共查询到17条相似文献,搜索用时 218 毫秒
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适度光反馈机制下线宽展宽因数的自动测量 总被引:2,自引:1,他引:2
介绍了光反馈自混合干涉(OFSMI)法测量半导体激光器线宽展宽因数(LEF)的基本原理。针对不同参数条件,分析了该测量方法的理论误差,找出了最佳测量条件和最佳测量条纹位置。并根据光反馈自混合干涉信号特点,设计了一个自动测量算法。该算法可以自动识别提取一个振动周期内的光反馈自混合干涉信号所有特征值,采用最佳测量条纹位置所对应的特征值,就可以精确得到线宽展宽因数。仿真数据验证了自动测量算法的正确性。实验结果表明,自动测量算法在实际数据处理时测量参数的精确度较好,当自混合信号的峰-峰值为1.75 V时,线宽展宽因数的相对标准差只有3.26%。 相似文献
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半导体激光器线宽展宽因数的估计方法 总被引:3,自引:1,他引:2
描述了一种利用光反馈自混合效应估计半导体激光器的线宽展宽因数α和光反馈水平因子C的方法,该方法采用一个弱光反馈机制下的自混合效应模型去最佳拟合所观测的自混合信号数据,拟合算法基于非线性最小二乘法。针对不同的情况,做了大量计算机仿真。给出了仿真结果,结果表明该算法参数估计精度较高,不受参数初值选取的影响,且抗噪性能较好。 相似文献
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反卷积方法是提高光谱仪分辨率的重要手段。采用空域迭代反卷积和频域维纳滤波对多纵模激光器光谱进行数据仿真,并在不同光谱仪采样率条件下,比较了迭代反卷积和维纳滤波结果。仿真结果表明,迭代反卷积和维纳滤波可以有效消除光谱仪仪器响应函数引起的光谱展宽,提高光谱仪分辨率。在光谱仪采样率低的情况下,迭代反卷积的分辨率增强效果优于维纳滤波。随着采样率的增加,维纳滤波的误差小于迭代反卷积。实验分别测量了单纵模和多纵模632.8nm He-Ne激光器光谱,并对测量结果进行反卷积处理。结果表明,低分辨率光谱仪测量的激光器光谱经反卷积处理后与高分辨率光谱仪直接测量结果一致。 相似文献
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提出了一种新的光反馈水平因子C和激光器线宽展宽因数α的测量算法。基于光反馈自混合干涉模型,通过深入研究适度光反馈(1相似文献
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提出了一种使用固定频率窄线宽激光器作为干涉光源的闭环谐振式光纤陀螺系统.该系统利用相位调制器对干涉光进行移频控制,完成对谐振腔逆时针方向谐振频率的跟踪和锁定.建立了陀螺系统Simulink模型并仿真研究了不同速率点下的陀螺输出特性,结果表明,±200(°)/s速率范围内逆时针谐振频率锁定时间小于15 ms,陀螺标度因数非线性为2.41×10-4.与采用传统频率可调谐窄线宽激光器的闭环谐振式光纤陀螺系统相比,两者锁频时间和标度因数非线性基本一致.该研究为低成本闭环谐振式光纤陀螺系统的实现提供了理论和数据支撑. 相似文献
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Jian-Ping Zhang 《Quantum Electronics, IEEE Journal of》1995,31(12):2127-2132
In this paper, a phenomenal analysis on the wavelength dependence of the gain temperature coefficient is presented. Based on this model, the relation between the dynamic properties and the lasing wavelength within the gain regime are investigated using the rate equations, including the wavelength dependence of both the differential gain and linewidth enhancement factor. Our calculation shows that when the lasing mode occurs in the negative damping rate regime, the relative intensity noise (RIN) is more than 43 dB higher, and the linewidth is broadened out more than 30 dB, which indicates laser being in a chaotic state. The stability of the vertical-cavity surface-emitting lasers with distant external optical feedback is analyzed numerically. The results for different cavity designs are compared. The effects of the nonlinear gain coefficient on RIN and spectral linewidth of the VCSEL's with external optical feedback is investigated 相似文献
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雾天图像增强具有重要现实意义。由于现有的图像去雾算法在提升图像全局对比度的能力上存在不足,为此将暗通道先验去雾算法与直方图均衡化算法的各自优势进行整合,该文提出一种雾天图像增强新算法。首先,分别采用基于导向滤波的暗通道先验去雾算法和基于HSV色彩空间的直方图均衡化算法处理雾天图像;然后,基于修正的透射率图构造权值因子,将上述两种处理结果加权融合,得到输出图像。仿真实验结果表明,该算法比现有去雾算法具有更高的标准差、平均梯度与信息熵,具有更好的全局与局部对比度增强效果。算法运行时间主要依赖于图像去雾环节,处理一般尺寸图像能够满足实时要求。 相似文献
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The linewidth enhancement factor α of strained quantum-well lasers is analyzed by the k -p perturbation method using the effective-mass approximation. It is found that the α factor in a strained In0.80Ga0.20As/InP quantum-well (QW) laser with 1.9% biaxial compression is less than 1.5. For a strained QW laser with p-type modulation doping (MD) of 5×10 18 cm-3, the α factor is as small as 0.8. It is also demonstrated that the spectral linewidth and wavelength chirping in the strained MD QW laser are significantly less than those in conventional bulk and QW lasers 相似文献
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The effective linewidth enhancement factor αeff of DFB lasers which have both gain and index coupling coefficients is theoretically analyzed. The unique reduction mechanism of αeff due to the optical negative feedback of modal phase and modal gain in gain coupled DFB lasers was found for the first time. The numerical result showed that αeff can be reduced to almost one half of the material defined linewidth enhancement factor α when there exists an index coupling coefficient comparable to the gain coupling coefficient 相似文献
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The linewidth reduction of DFB semiconductor lasers due to the wavelength detuning is estimated precisely. Firstly, the Schawlow-Townes linewidth, which excludes the enhancement due to the carrier effect, is determined from the AM noise spectrum. Secondly, the actual linewidth including the carrier effect is measured. Lastly, the contribution from the carrier effect is determined from both of the linewidths. The experimental result shows that the linewidth enhancement due to the carrier effect is four times larger in a 1.3 μm laser with a positive detuning (Δλ=+15 nm) than in a laser with a negative detuning (Δλ=-15 nm) 相似文献
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Kano F. Yamanaka T. Yamamoto N. Yoshikuni Y. Mawatari H. Tohmori Y. Yamamoto M. Yokoyama K. 《Quantum Electronics, IEEE Journal of》1993,29(6):1553-1559
The linewidth enhancement factor α in InGaAsP-InP modulation-doped strained multiple-quantum-well (MQW) lasers has been evaluated theoretically and experimentally. A reduction of the α-parameter due to modulation doping is demonstrated. A small α-parameter of less than 1 is obtained not at wavelength for the gain peak but within certain range of wavelength where the gain is positive. The smaller α-parameter in modulation-doped strained MQW lasers should result in performance improvements that are advantageous for optical communication system applications 相似文献
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Zhang X. Gupta J. A. Barrios P. J. Pakulski G. Hall T. J. 《Photonics Technology Letters, IEEE》2007,19(2):106-108
The properties of a high-characteristic temperature (T0=155K) 1.3-mum GaInNAs-GaAs laser are presented with an emphasis on laser dynamic characteristics evaluated by linewidth enhancement factor and relative intensity noise. It is found that the relatively high differential gain of GaInNAs-GaAs quantum wells leads to a small linewidth enhancement factor of 2.8, indicating a small magnitude of frequency modulation with modulation current. The relative intensity noise measurements indicate a relaxation frequency of 4.7 GHz at a moderate bias current, from which the maximum intrinsic modulation bandwidth was calculated to be 9.7 GHz. The experimental determination of the low linewidth enhancement factor and high relaxation frequency reinforce the potential of dilute nitride lasers for high-speed directly modulated fiber links 相似文献