利用非线性损耗提升全固态单频激光器输出功率研究进展(特邀)  

Research progress on enhancing the output power of all-solid-state single-frequency continuous-wave lasers by using intracavity nonlinear loss mode-selecting technology(invited)

作　　者：卢华东[1,2] 李佳伟 靳丕铦 苏静 彭堃墀[1,2] Lu Huadong;Li Jiawei;Jin Pixian;Su Jing;Peng Kunchi(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan 030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学光电研究所量子光学与光量子器件国家重点实验室,山西太原030006 [2]山西大学极端光学协同创新中心,山西太原030006

出　　处：《红外与激光工程》2024年第1期31-42,共12页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(61975100,62105192);国家重点研发计划项目(2022YFC2204003);山西省1331工程项目;山西省科技创新人才团队(202204051002005);山西省省筹资金资助回国留学人员科研项目(2022-015);山西省应用基础研究计划(杰出青年培育项目)(202103021221004);山西省高等教育机构创新人才培养计划项目;山西省专利转化专项计划项目(202305007);第一实验室-国创中心(山西)科技创新项目。

摘　　要：全固态单频连续波激光器因其噪声低、线宽窄、光束质量好、功率稳定性高等优点已经被广泛应用于产生非经典光场、冷原子物理研究、引力波探测等诸多领域。随着科学技术的不断发展,传统的全固态激光器的输出功率已经不能满足前沿领域的需求,因此亟需在保持全固态激光器整体性能的同时进一步提升激光器的输出功率。为此首先需要更高的泵浦功率,而这将使激光器内部增益提高,在腔内损耗不变的情况下,原非振荡模式也将满足起振条件,从而使激光器在跳模或多模状态下运转。此外,激光晶体的热效应和损伤阈值也限制了输出功率的提高。本文介绍了一种利用非线性损耗大幅度提升全固态单频连续波激光器的输出功率的技术和方法。通过在谐振腔中引入非线性损耗,使主模经受的非线性损耗是次模的一半。在模式竞争的作用下,谐振腔内的模式被更进一步的选择,从而允许全固态单频激光器在更高的增益下保持单纵模运转。通过在谐振腔内插入多块增益晶体可以有效缓解由于激光增益晶体热效应的限制,从而实现更高功率的单频激光输出。目前高功率全固态连续波激光器的输出功率已经达到了一百瓦的量级,且还在进一步提高。通过在谐振腔内引入非线性损耗,全固态单频连续波激光器的整体性能在得以保障和提高的同时,其应用范围也得到了进一步的推广。Significance:All-solid-state single-frequency continuous-wave(CW)laser have found extensive applications in diverse domains such as the generation of non-classical light fields,cold atom physics,detection of gravitational waves,and so on,which primarily attributed to their merits of low noise,narrow bandwidth,excellent beam quality,and high power stability.In line with the advancement in science and technology,the output power of the traditional all-solid-state laser(ASSL)cannot satisfy the application requirements of many frontier research fields,so it is necessary to further scale the ASSL power and simultaneously maintain other excellent performance.For the purpose of improving the output power of the ASSL,its pump power has to be primarily elevated.However,with the increasement of the pump power,the laser gain is enhanced,and the nonoscillating laser modes of the ASSL start to oscillate,which results in the mode-hopping or the multi-mode oscillating operation of the ASSL.Moreover,the severe thermal effect of the laser gain medium and its relatively lower damage threshold also further restrict the improvement of the ASSL power.In this paper,an effective method of improving the all-solid-state single-frequency CW laser power via deliberately introducing a nonlinear loss into the resonator was presented.When the nonlinear loss was introduced,the nonlinear loss of the lasing mode was half of that of non-lasing mode,and the non-lasing mode was effectively inhibited,under the mode competition of the laser.As a consequence,the stable single-longitudinal mode operation of the laser can be guaranteed at higher laser gain.In addition,the design of multi-laser-crystal resonator can be adapted to efficiently mitigate the negative impact of the thermal effects of the laser crystal.By combining the nonlinear loss technique and the multi-laser-crystal resonator scheme,the output power of the all-solid-state single-frequency CW laser had been scaled up to 100-watt level and continuously increased.Progress:First,the fundament

关 键 词：全固态激光器 非线性损耗 单频 高功率 

分 类 号：TN248.1[电子电信—物理电子学]