工业及医用准分子激光系统关键技术研究

发布时间：2018-05-01 09:08

本文选题：准分子激光器 + 电容充电电源　；参考：《中国科学技术大学》2017年博士论文

【摘要】：放电激励的准分子激光作为大功率紫外光源,具有峰值功率高、波长短、光子能量高等特点,广泛应用于工业及医疗领域。研制高稳定性准分子激光器实用产品是医疗和工业应用的一个重要方向,影响激光器产品稳定性的因素诸多,如激光头储能电容充电电源稳定性和充电精度、产品设备的电磁兼容性以及整机的反馈闭环稳定控制等。本文对上述影响因素展开研究,以期进一步提高准分子激光技术水平和激光器产品的整体性能,推进国产高端准分子激光设备的研发。论文首先回顾了准分子的发展历史、应用领域,概述了电激励准分子激光器的关键技术如低重频大能量技术、高重频技术、气体补偿技术等,介绍了准分子激光器储能电容充电电源的主要拓扑和相关技术,简述了准分子激光系统的电磁兼容性,重点阐述了本论文的研究意义和工作内容。为了满足工业及医用准分子激光器储能电容组的充电需求,分别开展了用于高重频和低重频电容充电电源研究。高重频电容充电电源基于LC串联谐振拓扑,引入辅助电路和时序控制系统实现电容的高重频高精度充电,在激光器储能电容5.44μF的情况下,获得最大充电电压1.92 kV、充电精度0.05%、工作重复频率4 kHz、充电能力40 kJ/s的输出特性;低重频电容充电电源采用推挽式拓扑结合有源低损吸收回路实现对电容的恒流充电,电源输出电压为10～35 kV,开关频率45 kHz,平均充电速率为2.6 kJ/s,激励一台储能电容为64 nF的KrF准分子激光器获得最大820 mJ的输出能量,两类电源的充电精度和性能满足工业及医用领域实际使用要求。电磁兼容性是准分子激光产品进入市场前需特别关注的一项重要指标,应满足国家标准,论文第四章对此项指标进行了研究,从实验的角度探索了准分子激光头的电磁辐射特性,并结合屏蔽理论和电磁兼容理论对系统进行了整体设计,设计的屏蔽体的屏蔽效能达40 dB以上,系统整机能可靠稳定运行。为了进一步提高准分子激光器的输出稳定性,开展了输出能量稳定的理论研究和实验验证,提出了基于电压补偿能量的PI算法,基于设计的低重频电容充电电源搭建了 308 nm准分子激光皮肤治疗仪,对PI算法的合理性进行了验证。治疗仪在107个脉冲内仍能维持目标能量17.5 mJ附近,能量相对标准差从0.2%缓慢上升至3%,各输出参数满足准分子激光皮肤治疗仪的实用要求。
[Abstract]:As a high power ultraviolet light source, the discharge excited excimer laser has the characteristics of high peak power, short wavelength and high photon energy. It is widely used in industrial and medical fields. The development of high stability excimer laser practical products is an important direction of medical and industrial applications. There are many factors that affect the stability of laser products, such as the stability and charging accuracy of laser head storage capacitor charging power supply. Electromagnetic compatibility of product equipment and feedback closed loop stability control of the whole machine. In order to further improve the excimer laser technology and the overall performance of laser products, the research on the above factors is carried out in order to promote the development of domestic high-end excimer laser equipment. Firstly, the history and application of excimer are reviewed, and the key technologies of electrically excited excimer laser, such as low repetition rate and large energy technology, high repetition frequency technology and gas compensation technology, are summarized. This paper introduces the main topology and related technologies of the energy storage capacitor charging power supply for excimer lasers, describes the electromagnetic compatibility of the excimer laser system, and emphasizes on the research significance and work content of this paper. In order to meet the charging requirements of industrial and medical excimer laser energy storage capacitors, the research of high repetition frequency and low repetition frequency capacitor charging power supply has been carried out respectively. Based on LC series resonant topology, the high repetition frequency and high precision charging of capacitor is realized by introducing auxiliary circuit and timing control system. The laser energy storage capacitance is 5.44 渭 F. The maximum charging voltage is 1.92 KV, the charging accuracy is 0.05, the working repetition rate is 4 kHz, and the charging capacity is 40 kJ/s. The low repetition rate capacitor charging power supply adopts push-pull topology combined with active low loss absorption circuit to realize the constant current charging of the capacitor. The output voltage of the power supply is 100.35kV, the switching frequency is 45kHz, and the average charge rate is 2.6kJ / s. A KrF excimer laser with a storage capacitance of 64nF is excited to obtain a maximum output energy of 820mJ. The charging accuracy and performance of the two types of power supply meet the practical requirements of industry and medical field. Electromagnetic compatibility (EMC) is an important index which should be paid special attention to before excimer laser products enter the market. The electromagnetic radiation characteristics of excimer laser head are explored from the point of view of experiment. The whole system is designed in combination with shielding theory and electromagnetic compatibility theory. The shielding efficiency of the designed shield is over 40 dB, and the whole system can run reliably and stably. In order to further improve the output stability of excimer lasers, theoretical research and experimental verification of output energy stability are carried out. A Pi algorithm based on voltage compensation energy is proposed. A 308 nm excimer laser skin therapy instrument is built based on the designed low repetition frequency capacitor charging power supply, and the rationality of Pi algorithm is verified. The instrument can maintain the target energy around 17.5 MJ within 107 pulses, and the relative standard deviation of energy increases slowly from 0.2% to 3. The output parameters meet the practical requirements of the excimer laser skin therapy instrument.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN24

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