运噪声自关联时间的变化、随信号频率的变化出现随机共振;同时也存在典型的信噪比随噪声强度的变化而出现的随机共振.而信噪比随量子噪声自关联时间的变化表现为抑制.
关键词:
信号调制
时间周期调制
噪声间关联程度
周期振荡型随机共振 相似文献
9.
A tunable single-mode laser is obtained by using a weakly coupled cavity structure involved in a coaxially packaged Fabry-Perot laser diode. The cleaved end facet of the coupling fiber becomes an optical reflector and forms an external cavity with a laser facet. The single-mode oscillation condition is controlled and stabilized by tuning the operating temperature. The tuning range is about 10 nm with the side-mode suppression ratio of more than 27 dB when the temperature changes from 11.5 degrees C to 25 degrees C. Direct modulation characteristics were investigated, and our results show that a shorter external cavity can bear deeper modulation depth. 相似文献
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The probability w
L
of Lorentzian ionization, which arises when an atom or ion moves in a constant magnetic field, is calculated in the quasiclassical
approximation. The nonrelativistic (v≲e
2/ℏ=1, v is the velocity of the atom) and ultrarelativistic (v→c=137) cases are examined and the stabilization factor S, which takes account of the effect of the magnetic field on tunneling of an electron, is found.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 5, 391–396 (10 March 1997) 相似文献
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A. S. Biryukov E. M. Kudryavtsev A. N. Logunov V. A. Shcheglov 《Journal of Russian Laser Research》1997,18(3):222-246
The second part of our work continues the analysis of the problem studied in the first par [J. Russ. Laser Res.,17, 205 (1996)]. We seek an answer to the following question: What is laser radiation from the viewpoint of the classical theory of wave fields? Here, we consider the statistical aspect of the problem. Moveover, we show how this aspect is connected with the formation of laser radiation from the level of spontaneous noise and how it governs the quality of laser radiation. 相似文献
15.
Haiming Wang 《Fiber and Integrated Optics》1991,10(3):245-256
A novel phase-perturbation method as well as an experimental system were established to study the deviation of the laser diode (LD) far-field intensity distribution from the ideal Gaussian. An analytical expression of the LD far-field intensity distribution and a numerical method based on the Monte Carlo calculation were developed to fit the measured results. The loss of the LD to the single-mode fiber (SMF) coupling system caused by this kind of deviation of the LD far-field intensity distribution was quantitatively analyzed. 相似文献
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The white-gain model and the white-loss model of a single-mode laser are investigated in the presence of cross-correlations between the real and imaginary parts of quantum noise as well as pump noise. It was found that, like the white cubic model (2001 Chin. Phys. Lett. 18 370), the amplitude equations are all decoupled from the phase equations for the two models, and the same novel term appears in the amplitude equations of the two models. So we can put the amplitude equations of all the models
into a general form, that is, the new amplitude equation. We further use this new amplitude equation to study specifically the stationary properties of the laser intensity for the white-gain model. 相似文献
17.
The premise is developed that the elementary act of lattice-restructuring in first-order phase transitions constitutes a transition of a cluster of ions from one phase into another. Based on a microscopic analysis, a procedure is proposed for determining the cluster parameters from the properties of the material and from the thermodynamic parameters of the phase transformation. The concept of lattice-restructuring rate is introduced. Starting from the cluster model of the lattice-restructuring, expressions are obtained for the activation energy of the growth of the new phase. The results are used to calculate numerically - transformations in rapidly heated iron. The results are in satisfactory agreement with experiment.Translation of Preprint No. 194, Lebedev Institute of Physics, Academy of Sciences of the USSR, Moscow, 1990. 相似文献
18.
采用线性化近似,计算了由具有色关联的受偏置信号调制的色泵噪声和色量子噪声驱动 的单模激光增益模型的光强相对涨落,发现相对涨落随噪声强度的变化曲线中存在极小值,分析了偏置信号的强度、周期信号频率、噪声间的互关联强度和互关联时间对曲线的影响; 对单模激光增益模型在偏置信号调制和直接信号调制两种方式下的输出光强相对涨落进行了比较,发现光强涨落与偏置信号的强度密切相关.
关键词:
偏置信号调制
光强相对涨落
线性化近似 相似文献
19.
Edwards DR Lee J Andrews J Wong A 《The Journal of the Acoustical Society of America》2008,123(5):EL111-EL115
A previous study by [J. Lee, G. Long, and C. Jeung, J. Acoust. Soc. Am. 119, S3332 (2006)] found that information at the onset or offset of modulation could be utilized for improved amplitude modulation (AM) depth discrimination in a continuous carrier condition (carrier presented 250 ms earlier and later than the modulator). In this study, the relative contribution of information at the onset or offset of the modulation was examined with an onset-fringe carrier condition (carrier begins 250 ms earlier than the modulator) and an offset-fringe condition (carrier ends 250 ms later than the modulator). The results suggest that modulation information at the onset might be utilized more than at the offset. 相似文献
20.
提出了一种实现异结构混沌系统反同步控制的方法。根据Lyapunov 稳定性理论给出控制器的结构。以单模激光Lorenz系统和Rossler系统为例,验证了这种控制器的有效性。进一步研究了不确定混沌系统的反同步,并以不确定单模激光Lorenz系统和Rossler系统为例,实现了混沌反同步控制,同时系统中不确定参数得到识别。仿真模拟结果验证了这种方法的有效性。设计的反同步控制方法可用于任意混沌系统,具有一定的普适性。 相似文献