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拉曼光谱检测常常受到荧光的干扰,影响了该技术的推广应用。移频激发差分拉曼光谱方法(SERDS方法)已被证明是一种有效的荧光抑制方法。SERDS实现荧光抑制的关键在于其特殊的激光光源,不仅要求其输出多个相近的波长,而且要求输出的激光功率较高、光谱线宽窄。采用Littrow光栅外腔半导体激光器原理设计实现了一种低成本、便携式的激光光源,可以在15nm的调谐范围内输出多个波长,光谱线宽小于0.2nm,输出功率可达80mW,适合用作移频激发差分拉曼光谱方法的多波长光源,实现拉曼光谱检测中对荧光干扰的抑制。 相似文献
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为了提高激光多普勒测速系统的性能,增强系统与应用场景适配性,文中对比电光和声光两种主要移频器件的特点,从器件移频原理出发,提出了简化频率变换关系的分析方法,从理论上研究激光多普勒测速系统中两种器件产生的移频特性,搭建铌酸锂电光调制和声光移频全光纤激光测速系统链路,将测试频率特征与理论特征进行对比研究,提出一种新型声电混合调制激光多普勒测速系统。结果表明,该新型系统兼具声光移频测速系统可测量运动目标运动方向、运动速度,完成电光调制测速系统多频率校正的特点,频率测量相对误差较小,动态范围大。通过研究两种移频方式对频率特性,为设计高性能激光多普勒测速系统提供了理论和实验支撑。 相似文献
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几种人工合成色素的荧光光谱与拉曼光谱研究 总被引:1,自引:0,他引:1
应用荧光光谱仪及微拉曼光谱仪分别对几种常见的人工合成色素溶液的荧光光谱和拉曼光谱进行了实验研究。一方面,首次测量其不同浓度合成色素溶液的荧光光谱,讨论其谱线特性。另一方面,以有致癌性的合成色素苋菜红为例,应用拉曼光谱技术进行定性和定量检测,验证拉曼光谱对色素检测的可行性。为了提高探测灵敏度,以55nm的金纳米粒子溶胶为基底,在785nm激发光下对不同浓度的苋菜红溶液进行了表面增强拉曼光谱探测,探测到的最低浓度为10-17mol/L。分析结果为这种色素的合理利用及安全快速检测提供了有效的光谱实验依据,也为其它色素的检测提供了参考方法。 相似文献
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基于壳层隔绝纳米粒子增强技术,开发了一种新型的等离激元拉曼光谱测试系统,该系统能够有效地提高被测物质的拉曼反射信号强度。壳层隔绝纳米粒子增强技术采用包裹了极薄的二氧化硅或者氧化铝壳层的单层金纳米粒子,能够产生较强的表面增强效应。整个测试系统的硬件部分主要包括双处理器(ARM和DSP)主控板、半导体激光光源、光谱仪、光纤探头和粒子施加装置;软件部分能够自动获取被测物质的拉曼谱图。这里,粒子施加装置用于自动地将壳层隔绝纳米粒子施加到被测样本中。在实验中,将测试系统用于检测食品违禁添加物三聚氰胺和孔雀石绿,以验证壳层隔绝纳米粒子增强拉曼光谱技术。实验结果表明,该测试系统具有较高的测试灵敏度和较短的测试时间,广泛地适用于食品安全中痕量物质快速检测。 相似文献
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精确地测量激光在大气传输后的光斑参数,是研究激光大气传播效应和分析激光发射系统性能的关键技术手段。测量激光远场参数的方法主要包括阵列探测法和相机成像法,目前在激光大气传输效应的测量评估中大都采用阵列探测法。由于探测器阵列靶受物理空间和研发成本等因素的限制不能均匀且高分辨率紧密排布,将造成采样光斑的失真,难以精确地测量远场光斑参数。针对此问题,利用相机分辨率高的特点,设计了一套基于漫反射屏成像法的激光参数测量系统。该系统最小测量分辨力小于0.39 mm,质心位置平均偏差为0.05 mm,测量光斑到靶功率不确定度优于10%。该系统能有效地测量激光发射系统的跟瞄精度和到靶功率,为分析激光大气传输效应和分析激光发射系统性能提供有效手段。 相似文献
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A. A. Biryukov B. N. Zvonkov S. M. Nekorkin V. Ya. Aleshkin V. I. Gavrilenko K. V. Marem’yanin S. V. Morozov V. V. Kocharovskii Vl. V. Kocharovskii 《Semiconductors》2007,41(11):1364-1368
An easily reproducible construction of two butt-joint laser diodes based on a GaAs/InGaAs/InGaP structure is fabricated and
investigated. The construction forms a composite cavity in which about half of stimulated emissions of a long-wavelength diode
transforms into emissions of a ground mode of a waveguide of a short-wavelength diode. It is found that the emission spectrum
from the composite cavity is represented not only by fundamental (close) frequencies of two diodes with a power of ∼1 W, but
also by their sum frequency and second harmonic with a power as high as 1 μW. The found nonlinear enrichment of the emission
spectrum of a two-frequency heterolaser with a composite cavity is caused by a lattice nonlinearity of the semiconductor and
allows one to plan equally effective intracavity generation of various frequencies in a far-IR range at room temperature.
Original Russian Text ? A.A. Biryukov, B.N. Zvonkov, S.M. Nekorkin, V.Ya. Aleshkin, V.I. Gavrilenko, K.V. Marem’yanin, S.V.
Morozov, V.V. Kocharovskii, Vl.V. Kocharovskii, 2007, published in Fizika i Tekhnika Poluprovodnikov, 2007, Vol. 41, No. 11,
pp. 1384–1388. 相似文献
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A universal fiber-optic measurement system, which is useful for measuring loss and dispersion in the1.06-1.6 mu m wavelength region, is described. The source is a silica fiber Raman laser pumped by a mode-locked andQ -switched Nd:YAG laser at 1.06 μm. Subnanosecond multiple-Stokes pulses in the1.1-1.6 mu m wavelength region are generated in a low-loss single-mode silica fiber. The use of this near-infrared fiber Raman laser for characterizing various transmission properties of single and multimode test fibers is demonstrated. Loss spectra, intramodal dispersion, and intermodal dispersion data are obtained in the wavelength region of minimum loss and minimum material dispersion for silica fibers. 相似文献
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为了缩短热物理激光光斑位置的测量周期,提高热物理激光光斑位置的测量水平,提出了基于计算机视觉的热物理激光光斑位置精确测量方法设计.利用计算机视觉技术计算热物理激光光斑的初始位置,根据热物理激光光斑位置特征的提取流程,完成了热物理激光光斑位置特征的提取;利用热物理激光光斑质心位置与解算值的关系式,得到了热物理激光光斑的估... 相似文献
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We have investigated GaInNAs-GaAsN multiquantum-well (MQW) lasers with two-QW (DQW), three-QW (TQW), and five-QW (5QW) active regions and emission in the 1.3-/spl mu/m range. A solid-source molecular beam epitaxy system has been used to grow the structures. Operation of a GaInNAs 5QW laser is reported. Low threshold currents of 22 (DQW) to 52 mA (5QWs) and external efficiencies of 0.25 W/A (DQWs) to 0.16 W/A (5QWs) per facet are realized under CW operation. T/sub 0/-values of 121 K are obtained. 相似文献
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Recrystallized silicon-on-oxide were analyzed by laser Raman scattering spectroscopy. By changing the excitation laser wavelength,
the in-depth stress profile was obtained. The in-depth stress change was strongly dependent on recrystallization power. Recrystallized
silicon structures were confirmed by cross sectional TEM observations. Dependent on recrystallization power, silicon film
structures changed from small grain or small and large two grain layers to continuous large grain films. 相似文献
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A theoretical expression is obtained for the time dependence of the Stokes power output of a pulsed Raman laser, the pump pulse duration being comparable to the relaxation time of the Raman excitation and the output saturation limited. A rate-equation approach is employed, and the pump beam is assumed to have a Gaussian intensity distribution. The theory is developed in terms of the practical example, stimulated spin-flip Raman scattering in InSb. 相似文献