Highly efficient 2 μm Tm:YAG ceramic laser

We have experimentally demonstrated a highly efficient diode-pumped Tm:YAG ceramic laser operating at 2 μm wavelength. The maximum output power of 6.05 W was realized with a slope efficiency as high as 65%. As far as we know, it is the highest slope efficiency reported for Tm:YAG ceramic laser. The wavelength tuning experiment of Tm:YAG ceramic laser was carried out and the results suggest that Tm:YAG ceramic laser could operate simultaneously at multiple wavelengths in a wide range of 1884-2017 nm.     

高重频2.94 μm Er:YAG激光器的研究

分析了Er3+离子的能级结构特性和Er:YAG四能级系统的激光速率方程。采用了双灯,双椭圆腔和窄脉冲放电等方式提高了抽运效率; 通过提高激光谐振腔的反射率,降低阈值,从而实现了输出2.94 μm的高重频窄脉冲激光; 采用高压高速层流冷却技术降低了热效应的影响。Er3+:YAG激光器的重复频率为40 Hz,单脉冲输出能量为0.5 J,满足实际应用需要。     

A 1.54 μm Er glass laser pumped by a 1.064 μm Nd:YAG laser

Laser oscillation in Er-glass, co-doped with Yb sensitiser, has been achieved by pumping with the 1.064 μm output of a Nd:YAG laser.     

Experimental investigation of pulse diodes side-pumped 2 μm Tm:YAG lasers

The free running and Q-switched operation of 2 μm Tm:YAG lasers side-pumped by pulse laser diodes were reported. In the free running mode the maximum output energies were 102.5 mJ at 1 Hz and 94.6 mJ at 10 Hz, respectively. With an acousto-optic modulator in the laser resonator, 21 mJ 2 μm Q-switched pulse was obtained, with a pulse width of about 330 ns. The dependences of the output energy and the efficiency on the laser resonator parameters were investigated.     

2.94 μm Er:YAG激光热效应数值模拟及实验研究

理论分析了Er:YAG激光晶体的热退偏效应,模拟计算了该晶体棒端面退偏的分布,并进行了偏光干涉实验验证。结果表明,数值模拟和实验结果完全一致,热退偏效应随抽运能量增大而增强,退偏分布呈十字形,最大退偏发生在晶体棒端面上与起偏器偏振方向成45°方位处。同时,还阐明了一种利用临界稳定腔来测量灯抽运脉冲Er:YAG激光器有效热透镜焦距的简单方法,测量出不同抽运功率下Er:YAG晶体的等效热焦距。     

High-peak-power passively Q-switched 1.3 μm Nd:YAG/V~(3+):YAG laser pumped by a pulsed laser diode

We demonstrate a high-pulse-energy, short-pulse-width passively Q-switched(PQS) Nd:YAG∕V3t:YAG laser at 1.3 μm, which is end-pumped by a pulsed laser diode. During the PQS regime, a maximum total output pulse energy of 3.3 m J is obtained under an absorbed pump pulse energy of 21.9 m J. Up to 400 μJ single-pulse energy is realized with the shortest pulse width of 6.16 ns and a pulse repetition frequency of 34.1 k Hz,corresponding to a peak power of 64.9 k W. The high-energy laser pulse is operated in the dual wavelengths of 1319 and 1338 nm, which is a potential laser source for THz generation.     

端面抽运Nd∶YAG陶瓷1.83 μm激光

报道了基于Nd∶YAG透明陶瓷4F3/2-4I15/2跃迁实现1.83 m激光输出的研究。采用简单紧凑的平凹腔结构,结合对腔镜镀膜参数的设计,控制其他能级跃迁谱线对应波长激光的透射损耗来抑制较强能级跃迁对应的激光振荡。在入射抽运功率14.6 W的808 nm波长半导体激光端面抽运Nd∶YAG透明陶瓷,获得了0.65 W的1.83 m激光输出,斜率效率5.8%。可见Nd∶YAG透明陶瓷可望成为获得1.8 m波段激光直接输出的激光介质。     

Efficient Tm：YAG Ceramic Laser at 2 μm

We demonstrate a high-efficiency continuous-wave Tm： YAG ceramic laser pumped with a Ti：sapphire laser. An output power up to 860mW is obtained under an absorbed pump power of 2.21 W at 785nm, corresponding to a slope efficiency of 42.1% and optical to optical efficiency of 22%. The measured central wavelength is 2012nm.     

1. 32μm Nd~(3 ): YAG Pulse Laser

Using specially coated mirrors, an output energy of 0.97 J at 1.32 μm from a Nd3 : YAG pulse laser is obtained with pumping energy of 66 J. The repetition rate is 1 pulse/sec and the slope efficiency is 1.7%. The repetition rate can be changed from 1 pulse/sec to 10 pulses/sec.     

Passively Q-switched and mode-locked 1.3 μm Nd:YAG laser with Co:LMA saturable absorber

An xenon-lamp-pumped passively Q-switched and mode-locked (QML) Nd:YAG laser with Co:LMA saturable absorber at 1.3 μm is realized in a straight cavity. The modulation depth of mode locking pulse has reached 100%. The pulse energy and the pulse width of QML laser have been measured. The pulse width of the mode-locking laser is estamated to be 940 ps.     

透0.45 μm～1.6 μm反8 μm～12 μm宽光谱分色滤光片的制备

光谱分色滤光片对成像光谱技术至关重要,是实现光电仪器体积小、质量轻的一个重要器件.根据金属膜具有高反射率的特点和可以进行诱增透的原理,介绍了透0.45 μm～1.6 μm反8 μm～12 μm光谱分色滤光片的膜料选择和膜系设计,并应用JGP560A2型磁控溅射镀膜机制备出了光谱性能和理化性能较好的宽光谱分色滤光片,其光谱性能达到0.45 μm～1.6 μm波段范围内,平均透过率大于80%;8 μm～12 μm波段范围内,平均反射率大于91%.     

2 μm single-frequency Tm:YAG laser generated from a diode-pumped L-shaped twisted mode cavity

A 2 μm single-frequency Tm:YAG laser was developed by using a diode pumped L-shaped twisted-mode-cavity. By suppressing the spatial hole-burning, the 2 μm single-frequency laser was obtained, with the output power of 1.46 W and the slope efficiency of 19.2%.     

Single-frequency distributed Bragg reflector Tm:YAG ceramic derived all-glass fiber laser at 1.95 μm

A 135 mW single-frequency distributed Bragg reflector fiber laser at 1.95 μm was obtained based on a Tm:YAG ceramic-derived all-glass fiber. The fiber laser achieved an optical signal-to-noise ratio of ～ 77 dB. Moreover, the threshold and linewidth of the single-frequency laser were measured to be 15.4 mW and 4.5 kHz, respectively. In addition, the measured relative intensity noise was less than -140 dB· Hz^-1 at frequencies of over 10 MHz. The results show that the as-drawn Tm:YAG ceramic-derived all-glass fiber is highly promising for ～ 2 μm single-frequency fiber laser applications.     

Efficient stable simultaneous CW dual-wavelength diode-end-pumped Nd:YAG laser operating at 1.319 and 1.338 μm

Efficient, simple, and compact laser sources of simulta-neous emissions at multiple wavelengths have shown lotsof application foregrounds in many fields, such as opti-cal communication, photodynamic therapy (PDT), opti-cal calculation, military interaction, environmental mon-itory, laser remote sensing, laser radar, spectroanalysis,medical instrumentation, and scientific research on non-linear optical mixers[1]. In addition, it can also be usedas a pump source of Terahertz-wave generated by n…     

High-energy PPMgLN optical parametric oscillator pumped by a 1.064 μm E-O Q-Switched Nd:YAG laser

A high-energy PPMgLN optical parametric oscillator (OPO) pumped by a E-O Q-switched Nd:YAG laser working at 1.064 μm was successfully illustrated. A maximum output pulse energy of 3.4 mJ was obtained with a pump threshold of 1.5 mJ and a slope efficiency of 30% around room temperature. The OPO output signal and idler wavelength were 1552 and 3384 nm, respectively. The damage to the input surface of PPMgLN crystal was carefully observed with a damage threshold of 4.6 J/cm².     

High peak power 1.0 μm and tri-wavelength 1.3 μm Nd:ScYSiO_5 crystal lasers

With a Nd:ScYSiO_5 crystal, a high peak power electro-optically Q-switched 1.0 μm laser and tri-wavelength laser operations at the 1.3 μm band are both investigated. With a rubidium titanyle phosphate(RTP) electro-optical switcher and a polarization beam splitter, a high signal-to-noise ratio 1.0 μm laser is obtained, generating a shortest pulse width of 30 ns, a highest pulse energy of 0.765 mJ, and a maximum peak power of 25.5 kW,respectively. The laser mode at the highest laser energy level is the TEM200 mode with the Mvalue in the X and Y directions to be M_x~2= 1.52 and M_y~2= 1.54. A tri-wavelength Nd:ScYSiO_5 crystal laser at 1.3 μm is also investigated. A maximum tri-wavelength output power is 1.03 W under the absorbed pump power of7 W, corresponding to a slope efficiency of 14.8%. The properties of the output wavelength are fully studied under different absorbed pump power.     

Efficient all-solid-state mid-infrared optical parametric oscillator based on resonantly pumped 1.645 μm Er:YAG laser

We first report an all-solid-state tunable mid-infrared singly resonant optical parametric oscillator based on a 1532 nm laser diode resonantly pumped, Q-switched 1.645 μm Er:YAG laser. An MgO-doped periodically poled lithium niobate was used as the nonlinear material. At the pulse repetition frequency of 2 KHz, a maximum overall average output power of 0.95 W with pump power of 2.8 W was achieved, corresponding to a conversion efficiency of 34% and a slope efficiency of 38%. The temperature tuning was performed giving signal and idler ranges of 2.67 to 2.71 μm and 4.18 to 4.31 μm, respectively.     

Short-term and long-term frequency characteristics of 2 μm single frequency Tm:YAG laser at room temperature

Placing one 0.1 mm YAG F-P etalon at nearly Brewster angle and combined use 1 mm fused silica in the cavity, a diode-pumped linear-polarized single-longitudinal-mode (SLM) Tm:YAG laser operating at 2 μm is achieved. This paper is focused on the stability of the linear-polarized SLM laser, including power stability, long-term frequency stability and short-term frequency stability. And the factors affecting the frequency characteristics of laser were also analyzed. The instability of the linear-polarization SLM laser is less than 1%. The long-term frequency stability is in the range from 1.16 × 10⁻⁷ to 1.75 × 10⁻⁷ monitored by the wave meter. And the short-term frequency stability is 97 Hz/μs measured with the self-beating heterodyne detection method.     

Nd∶YAG晶体1.064 μm受激发射截面随温度变化特性研究

测量了Nd∶YAG晶体从-70℃到+80℃不同温度下的荧光发射光谱和荧光寿命,计算了该晶体在不同温度下1.064 μm受激发射截面,首次获得在此温度变化范围内受激发射截面随温度的线性变化关系.     

Ti:sapphire Regenerative Amplifier at 1.056 μm

The design and performance of a Ti:sapphire regenerative amplifier operating at 1. 056 μm are described. A laser pulse with an initial pulsewidth of 100 fs is amplified to ≥1.5 mJ in the amplifier after firstly stretched to 850 ps. The amplified pulse can be re-compressed to ～300 fs with energy of ～1 mJ. Loss of the spectrum happens in the regenerative cavity since bandwidth of the coat of optics in the cavity is not enough adequate.