微片激光器的溫度特性研究
發(fā)布時間：2018-08-04 18:34
【摘要】：自1960年美國物理學(xué)家梅曼使用閃光燈泵浦紅寶石晶體獲得694 nm的紅色激光以來,激光技術(shù)開啟了高速發(fā)展的步伐,如今在現(xiàn)代社會生活的各個方面都出現(xiàn)了它們的應(yīng)用。使用片狀的摻雜晶體作為增益介質(zhì)的微片激光器相比于傳統(tǒng)的激光器有著體積小、光束質(zhì)量高、單位體積功率大的優(yōu)點,在光纖通信、空間通訊、大氣研究、醫(yī)療器械等領(lǐng)域都有深入的研究。此外,微片激光器的雙模輸出拍頻已經(jīng)成為具備競爭力的光生毫米波方案。與普通的固體激光器一樣,微片激光器的輸出性能同樣受晶體熱效應(yīng)的嚴重影響。本文對微片晶體的熱效應(yīng)進行了理論和仿真分析,并對晶體熱效應(yīng)引起的激光頻譜特性變化進行了實驗研究。具體有以下幾個方面:(1)簡單概述了微片激光器的發(fā)展歷程,并介紹了光生毫米波技術(shù)的實現(xiàn)方案及應(yīng)用前景,然后重點對國外和國內(nèi)微片激光器的研究近況分別進行了說明。(2)闡述了激光產(chǎn)生的基礎(chǔ)及穩(wěn)定放大的條件,并探討了激光器的三個組成部分,隨后對常見的激光增益介質(zhì)材料進行介紹和比較。在推導(dǎo)微片激光器的穩(wěn)態(tài)速率方程的基礎(chǔ)上,討論了微片激光器的工作特性及其影響因素,為提高微片激光器的輸出光束質(zhì)量提供了參考。理論分析微片激光器的溫度漂移現(xiàn)象,得到激光波長和晶體中心溫度呈線性關(guān)系的結(jié)論。(3)理論分析微片晶體的熱效應(yīng),并使用有限元法對微片激光器增益介質(zhì)的熱傳導(dǎo)模型進行了研究。微片晶體熱效應(yīng)產(chǎn)生的本質(zhì)原因在于泵浦源在晶體內(nèi)部產(chǎn)生的廢熱,熱效應(yīng)會導(dǎo)致微片晶體腔長和折射率的改變。通過ANSYS熱分析,得到了微片晶體的熱傳導(dǎo)模型。熱分析結(jié)果表明,LD泵浦功率和溫控溫度二者與晶體中心溫度均呈線性關(guān)系。在仿真數(shù)值范圍內(nèi),熱沉與晶體間的熱傳導(dǎo)系數(shù)只影響晶體溫度差,選定合適的熱傳導(dǎo)方式能獲得良好的散熱效果,但存在散熱極限。(4)對微片激光器的縱模理論及單縱模、雙縱模的形成條件進行了介紹,通過實驗對微片激光器的溫度特性和熱致頻譜匹配進行了研究。實驗結(jié)果表明,單頻激光的功率與溫控溫度近似為負線性關(guān)系,溫控溫度每升高10°C,激光功率下降約18%;激光波長與溫控溫度呈正線性關(guān)系,單頻激光的偏移率為9.4 pm/°C,雙頻激光的偏移率為10.9 pm/°C,由此確定溫控實現(xiàn)激光波長線性偏移的可行性,并證實熱傳導(dǎo)系數(shù)不受溫度影響;泵浦電流和溫控溫度滿足特定的線性關(guān)系式dT_o/dI=-16.8°C/A時可維持單頻激光的頻譜匹配。
[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 擄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/ 擄C, and that of dual-frequency laser is 10.9 pm/ 擄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 擄C / A.
【學(xué)位授予單位】：杭州電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：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 擄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/ 擄C, and that of dual-frequency laser is 10.9 pm/ 擄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 擄C / A.
【學(xué)位授予單位】：杭州電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN248
【參考文獻】
相關(guān)期刊論文 前10條
1 胡淼;張瑜;鞏續(xù)仁;蔡炬;周凱;李齊良;周雪芳;魏一振;盧e，
本文編號：2164749
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