共查询到19条相似文献,搜索用时 109 毫秒
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在基于谐波检测法的TDLAS(可调谐二极管激光吸收光谱)系统中,在通过改变激光器注入电流实现激光频率扫描和调制的同时引起激光强度的变化,激光器输出信号的强度-频率(IM/FM)相位延迟m的变化将直接导致谐波系数波动,带来系统误差。提出一种利用光纤迈克尔逊干涉仪实现激光器输出信号强度-频率(IM/FM)相位延迟m的测量方法,能在激光器调制测量的同时实时测量相位延迟m。实验结果表明,激光器输出信号强度-频率(IM/FM)相位延迟m与理论值π有一定差异。研究提出的方法可以用来实时补偿信号强度-频率(IM/FM)相位延迟m对气体浓度测量结果的影响。 相似文献
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利用傅里叶分解原理建立了幅度调制的船舶辐射宽带噪声信号数学模型,导出了基于平方解调算法船舶辐射噪声调制谱数学表达式。通过理论分析和仿真计算得到了关于调制谱分析两个新的结论:(1)解调性能与解调处理带宽关系:在声呐接收的船舶辐射噪声各频带调制度相同时,解调性能正比于解调所采用的带通滤波带宽,解调所采用的带通滤波带宽越宽,解调谱信噪比越高;(2)宽带解调谱和子频带解调谱之间关系:船舶辐射噪声宽带解调谱可以近似认为各子频带解调谱之和。为了验证以上两点结论,对实际船舶辐射噪声解调谱进行了相应处理,结果与仿真计算吻合较好。 相似文献
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高功率半导体激光器的结温上升, 不仅影响它的输出功率、斜坡效率、阈值电流和寿命, 而且还会产生光谱展宽和波长偏移. 因此, 热管理成为抽运激光器研发中的一个主要问题. 本文首先建立了噪声功率谱与结温变化的物理模型, 根据压缩感知理论, 将测量得到含有高斯白噪声和1/f噪声的混叠复合噪声信号稀疏化后, 进行基追踪算法去噪, 通过改变算法的迭代次数及测量矩阵大小, 获得1/f噪声电压功率谱与结温变化关系曲线, 避免了直接测量结温的复杂性.通过数值估计结果, 可以较好地指导高功率半导体激光器的热管理工作.
关键词:
f噪声')" href="#">1/f噪声
结温度
热阻
高功率半导体激光器 相似文献
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频率调制强吸收光谱中残余幅度调制的理论分析 总被引:1,自引:0,他引:1
由电光调制器(EOM)中双折射效应及线偏光不完全沿EOM调制方向诱发的残余幅度调制(RAM)使频率调制(FM)光谱技术在微量气体检测中的应用受到极大的限制。基于光场与晶体相互作用及光学干涉原理推导出存在RAM时FM光谱的线型表达式,确定出输入线偏光角度、EOM中双折射效应、FM系数等是影响线型的主要因素,且当入射EOM光的偏振角度偏离调制方向越大,双折射效应引起的特征偏振方向相位差越大,线型扭曲越严重;同时在FM色散光谱中存在一个受两者影响的直流偏置;最后给出通过伺服控制这两过程可以达到抑制RAM的目的。这些现象及线型的分析将为基于光纤器件的FM光谱提供必要的理论支持。 相似文献
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提出一种基于AlGaInAs材料的1.55-μm波段的大功率、高速直调分布反馈(DFB)激光器阵列。采用具有良好温度特性和高微分增益的AlGaInAs材料作为量子阱和波导层以实现大功率与高带宽的输出;引入稀释波导结构来减小有源区内部损耗,同时降低远场发散角;采用悬浮光栅并优化耦合系数以实现大注入电流下的单模稳定工作。最终实现了1.5-μm波段5波长的大功率直调激光器阵列,阵列波长间隔约为5 nm,室温连续波(CW)工作时各通道输出光功率均大于100 mW,单通道最大输出光功率为160 mW,500 mA工作电流范围内边模抑制比大于55 dB,小信号调制带宽可达7 GHz,激光器最小线宽为520 kHz,相对强度噪声低于-145 dB/Hz。 相似文献
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窄谱光纤激光器在光束合成等领域有着广泛的应用,然而模式不稳定效应的出现严重限制着窄谱光纤激光器的功率提升。提出并验证了采用新型981 nm稳波长泵浦方案,能够应用于窄谱激光放大并提升模式不稳定效应阈值,通过采用单端后向泵浦结构,将单模窄谱光纤放大器功率提至4 kW以上。实验中采用白噪声相位调制展宽单频激光作为窄谱种子,主放大级分别采用稳波长976 nm和981 nm两种泵浦源单端后向泵浦。在采用976 nm泵浦源泵浦时,窄谱激光最高放大至3.4 kW,出现典型的模式不稳定效应特征,功率提升受到限制。在采用981 nm泵浦源泵浦时,窄谱激光最高放大至4.05 kW,且并未出现模式不稳定效应,输出光束质量M2因子为1.3,进一步功率提升仅受限于泵浦功率。通过优化激光器设计、结合双向泵浦结构,有望实现更高功率的窄谱光纤激光输出。 相似文献
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在密集波分复用强度调制直接检测光纤系统中 ,导出了包含互相位调制和受激拉曼散射共同作用的强度/相位矩阵表达式。在计算强度噪声谱的基础上 ,研究了互相位调制和受激拉曼散射的相互耦合并用于密集波分复用系统的噪声分析。分析表明 ,受激拉曼散射主要引入低频串扰噪声 ,而互相位调制主要引入高频串扰噪声。相邻较近信道引入的串扰噪声主要来源于互相位调制 ,相邻较远信道引入的串扰噪声主要来源于受激拉曼散射。在单级传输 (无色散补偿 )系统中 ,系统性能一般首先受到互相位调制的限制 相似文献
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We describe a new method for semiconductor laser FM noise reduction. A Doppler-free Faraday resonance in Cs vapor provided optical feedback, and FM sideband saturation spectroscopy in a second Cs cell provided electronic feedback. The combined optical and electronic feedback allowed us to reduce the low-frequency FM noise power by more than 6 orders of magnitude, which resulted in a sub-100-Hz-linewidth semiconductor laser locked directly to an atomic transition frequency. 相似文献
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A fast-frequency modulated (FM) diode laser has been optically narrowed using the technique of resonant optical feedback, to provide linewidths in each FM mode of ≈ 200 kHz peak-to-peak. With a drive frequency of 50 MHz and modulation index of 0.2, the FM laser has been used for the first time to obtain Doppler-free FM spectra of the Rb D1 line at 795 nm. The potential use of this system for laser frequency stabilisation is discussed. 相似文献
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Real-time nanometer-vibration measurement with a self-mixing microchip solid-state laser 总被引:9,自引:0,他引:9
Nanometer vibration analysis of a target has been demonstrated by a self-aligned optical feedback vibrometry technique that uses a laser-diode-pumped microchip solid-state laser. The laser output waveform, which was modulated through interference between a lasing field and an extremely weak (<- 100-dB) frequency-modulated (FM) feedback field, was analyzed by the Hilbert transformation to yield the vibration waveform of the target. Experimental signal characteristics have been reproduced by numerical simulations. Real-time vibration measurement has also been achieved with a simple FM demodulation circuit. 相似文献
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We present theoretical results that demonstrate a new technique that can be used to improve the sensitivity of thermal noise measurements: intracavity intensity stabilization. It is demonstrated that electro-optic feedback can be used to reduce intracavity intensity fluctuations, and the consequent radiation pressure fluctuations, by a factor of 2 below the quantum-noise limit. We show that this reduction is achievable in the presence of large classic intensity fluctuations in the incident laser beam. The benefits of this scheme are a consequence of the sub-Poissonian intensity statistics of the field inside a feedback loop and the quantum nondemolition nature of radiation pressure noise as a readout system for the intracavity intensity fluctuations. 相似文献
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Tsuchida H 《Optics letters》2011,36(5):681-683
I propose and demonstrate the use of the recirculating delayed self-heterodyne (DSH) method for measuring FM noise power spectral densities (PSDs), which are the most fundamental measure characterizing the spectral purity of laser sources. By analyzing the DSH beat signals with 1, 10, and 160?km delays, the FM noise PSD of a narrow-linewidth fiber laser is evaluated for Fourier frequency range between 10?Hz and 100?kHz, which exhibits flicker noise as the dominant contribution. 相似文献
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It is shown by computer simulation and in experiments that chaotic generation caused by the external optical feedback in a laser diode can be suppressed by means of a delayed optoelectronic feedback controlled by the injection current. The suppression of chaotic generation is realized for an AlGaAs/GaAs laser of the quantum wall structure. In the presence of the external optical feedback provided by the mirror placed at a distance of 1~mm the noise of optical intensity is of the oder of 10 W, the single mode dominates in the spectrum, and its spectral width exceeds 600 MHz. The optoelectronic feedback controlled by the injection current reduces the noise by several times and narrows the generation line width down to 80 MHz. 相似文献
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S. Koke A. Anderson H. Frei A. Assion G. Steinmeyer 《Applied physics. B, Lasers and optics》2011,104(4):799-804
The noise performance of a feed-forward scheme for carrier-envelope phase stabilization is discussed. This scheme uses an
acousto-optic frequency shifter to directly correct for fluctuations of the carrier-envelope phase in a pulse train emitted
by a mode-locked laser without manipulating the intracavity dispersion. Generation of zero-offset frequency combs is demonstrated.
Furthermore, it is shown that pump laser noise has only a minor effect on the achievable performance. Limited only by the
travel time of the acoustic wave in the shifter, pump laser noise can be corrected up to near-megahertz frequencies, which
yields superior noise performance compared to traditional feedback operation. Residual phase jitters down to 45 mrad are experimentally
verified. 相似文献