High power semiconductor laser array with single-mode emission

The semiconductor laser array with single-mode emission is presented in this paper.The 6-μm-wide ridge waveguides(RWGs)are fabricated to select the lateral mode.Thus the fundamental mode of laser array can be obtained by the RWGs.And the maximum output power of single-mode emission can reach 36 W at an injection current of 43 A,after that,a kink will appear.The slow axis(SA)far-field divergence angle of the unit is 13.65.The beam quality factor M;of the units determined by the second-order moment(SOM)method,is 1.2.This single-mode emission laser array can be used for laser processing.

High wall-plug efficiency 808-nm laser diodes with a power up to 30.1 W

A very highly efficient InGaAlAs/AlGaAs quantum-well structure was designed for 808 nm emission,and laser diode chips 390-μm-wide aperture and 2-mm-long cavity length were fabricated.Special pretreatment and passivation for the chip facets were performed to achieve improved reliability performance.The laser chips were p-side-down mounted on the AlN submount,and then tested at continuous wave(CW)operation with the heat-sink temperature setting to 25℃using a thermoelectric cooler(TEC).As high as 60.5%of the wall-plug efficiency(WPE)was achieved at the injection current of 11 A.The maximum output power of 30.1 W was obtained at 29.5 A when the TEC temperature was set to 12°C.Accelerated life-time test showed that the laser diodes had lifetimes of over 62111 h operating at rated power of 10 W.

Research on quantum well intermixing of 680 nm AlGaInP/GaInP semiconductor lasers induced by composited Si-Si_(3)N_(4) dielectric layer

The optical catastrophic damage that usually occurs at the cavity surface of semiconductor lasers has become the main bottleneck affecting the improvement of laser output power and long-term reliability.To improve the output power of 680 nm AlGaInP/GaInP quantum well red semiconductor lasers,Si-Si_(3)N_(4)composited dielectric layers are used to induce its quantum wells to be intermixed at the cavity surface to make a non-absorption window.Si with a thickness of 100 nm and Si_(3)N_(4)with a thickness of 100 nm were grown on the surface of the epitaxial wafer by magnetron sputtering and PECVD as diffusion source and driving source,respectively.Compared with traditional Si impurity induced quantum well intermixing,this paper realizes the blue shift of 54.8 nm in the nonabsorbent window region at a lower annealing temperature of 600 ℃ and annealing time of 10 min.Under this annealing condition,the wavelength of the gain luminescence region basically does not shift to short wavelength,and the surface morphology of the whole epitaxial wafer remains fine after annealing.The application of this process condition can reduce the difficulty of production and save cost,which provides an effective method for upcoming fabrication.

Correlation of Electrical Noise with Non-radiative Current for High Power QWLs

The characteristics of low frequency electrical noise, voltage current ( V I ) and electrical derivation for 980 nm InGaAsP/InGaAs/GaAs high power double quantum well lasers(DQWLs) are measured under different conditions. The correlation of the low frequency electrical noise with surface non radiative current of devices is discussed. The results indicate the low frequency electrical noise of 980 nm DQWLs with high power is mainly 1/ f noise and has good relation with the device surface current at low injection.

Researching the 915 nm high-power and high-brightness semiconductor laser single chip coupling module

Based on the high-speed development of the fiber laser in recent years, the development of researching 915 nm semiconductor laser as main pumping sources of the fiber laser is at a high speed. Because the beam quality of the laser diode is very poor, the 915 nm laser diode is generally based on optical fiber coupling module to output the laser. Using the beam-shaping and fiber-coupling technology to improve the quality of output beam light, we present a kind of high-power and high-brightness semiconductor laser module, which can output 13.22 W through the optical fiber. Based on 915 nm GaAs semiconductor laser diode which has output power of 13.91 W, we describe a thoroughly detailed procedure for reshaping the beam output from the semiconductor laser diode and coupling the beam into the optical fiber of which the core diameter is 105 μm and the numerical aperture is 0.18. We get 13.22 W from the output fiber of the module at 14.5 A, the coupling efficiency of the whole module is 95.03% and the brightness is 1.5 MW/cm2-str. The output power of the single chip semiconductor laser module achieves the advanced level in the domestic use.

A 12.1-W SESAM mode-locked Yb:YAG thin disk laser

Pumped by a 940 nm fiber-coupled diode laser, a passively mode-locked Yb：YAG thin disk oscillator was demonstrated with a semiconductor saturable absorber mirror（SESAM）. 12.1 W mode-locked pulses were obtained with pulse duration of 698 fs at the repetition rate of 57.43 MHz. Measurement showed that the beam quality was close to the diffraction limit.

A Comparative Study of Epi-up and Epi-Down Bonding of High Power 980 nm Single-Mode Semiconductor Lasers

Epi-up and epi-down bonding of high power 980nm lasers have been studied in terms of bonding process, thermal behavior, optical performances, thermal stress effects and long-term laser reliability. We demonstrated that epi-down bonding can offer lower thermal resistance and improved optical performances without significantly degrading the long-term laser reliability.

应用于宽带的AlGaN/GaN MIS-HEMT高效率器件

本文采用等离子体增强原子层沉积(PEALD)生长的SiN_(x)栅介质制备了宽带应用的AlGaN/GaN金属绝缘体半导体高电子迁移率晶体管(MIS-HEMTs),并在直流、小信号及大信号测试中评估了该介质层对器件性能的提升。测试结果表明改进器件具有高质量界面、宽栅极控制范围、良好的电流崩塌控制等优势,并确认了其在超过5 GHz下工作时仍能保持较高的功率附加效率(PAE)。在5 GHz连续波模式下,漏极电压V_(DS)=10 V时,MIS HEMT输出功率密度为1.4 W/mm,PAE可达到74.7%;V_(DS)增加到30 V时,功率密度提升到5.9 W/mm,PAE可保持在63.2%的水平;测试频率增加30 GHz,在相同的输出功率水平下,器件的PAE达到50.4%。同时,高质量栅极介电层还可允许器件承受高的栅极电压摆动:在功率增益压缩6 dB时,栅极电流保持在10^(-4)A/mm。上述结果证实了该SiN_(x)栅介质对器件性能的提升,使其满足宽带应用的高效率、高功率和可靠性要求,为系统和电路的宽带设计提供器件级的保障。

一种高电压大功率半导体激光器驱动电路的设计

介绍了一种高电压大功率半导体激光器驱动电流源的设计,该电流源基于“电压源+MOSFET”方案,电压源采用两个相同DC-DC电源模块的串联结构,大幅度提高了负载电压自适应的范围,且输出电流稳定度高,适用于高电压大功率半导体激光器的驱动。

高功率蓝光半导体激光器巴条的封装技术研究

为实现高功率的蓝光半导体激光输出,对蓝光巴条的封装技术进行了研究。利用金锡硬焊料封装了高功率氮化镓(GaN)蓝光半导体激光巴条,应用铜钨过渡热沉作为缓冲层抑制了铜热沉和GaN激光芯片之间封装残余应力,采用高精度贴片机将芯片共晶键合在铜钨过渡热沉上。贴片质量的好坏直接影响了器件的输出特性,所以重点分析了贴片机的焊接温度焊接压力、焊接时间对器件的影响。实验结果表明:当贴片机的焊接温度为320℃、焊接压力为0.5 N、焊接时间为40 s时,焊料层界面空洞最少,热阻最低为0.565℃/W,阈值电流最低为4.9 A,在注入电流30 A时,输出光功率最高为32.21 W,最高光电转换效率达到了23.3%。因此,在优化焊接温度、焊接压力、焊接时间后,利用金锡硬焊料将蓝光半导体激光芯片共晶键合在铜钨过渡热沉的技术方案是实现蓝光半导体激光巴条高功率工作的有效途径。

High power AlGaInP laser diodes with zinc-diffused window mirror structure

The technology of zinc-diffusion to improve catastrophic optical damage (COD) threshold of compressively strained GaInP/AlGaInP quantum well laser diodes has been introduced. After zinc-diffusion, about 20 μm-long region at each facet of laser diode has been formed to serve as the window of the lasing light. As a result, the COD threshold has been significantly improved due to the enlargement of bandgap by the zinc-diffusion induced quantum well intermixing, compared with that of the conventional non-window structure. 40-mW continuous wave output power with the fundamental transverse mode has been realized under room temperature for the 3.5μm-wide ridge waveguide diode. The operation current is 84 mA and the slope efficiency is 0.74 W/A at 40 mW. The lasing wavelength is 656 nm.

1.06 μm high-power InGaAs/GaAsP quantum well lasers

The high power and low internal loss 1.06 μm InGaAs/GaAsP quantum well lasers with asymmetric waveguide structure were designed and fabricated. For a 4000 μm cavity length and 100 μm stripe width device,the maximum output power and conversion efficiency of the device are 7.13 W and 56.4%, respectively. The cavity length dependence of the threshold current density and conversion efficiency have been investigated theoretically and experimentally; the laser diode with 4000 μm cavity length shows better characteristics than that with 3000 and 4500 μm cavity length： the threshold current density is 132.5 A/cm^2, the slope efficiency of 1.00 W/A and the junction temperature of 15.62 K were achieved.

基于调制转移的大功率半导体激光器频率稳定控制

为了提高大功率半导体激光器输出频率稳定控制的效果,提出基于调制转移的大功率半导体激光器频率稳定控制方法。首先分析大功率半导体激光器工作原理,利用光电调制器对激光器泵浦光相位进行调制,获取大功率半导体激光器光波附加相位和泵浦光电场矢量;然后以附加相位和泵浦光电场矢量为基础,使用调制转移技术建立调制转移光谱锁频环路模型,计算大功率半导体激光器探测光和边带拍频信号;最后建立调制转移光谱锁频环路模型表达式,通过求解该表达式,得到大功率半导体激光器的锁频数值,实现激光器输出频率的有效控制。实验表明,文中方法计算大功率半导体激光器拍频信号较为准确,降低其输出拍频信号区间,响应时间最大为0.07 s,响应较为迅速,控制精度较高,具备较好的频率稳定控制能力,控制效果好。

高功率半导体激光器技术发展与研究

高功率半导体激光器及阵列具有可用激光波长丰富、电光转换效率高、调制特性好等许多优点,特别是作为固体激光器和光纤激光器的高效率泵浦源而获得的全固态紧凑型激光器,持续受到极大的关注,得到快速发展。近年来在高功率阵列半导体激光器模块化技术、超高效率、高效冷却技术、半导体激光器及阵列的光束质量优化、高效电源驱动技术等方面都取得了长足的进步,促进了其广泛应用。将结合高功率半导体激光国家重点实验室的研究工作,概述近年来国内外半导体激光器技术的研究进展状况和发展趋势。

68.5 W连续输出1 060 nm波段半导体激光列阵模块

利用InGaAs/InGaAsP应变量子阱外延层材料制作出高功率半导体激光列阵模块。激光芯片宽1 cm,腔长1 200μm,条宽200μm,填充密度为50%,前后腔面光学膜分别为单层Al2O3和Al2O3/5(HfO2/SiO2)/HfO2,室温连续输出功率达到68.5 W,器件光谱中心波长为1 059 nm,光谱宽度(FWHM)为9 nm。

高功率半导体激光泵浦源研究进展

高功率半导体激光器是固体激光器和光纤激光器的主要泵浦源。激光泵浦源性能的大幅提升直接促进了固体激光器、光纤激光器等激光器的发展。主要介绍了8xx nm和9xx nm系列半导体激光泵浦源的最新研究进展,8xx nm单管输出功率已达18.8 W@95μm,巴条输出功率已达1.8 kW(QCW),9xx nm单管输出功率已达35 W@100μm,巴条输出功率已达1.98 kW(QCW)。谱宽<1 nm的窄谱宽半导体激光器输出功率可达14 W。展望了未来半导体激光器泵浦源的发展趋势。

百瓦级半导体激光器模块的风冷散热系统分析

对百瓦级半导体激光器风冷散热系统进行分析,利用ANSYS有限元分析软件对高功率半导体激光模块器件的温度场分布进行了模拟和优化设计。为百瓦级大功率半导体激光模块风冷系统工艺方案的选择提供了依据,并据此进行了实验验证。

国内大功率半导体激光器研究及应用现状

近年来,国内外在大功率半导体激光器方面的研究均取得了很大的进展。其中,大功率半导体激光器列阵的研究和应用成为最大的亮点,如超高电光转换效率、高亮度和高可靠性等主要光电特性均实现了巨大的突破。针对国内大功率半导体激光器主要研究内容和关键技术进行了总结,在外延片结构中广泛采用应变量子阱结构、无铝有源区宽波导大光腔结构及非对称波导结构来提高端面光学灾变损伤光功率密度,还从腔面光学膜、器件封装、器件可靠性、光束整形与耦合以及器件应用等几个方面给予介绍。

808nm高占空比大功率半导体激光器阵列

采用渐变折射率分别限制单量子阱宽波导结构,通过降低非辐射复合、有源层载流子泄露、散射和吸收损耗来提高出射效率和降低激光阈值电流,从而提高半导体激光器阵列的输出功率;同时使P面具有更高的粒子掺杂数密度,优化N面合金条件,降低半导体激光器的串联电阻,降低焦耳热,提高了半导体激光器阵列的转换效率。利用金属有机化学气相淀积技术生长GaInAsP/InGaP/AlGaAs渐变折射率分别限制单量子阱宽波导结构激光器材料,利用该材料制成半导体激光线阵列在20%高占空比的输入电流下,半导体激光器的输出峰值功率达到189.64 W(180 A),斜率效率为1.1 W/A,中心波长为805.0 nm,阈值电流为7.6 A,电光转换效率最高可达55.4%;在1%占空比的输入电流下,阵列的输出峰值功率可达324.9 W(300 A),斜率效率为1.11 W/A,阈值电流为7.8 A,电光转化效率最高达55.6%,中心波长为804.5 nm。

用于纳秒级窄脉冲工作的大功率半导体激光器模块

介绍了一种将脉冲半导体激光器发射系统中的脉冲整形电路、驱动电路、激光器保护电路、激光器集成封装成一个激光器模块的方式。当激光器工作于纳秒级窄脉冲状态下时,激光器封装引腿产生的电抗会使得耦合进激光器的脉冲波形劣化,导致能量损失。为得到上升时间短,波形半宽窄,峰值功率大的光输出,改进了激光器管芯的结构并采用混合光电子集成的方式将驱动电路和激光器管芯封装在一个模块内,使得窄脉冲电信号高效地耦合进半导体管芯。分析验证表明,改进后的激光器模块的各项输出参数均得到改善。同等条件下,改进后的模块在光脉冲宽度为4.5 ns时,峰值功率比单独封装激光器提高6倍多。测试了激光器模块U-P曲线,得到了脉冲宽度7 ns左右,峰值光功率176 W的光脉冲输出。