Diode Pumped Operation of Tm,Ho：YVO4 Microchip Laser

A cryogenic and room-temperature diode pumped Tm,Ho：YVO4 microchip laser with 0.5 mm crystal length lasing around 2μm is demonstrated for the first time to our knowledge. Under cryogenic temperature of 77 K, as much as 1.2 W output and slope efficiency of 35% with respect to absorbed pump power are obtained. At temperature of 5℃ the maximum output power of 48mW is obtained at an absorbed pump power of 503 mW, representing a 9.5% optical to optical conversion efficiency. In addition, as much as 8 mW single-frequency output lasing at 2052.6 nm is achieved at room temperature of 15℃.     

Ld-Clad-Pumped All-Fiber Tm^3＋-Doped Silica Fiber Laser

The CW 39.4 W all-fiber LD-clad-pumped Tm^3＋-doped fiber laser output is reported with a slope efficiency of 34% in respect to the pump power. The all-fiber laser is made up by progressively splicing the pigtail fiber, matched FBG fiber and Tin-doped fiber. The reflective FBG and Tm-doped fiber end fresnel reflection build up the laser resonance cavity. Due to the multi-mode FBG as the reflective mirror, the output laser spectrum is multi-peaks at high power output, whereas the total spectrum width is less than 2nm at nearly 1.94μm.     

Comparative investigation of long-wave infrared generation based on ZnGeP2 and CdSe optical parametric oscillators

Long-wave infrared (IR) generation based on type-II (o→e+o) phase matching ZnGeP₂ (ZGP) and CdSe optical parametric oscillators (OPOs) pumped by a 2.05 μm Tm,Ho:GdVO₄ laser is reported. The comparisons of the birefringent walk-off effect and the oscillation threshold between ZGP and CdSe OPOs are performed theoretically and experimentally. For the ZGP OPO, up to 419 mW output at 8.04 μm is obtained at the 8 kHz pump pulse repetition frequency (PRF) with a slope efficiency of 7.6%. This ZGP OPO can be continuously tuned from 7.8 to 8.5 μm. For the CdSe OPO, we demonstrate a 64 mW output at 8.9 μm with a single crystal 28 mm in length.     

室温下高效率连续波激光二极管端面抽运Tm:YAP激光器

报道了一种室温下高效率运行的激光二极管(LD)端面抽运Tm:YAP连续波激光器.抽运源使用波长为795 nm的光纤耦合二极管激光器,Tm:YAP晶体c轴切割,掺杂原子数分数为3%,尺寸为3 mm×3 mm×7 mm.当输出镜透过率T为10%时,获得8.12 W的1.94 μm连续波激光输出,相对应的抽运功率为26.2 W,阈值抽运功率为4.67 W,斜率效率为52.1%,光一光转换效率为31.0%.使用光栅单色仪测得激光器输出中心波长为1938.2nm,谱线半峰全宽约为2.9 nm.     

Analysis and compensation of thermal lens effects in Tm：YAP lasers

The thermal lens effects in Tm：YAP laser are analyzed by solving the Poisson equation with finite difference method. The thermal focal lengths measured are in the range of 40-90 mm at the pump power of 16-34 W, consistent with the simulation results. The temperature contribution coefficient （the linear coefficient between the maximum temperature in the laser crystal and the pump power） of 1.19 K/W is also obtained. The convex lens and plano-concave mirror thermal lens compensation methods are proposed and applied to a high power pumped Tm：YAP laser.     

低温下运行的LD抽运Tm,Ho:YLF激光器

研究了在低温条件下,利用功率为2 W的激光二极管(LD)抽运液氮制冷Tm(6%),Ho(0.5%):YLF激光器,产生波长为2.05 μm的线偏振连续激光输出,最大功率350 mW,光-光转换效率为20%.     

种籽光注入非谐振KTP光参量振荡器

采用Nd:YAG激光倍频后剩余的1.064μm基频光抽运非临界相位匹配KTP光参量振荡器(OPO),产生的1.57μm激光作为种籽光注入到Nd:YAG 532 nm倍频激光抽运的非谐振汉晶体走离补偿的KTP OPO谐振腔中,使得OPO阈值降低30％,能量转换效率提高5％。     

一种对双包层大芯径光纤光栅反射率和纤芯折射率调制估算的方法

报道了一种简单而又实用对双包层大芯径光纤光栅反射率和纤芯折射率调制的估算方法．通过监测和记录光栅刻写过程中光纤激光器输出功率随时间的变化,将实验数据和掺铥光纤激光器的速率方程理论相结合,对刻写光栅反射率和纤芯折射率变化进行估算．光纤光栅的最大反射率大约为96．4％,纤芯折射率调制达到1．2×10^-3．利用显微镜对光栅进行观测,纤芯的折射率调制变化均匀,且周期与模板周期一致．将光纤光栅应用在全光纤化掺铥光纤激光器中,在抽运功率为51．6W时,获得15．5w的1950．6nm激光输出,斜率效率为37．9％,并在输出功率为15w时,利用刀口法测得光束质量M2≈1．4．     

A 52-mJ Ho：YAG Master Oscillator and Power Amplifier with Kilohertz Pulse Repetition Frequency

We report on a high energy, high repetition rate Ho：YAG master oscillator and power amplifier （MOPA）, res- onantly dual-end-pumped by Tm：YLF lasers at room temperature. At the pulse repetition frequency of i kHz, we demonstrate a maximum energy of 30mJ per pulse with a 28.2ns pulse width in a Ho：YAG oscillator system resonantly double-end-pumped by Tm：YLF lasers. A maximum energy of 52mJ per pulse with a 30.5ns pulse width is achieved in the Ho： YA G amplifier, corresponding to a peak power of approximately 1.7 MW. The output wavelength is at 2090.6nm and 2096.9nm, and a beam quality factor of M2-2.1 is achieved.     

受激布里渊散射相位共轭腔及腔内光学参量振荡器

利用受激布城渊散射相位共轭特性和Ｑ开关特性组成Ｎｄ：ＹＡＧ激光谐振腔,代替传统激光器全反镜和调Ｑ装置,获得能量１００ｍＪ,脉宽１３ｎｓ的线偏振相位共轭激光输出,相应的激光器总体转换效率为０．４７％,同时将单共振ＫＴＰ光学参量振荡器置入腔内,得到波长１．５７μｍ、能量１５ｍＪ的参理振荡激光,实验证实了受激布城渊散射相位共轭腔内光学参量振荡器运行的可行性。