基于声光调制的激光功率稳定控制系统

发布时间：2018-12-31 18:26

【摘要】：在光辐射计量领域中,低温绝对辐射计采用了电替代、超低温、超电导和双层冷屏蔽等先进技术方法,使得光辐射计量的精度得到了大幅的提高。为了能够最大限度的发挥低温绝对辐射计的技术优势,要求其配备的激光光源能够输出功率高稳定度的激光信号,而常见的激光器由于受到电源注入电流、工作温度、模式跳变以及增益系数等因素的影响,使得其输出激光信号的功率波动通常不小于1%,为了满足这一实际应用需求,需要研制一套激光功率稳定控制系统,使其能够输出功率更加稳定的激光信号。基于这一应用背景,本文设计了一套基于声光调制的激光功率稳定控制系统,并通过搭建实际系统完成了系统功能验证的工作。本文在对国内外有关激光器输出功率稳定控制技术的研究基础上,说明了目前相关技术手段的优势及其限制,然后简要介绍了激光器的发展,并对激光器的分类做了解释说明。在对氦氖激光器和半导体激光器的输出功率波动的原因分析后,引出了各类功率稳定控制技术,重点介绍了以声光调制为代表的外调制技术。由于外调制可以实现高稳定度的激光功率控制,因此本文采用声光调制的方式来稳定激光功率,设计的激光功率稳定控制系统主要由光路控制模块、光电放大模块以及反馈控制器组成。其中反馈控制器使用FPGA作为主控芯片,配合使用PID算法,完成对激光功率控制的功能。根据设计方案搭建了系统并详细分析了在不同实验条件下得到的实验数据,通过实验数据分析证明了本功率稳定系统可以适用于不同波长激光器的激光功率控制,能够长时间稳定工作。多次重新搭建系统在红外及紫外波段均得到了输出激光功率稳定度优于0.05%/h的控制效果,使用本功率稳定控制系统后输出的激光可以作为低温绝对辐射计等精密测量系统的稳定光源。
[Abstract]:In the field of optical radiation measurement, the precision of optical radiation measurement has been greatly improved by using advanced techniques such as electric substitution, ultra-low temperature, super conductivity and double layer cold shielding. In order to maximize the technical advantages of the cryogenic absolute radiometer, it is required that the laser light source be equipped with a laser source capable of outputting laser signals of high power stability, while common lasers are subjected to power injection current and work temperature. The power fluctuation of the output laser signal is usually not less than 1 because of the influence of the mode jump and gain coefficient. In order to meet this practical application demand, a set of laser power stability control system should be developed. Enable it to output more stable laser signals. Based on this application background, a laser power stability control system based on acousto-optic modulation is designed, and the system function verification is completed by building an actual system. On the basis of the research on laser output power stability control technology at home and abroad, this paper explains the advantages and limitations of the current related techniques, and then briefly introduces the development of lasers, and explains the classification of lasers. After analyzing the reason of the output power fluctuation of He-Ne laser and semiconductor laser, various kinds of power stability control techniques are introduced, especially the external modulation technology represented by acousto-optic modulation. Since external modulation can achieve high stability of laser power control, this paper uses acousto-optic modulation to stabilize laser power. The designed laser power stability control system is mainly controlled by optical path module. Photoelectric amplifier module and feedback controller. The feedback controller uses FPGA as the main control chip and PID algorithm to complete the laser power control function. According to the design scheme, the system is set up and the experimental data obtained under different experimental conditions are analyzed in detail. It is proved that the power stability system can be applied to laser power control of different wavelength lasers. Able to work steadily for a long time. The stability of output laser power is better than 0.05 / h in infrared and ultraviolet band. The laser output from this power stability control system can be used as a stable light source for precision measurement systems such as cryogenic absolute radiometers.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248;TP273

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