自调Q掺铒光纤激光器动态特性研究

为了研究自调Q掺铒光纤激光器输出动态特性,采用搭建全光纤结构的线形腔和环形腔自调Q掺铒光纤激光器进行了理论分析和实验验证。实验中,当抽运功率达到起振阈值后,随着抽运功率的增加,用示波器观察输出激光,线形腔输出激光依次经历了连续波、自调Q两种运行状态,由于抽运功率的限制,未能再次出现连续波运行状态,而环形腔输出激光则先经历了自调Q运行状态,然后是连续波运行状态;线形腔在抽运功率21mW~190mW的范围内,可获得脉冲宽度8s ~100s范围内可调、重复频率2.5kHz~54kHz范围内可调的自调Q脉冲;环形腔在抽运功率为16.2mW~110mW时,可获得的脉冲宽度在165s左右。结果表明,自调Q掺铒光纤激光器因腔结构的不同,输出激光动态特性也不同;线形腔和环形腔均有自调Q脉冲输出,但线形腔自调Q范围更大。     

High-power continuous-wave operation of quantum-cascade lasers up to 60/spl deg/C

High-temperature high-power continuous-wave (CW) operation of high-reflectivity-coated 12-/spl mu/m-wide quantum-cascade lasers emitting at /spl lambda/ = 6 /spl mu/m with a thick electroplated Au top contact layer is reported for different cavity lengths. For a 3-mm-long laser, the CW optical output powers of 381 mW at 293 K and 22 mW at maximum operating temperature of 333 K (60/spl deg/C) are achieved with threshold current densities of 1.93 and 3.09 kA/cm/sup 2/, respectively. At 298 K, the same cavity gives a maximum wall plug efficiency of 3.17% at 1.07 A. An even higher CW optical output power of 424 mW at 293 K is obtained for a 4-mm-long laser and the device also operates up to 332 K with an output power of 14 mW. Thermal resistance is also analyzed at threshold as a function of cavity length.     

LD抽运的Nd~(3+):YAG-Cr~(4+):YAG组合单晶自调Q激光器的研究

用激光二极管 (LD)连续抽运单体复合型Cr4+∶YAG Nd3 +∶YAG单晶微棒 ,获得重复频率为 10kHz ,脉冲宽度为 10ns的调Q激光输出。输出平均功率为 18mW ,实验结果与理论计算的脉冲宽度和重复频率与抽运功率之间的关系基本相符     

Uniform and high-power characteristics of 780-nm AlGaAs TQW laserdiodes fabricated by large-scale MOCVD

An approach to large-scale fabrication of high-power laser diodes lasing at a wavelength of around 780 nm is described. Heterostructures with AlGaAs triple quantum well (TQW) active layers are grown by using a metalorganic chemical vapor deposition (MOCVD) system which has a capacity of more than 12 2-in φ wafers. Taking the limitations of uniformity and the controllability of the MOCVD growth into account, we have designed the TQW-SCH (separate confinement heterostructure) structure which is suitable for high-power operation. The designed TQW-SCH structures are formed with sufficient controllability by the MOCVD. In the lasers sampled from ten epitaxial wafers grown at one time, the various room temperature characteristics exhibited excellent uniformity. The linear CW light output power versus current characteristics up to 100 mW even at 60°C are uniformly obtained over each epitaxial wafer. In preliminary aging tests at 60°C and 50 mW, a highly stable operation over 500 h has been realized. A maximum CW output power of 170 mW and a fundamental transverse mode up to 100 mW are realized at room temperature. Even at 95°C, a CW light output power of 100 mW is obtained     

Efficient, scalable, internally folded Nd:YAG laser end-pumped bylaser diodes

A scalable diode-pumped Nd:YAG laser is described in which the gain element resembles a penta-prism. This design allows longitudinal pumping along five separate axes. Using five high-power single stripe laser diodes, 4.16 W of absorbed power produced 2.3 W CW at 1.06 μm. The slope efficiency was 56%, the output was plane polarized, and the laser operated in the TEM₀₀ mode. The threshold power, was 48 mW. No evidence of thermal saturation was observed up to the maximum pump power. With an intracavity KTP crystal, 431 mW of CW amplitude-stable output at 532 nm was generated. Repetitive Q-switched operation is also reported     

Laser-diode-pumped Cr:LiSrGaF6 laser

Diode-pumped operation of a Cr:LiSrGaF₆ laser is described. Efficient performance was obtained between 810 and 855 nm. The maximum output power was 130 mW at 810 nm, and the slope efficiency was 26%. The sample was pumped with a total incident power of 560 mW using two polarization-combined high-power visible laser diodes. These results represent the CW power reported for a diode-pumped Cr-doped laser     

二极管激光泵浦的微型绿光调QNd:YVO4激光器

介绍了一种高效率腔内倍频及调QNd:YVO4激光器。激光器的Q开关工作是通过一块腔内KTP晶体实现的,该晶体同时用作倍频晶体,实现类相位匹配。连续工作情况下,在泵浦功率800mW时,得到115mW的绿光输出,光-光转换效率为14.4%。调Q工作时,获得脉宽为5.45ns,峰值功率为74W的脉冲绿光,工作频率为100Hz。     

利用LiNbO_3电光调制器实现宽频带激光输出

利用ＬｉＮｂＯ３电光调制器理论上可以获得宽度达１００ＧＨｚ的宽频带激光输出，并且其输出激光脉冲的宽度和形状都能够由一台电脉冲发生器很方便地进行控制。报道了宽频带激光器的实验结果，利用ＬＤ泵浦的单纵模连续激光器作为光源，可获得峰值功率为４．２ｍＷ，带宽为４２ＧＨｚ的激光脉冲输出。     

Gain switching of waveguide laser based on Nd-doped silica planarlightwave circuit pumped by laser diodes

A gain-switched Nd-doped silica waveguide laser pumped by laser diodes (LDs) was successfully realized. The light from two CW operated and modulated LDs was synthesized and used to investigate gain switching characteristics under various pump conditions. Pulses with a peak power of 1.0 mW and a full width at half maximum of 480 ns were obtained at a repetition rate of 150 kHz. The average modulated pump power was 17 mW and the bias pump power was 35 mW. A gain-switched pulse repetition rate of 25 to 150 kHz was achieved by controlling the pump power of a CW operated and a modulated LD     

全固化可调谐Yb:YAG激光器

实现了半导体激光器抽运的全固化Yb:YAG激光器的可调谐运转,当吸收抽运功率为900mW时,在中心波长1049.5nm处得到66mW的连续激光输出.采用1%的输出耦合镜时单侧抽运阈值为410mW,双侧抽运阈值为380mW,斜率效率为12.7%.对该激光器的可调谐特性进行了详细的研究,得到1030.5～1055.5nm范围内的连续可调谐.同时得到自调Q脉冲序列.     

半导体可饱和吸收镜调Q的Yb∶LSO激光器

报道了一个激光二极管(LD)抽运多波长连续输出的激光器和一个被动调Q的固体激光器。该激光器的增益材料是一种新型掺Yb3 的晶体Yb3 ∶Lu2SiO5(Yb∶LSO)。当吸收的抽运功率为2.57 W时,连续输出的最大功率为490 mW,斜率效率为22.2%,光-光转换效率为14.2%,激光阈值为299 mW,输出激光波长为1084 nm。多波长输出时,波长调谐范围为1034~1085 nm。利用InGaAs可饱和吸收镜实现调Q输出时,斜率效率为3.0%,激光波长为1058 nm。脉冲重复频率为25~39 kHz,重复频率随着抽运功率的增加而增加。     

二硫化钼掺镱光纤激光器连续和调Q实验研究

采用环形腔结构,实现了1063 nm双包层掺镱光纤激光器的连续和调Q运转.光纤激光器连续输出结果表明,在输出透过率和泵浦功率固定时,存在最佳输出光纤长度.在3m最佳光纤长度时,得到平均输出功率270 mW,中心波长1063 nm、斜率效率为21.5％的连续激光输出.采用自制的二硫化钼(MoS2)作为可饱和吸收体(SA)...     

High output power and high temperature operation of 1.5 μmDFB-PPIBH laser diodes

Highly efficient 1.5-μm distributed-feedback (DFB) p-substrate partially-inverted buried heterostructure laser diodes with a thin active layer developed using a metal-organic chemical vapor deposition technique are discussed. An average slope efficiency of 0.26 mW/mA (quantum efficiency 33%) and maximum slope efficiency of 0.39 mW MW/mA (49%) were achieved. The full width at half maximum in the direction perpendicular to the junction plane of 25° was obtained. A high output power of 77 mW was obtained under CW conditions at room temperature. This laser diode lased up to 120°C, and more than 10 mW was obtained, even at 90°C     

LD泵浦Nd:YAG人眼安全波段1.44μm激光器

利用808 nm LD作泵浦源,通过合理的谐振腔镜膜层设计,实现了Nd:YAG的4Fa/2→4I13/2能级跃迁,获得了1.44 μm人眼安全波段激光的连续和脉冲运转.在泵浦功率为1.5 W的条件下,激光器连续运转时,腔内放入布氏片,获得268 mW的稳定TEM00模线偏振激光输出,激光阈值380 mW,斜效率达23.9%,M2因子小于1.3.用新型饱和吸收体V:YAG代替布氏片垂直于光路放置,获得了平均输出功率36 mW,脉冲宽度106 ns,脉冲重复频率52 kHz仍然是线偏振的激光输出,相应脉冲峰值功率和单脉冲能量分别为6.5 W和0.69μJ.     

High-power operation of index-guided inverted channel substrate planar (ICSP) lasers

An easily fabricated high-power index-guided laser, the inverted channel substrate planar (ICSP) structure, has been developed using the two-step metal-organic chemical vapour deposition (MOCVD) technique. Linear output power characteristics were observed to 30 mW CW on submount with junction side up without facet coatings. The device operated in a stable single mode to a power >25 mW. Improved ICSP lasers with facet coatings demonstrate a stable high output power of 65 mW CW and a differential quantum efficiency of 60%.     

高频大功率InGaAsP/InP SPB-BC激光器

在普通掩埋新月型激光器的基础上,提出了一种高频大功率的InGaAsP/InP激光器结构——选择性质子轰击掩埋新月型(SPB-BC),并对激光器结构模型进行了理论分析。采用p-InP衬底,最大输出功率为80mW。500μm腔长激光器,它的调制带宽可以达到6.0GHz。     

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     

High-power single-mode 2.0 μm laser diodes

Data are presented on high-power single-mode index-guided laser diodes fabricated from a strained-layer InGaAs-InGaAsP double quantum well heterostructure epitaxial design. The total maximum power and external efficiency achieved are 50 mW and 43%, respectively. The far-field is measured to be 31° by 46° in the parallel and perpendicular directions, yielding an aspect ratio of 1.5 for the single-mode laser diode. The optical output of the laser diode is a multi-longitudinal mode spectrum spanning 1.98-2.00 μm at an output power of 50 mW CW. The characteristic temperature of the laser diode is 48 K     

A single frequency Nd:YAG ring laser pumped by laser diodes

The design and operation of a diode-pumped Nd:YAG ring laser is described. The laser is shown to be a highly versatile device, capable of efficient generation of both the fundamental and second harmonic frequencies, CW and Q-switched. Single-frequency outputs in excess of 540 mW at 1.06 μm and 18.9 mW at 532 nm output were obtained, whereas multi-longitudinal mode Q-switched operation produced 22.4 μJ per pulse at 5 kHz in the fundamental and 7.3 μJ power pulse at 532 nm     

被动调Q锁模掺镱光纤激光器

报道了基于偏振旋转技术等效快可饱和吸收体的被动调Q锁模光纤激光器,采用976 nm半导体激光器作为抽运源,高掺杂浓度的Yb3 光纤作为增益介质构成环形腔,通过调节抽运光功率和偏振控制器的角度得到了调Q,调Q锁模与锁模三种稳定的输出脉冲。获得的锁模脉冲中心波长为1.05μm,重复频率为20 MHz,脉冲光谱宽度为13.8 nm,抽运功率为270 mW时,锁模平均输出功率为15.82 mW;调Q频率为17.54 kHz,调Q脉冲宽度为8μs,光谱宽度为4.7 nm;调Q锁模中调Q重复频率为300 kHz。