Streak camera analysis of an N2-1aser-pumped picosecond dye laser

The temporal behavior of a TEA N2-laser-pumped dye laser was thoroughly examined. It was found that both the pulse shape and the duration were affected strongly by the tuned wavelength, cavity length, pumping intensity, and the feedback signal from both the front and the back reflectors. A single output pulse as short as 40 ps could be generated by optimizing the operating parameters. This output can be used effectively to pump a short cavity dye laser to produce transform-limited 7 ps pulses.     

主动锁模和调Q Nd:YAG激光倍频同步泵浦染料激光器特性研究

本文介绍一种主动锁模和调Q Nd:YAG激光倍频同步泵浦可调谐染料激光器。由此激光器已获得脉冲宽度为70ps,脉冲能量为0.1μJ,调Q重复率达7kHz,调谐范围为580～610nm的微微秒脉冲,本文还研究了这一激光器的时间和频谱特性,分析了腔长失配对脉宽和中心波长的影响。     

波长可调的ps超短腔染料激光器的研究

本文报道了用锁模磷酸盐玻璃激光的倍频光泵浦若丹明B超短腔染料激光器的实验装置和实验结果,用TPF和OSA的组合装置研究了磷酸盐玻璃激光器的最佳运转条件,得到了脉宽～5ps的锁模脉冲系列,以此ps光源泵浦的染料激光器获得了波长为620.1～641.6nm,脉冲宽度小于4ps的单模可调谐激光输出。     

A cascade pumped picosecond dye laser system

A picosecond dye laser system producing 4 μJ in a 10 ps pulse is described. This highly stable compact system consists of a nitrogen laser and two cascade pumped dye laser oscillators followed by one amplifier. The Roess-Lin cavity transient technique was applied to compress the input 60 μJ 300 ps N2pulse twice to produce a final output duration of 10 ps. Discrete output wavelengths can be varied by changing the dye laser solution. Spectral and temporal measurements were performed to characterize this laser. A broad spectral emission of ∼ 160 cm^-1was observed, consistent with the observed fine temporal structures of 0.09 ps. A model rate equations calculation was also performed with parameters pertinent to the present laser system. This picosecond laser system should find applications in testing and calibration in the picosecond timescale.     

自启动、宽调谐的ps掺Yb双包层光纤激光器

对连续泵浦的自启动、宽调谐的ps脉冲掺Yb^3＋双包层光纤激光器进行了实验研究。采用20m单模掺Yb^3＋双包层光纤作为增益介质,利用77MHz射频信号的声光调制器（AOM）作为频移器以及体光栅构成外腔,得到了重复频率为1GHz、平均功率为56．3mW以及脉宽小于60ps的脉冲,激光器的调谐范围超过40nm。     

Phase-conjugation property of one-photon pumped backward stimulatedemission from a lasing medium

Optical phase-conjugation properties of the backward stimulated radiation from a one-photon pumped lasing medium have been studied. The gain medium is a dye solution (pyrromethene 597 in ethanol) or the same dye doped poly(methyl methacrylate) (PMMA) rod pumped with ~7-ns and 532-nm laser pulses. A highly directional and phase-conjugate backward stimulated emission at ~573 nm wavelength could be obtained with a conversion efficiency of ~42% by using a 1-cm-long dye solution sample at the concentration level of d₀=0.000 15 mol/L. The spectral, temporal, output/input, and phase-conjugation properties of this backward stimulated emission are presented in detail. The induced aberration influence, which is much larger than the divergence angle of the input pump beam, can be basically removed by the backward stimulated emission; however, the fidelity of the near-field detail for the backward stimulated emission is relatively poor. A quasi-collinear holographic interaction model and a mathematical analysis are presented to explain the basic experimental results     

Femtosecond pulse generation in the red/deep red spectral region

Optical pulses as short as 55 fs in duration have been generated near 675 nm in a synchronously pumped, hybridly mode-locked, sulforhodamine 101 dye laser. Hybrid mode locking of rhodamineBin the same cavity arrangement yielded 187 fs pulses at 650 nm.     

High-peak-power 532-nm pumped dye laser

A dye laser, pumped by the second harmonic of a flash-pumpedQ-switched Nd:YAG oscillator/amplifier chain is described. The dye laser produces 8-ns-long pulses with energies as great as 140 mJ and peak powers of 20 MW. At a repetition rate of 10 pulses/s, the average power obtained is 1.4 W and the conversion efficiency (532 nm to dye) is approximately 50 percent.     

Dual frequency subnanosecond pulses from a millimeter-cavity dye laser

Dual frequency dye laser pulses of subnanosecond duration can be achieved by taking advantage of the spiking behavior of two lasing dyes within a single high-loss cavity. Two 10-kW pulses 1.5 ns apart were observed, each of 600-ps width, at wavelengths of 565 and 615 nm, respectively. The phenomenon of spiking in organic dye lasers has received attention as a potential mechanism for the creation of useable short pulses [1]-[4]. The feasibility of this was recently demonstrated by Lin and Shank [5], who achieved subnanosecond pulses from a nitrogen laser pumped dye laser with a high-loss cavity. By maintaining proper control of the pumping level and the cavity loss, they were able to isolate the initial dye laser spike which occurs with each pump pulse, while suppressing the formation of the relaxation oscillations which usually follow it.     

Passive Q-switching of an intracavity frequency doubled diode-pumped Nd:YVO/sub 4//KTP green laser with Cr/sup 4+/:YAG

A compact diode-pumped green-pulse laser has been demonstrated by using Cr/sup 4+/:YAG as a saturable absorber in a simple cavity formed by a coated Nd:YVO/sub 4/ crystal and a coated KTP crystal. When continuous-wave (CW) pumped with a fiber-coupled laser diode, the laser produces green pulses of 20-35-ns duration at 532 nm, with a repetition rate of 15-70 kHz. The highest green peak power was 80.8 W, obtained at 1.2 W of pump power, which is 320 times enhancement in comparison to a green output power of 250 mW under CW.     

Tunable two-wavelength mode locking of the CW dye laser

Tunable model-locked laser output is achieved at two wavelengths with a CW dye laser containing a rhodamine 6G and a cresyl violet jet. Rhodamine 6G is pumped by a mode-locked argon laser. Output pulses of 4-5 ps duration are obtained.     

Narrow-band infrared picosecond pulses tunable between 1.2 and 1.4 µm generated by a traveling-wave dye laser

A novel type of picosecond light source is the traveling-wave dye laser. It consists of a generator and an amplifier cell, both pumped by single pulses. Using the fast switching dye No. 5 with a fluorescence quantum efficiency of5 times 10^{-4}, one obtains an energy conversion of the pump to the IR pulse of up to 10 percent. The spectral width of the IR pulses is 15 cm^-1over the tunability range of1.18-1.4 mum. At 1.33 μm we observe Gaussian shaped pulses of 4.4 ps duration for pump pulses of 4.5 ps generated by a mode-locked Nd:glass laser. The output pulses show a high stability with a jitter of less than 0.2 ps.     

Electronically tuned synchronously pumped dye laser

We have demonstrated electronically tunable pulses as short as 1.3 ps with a tuning rate of 150 Å/kV using a synchronously pumped rhodamine dye laser. Electronically tunable transform limited pulses of 5 ps duration have also been produced.     

Properties of two-photon pumped cavity lasing in novel dye dopedsolid matrices

Two-photon pumped frequency upconversion cavity lasing at ~600 nm is accomplished in three types of dye-doped solid rods pumped with ~10 ns and 1.06-μm IR laser pulses. The dopant is a new dye, trans-4-[p-(N-ethyl-N-(hydroxyethyl)amino)styryl]-N-methylpyridinium tetraphenylborate, abbreviated as ASPT, which possesses a greater two-photon absorption cross section and stronger upconversion fluorescence emission than common commercial dyes (such as rhodamine). Three different materials were chosen as solid matrices: poly(2-hydroxyethyl methacrylate), VYCOR porous glass, and sol-gel glass. Using a Q-switched Nd:YAG pulse laser as the pump source, strong cavity lasing could be achieved in these three ASPT doped solid rods as well as in ASPT solution in a liquid cell. The spectral, temporal, and spatial characteristics of the cavity lasing output have been systematically investigated. The measured output-input characteristics, lasing lifetime, and damage threshold for the three different rods are presented     

Measurement of dispersion using short lengths of an optical fiber and picosecond pulses from semiconductor film lasers

Group velocity dispersion spectra have been determined for 7.8-m lengths of a single-mode optical fiber. The dispersion spectra are derived from measurement of the transit delay time of picosecond pulses (4-10 ps) from optically pumped ultrashort cavity semiconductor film lasers. The delay time spectra have been measured to 1 ps precision over the range from 1.11 to 1.53 μm for single-mode step-index and quadruple-clad fibers. This is the highest temporal resolution achieved for any pulse delay measurement in optical fibers. The resulting dispersion spectra are in good agreement with measurements made for the same fibers by other techniques.     

550～689nm重复率YAG激光同步泵浦染料激光器

用重复率脉冲锁模YAG激光同步泵浦四种激光染料,获得脉冲重复率20Hz、峰值功率MW级、平均功率mW级、脉宽30ps染料激光。波长复盖范围为550.0～689.0nm,谱线宽度0.05nm。实验比较了L_D=1/2L_PF和L_D=L_P两种匹配腔的输出特性。     

Subnanosecond laser pulses from a grazing incidence dye laser

Dye laser pulses with a duration of 160-350 ps and a spectral width of 0.06 nm were obtained by pumping a grazing incidence dye laser with aQ-switched Nd : YAG laser. The pulse shortening was due to a cavity transient effect which has also been observed in N2laser-pumped dye lasers.     

Diode-pumped Q-switched Extra-cavity Frequency-doubled Nd：YVO4/KTP Green Laser

A diode-pumped acousto-optical（A-O） Q-switched extra-cavity frequency-doubled Nd：YVO4/KTP （KTiOPO4） green laser formed with a simple plane-plane cavity has been demonstrated. With the incident pump power of 12.7W, A-O Q-switched average output power at 1064nm was 3.81W with a duration of 25 ns at a repetition rate of 20 kHz, extra-cavity frequency doubling with KTP as the nonlinear crystal yielded the maximum output power of 1. 92 W at 532 nm, the corresponding optical conversion efficiency from 1064nm to 532nm light is 50.4%. The continuous-wave（CW） laser properties of diodepumped Nd：YVO4 crystal operating at 1064nm have been studied. With the incident pump power of 25 W, the maximum CW output power of 13.81 W was obtained with the corresponding optical conversion efficiency of 55.24%.     

Characteristics of organic dye lasers as tunable frequency sources for nanosecond absorption spectroscopy

The properties of 1, 1' diethyl-γ-cyano-2,2'-di-carbocyanine-tetrafluoroborate (DTCDCT)and 1, 1'-diethyl-γ-nitro- 4, 4'-di-carbocyanine-tetrafluoroborate (DTNDCT) lasers have been investigated. High-efficiency (25 percent) spectral narrowing of the normal 150-Å-wide, 2-MW output of DTCDCT (around λ 7600 Å) to <0.01 Å, corresponding to a single longitudinal mode, is achieved with a novel longitudinally pumped (by giant pulse ruby laser) dye laser cavity. Beam divergence is <0.5 mrad, and spectral tunability is obtained by rotating the echelle grating and Fabry-Perot etalon cavity elements. DTNDCT transversely pumped by a mode-locked ruby laser (>150 MW peak power) produces a train of 100 percent modulated mode-locked dye laser pulses whose risetimes (<0.5 ns) and pulse widths (0.6 ns) are detector limited. The production of broad continua for nanosecond absorption spectroscopy is also described, together with measurements on the synchronization of the pumping and dye laser pulses. Finally, the direct spectrographic detection of near-resonant optical-frequency Stark effects in potassium is briefly described. Employing the DTCDCT continuum as absorption source, a red shift of75 times 10^{-3}cm^-1of the λ 7699-Å resonance line was detected for a ruby laser perturbing field of power density ∼ 30 MW/cm^-2.     

双棱镜扩束、光栅调谐的ps染料激光器

用重复率脉冲锁模YAG激光同步泵浦双棱镜扩束的光栅染料激光腔,对于R-6G激光染料,获得脉冲列重复率为20Hz、脉冲峰值功率为7.6MW、平均功率为9.5mW的30ps可调谐激光,其谱线宽度为0.04nm,接近变换极限宽度。激光输出稳定,调谐方便。