微片激光器的温度特性研究
发布时间：2018-08-04 18:34
【摘要】：自1960年美国物理学家梅曼使用闪光灯泵浦红宝石晶体获得694 nm的红色激光以来,激光技术开启了高速发展的步伐,如今在现代社会生活的各个方面都出现了它们的应用。使用片状的掺杂晶体作为增益介质的微片激光器相比于传统的激光器有着体积小、光束质量高、单位体积功率大的优点,在光纤通信、空间通讯、大气研究、医疗器械等领域都有深入的研究。此外,微片激光器的双模输出拍频已经成为具备竞争力的光生毫米波方案。与普通的固体激光器一样,微片激光器的输出性能同样受晶体热效应的严重影响。本文对微片晶体的热效应进行了理论和仿真分析,并对晶体热效应引起的激光频谱特性变化进行了实验研究。具体有以下几个方面:(1)简单概述了微片激光器的发展历程,并介绍了光生毫米波技术的实现方案及应用前景,然后重点对国外和国内微片激光器的研究近况分别进行了说明。(2)阐述了激光产生的基础及稳定放大的条件,并探讨了激光器的三个组成部分,随后对常见的激光增益介质材料进行介绍和比较。在推导微片激光器的稳态速率方程的基础上,讨论了微片激光器的工作特性及其影响因素,为提高微片激光器的输出光束质量提供了参考。理论分析微片激光器的温度漂移现象,得到激光波长和晶体中心温度呈线性关系的结论。(3)理论分析微片晶体的热效应,并使用有限元法对微片激光器增益介质的热传导模型进行了研究。微片晶体热效应产生的本质原因在于泵浦源在晶体内部产生的废热,热效应会导致微片晶体腔长和折射率的改变。通过ANSYS热分析,得到了微片晶体的热传导模型。热分析结果表明,LD泵浦功率和温控温度二者与晶体中心温度均呈线性关系。在仿真数值范围内,热沉与晶体间的热传导系数只影响晶体温度差,选定合适的热传导方式能获得良好的散热效果,但存在散热极限。(4)对微片激光器的纵模理论及单纵模、双纵模的形成条件进行了介绍,通过实验对微片激光器的温度特性和热致频谱匹配进行了研究。实验结果表明,单频激光的功率与温控温度近似为负线性关系,温控温度每升高10°C,激光功率下降约18%;激光波长与温控温度呈正线性关系,单频激光的偏移率为9.4 pm/°C,双频激光的偏移率为10.9 pm/°C,由此确定温控实现激光波长线性偏移的可行性,并证实热传导系数不受温度影响;泵浦电流和温控温度满足特定的线性关系式dT_o/dI=-16.8°C/A时可维持单频激光的频谱匹配。
[Abstract]:Since 1960, when American physicist Maiman used flash lamp to pump ruby crystal to obtain 694 nm red laser, laser technology has begun to develop at a high speed, and now it has been applied in every aspect of modern society. Compared with the conventional laser, the microchip laser, which uses chip doped crystal as gain medium, has the advantages of small volume, high beam quality and large unit volume power. It is studied in optical fiber communication, space communication and atmosphere. Medical devices and other fields have in-depth research. In addition, the two-mode output-beat of microchip laser has become a competitive scheme of photoluminescence millimeter wave. Like ordinary solid-state lasers, the output performance of microchip lasers is also seriously affected by the thermal effect of crystals. In this paper, the thermal effect of microchip crystal is analyzed theoretically and simulated, and the laser spectrum characteristics caused by the thermal effect are studied experimentally. The specific aspects are as follows: (1) the development course of microchip laser is briefly summarized, and the realization scheme and application prospect of optical millimeter wave technology are introduced. Then, the research status of microchip laser at home and abroad is explained. (2) the basis of laser generation and the condition of stable amplification are expounded, and the three components of laser are discussed. Then the common laser gain dielectric materials are introduced and compared. Based on the steady-state rate equation of microchip laser, the working characteristics of microchip laser and its influencing factors are discussed, which provides a reference for improving the output beam quality of microchip laser. The phenomenon of temperature drift of microchip laser is analyzed theoretically, and the conclusion that the wavelength of laser is linearly related to the temperature of crystal center is obtained. (3) the thermal effect of microchip crystal is analyzed theoretically. The heat conduction model of gain medium of microchip laser is studied by finite element method. The essential reason for the thermal effect of microchip crystal is the waste heat produced by the pump source inside the crystal. The thermal effect will lead to the change of the cavity length and refractive index of the microchip crystal. The thermal conduction model of microcrystal was obtained by ANSYS thermal analysis. The thermal analysis results show that the LD pump power and temperature control temperature are linearly related to the crystal center temperature. In the range of simulation value, the heat conduction coefficient between heat sink and crystal only affects the temperature difference of crystal. The suitable heat conduction mode can obtain good heat dissipation effect, but there is a heat dissipation limit. (4) the longitudinal mode theory and single longitudinal mode of microchip laser are studied. The conditions for the formation of double longitudinal modes are introduced. The temperature characteristics and thermal spectrum matching of microchip lasers are studied experimentally. The experimental results show that the power of single-frequency laser is approximately a negative linear relationship with the temperature control temperature, the laser power decreases by about 18 percent for every 10 掳C increase in the temperature control temperature, and the laser wavelength has a positive linear relationship with the temperature control temperature. The migration rate of single-frequency laser is 9.4 pm/ 掳C, and that of dual-frequency laser is 10.9 pm/ 掳C. the feasibility of temperature control to realize the linear shift of laser wavelength is determined, and it is proved that the thermal conductivity is not affected by temperature. The single frequency laser spectrum matching can be maintained when the pump current and the temperature control temperature satisfy the specific linear relation dT_o/dI=-16.8 掳C / A.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN248
[Abstract]:Since 1960, when American physicist Maiman used flash lamp to pump ruby crystal to obtain 694 nm red laser, laser technology has begun to develop at a high speed, and now it has been applied in every aspect of modern society. Compared with the conventional laser, the microchip laser, which uses chip doped crystal as gain medium, has the advantages of small volume, high beam quality and large unit volume power. It is studied in optical fiber communication, space communication and atmosphere. Medical devices and other fields have in-depth research. In addition, the two-mode output-beat of microchip laser has become a competitive scheme of photoluminescence millimeter wave. Like ordinary solid-state lasers, the output performance of microchip lasers is also seriously affected by the thermal effect of crystals. In this paper, the thermal effect of microchip crystal is analyzed theoretically and simulated, and the laser spectrum characteristics caused by the thermal effect are studied experimentally. The specific aspects are as follows: (1) the development course of microchip laser is briefly summarized, and the realization scheme and application prospect of optical millimeter wave technology are introduced. Then, the research status of microchip laser at home and abroad is explained. (2) the basis of laser generation and the condition of stable amplification are expounded, and the three components of laser are discussed. Then the common laser gain dielectric materials are introduced and compared. Based on the steady-state rate equation of microchip laser, the working characteristics of microchip laser and its influencing factors are discussed, which provides a reference for improving the output beam quality of microchip laser. The phenomenon of temperature drift of microchip laser is analyzed theoretically, and the conclusion that the wavelength of laser is linearly related to the temperature of crystal center is obtained. (3) the thermal effect of microchip crystal is analyzed theoretically. The heat conduction model of gain medium of microchip laser is studied by finite element method. The essential reason for the thermal effect of microchip crystal is the waste heat produced by the pump source inside the crystal. The thermal effect will lead to the change of the cavity length and refractive index of the microchip crystal. The thermal conduction model of microcrystal was obtained by ANSYS thermal analysis. The thermal analysis results show that the LD pump power and temperature control temperature are linearly related to the crystal center temperature. In the range of simulation value, the heat conduction coefficient between heat sink and crystal only affects the temperature difference of crystal. The suitable heat conduction mode can obtain good heat dissipation effect, but there is a heat dissipation limit. (4) the longitudinal mode theory and single longitudinal mode of microchip laser are studied. The conditions for the formation of double longitudinal modes are introduced. The temperature characteristics and thermal spectrum matching of microchip lasers are studied experimentally. The experimental results show that the power of single-frequency laser is approximately a negative linear relationship with the temperature control temperature, the laser power decreases by about 18 percent for every 10 掳C increase in the temperature control temperature, and the laser wavelength has a positive linear relationship with the temperature control temperature. The migration rate of single-frequency laser is 9.4 pm/ 掳C, and that of dual-frequency laser is 10.9 pm/ 掳C. the feasibility of temperature control to realize the linear shift of laser wavelength is determined, and it is proved that the thermal conductivity is not affected by temperature. The single frequency laser spectrum matching can be maintained when the pump current and the temperature control temperature satisfy the specific linear relation dT_o/dI=-16.8 掳C / A.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN248
【参考文献】
相关期刊论文 前10条
1 胡淼;张瑜;巩续仁;蔡炬;周凯;李齐良;周雪芳;魏一振;卢e，
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