共查询到19条相似文献,搜索用时 62 毫秒
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介绍了在普通通讯用单模GeO2/SiO2石英光纤中从近红外到可见光的频率上转换过程。利用1.313μm的调Q锁模Nd:YLF激光脉冲泵浦单模石英光纤,产生了588nm的黄光,峰值功率达20W,对应0.09%的转换效率。 相似文献
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用10 m长单模石英光纤进行受激拉曼散射温度特性研究, 实验中发现在泵浦光和一级Stokes左右出现了附加峰(称为双峰), 其峰强度随温度的升高(80~295 K)呈现先增加后减弱现象。当温度达到295 K时, 一级Stokes双峰消失。由受激四光子混频理论计算可知,这种双峰现象是受激四光子混频的结果。同时对SRS一级Stokes所产生的受激四光子混频的Stokes频移随温度升高由706.9 cm-1增大到712.9 cm-1和其半宽度由1.75 nm增至2.18 nm的现象也进行了解释。 相似文献
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本文根据单模光纤模场直径的横向位移定义,提出了一种测量模场直径的新方法——远场高斯掩模匹配法.讨论了几种测量及数据处理方法.最后给出了初步的实验结果. 相似文献
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本文报道了用熔融法由常规的单模通信光纤制造宽温工作的低损耗单模光纤定向耦合器.工作波长为1.52μm,分束比为50%的封装器件;工作温度在-30~+70℃范围,分束比容差小于±5%,插入损耗<0.2dB,隔离度>40dB.工作波长的变化对分束比影响十分明显,但入射光的偏振态对其无实际影响. 相似文献
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Joyce Kilmer 《Fiber and Integrated Optics》2013,32(2):79-91
This paper introduces and analyzes revolutionary laser system architecture capable of dramatically reducing the complexity of laser systems while simultaneously increasing capability. The architecture includes three major subsystems. The first is a phased array of laser sources. In this article, we discuss diode-pumped fiber lasers as the elements of the phased array, although other waveguide lasers can also be considered. The second provides wavefront control and electronics beam steering, as described in an IEEE Proceedings article on “Optical Phased Array Technology” [1]. The third is subaperture receiver technology. Combining these three technologies into a new laser systems architecture results in a system that has graceful degradation, can steer to as wide an angle as individual optical phased array subapertures, and can be scaled to high power and large apertures through phasing of a number of subapertures. Diode-pumped fiber lasers are appealing as laser sources because they are electrically pumped, efficient, relatively simple, and scalable to significant power levels (over 100 Watts has been demonstrated from a single diode-pumped fiber laser) [2]. The fiber laser design also lends itself to integration into a phased array. Fiber lasers have been phased. Initial phasing demonstrations have been at low power and were conducted by taking a single source, dividing it into multiple fibers, then phasing them together. To develop this technology further we need to use independent fiber lasers or fiber amplifiers, seeded by a common source, and to increase laser power. As we increase laser power, we will have to learn to cope with nonlinearities in the laser amplifiers. Optical Phased Array technology has demonstrated steering over a 90-degree field of regard [4], although this approach used additional optical components. If we use straightforward optical phased array beam steering without additional optics we can steer with high efficiency to about one-third λ/d, where d is the smallest individually addressable element. The one-third factor depends on the efficiency threshold. For example, if we use 1.5 μm light, and 5 μm center-to-center spacing, we can steer with high efficiency to about ±6 degrees, or a field of regard of 12 degrees. Last, we need to develop a subaperture receive technology. This can be a pupil plane receiver, an image plane receiver, or some combination of the approaches. When we have matured each individual technology and combined them into new laser systems architectures, we will have the ability to build simpler and more capable laser systems. The vision for an integrated, phased array laser concept is to enable a new class of laser systems with significant advantages, including high-efficiency, all-electric laser source; all waveguide beam transport; wavefront control at the sub-aperture level (enabling wavefront compensation, conformal apertures, and wide-angle electronic beam steering); random access beam pointing over wide angles; multiple simultaneous beam generation and control; and graceful degradation. 相似文献
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锥台光纤在激光束到单模光纤以及多模光纤到单模光纤的耦合中,在一些需要质量很高光束的同时有较高功率要求的场合有广泛应用。在这些应用中,锥台光纤的功率转换效率是很重要的一个参数。介绍了锥台光纤的熔拉研磨制作方法,分析了锥台光纤的传输特性。建立了高斯近似模型,采用模场耦合理论,计算了锥台光纤的功率转换效率。在以下参数条件下对细端半径分别为(4±1)μm,(5±1)μm,(6±1)μm,(7±1)μm和(8±1)μm的锥台光纤的功率转换效率进行了实验测定,激光器输出光波长532 nm;多模光纤NA=0.11,纤芯半径a=12.5 μm;得到了与理论计算吻合的结果。 相似文献
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提出了一种基于包层模谐振的光纤温度传感器. 它是通过将三包层石英特种光纤(TCQSF)两端分别与普通单模光纤(SMF)电弧熔接构成的SMF-TCQSF-SMF结构. 根据耦合模理论, 首先将TCQSF等效为三个同轴波导, 按各波导模场的分布特点标量计算其传输模式的色散曲线, 并深入研究其耦合长度与传输谱线之间的关系; 其次根据光纤的热光效应及热膨胀效应, 分析计算该传感器的温度灵敏度; 最后选取耦合长度为一个拍长时的传感器进行温度传感实验. 实验结果表明, 在35-95 ℃的温度变化范围内, 其温度灵敏度为73.74 pm/℃, 与理论计算结果一致. 因此, 该传感器具有结构简单、制备容易、灵敏度高、包层模激发可控等优点, 可用于工业生产、生物医学等温度传感领域. 相似文献
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Fiber optic evanescent field absorption sensor: Effect of fiber parameters and geometry of the probe 总被引:5,自引:0,他引:5
A comparative experimental study of the fiber-optic evanescent field absorption sensor based on straight and U-shaped probes is presented. The effects of numerical aperture and the core radius of the fiber on the sensitivity of the sensor are experimentally investigated. Increase in the numerical aperture of the fiber increases the sensitivity of the sensor in the case of both the probes. The effect of core radius on the sensitivity depends on the bending radius of the probe. In the case of straight probe (i.e. infinite bending radius) the fiber with smaller core radius has high sensitivity while in the case of U-shaped probe with 0.17 cm bending radius, the fiber with larger core radius has high sensitivity. Thus, which fiber (with small or large core radius) has maximum sensitivity depends on the bending radius of the probe. For a given fiber, decrease in the bending radius increases the sensitivity of the U-shaped probe. An inverse power law relationship between the bending radius and the evanescent absorbance and hence the sensitivity is established. 相似文献
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