基于MgO:PPLN的窄线宽光参量振荡器特性研究

发布时间：2018-11-14 17:29

【摘要】：光学参量振荡器(Optical parametric oscillator, OPO)作为可调谐光源,弥补了传统激光器输出波长单一的缺点,拓展了输出波长的范围,有极高的应用价值,在激光光谱学、军事、医疗等领域得到广泛应用。随着非线性光学材料加工工艺以及激光技术的不断进步,光学参量振荡器的类别越来越多,波长拓展范围越来越大,转换效率也越来越高,应用范围也越来越广泛。本文主要对基于PPLN晶体准相位匹配技术的宽调谐窄线宽的光学参量振荡器的特性进行了研究。1. 实验采用频率为IKHz、波长为1064nm、脉冲时间宽度约为8ns的纳秒脉冲激光器对PPMgLN晶体进行泵浦,采用单谐振、环形腔结构,实现了近红外激光的稳定输出。采用周期调谐与温度调谐相结合的调谐方式,实现了1483-1527nm的连续可调谐信号光输出。在泵浦功率为1.59W时达到最大转换效率23.1%,此时信号光功率为0.367W。实验中得到了较窄的线宽展宽,在泵浦光为0.8W时,信号光线宽展宽只有0.5nm,随着功率的增加,由于高增益的原因在泵浦光功率饱和(2.4W)情况下,信号光线宽展宽变为0.8nm。2. 实验中进一步采用了延时光路系统,将单个泵浦脉冲在时间上变为两个紧邻的脉冲。延时为8ns时,光转换效率最大为30%,此时输入泵浦光功率为3.06W,输出信号光功率为0.918W。在泵浦光为5W时,信号光展宽仅为0.6nm。为了进一步压窄线宽,我们分别在腔体中加入FP标准具。在泵浦光为1.4W的情况下,信号光线宽展宽为0.05nm,泵浦光为5W时,信号光线宽展宽仅为0.2nm。由于FP标准具的反射以及吸收,泵浦光转换效率会受到一定的影响,在加入FP标准具的情况下,光转换效率最高为17%,此时输入泵浦光功率为2.79W,输出信号光功率为0.47W。
[Abstract]:Optical parametric oscillator (Optical parametric oscillator, OPO), as a tunable light source, makes up for the shortcoming of single output wavelength of traditional laser, expands the range of output wavelength, and has high application value in laser spectroscopy, military, Medical and other fields have been widely used. With the development of nonlinear optical material processing technology and laser technology, the optical parametric oscillator (OPO) has more and more kinds, wider wavelength range, higher conversion efficiency and wider application. In this paper, the characteristics of a wide tuned narrow linewidth optical parametric oscillator based on PPLN crystal quasi phase matching technique are studied. 1. A nanosecond pulse laser with IKHz, wavelength of 1064 nm and pulse time width of about 8ns is used to pump the PPMgLN crystal. A single resonant ring cavity structure is used to realize the stable output of the near infrared laser. The continuous tunable signal optical output of 1483-1527nm is realized by the combination of periodic tuning and temperature tuning. When the pump power is 1.59W, the maximum conversion efficiency is 23.1W, and the signal optical power is 0.367W. The narrower linewidth is obtained in the experiment. When the pump light is 0.8 W, the signal light width is only 0.5 nm. With the increase of power, the high gain is caused by the pumping power saturation (2.4 W). The width of the signal light is widened to 0.8nm.2. In the experiment, a delay optical path system is used to transform a single pump pulse into two adjacent pulses in time. When the time delay is 8ns, the maximum optical conversion efficiency is 30. The input pump power is 3.06W and the output signal optical power is 0.918W. When the pump light is 5 W, the signal light width is only 0.6 nm. In order to further narrow the linewidth, we add FP standard tools into the cavity. When the pump light is 1.4 W, the width of the signal light is 0.05nm, and when the pump light is 5W, the width of the signal light is only 0.2 nm. Because of the reflection and absorption of the FP standard device, the pump light conversion efficiency will be affected to some extent. When the FP standard is added, the maximum optical conversion efficiency is 17, and the input pump power is 2.79 W. The output signal optical power is 0.47W.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN753.2

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