1.3μm波段单横模大功率输出量子点激光器

为了制备大功率、单横模输出的量子点激光器,对有源多模干涉波导结构进行了研究。通过优化器件结构设计,采用1×1型有源多模干涉波导结构,以均匀多层InAs/InGaAs/GaAs量子点材料作为有源区,制备了1.3μm波段的有源多模干涉结构量子点激光器。连续电流注入条件下的测试结果表明,与传统的均匀波导结构器件相比,有源多模干涉结构器件具有更低的串联电阻和更好的散热性能;在连续电流为0.5A的小注入情况下,器件的输出功率可达114mW、中心波长为1332nm。结果表明,有源多模干涉结构器件是制备大功率、单横模输出光发射器件的一种有效的器件结构。     

Active multimode interferometer laser diode demonstrated via 1.48μm high power application

An active multimode interferometer (MMI) laser diode (LD) concept is presented. It has been verified via a 1.48 μm high power application. The active MMI-LDs, having a larger pumping area compared to that of regular single-stripe LDs with the same length, showed no significant degradation in slope efficiency and up to 50 mW power improvement resulting in 170 mW saturated output power     

A 780 nm high-power and highly reliable laser diode with a longcavity and a thin tapered-thickness active layer

Conventional AlGaAs laser diodes with uniform thickness active layers of various cavity lengths are investigated. It is recognized that the extension of the cavity length is effective in the improvement of the maximum output power, the temperature characteristics, and the operating life in high-temperature conditions. A 780-nm, high-power laser diode having a 350-μm-long cavity with a thin tapered-thickness active layer was fabricated. The optical power density near the mirror facets, the thermal resistance, the current density, and the carrier density were reduced by this structure. The laser emitted over 100 mW of CW (continuous-wave) output power at temperatures up to 80°C. A maximum output power level of 160 mW was achieved at room temperature. The fundamental transverse mode was confirmed at least up to 120 mW     

1064 nm脉冲激光前置放大器研究

采用级联波分复用的泵浦耦合方式,对平均功率0.5 mW、脉宽20 ns、重复频率50 kHz的小信号纳秒脉冲进行单模放大,采用分段泵浦技术,优化两级泵浦功率值,获得了平均功率26 mW,信噪比25 dB的脉冲输出,相应增益为17.1 dB。为高功率放大提供了性能优良的脉冲种子源。     

High power single mode operation of AlGaInP visible laser diodewith lateral leaky waveguide structure

AlGaInP visible laser diode with lateral leaky waveguide structure employing 0.025 of negative refractive index step have been fabricated. In comparison to conventional loss guided structure, lateral leaky waveguide structure indicated stable fundamental mode operation. The output power at kink for lateral leaky waveguide laser was around 1.5 times higher than loss guided structure for same stripe widths. The stability was attributed to large mode discrimination against higher order mode. The lateral leaky waveguide laser with 560 μm cavity length employing the antireflection (5%)/high reflection (82%) showed 66 mW of output power with no kinks at 25°C     

Multiple-quantum-well GaInAs/GaInAsP tapered broad-area amplifierswith monolithically integrated waveguide lens for high-powerapplications

A 1.48-μm tapered broad-area semiconductor laser amplifier with a monolithically integrated waveguide lens as demonstrated. The gain saturation characteristics of the tapered amplifier were examined. A maximum output power of 300 mW and a 3-dB saturation power of 200 mW under quasi-CW conditions were obtained from the amplifier without the waveguide lens. Output power of 200 mW was obtained with a broad emission spectrum of ~30 nm when the device was used as a superluminescent diode. The amplified output was focused to a single lobe by the monolithically integrated aspheric waveguide lens, which may be useful for efficient coupling of the output into a single-mode fiber     

声光调Q内腔式Nd:YAG/RTP级联拉曼激光特性

报道了基于磷酸钛氧铷（RTP）晶体的内腔式级联拉曼激光输出特性。采用半导体激光端面抽运声光调Q Nd:YAG晶体产生的1 064 nm激光作为基频光,尺寸为4420 mm3、沿x轴切割的RTP晶体作为拉曼增益介质。分别对X（ZZ）X和X（YY）X几何配置的RTP拉曼激光系统进行实验研究。X（YY）X几何配置的拉曼增益相对较低,导致腔内不同非线性频率变换过程的竞争,只测量到对应光参量振荡激光的输出。在X（ZZ）X几何配置下成功获得了271 cm-1和687 cm-1两个拉曼频移共同参与级联拉曼激光输出。高阶Stokes光随着抽运功率的增加而依次出现。在10 W入射抽运功率和15 kHz脉冲重复频率下,获得了总平均输出功率480 mW,转化效率4.8%的多波长激光输出。波长涵盖了1 000~1 200 nm之间各阶Stokes光。     

蓝光二极管双端抽运Pr:YLF晶体320 nm紫外激光器（特邀）

设计了一种采用不同波长的蓝光二极管合光作为抽运源并采用双端抽运的方式抽运Pr:YLF晶体320 nm紫外激光器。该激光器结构采用V型折叠腔结构,使用波长分别为444 nm和469 nm、抽运功率分别为3 W和1.4 W的蓝光激光二极管作为抽运源,对12 mm长、0.3%掺杂浓度的Pr:YLF晶体进行抽运,并且使用三硼酸锂晶体作为倍频晶体来实现倍频,匹配方式为I类相位匹配。通过对谐振腔参数进行优化,当5700 mW的抽运功率注入晶体时,输出了1005 mW最大输出功率的320 nm紫外连续激光,光光转换效率约为17.6%。     

High pak power femtosecond pulses from modelocked semiconductor laser in external cavity

The generation of high peak power femtosecond pulses from an all semiconductor laser system is demonstrated. The system is based on a passively modelocked two-section laser diode in an external cavity, a tapered amplifier and a compact external pulse compressor. Pulse durations are achieved below 600 fs with an average optical power above 500 mW at a repetition rate of 330 MHz. This corresponds to a peak power of 2.5 kW, which is the highest value reported for an all semiconductor ultrafast laser system so far.     

High-power 980-nm ridge waveguide laser diodes including an asymmetrically expanded optical field normal to the active layer

We propose a new ridge waveguide laser diode (LD) which supports an asymmetrically expanded optical field normal to the active layer in order to increase the maximum kink-free output power and reduce the aspect ratio of output beams. The dependence of maximum kink-free output power on facet reflectivity was analyzed from the viewpoint of the total optical power in the cavity. It was clarified that the maximum kink-free output power is influenced by the facet reflectivity which affects the refractive index changes of the ridge region via the total optical power in the cavity. More than 600 mW of maximum kink-free output power and an aspect ratio of less than 2.5 were achieved in experiments with 980-nm ridge waveguide LDs by means of this proposed new structure.     

Laser operation of epitaxially grown Yb:KLu(WO/sub 4/)/sub 2/--KLu(WO/sub 4/)/sub 2/ composites with monoclinic Crystalline structure

Epitaxial monoclinic double tungstate composites based on the strongly anisotropic KLu(WO/sub 4/)/sub 2/ (KLuW) were grown with high crystalline quality and laser operation of ytterbium was demonstrated for the first time. Highly efficient CW laser emission of an Yb:KLuW-KLuW crystal was achieved near 1030 nm. The 100-/spl mu/m-thick Yb:KLuW layer was pumped at wavelengths near 980 nm by a tapered diode laser as well as by a Ti:sapphire laser. More than 500 mW of CW output power and slope efficiencies up to 66% were obtained at room temperature without cooling.     

1.3 μm InGaAsP低电流超辐射发光二极管组件

设计并制作了用于高精度光纤陀螺的 1.3μm低电流超辐射发光二极管组件。采用隐埋异质结结构 ,实现了良好的电流限制和光限制 ,同时采用长腔结构来提高器件单程增益 ,从而获得了高的输出功率。组件具有工作电流小、输出功率高 ,以及光谱特性好等特点。测试结果表明 ,在 70mA工作电流下 ,组件尾纤输出功率大于 0 .1mW ,光谱宽度大于 30nm。     

窄线宽LD泵浦双包层光纤激光器

报道了LD泵浦的窄线宽双包层光纤（DCF）激光器，从理论和实验数值模拟了激光输出功率对输出镜反射率，光纤长度和吸收泵浦功率的依赖关系，进而进行了实验，实验中选用光纤布拉格光栅（FBG）作为输入腔镜，利用光纤端面菲涅耳反射作为输出腔镜，得到了窄线宽的单模激光输出。最大输出功率421mW，斜率效率78.2%，激光中心波长1086.92nm，谱线宽度0.16nm。     

两种透射率入射腔镜对894.6nm倍频腔转换效率的比较

为了在对基频光透射率分别为5%和10%的两种入射腔镜(其它参数相同)中择优, 利用波长对应于铯原子D₁线的894.6nm半导体激光作为基频光, 抽运以周期极化磷酸氧钛钾(PPKTP)晶体作为非线性介质的两镜驻波倍频腔, 通过外腔倍频过程产生447.3nm蓝光, 对利用这两种腔镜搭建倍频腔所产生的蓝光进行了对比。结果表明, 在注入350mW基频光、倍频腔采用透射率为5%的入射腔镜时, 制备了178mW蓝光, 倍频效率为50.8%, 0.5h功率起伏为1.4%;采用10%透射率腔镜的倍频腔获得131mW蓝光, 倍频效率为37.4%, 0.5h功率起伏为0.7%;使用5%透射率入射腔镜的倍频效果更好。该研究对产生铯原子D₁线非经典光场所需高质量抽运源的制备具有重要指导意义。     

1.06μm注入锁定增益开关半导体激光器特性分析与功率放大研究

报道了1.06 m增益开关半导体激光器的详细特性分析和功率放大研究。用高频正弦信号调制中心波长1.06 m的F-P腔半导体激光器得到脉宽约为100 ps、平均功率约为20 mW,重频从500 MHz到2 GHz连续可调的稳定短脉冲激光输出。采用注入锁定改善增益开关半导体激光器的输出特性。研究和分析了调制信号的频率、功率和偏置电流的大小以及注入锁定的功率、温度对激光器输出特性的影响。将该激光器作为种子,用108 W的抽运光进行两级全光纤功率放大得到了82 W的高功率输出,光光转换效率达到76%。     

2.0 W CW, diffraction-limited tapered amplifier with diode injection

The authors have demonstrated an all-semiconductor discrete-element 1.5 mm length tapered-amplifier MOPA (master oscillator power amplifier) emitting up to 2.0 W CW in a diffraction-limited pattern. The tapered single-pass amplifier MOPA exhibits a very high differential efficiency of 72% and a total energy conversion efficiency of 39% at 2.0 W CW output power. The high efficiency of the MOPA is attributed to the tapered amplifier design, which maximises extraction efficiency with a low-power injected beam of 25 mW from a single-mode laser diode. Such an MOPA will have applications where compact, high-efficiency, diffraction-limited sources of radiation are required, such as frequency doubling and free-space communication.<>     

输出高重复频率脉冲列的全固态激光器

报道了利用声光振幅调制锁模的方法,在激光二极管端面抽运Nd∶YVO4激光器上获得320MHz高重复频率脉冲列的实验结果。实验采用平平腔结构,腔长452mm,耦合输出镜透过率为3.6%。所用声光介质为熔融石英晶体,以铌酸锂作换能器,在驱动功率4.5W时,对1064nm波长衍射效率为5%,相应的调制深度为0.31。在最佳锁模状态下,激光二极管抽运功率为3.5W,此时激光平均输出功率为15mW,示波器记录脉冲宽度680ps,实测光束质量因子M2小于1.5。并在实验基础上对激光器工作的稳定性进行了分析,结果表明在腔长变化不超过±100μm时,输出波形仍是稳定的。     

一种分布反馈注入放大半导体激光器的研制

研制了一种小型大功率半导体激光器系统。将分布反馈半导体激光器输出的小功率光注入到锥形芯片放大器后实现功率放大,得到功率大于700 mW,波长连续可调谐范围大于1 nm的输出激光。该激光器系统不但结构紧凑、输出功率稳定,而且操作方便。该系统可在激光冷却与囚禁、超冷量子气体、量子信息、原子频标及相关空间实验研究中得到应用。     

LD纵向泵浦腔内倍频激光器腔参数的选择

从理论上研究了在一定长ＫＴＰ情况下ＬＤ纵向泵浦Ｎｄ：ＹＶＯ４／ＫＴＰ腔内倍频激光器的绿光输出与腔长、输出镜曲率半径及泵浦光斑半径等参数的关系。根据分析选择了一组实验参数，在入射泵浦功率为６６８．７ｍｗ时获得了１５３．９ｍｗ的绿光输出，光一光转换效率为２３％。将实验结果与理论计算值进行了比较，两者符合较好。     

高稳定性单纵模布里渊光纤激光器的实验研究

本文提出了一种用可调谐半导体激光器（TLS）泵浦的高稳定性单纵模布里渊光纤激光器（SLMBFL）。该激光器利用Brillouin泵浦光（TLS激光）只在环形器内运行一次,这样Brillouin泵浦光就不会在谐振腔内共振,确保了激光器谐振腔的高稳定性从而使Brillouin激光在该谐振腔内形成共振而输出。实验发现当Brillouin增益介质光纤的长度缩短到13．4m时谐振腔的自由光谱范围变为15．2MHz,正好与光纤的Bfillouin增益带宽接近,此时SLMBFL开始表现为单纵模振荡。实验结果表明,该光纤激光器的功率转化效率为42．5％,最大输出功率为267．6roW。单纵模激光输出的信噪比与其泵浦激光的信噪比提高近10dB。SLMBFL对TLS的高频噪声有很好的抑制作用,其输出线宽小于5KHz。