连续Nd~(3 ):YAG激光对视网膜损伤阈值的研究

连续Nd~(3 ):YAG激光照射青紫蓝灰兔眼100只,1000个照射点,求得照射时间平均1.02s及0.12s,检眼镜可见视网膜损伤阈值,其ED_(50)分别为角膜平均入射2.52W/cm~2及5.42W/cm~2.     

环形腔YAG:Nd~(3 )激光器

在带有附加反馈镜的YAG:Nd~(3 )环形腔中,得到了定向比为30的单向输出。谱线宽度较之驻波腔压缩了十倍,输出功率并不降低。对其振荡时间特性提出了新的见解。     

1.3188微米和1.3382微米钇铝石榴石连续激光器

报导了1.3188微米和1.3382微米钇铝石榴石连续激光的阈值、输出功率和激光谱。并且用LiNbO_3倍频出6690孟和6590且红光。     

Thermal effects of a continuously pumped Nd3+:YAG laser

Thermal effects in a Nd:YAG laser rod, which is pumped continuously by tungsten iodine lamps, are described. Measurements using a 0.6328-μman probe beam yielded temperature distribution in and at the boundary of the rod. The results of birefringence and focal length are consistent with theoretical treatments, if an effective heat conversion coefficient peculiar to the apparatus is assumed. The resonance condition of an optical resonator containing a rod exhibiting focusing effect is discussed.     

Carrier-frequency-controlled gigabit pulse generation with a Nd3+: YAG laser

Optical pulses up to 1.25 Gbit/s were obtained with a Nd³⁺:YAG laser by multiple mode locking. The carrier frequency of mode-locked pulses was tuned through several tens of gigahertz by tilting an intracavity tuning etalon. Some detuning effects in forced mode locking will be also presented.     

1.05-1.44 µm tunability and performance of the CW Nd3+:YAG laser

The Nd³⁺:YAG laser pumped by a CW 5-kW krypton arc-lamp was tuned to 19 different transitions from 1.052 to 1.444 μm by means of intracavity thin solid etalons and appropriately coated resonator mirrors. Each transition was tunable over 6-12 wavenumbers and most exhibited 10-30-W CW output, attaining 37 W at 1.319 μm and 52 W at 1.112 μm. The 1.061-μm line is 90 percent as strong as at 1.064 μm, and wavelength shift with temperature variation was measured for both. TEM00output of 20 W was available by using apertures, and compensation of thermal lensing resulted in 60 W combined TEM00+ TEM01output.     

双掺(Ce~(3+)、Nd~(3+)):YAG晶体对撞脉冲锁模的研究

一、引 言 新晶体双掺(Ce~(3+)、Nd~(3+)):YAG是一种具有高转换效率的激光增益介质~[1],它利用Ce~(3+)、Nd~(3+)的敏化途径提高激光效率。晶体中的Ce~(3+)离予通过辐射和非辐射二种方式向Nd~（3+）转     

Self-Q-switched Nd3+: YAG and ruby lasers

Self-Q-switched operation of Nd³⁺: YAG lasers at 77°K and ruby lasers at 300 and 77°K pumped by the 5145-Å output of a pulsed argon ion laser is described. Self-Q-switched operation was obtained 1) by static mirror misalignment and 2) by static misalignment of the filament of the pumped laser material with respect to the mirror resonator axis. An output that consisted of a single giant pulse could be obtained for ruby by either method; for Nd³⁺: YAG, the output always consisted of one or more giant pulses and characteristic relaxation oscillations.     

用于显微光谱分析的光再生电光调Q Nd~(3 ):YAG激光器

将不稳定光学谐振腔光再生电光调Q Nd~(3 ):YAG激光器用于显微光谱分析。使激光稳定性在自由振荡情况下相对均方误差达0.92％,调Q时<5％,取样直径5～450微米,对样品的适应性和可靠性有较大提高。     

Parasitic noise on the output of a CW YAG:Nd+3laser

An experimental investigation was conducted to reduce the parasitic noise appearing on the output of a 6-W CW YAG:Nd⁺³laser. Initially, low-frequency fluctuations as high as 30 percent and relaxation oscillation bursts exceeding 80 percent of the CW power level were present. Low-frequency modulation was reduced by the addition of an active feedback loop to control lamp current. Relaxation oscillations were determined to be influenced by laser rod cooling, pump-lamp aging, vibration, and intracavity optical interface quality. At the conclusion of the program, low-power fluctuations and relaxation oscillation excursions did not exceed 2 percent.     

Separation of mode-locked states in the intracavity phase-modulated Nd3+:YAG laser

It has been observed that the frequency difference between the two modes for the mode-locked Nd³⁺:YAG laser by synchronous internal phase modulation depends on the pumping power and is several hundreds of kilohertz for a realistic pumping power. By finely tuning the mode-locking frequency, the two modes can be excited separately.     

Efficient integrated Nd3+ fiber laser

An efficient, integrated, low-threshold, tunable, laser-diode pumped Nd³⁺ fiber laser has been fabricated. The integrated fiber laser incorporated two highly reflecting intracore Bragg reflectors, which were formed holographically by transversely exposing the core to a UV two-beam interference pattern. When the fiber laser was diode pumped, a maximum output of 2.3 mW was observed at 1.088 μm, and a slope efficiency of 41% was measured     

Cr3+→Nd3+ energy transfer and Nd3+ laser action studies of La3Ga5SiO14:Cr3+,Nd3+ co-doped crystal

Energy transfer between Cr³⁺ and Nd³⁺ ions has been investigated in the 4.2-300-K temperature range by using steady-state and site-selective time-resolved laser spectroscopy. Radiative and nonradiative energy transfer has been studied from the time-resolved emission spectra and the donor fluorescence decays. The transfer efficiency was calculated as a function of temperature by using the Cr³⁺ lifetimes of the single doped and co-doped samples. Laser experiments were carried out in a diffusive cavity by pumping a co-doped rod 54 mm long and 5 mm in diameter with xenon flashlamps. The laser spectral emission shows a complex structure which varies as a function of pump energy. The temporal evolution of the laser spectrum is discussed in terms of a simple four-level spectral rate-equation laser model which takes into account the existence of two main broad Nd³⁺ site distributions with a large spectral overlap     

高稳定1.3414μmTEM_(00)模Nd~(3+):YAP连续激光器

分析研究了1.3414μm Nd~(3+):YAP连续激光器波动的原因,探索了抑制波动的技术,研制成功高稳定 1.3414μm TEM_(00)模激光器.激光输出功率5.3W,在0～25kH_z频率范围内波动 ≤±O.87%,未观察到由弛豫振荡引起的尖峰,激光接近线偏振光.     

FTIR-Q开关的YAG:Nd~(3 )激光器巨脉冲特性的研究

根据速率方程,解出了FTIR-Q开关下YAG:Nd~(3 )的激光输出特性。给出了FTIR-Q     

Polarization states of a single-mode (microchip)Nd3+:YAG laser. I. Theory

We present a microscopic mathematical model for the polarization states of a single-frequency Nd³⁺:YAG laser. It is a plane wave, mean field, vector model carried to all orders in the laser field. The crystal is assumed to be optically pumped longitudinally with a laser of specified polarization. For D₂ site symmetry and an odd number of electrons, we establish the phase relationships between the components of the electric dipole matrix elements between the Kramers states. These relationships are central in determining the site-specific coupling between both, the pump and laser fields to the Nd ³⁺ ions. The laser cavity is assumed to be linear and quasi-isotropic. The residual optical anisotropies are included using a round-trip Jones matrix formalism     

Pump-power-dependent efficiency in a YAG: Nd3+laser

The efficiency of a YAG: Nd³⁺-laser and the influence of pump-power level and of spectral filtering the pump light was studied. The laser was pulsed high above threshold. Without filtering the pump light, the maximum laser emission was reached 30 μs before the maximum pump power. With filtered pump light, the efficiency is doubled and the laser emission roughly follows the pump power. Dynamic input-output characteristics show an efficiency minimum at the pump-power maximum.     

Output properties of the Nd+3:SeOCl2liquid laser

Laser action in the liquid medium Nd⁺³: SeOCl2is described. Details concerning the cell construction and the dependence of output on cell geometry and optical feedback are presented. Output energies of 13 joules with a differential efficiency of 1 percent are reported. An interpretation is offered for the phenomenon of self-Q-switching or the generation of multimegawatt spikes at low values of optical feedback.     

高稳定主被动锁模重复率Nd~(3 ):YAG激光器

本文介绍的是利用可饱和吸收体五甲川与100兆赫驻波型声光调制器联合运行的主被动锁模重复率Nd~(3 ):YAG激光器。在正常运转的情况下,它是借助于声光调制“窗口”有效地克服“尖峰”群的随机竞争,从而获得既稳又窄的光脉冲输出的。 通过下列途径和措施增强了稳定性和多功能性: 1.采用频率合成式高频大功率声光驱动源,有效地克服因环境温度变化、介质加工精度等因素造成的声光街射效率下降和消失的特点。 2.采用机械组合式的一体化染料盒,有效地克服籽腔振荡。