飞秒激光直写Nd:YVO4晶体包层波导激光

采用飞秒激光(500 kHz重复频率)直写技术,在Nd:YVO4晶体中制备了埋藏晶体表面以下的包层光波导.具体研究了脉冲能量、深度、扫描速度和飞秒激光偏振等写入条件对光波导性能的影响.1.06μm波长的激光在光波导中传播时,光波导的插入损耗低至2.4 dB.利用808 nm波长的激光泵浦,在室温下实现了1064 nm波长发射的连续波导激光器.对不同直径的光波导,均实现了多模光波导和波导激光.直径为60μm的波导产生的最大输出功率为143 mW,斜率效率为21.3%.利用微拉曼光谱对光波导进行了表征,激光直写轨迹处晶格被破坏,伴随折射率降低.

High power diode-pumped passively mode-locked Nd:YVO_4 laser at repetition rate of 3.2 GHz

A compact high power diode-pumped passively mode-locked Nd:YVO_4 laser with high repetition rate is realized.Using an Nd:YVO_4 crystal and a semiconductor saturable absorber mirror(SESAM) in the oscillator, the picosecond pulse output with an average power of 1.38 W, a repetition rate of 3.24 GHz, and a pulse duration of 11.4 ps is achieved. After one stage of amplification, the final output power reaches 11.34 W, corresponding to a total optical-to-optical efficiency of about 32%. The root mean square(RMS) value of power fluctuation is demonstrated to be less than 0.6% in 24 hours,showing a superior stability with the compact configuration.

The thermal effect in diode-end-pumped continuous-wave 914-nm Nd:YVO_4 laser

The thermal effect and the heat generation in diode-end-pumped continuous-wave 914-nm Nd：YVO4 lasers are investigated in detail. A theoretical model of a diode end-pumped solid-state laser is constructed to analyse the influence of fractional thermal loading on the thermal effect in the Nd：YVO4 laser based on finite element analysis. The thermal focal lengths and the end-surface deformations of laser rods in Nd：YVO4 quasi-three-level and four-level lasers are measured and compared with the results obtained by ordinary interferometry for the demonstration of higher thermal loading in 914-nm laser. Finally the fractional thermal loading in the Nd：YVO4 quasi-three-level laser is calculated by matching the experimental and the simulated end deformations.

A 200 kHz Q-Switched Adhesive-Free Bond Composite Nd:YVO4 Laser using a Double-Crystal RTP Electro-optic Modulator

A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-switch.At the repetition rate of 200kHz,the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65ns are achieved at an incident pump power of 27 W,corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%,respectively.To the best of our knowledge,this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.

Efficient and high-power laser-diode single-end-pumped Nd：YVO4 continuous wave laser at 1342nm

A compact, efficient and high-power laser diode （LD） single-end-pumped Nd：YVO4 laser with continuous-wave emission at 1342 nm is reported. With a single crystal single-end-pumped by fibre-coupled LD array, an output power of 7.36W is obtained from the laser cavity of concave-convex shape, corresponding to an optical-to-optical efficiency of 32.8%. The laser is operated in TEM00 mode with small rms amplitude noise of 0.3%. The influences of the Nd concentration, transmissivity of the output mirror and the cavity length on the output power have been studied experimentally.

Laser-Diode End-Pumped Nd：YVO4 Slab Laser under Direct Pumping into the Emitting Level

我们在场一根 880-nm 激光二极管部分抽结束的 Nd : 有由使用一个混合共鸣器的输出 126.7 W 的 YVO4 平板 cw 激光。关于抽力量吸收的 slop 效率和 optical-to-optical 效率分别地是 73.2% 和 58.7% 。在 100 W 的产量力量，横梁繁殖 M2 因素在不稳定的方向是 1.1 并且 1.15 在稳定的方向。

Efficient Nd:YVO4 laser in-band pumped by wavelength-locked 913.9-nm laser diode and Q-switch operation

An efficient 1064-nm Nd：YVO_4laser in-band pumped by a wavelength-locked laser diode（LD） at 913.9 nm was demonstrated. The maximum continuous wave（CW） output power of 23.4 W at 1064 nm was realized with the incident pump power of 40 W, corresponding to a total optical-to-optical efficiency of 58.5%. This is to the best of our knowledge the highest total optical-to-optical efficiency and output power of Nd：YVO_4laser in-band pumped by a 913.9-nm laser diode.The Q-switched operation of this laser was also investigated. Through a contrast experiment of pumping at 808 nm, the experimental results showed that an Nd：YVO_4laser in-band pumped by a wavelength-locked LD at 913.9 nm had excellent pulse stability and beam quality for high repetition rate Q-switching operation.

Efficient Mode-locked and Q-switched Nd∶YVO_4 Laser with Semiconductor Saturable Absorber Mirror

We reported an efficient diode pumped Nd∶YVO4 1 064 nm laser passively mode-locked and Q-switched by a semiconductor saturable absorber mirror(SESAM). At the incident pump power of 7.5 W, 2.81 W average output power was obtained during stable CW mode locking with a repetition rate of 111 MHz. The optical conversion efficiency was 37.5%, and the slope efficiency was 39%. So far as we know, this is the highest optical-optical conversion efficiency with a SESAM at home.

A Stable 22-W Low-Noise Continuous-Wave Single-Frequency Nd:YVO_(4) Laser at 1.06 μm Directly Pumped by a Laser Diode

We report a low-noise continous-wave single-frequency Nd:YVO4 laser at 1.06μm directly pumped by an 880-nm laser diode.A maximum output power of 22 W is achieved with an optical-to-optical conversion efficiency of 46.3%.The stability of the output is better than ±0.7% in the given four hours.The output beam is almost diffraction-Iimited with a measured beam quality of M^(2)_(x) =1.05 and M^(2)_(y) =1.02.The intensity noise and the phase noise of the laser reach the shot-noise limit at an analysis frequency of 5 MHz.

Passively Q-Switched Nd:YVO_4 Laser Using a Gold Nanotriangle Saturable Absorber

A passively Q-switched Nd：YVO4 laser at 1064 nm is demonstrated based on a gold nanotriangle saturable absorber（GNT SA）.Under a pump power of 3.82 W,the maximum average output power of 218mW is achieved,corresponding to a slope efficiency of 12.9%.The minimum pulse width is 165ns and the maximum pulse repetition rate is 300kHz at the pump power of 3.48 W.Our results prove that the GNT SA is a promising saturable absorber for near-infrared lasers.

A Single-Longitudinal-Mode Passively Q-Switched Nd:YVO4 Laser Using Black Phosphorus Saturable Absorber

A black phosphorus (BP) saturable absorber (SA) solution with different concentrations (1.0 and 0.5 mg/ml) is fabricated with the liquid-phase exfoliation method. By using the BP-SA, a compact diode-pumped passively Q-switched Nd:YVO4 laser is demonstrated. One reflecting Bragg gratings is used as the output coupler for mode selection. By inserting those BP-SA solutions in the laser cavity, the maximum single longitude mode, Q-switched output powers of 126mW at 692.5 kHz and 149mW at 630.3 kHz are achieved at the pump power of 8.0 W, corresponding to the pulse durations of 144 ns and 196 ns, respectively. Moreover, longitudinal-mode characteristics of Q-switched output laser in different optical cavity lengths based on two-kind BP-SA solution concentrations are investigated. Our results show that BP-SA could also be developed as an effective SA for the Q-switched, single longitudinal mode pulse laser.

Efficient Diode-Pumped Actively Q-Switched Ceramic Nd:YAG/YVO4 Raman Laser Operating at 1657 nm

A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved. A maximum output power of as high as 612mW is obtained under a pump power of 20. 7 W and at a pulse repetition frequency rate of 20kHz, corresponding to an optical-to-optical conversion efficiency of 3%.

A novel orthogonally linearly polarized Nd:YVO_4 laser

We presented a novel orthogonally linearly polarized Nd：YVO4 laser. Two pieces of a-cut grown-together composite YVO4/Nd：YVO4 crystals were placed in the resonant cavity with the c-axis of the two crystals orthogonally. The polarization and power performance of the orthogonally polarized laser were investigated. A 26.2-W orthogonally linearly polarized laser was obtained. The power ratio between the two orthogonally polarized lasers was varied with the pump power caused by the polarized mode coupling. The longitudinal modes competition and the corresponding variable optical beats were also observed from the orthogonally polarized laser. We also adjusted the crystals with their c-axis parallele to each other, and a 40.7-W linearly polarized TEM00 laser was obtained, and the beam quality factors were Mx^2 = 1.37 and My^2 = 1.25.

The 5.2 kW Nd：YAG Slab Amplifier Chain Seeded by Nd：YVO4 Innoslab Laser

A high power Nd：YAG end-pumped slab amplifier chain with a Nd：YVO4 innoslab laser as the master oscillator is demonstrated. A chain output power of 5210 W with beam quality of 4 times the diffraction limit is achieved by double-passing the first amplifier stage and single-passing the second stage with an optical efficiency of 29% while working at a frequency of 1kHz and pulse width of 200 μs.

High-power and high optical conversion efficiency diode-end-pumped laser with multi-segmented Nd：YAG/Nd：YVO-4

A novel flat-flat resonator consisting of two crystals（Nd：YAG ＋ Nd：YVO4） is established for power scaling in a diode-end-pumped solid-state laser. We systematically compare laser characteristics between multi-segmented（Nd：YAG ＋ Nd：YVO4） and conventional composite（Nd：YAG ＋ Nd：YAG） crystals to demonstrate the feasibility of spectral line matching for output power scale-up in end-pumped lasers. A maximum continuous-wave output power of 79.2 W is reported at 1064 nm, with Mx2= 4.82, My2= 5.48, and a pumping power of 136 W in the multi-segmented crystals（Nd：YAG ＋ Nd：YVO4）. Compared to conventional composite crystals（Nd：YAG ＋ Nd：YAG）, the optical-optical conversion efficiency of multi-segmented crystals（Nd：YAG ＋ Nd：YVO4） from 808 nm to 1064 nm is enhanced from 30% to 58.8%,while the laser output sensitivity as affected by the diode-laser temperature is reduced from 55% to 9%.

High-Repetition-Rate and High-Beam-Quality Laser Pulses with 1.5 MW Peak Power Generation from a Two-Stage Nd:YVO4 Amplifier

We develop a two-stage end-pumped Nd:YVO4 amplifier seeded by a passively Q-switched microchip laser. An average output power of 13.5 W with repetition rate up to 7 kHz and pulse duration of ~1.24 ns is obtained,corresponding to a pump extraction efficiency of 16.1%(19.5% for the second stage) and peak power of ~1.5 MW.The beam quality factors at maximum output power are measured to be Mx2= 1.56 and My2= 1.48. We introduce an analytical model to estimate gain and beam quality after amplification. This model focuses on the influence of ratio of seed spot radius to pump spot radius when designing an amplifier. Moreover, our experiments reveal that the re-imaging system in the double-pass configuration can be used to enhance the beam quality.

Simulation of Patterns and Qualitative Analysis of Pattern Rotation in an End-Pumped Nd：YVO4 Laser

我们模仿在我们采用 Laguerre-Gaussian 模式的重叠的以前的实验观察的一些激光产量模式。旋转模式是从放射激光的水晶的当代的空间燃烧洞效果的点分析的品质上。

Comparison between Two Kinds of Semiconductor Absorbers for Mode-Locking in Nd：YVO4 Laser

我们示威了被动在 diode-end-pumped Nd 锁模式:用区域其松驰来自在低温度(副)和 GaAs/air 接口种的 In0.25Ga0.75As 的二种半导体吸收器的 YVO4 激光分别地锁模式用 theGaAs/air 接口松驰区域的吸收器，用副 In0.25Ga0.75As 松驰区域的吸收器比那有更少的 切换Q 趋势和更高平均的产量力量的特征，但是不象后者一样稳定。

Diode-end-pumped Nd:YVO_4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave(CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd:YVO4 and using LBO as the intra-cavity SHG crystal.With the optimization of laser cavity and crystal parameters,the laser operates at a very high efficiency.When the pumping power is about 31 W,the output at 457 nm reaches 4.2 W,and the optical to optical conversion efficiency is about 13.5% accordingly.The stability of the output power is better than 1.2% for 8 h continuously working.

Laser Diode Pumped 1342 nm Nd：YVO4 Slab Laser with a Compact Hybrid Resonator

880-nm 激光二极管栈抽结束的 cw 1342nm Nd : 有一个紧缩的积极共焦的不稳定马厩的混合共鸣器的 YVO4 平板激光被表明。在 115 W 的吸收的泵力量，产量力量 32.4 W 被获得。斜坡效率和 optical-to-optical 变换效率分别地是 42% 和 28.2% 。在 22 W 的产量力量，稳定的方向 M2 是 1.3，不稳定的方向 M2 是 1.2。[从作者抽象]