4.3μm级联振荡Dy···PbGa2S4高功率中红外激光的理论研究

数值模拟了基于级联振荡产生4.3μm高功率连续激光的Dy···PGS激光器。模拟了级联振荡Dy···PGS激光器实现稳定连续输出的全过程,计算给出了激光功率和粒子数密度在谐振腔内的空间分布,分析了泵浦光功率、晶体长度和输出镜反射率对4.3μm激光输出的影响。计算结果表明：级联振荡能有效去除Dy···PGS晶体的自终止效应,获得高功率、高效率的4.3μm激光输出;当1.7μm泵浦光功率为10 W时,4.3μm激光的输出功率可达2.535W,斜率效率为29%;晶体最佳长度区间为12～24mm,闲频光输出镜反射率越高越好,信号光输出镜反射率最佳区间为0.8～0.9。     

掺Er3+氟化物光纤振荡器中红外超短脉冲的产生

基于非线性薛定谔方程建立了氟化物(ZrF₄-BaF₂-LaF₃-AlF₃-NaF, ZBLAN)光纤振荡器中产生中红外超短脉冲的理论模型, 在此基础上研究了中红外超短脉冲在氟化物光纤振荡器中形成的物理机理, 数值模拟了氟化物光纤振荡器中中红外超短脉冲的演化过程. 分析了腔内净色散和小信号增益系数对振荡器中锁模脉冲产生的影响, 并给出了参数设置范围. 研究发现: 当掺Er³⁺氟化物光纤长度, 小信号增益系数, 不饱和损耗为一定值时, 腔内净色散在一定范围内才会出现稳定的锁模脉冲, 且随着腔内净色散增加脉冲宽度变宽, 光谱变窄, 峰值功率降低; 当掺Er³⁺氟化物光纤长度及不饱和损耗一定, 腔内净色散量为合理值, 小信号增益系数在合理的范围时可以得到稳定的锁模脉冲, 且随着小信号增益系数的增加脉冲宽度变宽, 光谱变宽, 峰值功率增加.     

Generation of Laguerre-Gaussian beam from end-pumped and c-cut Nd:YVO4 laser

We demonstrate an end-pumped,c-cut Nd:YVO4 laser that emitted first-order Laguerre-Gaussian(LG01) beam by adjusting the position of focused pump beam relative to laser crystal.The pumping light reached the laser crystal has circular and solid intensity profile.The laser is compact and stable,and the obtained LG01 beam power reaches 202 mW with ～25% slope efficiency.     

Transverse mode transition and LG01-mode generation in an end-pumped Nd：YV04 laser

A laser-diode end-pumped Nd：YVO4 crystal laser is demonstrated to emit the first-order Laguerre- Gaussian （LGm） mode with 502-mW laser power and 22% slope efficiency. Tile LGm-mode is lased only when the pumping area locates in the central part of the laser crystal＇s front surface, and thereafter the symmetrical LGm-HGol-TEM00 mode transition happens when laser crystal is moved laterally inside several-tens-micron area. The possible mechanism responsible for the phenomenon of symmetrical mode transition is also discussed.