Compact oscillator-amplifier XeCl laser with high brightness

In this work we present the behavior of a very compact XeCl laser system.Itconsists of an oscillator and an amplifier,both with lateral UV-preionization.Both dischargeelectrodes are contained in a single vessel.An unstable optical cavity is applied to the oscilla-tor.An output beam of 105 mJ,with a brightness of 5.5× 10~(l3)Wcm~(-2)Sr~(-1) and with a diver-gence of 0.9 mrad has been obtained.     

A simple and reliable short-pulse dye laser

A simple technique is described that allows the generation of a short pulses (1 ns) from dye lasers pumped by a much longer (7 ns) N₂-laser pulse. Dye-laser pulses, either with a narrow bandwidth or a short duration, can thus be obtained with the same N₂-laser pump.     

高重复频率XeCl准分子激光器

本文报道一台高重复频率XeC准分子激光器的结构及其特性。采用接地栅金属陶瓷闸流管开关和气体横向流动系统及自动紫外火花预电离的放电结构。该激光器最高单脉冲能量为200mJ,最高重复脉冲频率为107Hz,最大平均功率18W。     

High brightness operation of a XeCl laser with negative branch unstable resonators

Confocal and non-confocal negative branch unstable resonators with an intracavity spatial filter have been applied to a high-gain short-pulse UV preionized XeCl laser. The near- and far-field radiation characteristics have been investigated in both configurations. Laser beams of larger brightness have been obtained with non-confocal schemes. A maximum beam brightness of 1.3×10¹⁴ Wcm^–2Sr^–1 has been achieved.     

A high spectral brightness Fourier-transform limited nanosecond Yb-doped fiber amplifier

In this paper, we present a frequency-doubled pulsed Yb-doped fiber amplifier exhibiting Fourier-transform limited 10-ns pulses at a repetition rate of up to 5 kHz. The amplifier is seeded by an external cavity diode laser whose output is chopped into light pulses of 10- to 1200-ns duration. The first stage is operated with a single-mode fiber, while the other two stages employ multi-mode double clad fibers. Output energies of up to 516 μJ per pulse have been recorded. The output power is limited by the onset of stimulated Brillouin scattering. As an example of the possible applications, we demonstrate the temperature measurement of water by Brillouin scattering employing the frequency-doubled radiation from the amplifier.     

Continuously tunable, high-power, single-mode radiation from a short-pulse free-electron laser

This paper gives the first demonstration of high-power, continuously tunable, narrowband radiation that is produced by means of a free-electron laser (FEL) in the far-infrared region of the electromagnetic spectrum. A Fox-Smith intracavity étalon was used to induce phase coherence between the 40 optical micropulses that were circulating in the laser cavity. The corresponding phase-locked spectrum consisted of a comb of discrete frequencies separated by 1 GHz. A pair of external Fabry-Pérot étalons was used to filter out a single line from this spectrum. The power in the selected narrow line at 69 microm wavelength was equal to 250 mW during the macropulse of the laser. The spectral width of the selected line is as small as that of a single cavity mode, i.e., a fraction of 25 MHz, in single macropulses of the laser. The average bandwidth of 25 MHz is determined by mode hopping of the phase-locked FEL. The selected frequency hops over 25 MHz between the extrema of this band. The influence of partially coherent spontaneous emission and mode hopping on the final linewidth was studied. The narrow-linewidth radiation was scanned in frequency over 1 GHz. We show that the possibilities to scan over smaller or larger frequency intervals are unlimited.     

Solid-state active media of tunable organic-compound lasers pumped with a laser. I. An XeCl laser

The lasing properties of organic compounds in a polymethylmethacrylate matrix radiating in the blue-green (paraterphenyle and coumarine derivatives) and red (phodamine and phenalemine derivatives) regions of the spectrum pumped by an XeCl laser are studied. The lasing efficiency and photostability of the solid-state active media are compared with corresponding characteristics of the same liquid active media. Received: 14 March 2001 / Published online: 7 June 2001     

高重复率XeCl准分子激光器的放电特性

本文报道紫外预电离放电泵浦的高重复率XeCl准分子激光器的放电特性,分析了放电参数的改变对放电过程的影响.最佳转换效率达2.2%.     

400 Hz高光束质量高功率短脉冲激光器

研制了大能量高光束质量短脉冲激光器,系统采用主振荡+预放大器+主放大器2级主振荡功率放大器(MOPA)结构。采用双棒热效应补偿改善光束质量的措施,在重复频率400 Hz时实现单脉冲能量40 mJ、光束质量因子约为1.2的激光输出。激光器放大后实现单路脉冲能量712.5 mJ、脉宽12.4 ns的激光输出,采用球差补偿的方法提高了激光器的光束质量,在最大输出功率下实现了光束质量因子小于2.3,光光效率27.7%。偏振合束后,激光器输出能量大于1.4 J。     

高速宽波长范围可调谐光纤激光器

研制了一台高速波长连续扫描光纤激光器。使用SOA作为增益介质,用高速可调谐法珀滤波器作为波长调谐器件,构成的环形腔激光器。测量结果表明,激光器的平均输出功率2.6mW,波长扫描范围40nm,波长扫描范围内功率波动范围小于±0.4dBm,线宽小于0.01nm,扫描速度达到2kHz。     

XeCl laser excitation by high power microwave pulses

Considerable progress of microwave pumping of excimer laser gas mixtures has been achieved. The present measurable best values for the pulse energy lie in the mJ range. A microwave pulse compression technique is applied using a resonantly charged microwave cavity. The stored energy is extracted by igniting a high density plasma in a quartz tube which acts as a switch and as a laser amplifier yielding a high energy laser pulse.Presented at LASERION '91, June 12–14, 1991, Müchen (Germany)     

A high sensitivity spectrometer with tunable diode laser for ambient methane monitoring

Tunable diode laser absorption spectroscopy (TDLAS) has been widely employed in atmospheric trace gases detection. In the measurement of these trace gases, harmonic detection combined with a multi-pass white cell could remarkably enhance the detection sensitivity. In this paper, a portable TDLAS system built specifically for long time monitoring methane in the atmosphere is introduced. The detection limit is below 100 ppb that is enough for the monitoring of ambient methane, and the long time monitoring results obtained in Beijing are given, which is well coincident with that of the Fourier transform infrared (FTIR) spectroscopy.     

A simple,high power nitrogen laser

A simple high-power nitrogen laser is described giving a peak power of 1.2 MW in an active length of only 30 cm. We also report results for operation with air and for operation with a helium-nitrogen mixture at atmospheric pressure.     

Compact,wide aperture X-ray preionized XeCl laser with high specific optical power

An X-ray preionized, discharge-pumped XeCl laser with a variable beam cross-section of up to 6×6 cm² is described. It uses flat electrodes and the beam width is determined by X-ray collimation. Its operation characteristics concerning reduced electric field strength (E/p) and X-ray dose are discussed in detail. The inductance of the discharge loop is minimized using a water capacitor arrangement. A very high specific optical power (90 MW/l) is achieved in an active volume of 1.2 l. The pulse energy exceeds 5 J in a 45 ns pulse (FWHM). Komatsu Ltd., Manda 1200, Hiratsuka-shi, Kanagawa 254, Japan Institute of Optics and Fine Mechanics, Department of Plasma Physics, Academia Sinica, Shanghai, P.R. China     

Double XeCl laser with lateral UV preionization

We present a very compact and very reliable laser system formed of two discharge sections both with lateral UV preionization. The discharge electrodes are contained in a single vessel and form an oscillator-amplifier system. A single spark gap switches on both circuits. By applying a generalized self-filtering unstable resonator to the oscillator and injecting the laser beam into the single pass amplifier, an output beam of 105 mJ, with a brightness of 5.5×10¹³ W cm^–2Sr^–1 has been obtained. Moreover, by applying a pulse-forming network in one discharging circuit, the duration of the discharge breakdown has been increased and output laser pulses of 40 ns FWHM, and 80 ns base width duration (at 10% points) and of energy 100 mJ are obtained.     

A one joule,XeCl pumped dye laser

A 4 J XeCl (308 nm) laser has been used to produce 1 J of dye laser output from selected dyes whose lasing wavelengths sample the spectral range from 330 to 600 nm.     

大功率高亮度固体激光腔的选择

分析了大功率激光器可供选择的几种腔型的动力稳定区。并对最近报道的两种固体激光腔型进行了评价,指出了存在的问题,提出采用小曲率半径的凹面镜和一凸面镜构成谐振腔是设计大功率高亮度固体激光器的较好方案。     

大功率高亮度固体激光腔的选择

 分析了大功率激光器可供选择的几种腔型的动力稳定区。并对最近报道的两种固体激光腔型进行了评价，指出了存在的问题，提出采用小曲率半径的凹面镜和一凸面镜构成谐振腔是设计大功率高亮度固体激光器的较好方案。