摘要
通过分析LD阵列端面泵浦片状放大器的工作特点,建立了对增益介质Nd:YLF进行热特性研究的有限元模型。针对泵浦能量空间均匀分布、高斯分布、超高斯分布三种情况,计算出了LD泵浦功率56kW,脉冲宽度520μs,重复频率10 Hz状态下晶体瞬时3维温度和热应力分布。研究结果表明:由于脉冲工作方式,晶体各节点温度随时间呈锯齿形变化,经过一段时间后吸热和冷却效果达到平衡,介质温度呈周期性变化;在相同泵浦峰值功率条件下,超高斯泵浦能量分布引起的温升和热应力最小,其最大值分别为103.3℃和47.6 MPa;有效泵浦功率密度达到10 kW/cm2量级时,介质极可能发生热致断裂。
By analysing the performance features of laser diode array end-pumped disk laser amplifier, a finite element thermal model of laser crystal Nd：YLF was established. 3D and transient distributions of temperature and thermal stress of Nd：YLF pumpedwith 5 6 kW, 5 2 0 μs and 1 0 Hz LD were respactively calculated when the transverse distribution of pump energies was uniform, Gaussian and Super-Gaussian. The result shows that the thermal effect of the crystal under Super-Gaussian transverse distribution is the weakest, the maxmum temperature is 103.3℃, and the maxmum Mises stress is 47.6 MPa. When the effective pump energy reaches up to 10 kW/cm^2 , the fracture due to thermal stress will occur.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2006年第12期1979-1982,共4页
High Power Laser and Particle Beams
基金
国家自然科学基金资助课题(10576038)
