Photodecomposition in POPOP dye vapor lasers

Experimental evidence is presented which shows that the premature termination of dye vapor laser gain observed in optical pumping experiments is due to photodecomposition. Addition of up to 4 atm of buffer gases was found to have little effect.     

Timing and detuning studies of a synchronously pumped mode-locked dye laser

The timing relationship between a synchronously pumped mode-locked dye laser and its pump laser is explored experimentally and theoretically. The experimental data is in quantitative agreement with numerical solutions of a semiclassical model that includes no free parameters. The data also agrees qualitatively with an approximate, analytic distillation of this model which is presented here for the first time. Our study has a direct bearing on the jitter and the long term stability of these important ultrashort pulse lasers.     

半导体泵浦铯蒸气实现激光输出

采用线宽0.26nm的Littrow外腔巴条半导体激光器泵浦增益长度8mm缓冲气体为80kPa甲烷的铯(Cs)蒸气室,在Cs蒸气室温度120℃时,我们获得了394mW的894.6nm线偏振Cs蒸气激光,光光效率7.4%,斜率效率11.2%,阈值功率为1.72W。     

半导体泵浦铯蒸气实现激光输出

采用线宽0.26 nm的Littrow外腔巴条半导体激光器泵浦增益长度8 mm缓冲气体为80 kPa甲烷的铯（Cs）蒸气室,在Cs蒸气室温度120 ℃时,我们获得了394 mW的894.6 nm线偏振Cs蒸气激光,光光效率7.4%,斜率效率11.2%,阈值功率为1.72 W。     

Electron beam excitation studies of potential dye vapor phase laser systems

Excitation processes of selected dye vapor-rare gas mixtures pumped by an electron beam have been studied. These experiments revealed the importance of effective collisional electron energy transfer pumping via a dense rare gas rather than a radiative energy transfer from an excimer laser gas mixture to achieve population inversion in an organic dye vapor. Work supported in part by the Energy Research and Development Adinistration, the Robert A. Welch Foundation and the National Science Foundation.     

Time evolution of synchronously pumped dye laser pulses: Picosecond pulse formation studies

The pulse-by-pulse evolution and compression of the output of a synchronously pumped dye laser as a function of the number of pump pulses was investigated with a high resolution, variably triggered streak camera. The measured pulse durations and energies for the pulse compression process are demonstrated to be in disagreement with the predictions of recent classical rate equation models. This is shown not to be due to the complete breakdown of the model but, rather, is caused by the failure to include two key loss terms in the rate equation treatment, namely, excited state absorption and thermal lensing. In addition, a highly durable dye laser compatible with the 100 MHz output of commercially available QS and ML YAG lasers is presented which is capable of 50 μJ, 20–30 ps transform limited pulses without the need of amplification. Further refinements of this laser system are discussed, based on the experimental work reported, which will lead to tunable ～ 100 fs pulses with energies in the μJ range from a single laser pump source.     

Theory of synchronously pumped dye lasers

An analysis of cw synchronously pumped dye lasers is presented. Under the assumption that the cavity (tuning element) bandwidth is much wider than the bandwidth of the transform limited pulses generated, the pulse forming dynamics is rigorously treated. It is shown that for a finite mismatch between the lengths of the dye and the pump lasers, a steady-state pulse develops in the dye laser cavity with a conserved pulseshape. The characteristics (energy, shape, peak power, duration) of these pulses of ultimate width are quantitatively determined as a function of cavity mismatch. An analytical solution for the pulse envelope is determined, which yieldsI(t)∝Sech²(t/t _p ) to a good approximation.     

Efficient diode pumped cesium vapor amplifier

An efficient diode laser pumped Cs vapor amplifier has been demonstrated. Using a 2 cm long Cs vapor cell pumped by an 18 W laser diode array, an amplification factor of 145 for low power Cs laser radiation was achieved. Such an amplifier or chain of amplifiers can significantly simplify the use of multiple pump sources for scaling the output power of alkali lasers.     

Threshold singularities of optically pumped dye lasers

A complete theoretical model for optically pumped dye lasers is studied using the rate equation approach which includes excited singlet and triplet state absorption effects. Closed-form solutions under steady-state conditions reveal a novel nonlinear threshold phenomenon: partial reabsorption of the excited laser light can lead to a discontinuous onset of laser oscillation above laser threshold. Theoretical and experimental results for a transversely and longitudinally pumped rhodamine 6G laser are presented in terms of softmode and hardmode behavior at threshold.     

Wavelength tuning of nitrogen pumped dye laser

In this paper a method is described for continuous wavelength tuning of nitrogen pumped dye laser by changing the concentration of an additional dye in the lasing solution.     

Highly efficient optically pumped cesium vapor laser

We have demonstrated an optically pumped continuous wave Cs vapor laser with an input power to output power slope efficiency of 81%. The laser power was 0.35 W for an input power of 0.57 W, yielding an overall optical efficiency of 63%.     

Phase-modulation effects in synchronously pumped dye lasers

We report the numerical calculation of pulse generation in SPDL including phase-modulation effects due to gain saturation. The steady-state pulses are strongly down-chirped at the leading edge if the laser frequency is detuned from the line centre of the amplifying dye. The pulse duration is found to be almost independent of wavelength detuning.     

High-energy dye laser pumped by wall-ablation lamps

A guideline for the optimum design of linear wall-ablation lamps is presented with a simple empirical formula which describes the luminescent characteristics of lamps. The absolute luminescent efficiency of the wall-ablation lamp was measured. A high-energy dye laser with a quadruple-elliptical cylindrical cavity was constructed using these lamps, and an output energy of 23.3 J (11.6 MW) was obtained with an overall efficiency of 0.31 %. The energy-flow diagram of this laser system was computed with a rate-equation analysis, and the conversion efficiency from electrical input to laser output was determined. One can expect an overall efficiency of about 2 %.     

Flashlamp pumped tunable dye laser of ultra-narrow bandwidth

A flash lamp pumped dye laser with a ring cavity is injected with the light beam coming from a stabilized singlemode c.w. dye laser. The light emitted by the pulsed laser is analysed either by a Fabry Perot etalon, or by producing a Doppler-free two-photon transition. The bandwidth of the pulsed laser is identical to the one of the c.w. laser; but the pulsed light is shifted to higher frequency by an amount of a few MHz.     

半导体泵浦铷蒸气激光器出光实验

针对中心波长780 nm的商用连续波半导体激光器,使用斩波器将连续激光变为脉冲输出形式,用2400 line/mm的平面全息光栅搭建Littrow外腔将线宽压窄至0.2 nm以下。采用透镜组对线宽压窄后的半导体激光进行光束整形,半导体激光经线宽压窄和光束整形后,经透镜聚焦进长约8 mm的铷蒸气泡进行半导体泵浦碱金属激光实验。首次出光得到17.5 mW的基模线偏振铷激光;在最新的改进实验中,半导体泵浦铷激光输出功率已达到2.8 W。     

半导体泵浦铷蒸气激光器出光实验

针对中心波长780 nm的商用连续波半导体激光器,使用斩波器将连续激光变为脉冲输出形式,用2400 line/mm的平面全息光栅搭建Littrow外腔将线宽压窄至0.2 nm以下。采用透镜组对线宽压窄后的半导体激光进行光束整形,半导体激光经线宽压窄和光束整形后,经透镜聚焦进长约8 mm的铷蒸气泡进行半导体泵浦碱金属激光实验。首次出光得到17.5 mW的基模线偏振铷激光;在最新的改进实验中,半导体泵浦铷激光输出功率已达到2.8 W。     

Pulse structure studies and absolute cavity length determination for a synchronously pumped picosecond dye laser

Second harmonic cross correlation functions of a pulse with its near neighbor have been studied in a synchronously pumped cw dye laser. Measurements were made both as a function of dye laser cavity length mismatch and the number of cavity round trips separating the correlated pulses. The pulse envelope is found to have a characteristic interpulse frequency determined by the pump laser, whereas the pulse substructure has a characteristic frequency determined by the dye laser cavity length. The cross correlation measurements allow experimental determination of the dye laser length corresponding to exact synchrony. In contrast to theoretical predictions the length of exact synchrony corresponds to optimum pulse shape and duration. Our results are discussed in terms of a simple model which leads to pulse duration estimates as much as twice those obtained by conventional analysis of autocorrelation traces.