低温生长GaAs实现半导体泵浦红外激光器被动调Q锁模研究

用低温生长GaAs红外晶体材料作为饱和吸收体兼输出镜，在二极管泵浦全固态激光器上实现了调Q锁模。激光器调Q运转阈值为2W。当注入泵浦功率为3．6W时，调Q锁模开始出现。当注入泵浦功率为8．4W时，平均输出功率达到837mW，调Q包络的重复频率为100kHz，锁模脉冲的重复频率为760MHz。     

调Q锁模运转的全固态Tm:LuAG陶瓷激光器

采用垂直生长法制备的氧化石墨烯（Graphene oxide, GO）作为可饱和吸收体,利用典型“X”型折叠腔在全固态Tm:Lu₃Al₅O₁₂(Tm:LuAG)陶瓷激光器中实现了调Q锁模运转。以790 nm激光二极管(Laser diode, LD)作为泵浦源,当泵浦功率大于8 W时,激光器进入稳定的调Q锁模状态。当输出镜透过率为5%时,连续光最高输出功率为714 mW,斜效率为4.94%。当泵浦达到16 W时,激光器最大输出功率为200 mW , 光谱中心波长为2024 nm,脉冲宽度约为695 ps,对应的锁模脉冲重复频率为108.7 MHz,调Q包络中锁模脉冲的调制深度接近100%。该2 μm超短脉冲激光器在生物医学和激光通讯等领域具有非常重要的应用。     

LD泵浦Nd:YVO4／SESAM锁模激光器实验研究

报道了利用LD泵浦Nd∶YVO4激光器,用半导体可饱和吸收镜(SESAM)做被动锁模元件,实现了高效的连续锁模运转,输入功率7.5W时得到2.45W的激光输出,光-光转换效率达32.7%,锁模脉冲的重复频率为108MHz.     

高单脉冲能量被动调Q锁模Tm,Ho: LLF激光器

报道了一种采用氧化石墨烯作为可饱和吸收体的二极管泵浦的被动调Q和调Q锁模运转的Tm, Ho: LLF激光器。采用透过率分别为3%、5%和9%的输出镜,首先研究了Tm, Ho: LLF激光器的连续运转特性。实验和模拟结果均表明采用透过率为9%的输出镜输出特性最好,当最大泵浦功率为20 W时,连续光输出功率高至1793 mW。接着以氧化石墨烯为饱和吸收体,采用透过率为9%的输出镜研究了Tm, Ho: LLF激光器的调Q和调Q锁模特性。实验表明:当790 nm LD泵浦功率小于7.26 W时,激光处于单纯调Q运转状态;当大于7.26 W时,激光器进入稳定的调Q锁模状态,当最大泵浦功率为20 W时,最大输出功率为1052 mW,锁模重复频率为53.19 MHz,对应的平均单脉冲能量为19.77 nJ,该单脉冲能量是目前2 μm锁模激光器的最高指标,同时证实了氧化石墨烯材料在大能量高功率激光锁模中是发展潜力优良的二维锁模材料。     

正交增益型被动调Q激光器的设计与实现

为了改善被动调Q激光器输出不稳定的现象,利用Nd:YVO4具有增益方向性的特点,使用电光晶体将线偏振光光矢量方向旋转90,实现腔内增益突变,进而实现被动调Q稳定输出。利用该方法,在LD连续泵浦Nd:YVO4被动调Q实验中,当耦合输出镜反射率为80%,饱和吸收体初始透射率为83.06%,泵浦功率为22 W时,输出功率为4.68 W,调Q序列脉冲的重复频率为49.16 kHz,脉冲宽度为26.28 ns。并且在泵浦功率从10~22 W的情况下,获得了稳定的被动调Q激光输出。脉冲幅度波动性低于2.4%,脉冲时间波动性低于5%,重复频率的不稳定性低于1%,光光转换效率斜效率达到21.27%,斜效率为34%。     

光参量产生器泵浦源的优化设计与实验研究

研究了作为光参量产生器的泵浦源的1064nm Nd∶YAG激光器输出特性和运转特性。通过调Q脉冲的速率方程的数值计算得到脉冲形状,分析了脉冲形状对光参量振荡的影响。在泵浦功率为9. 3W, Q 开关重复频率为20kHz时,输出TEM00模1064nm 激光平均功率为3. 20W,光光转换效率34. 4% ,峰值功率为60kW。高峰值功率、窄脉宽的泵浦源为产生高质量、宽调谐、高转换效率的光参量产生器创造了条件。     

新型钒酸盐混晶Nd:Gd0.42Y0.58VO4/Cr4+:YAG被动调Q锁模特性研究

研究了Nd：Gd0.42 Y0.58 VO4混晶的激光运转特性。采用Cr^4＋：YAG晶体作为被动可饱和吸收体，实现了Nd：Gd0.42 Y0.58 VO4混晶的调Q锁模激光运转。实验测量了不同Cr^4＋：YAG初始透过率情况下激光器的输出特性。在Cr^4＋：YAG初始透过率T0=86.3%，输出镜透过率T=10%时，调Q锁模运转阈值为2.8W，随着抽运动率的增加，调制深度逐渐加大。采用透过率T=20%的输出镜，注入抽运动率10.3W时，调Q锁模深度红为70%，相应的脉冲包络重复频率为40kHz，半高度为25ns，平均输出功率为2.58W，光-光转换效率为25%。     

一种基于Cr4+:YAG晶体的紧凑高效被动调Q脉冲激光器

研究并设计了一种基于Nd:YVO4晶体的紧凑高效全固态1064nm激光器。在连续波运转状态下,当泵浦功率为7.8W时,激光器最大输出功率为2.49W,相应的光-光转化效率为31.92%,斜率效率为35.77%。在此基础上,利用尺寸为Cr4+:YAG晶体作为被动调Q元件,实现了1064nm稳定调Q脉冲运转。当激光器谐振腔优化为9 cm、泵浦功率为7.8W时,实验获得了2.13 W的调Q脉冲输出,相应的光-光转换效率为27.31%,重复频率为357.1KHz,脉冲宽度为75ns。     

LD端面泵浦Nd∶YVO4/YVO4键合晶体声光调Q激光脉宽研究

利用半导体激光器(LD)端面泵浦YVO4/Nd∶YVO4键合晶体,实现声光调Q 1064nm的窄脉宽激光输出。从理论和实验上分析了泵浦功率和重复频率对输出调Q脉宽的影响。在泵浦功率为20W情况下,重复频率为2kHz时,获得最短脉冲宽度为16.4ns;重复频率为40kHz时,获得了最大平均输出功率为6.9W,光-光转换效率为34.5％。     

新型钒酸盐混晶Nd∶Gd_(0.42)Y_(0.58)VO_4/Cr~(4+)∶YAG被动调Q锁模特性研究

研究了Nd∶Gd0.42Y0.58VO4混晶的激光运转特性。采用Cr4+∶YAG晶体作为被动可饱和吸收体,实现了Nd∶Gd0.42Y0.58VO4混晶的调Q锁模激光运转。实验测量了不同Cr4+∶YAG初始透过率情况下激光器的输出特性。在Cr4+∶YAG初始透过率T0=86.3%,输出镜透过率T=10%时,调Q锁模运转阈值为2.8 W,随着抽运功率的增加,调制深度逐渐加大。采用透过率T=20%的输出镜,注入抽运功率10.3 W时,调Q锁模深度约为70%,相应的脉冲包络重复频率为40 kHz,半高宽度为25 ns,平均输出功率为2.58 W,光-光转换效率为25%。     

Passive mode locked diode-pumped Nd:GdYVO4 laser with a GaAs absorber

A passively Q-switched mode-locked Nd：GdYVO4 laser is successfully demonstrated by using a piece of GaAs crystal grown at low temperature as the passively saturated absorber and the output coupler. Fundamental properties of the Nd： GdYVO4 laser are investigated. The maximum average output power of 3.5 W is obtained by using plainsphere when the incident pumping power is 10 W, which corresponds to an optical-optical coversion efficiency of 35%. The threshold power for the Q-switching mode-locked is 1.2 W. The maximum average output power of 1.72 W is obtained by using GaAs when the incident pumping power is 10 W, mode-locked pulse train with a repetition rate of - 113 MHz is achieved. At the incident laser pumping power of 7 W, the modulation depth is 100%.     

Passive mode locked diode-pumped Nd:GdYVO4 laser with a GaAs absor ber

A passively Q-switched mode-locked Nd:GdYVO4 laser is successfully demonstrated by using a piece of GaAs crystalgrown at low temperature as the passively saturated absorber and the output coupler. Fundamental properties of the Nd:GdYVO4 laser are investigated. The maximum average output power of 3.5 W is obtained by using plainsphere when theincident pumping power is 10 W, which corresponds to an optical-optical coversion efficiency of 35%. The thresholdpower for the Q-switching mode-locked is 1.2 W. The maximum average output power of 1.72 W is obtained by usingGaAs when the incident pumping power is 10 W, mode-locked pulse train with a repetition rate of -113 MHz is achieved.At the incident laser pumping power of 7 W, the modulation depth is 100%.     

Q-switched mode-locked diode-pumped Nd:YVO4 laser with a saturable Bragg reflector

We demonstrated a diode-pumped passively Q-switched mode-locked Nd:YVO4 laser by using a relaxed saturable Bragg reflector (SBR). Stable mode-locked pulse train with the repetition rate of ～230 MHz was achieved and the pulse train was modulated by the Q-switched envelope with the repetition rate of ～150kHz. The maximum output of 4 W was obtained under the pump power of 13.5 W. The optical-to-optical efficiency was 30%. We also discussed the transition of each process having emerged.     

基于石墨烯可饱和吸收体的被动锁模、被动调Q掺镱光纤激光器

报道了石墨烯材料作为可饱和吸收体的被动锁模、被动调Q掺镱全光纤激光器。采用环形腔结构,在抽运功率为1.2W时,有稳定的重复频率为1.04MHz的自锁模脉冲发生,平均输出功率为46mW;当抽运功率增加到2.3W时,平均输出功率为170mW,相应的单脉冲能量高达163nJ,脉冲宽度约为680ps。采用线形腔结构,实现了石墨烯被动调Q激光脉冲输出,其重复频率在140～257kHz可调,最窄激光脉冲宽度为70ns,最大平均功率为12mW,相应最大单脉冲能量为46nJ。     

Q-switched and Mode-locked Characteristics of Cr^4＋： YAG Crystal

The passively Q-switched and mode-locked （QML） characteristics in a diode-pumped Nd： GdVO4 laser with Cr^4＋： YAG saturable absorbers have been demonstrated. A maximum average output power of 710 mW has been obtained in the QML laser. The maximum energy of a single Q-switched pulse is 52.5μJ, with the corresponding pulse width of 30 ns and the peak power of 1.75 kW, at the incident pump power of 7. 75 W. The repetition rates of the Q-switched envelope and the mode-locked laser pulse are 16.7 kHz and 680 MHz, respectively.     

端面抽运全固态皮秒被动锁模激光器

利用国产半导体可饱和吸收镜(SESAM),设计了不同的腔型结构,实现了平均功率5W单路输出,5W双路输出,输出透过率可调节的半导体可饱和吸收镜线型腔连续锁模(CWML)激光器,双向输出六镜环行腔连续锁模激光器等。将半导体可饱和吸收镜放在腔内的特殊位置,利用一种新的技术方法实现了锁模激光器的频率翻倍。利用由非线性晶体KTP和双色镜构成的非线性镜(NLM),实现了端面抽运Nd∶YVO4激光器的4W锁模输出。     

Q-switched and Mode-locked Characteristics of Cr4+:YAG Crystal

The passively Q-switched and mode-locked(QML) characteristics in a diode-pumped Nd:GdVO4 laser with Cr4 :YAG saturable absorbers have been demonstrated. A maximum average output power of 710 mW has been obtained in the QML laser. The maximum energy of a single Q-switched pulse is 52.5 μJ,with the corresponding pulse width of 30 ns and the peak power of 1.75 kW,at the incident pump power of 7.75 W. The repetition rates of the Q-switched envelope and the mode-locked laser pulse are 16.7 kHz and 680 MHz,respectively.     

GaAs被动调Q固体激光特性研究

使用紧凑的直线平-凹腔结构,利用半导体饱和吸收片GaAs实现了二极管(LD)端面抽运Nd:GdVO4高重复频率的被动调Q 1.06μm激光运转,在8 W的泵浦功率下获得平均输出功率达0.98 W的稳定激光输出,最小脉冲宽度为60 ns.最高重复频率达240 kHz.