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1.
本文综述介绍了用DFDL产生ps量级超短脉冲的方法,着重讨论了用DFDL产生超短脉冲的机制理论分析。分析表明:用DFDL产生超短脉冲可以通过建立适当的速率方程,恰当设置参数求解来预言其总体行为。通过理论和实验结果的比较,可以认为DFDL产生超短脉冲的机制是自Q调制。 相似文献
2.
The distributed feedback dye laser (DFDL) generates a train of picosecond pulses when pumped well above threshold. This DFDL emission can be quenched by injecting a laser pulse into DFDL. By proper timing of the quencher laser pulse, only the first DFDL pulse is generated while the successive pulses are suppressed. Operational characteristics and practical design considerations of such a quenched DFDL are given. With 2.5 ns long pump pulses from a N2 laser, a shortest DFDL pulse of 17 ps was obtained at 380 nm. 相似文献
3.
Simple possibility of single tunable picosecond pulse generation in a conventional inexpensive distributed feedback dye laser (DFDL) is demonstrated. It is shown that when a TEA N2-laser is used for pumping no diffraction grating is necessary in the DFDL optical scheme for operation in the picosecond regime. Hence wide-range spectral tuning from 357 to 665 nm was easily achieved. When pumped with a 0.6 ns 40 kW pulse of the TEA N2-laser the DFDL generated pulses as short as 7 ps with time-bandwidth product better than 0.6 and peak power ? 10 kW. At a repetition rate of 50 pps the shot-to-shot energy stability of a single picosecond pulse was ±18% at ±7% stability of the TEA N2-laser. 相似文献
4.
Zs. Bor 《Applied Physics A: Materials Science & Processing》1979,19(1):39-41
It is shown that when a distributed feedback dye laser is used to generate a train of picosecond pulses, the narrow lines
observed in the spectrum are not longitudinal modes, but are due to the intrapulse refractive index changes caused by the
heating effect of the pumping pulse. 相似文献
5.
A tunable single short pulse laser system with a transform–limited bandwidth pumped by a picosecond Nd:YAG laser (ca. 120 ps
pulse width) is demonstrated. With this configuration, the relaxation oscillations coming from a distributed feedback dye
laser cavity are completely removed. Because the pumping pulsewidth is shorter than the lifetime of dye molecule on the upper
laser state, the gain of the laser medium is depleted by the first pulse. The laser wavelength could be precisely tuned with
the transform-limited bandwidth (for example, a linewidth of 0.02 nm). After amplification, we obtain a single short laser
pulse energy up to 500 μJ at the pulsewidth of 8.2 ps. 相似文献
6.
Various methods for the determination of the S1-state lifetime of dye solutions (laser dyes and modelocking dyes) are analysed. A general model of interaction of laser light with dye molecules is presented and reduced to a dye energy level scheme of six levels. Fluorescence emission, light amplification and absorption recovery techniques are investigated theoretically and their limitations revealed. The determination of the S1-state lifetime of saturable absorbers by single picosecond pulse bleaching experiments is very thoroughly discussed. The influence of various laser and dye parameters on the bleaching experiments are analysed numerically. The results are compared with isotropic steady state two- and three-level dye models. 相似文献
7.
Zs. Bor 《Optics Communications》1979,29(1):103-108
A novel excitation scheme for a N2 laser pumped distributed feedback dye laser is described. The dye laser generates 80–100 ps pulses with a time-bandwidth product better than 0.6. Several tuning methods are proposed, and a number are investigated experimentally. Continuous tuning over a 50 Å range without mode-hopping is demonstrated. 相似文献
8.
A mathematical model has been developed to describe the dynamic emission of a distributed feedback dye laser (DFDL) pumped
by a Nd-glass laser. The model is based on the coupled-wave theory. It allows the investigation of the temporal behavior of
the Nd-glass pumping laser source and the DFDL pulses. The model allows studying the effect of the variation of the laser
input parameters of the Nd-glass laser, such as maximum amplification coefficient, loss coefficient and pumping rate on the
characteristics of DFDL pulses regarding the pulse width, delay time and separation time. The feedback process of the DFDL
is provided either by changes of the refractive index or by optical gain or by both together. The model estimates the following:
temporal behavior of the density of emitted radiation, energy densities of the first excited singlet and triplet states, DFDL
output power, cavity decay time and the temperature of the produced grating. The numerical solution of the nonlinear coupled
rate equation system predicts the generation of DFDL picosecond pulses. The calculated results are in good agreement with
the available experimental data. The calculations were done using rhodamine 6G dissolved in ethanol as the investigated matrix. 相似文献
9.
D. Q. Hoa V. Duong V. T. T. Duong C. V. Ha 《Applied physics. B, Lasers and optics》2012,107(3):823-826
We report a new configuration of a picosecond distributed feedback dye laser system, which can be pumped by various wavelengths. The optical characteristics of the system are presented. By using a triangle mirror functioned beam splitter and a right-angle prism attached to the front face of the cell in the pumping geometry, continuously and widely tunable laser wavelengths have been obtained for a range of more than 100 nm. A quenching mirror adhered to a face on the side of the cell, functioning as a high-Q cavity shared common gain medium, has been employed to observe single short laser pulses with transform-limited bandwidth. 相似文献
10.
A laser system comprising a synchronously pumped picosecond dye laser with combined cavity-distributed feedback and a two-stage
dye amplifier is described. The dependence of the laser pulse duration on the detuning of the cavity length, the pumping level
of the active medium, and the pulse number in the pulse train was investigated. It is shown that the combination of the two
types of feedback provides more than ten-fold shortening of the dye laser ultrashort pulse duration.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 47–55, January–February, 1998. 相似文献
11.
Spectrally Adjustable Picosecond Dye Laser Pulses Generated with Nanosecond Nitrogen Lasers 总被引:2,自引:0,他引:2
Nguyen Dai Hung Pham Long Dinh Van Trung Nguyen Van Tien Le Hoang Hai Nguyen Ha 《Chinese Journal of Lasers》1995,4(5):385-392
SpectrallyAdjustablePicosecondDyeLaserPulsesGeneratedwithNanosecondNitrogenLasersNguyenDaiHung;PhamLong;DinhVanTrung;NguyenVa... 相似文献
12.
J. Chen H. Mizuno H. Kawano A. Miyawaki K. Midorikawa 《Applied physics. B, Lasers and optics》2006,85(1):45-48
We experimentally demonstrated two-photon pumping of random lasers using picosecond and nanosecond pump lasers. The picosecond laser pumping experiment was performed with 400 ps laser pulses at 770 nm, and the gain media was a Coumarin 480D dye solution doped with TiO2 nanoparticles. Onset of laser action was observed at a pump laser pulse energy below 500 μJ. The nanosecond laser pumping experiment was performed with 7 ns laser pulses at 1064 nm, and the gain media was a Rhodamine 640 dye solution doped with TiO2 nanoparticles. Onset of laser action was observed at a pump laser energy ∼18 mJ. Our results suggest that there exists an optimal pulse duration of the pumping laser in two-photon pumped random lasing that leads to minimum photodamage of the gain media and still keeps a high pumping efficiency. PACS 33.50.Dq; 42.55.Mv; 42.55.Zz 相似文献
13.
A simple and flexible distributed feedback dye laser source pumped by the harmonic of a mode-locked YAG laser is described. Measurements of dephasing times of isotopic and hot bands in CS2 liquid exploiting both the frequency and time-resolution of this source are reported. 相似文献
14.
A miniaturized, high repetition rate, picosecond all solid state photo-induced distributed feedback (DFB) polymer-dye laser
is described by applying a passively Q-switched and frequency-doubled Cr4+:Nd3+:YAG-microchip laser (pulse width Δτ=540 ps, repetition rate ν=3 kHz, pump energy Epump=0.15 μJ) as a pump source. A poly-methylmethacrylate film doped with rhodamine B dye serves as active medium. The DFB-laser
pulses are temporally and spectrally characterized, and the stability of the thin polymer/dye film at high repetition rates
is analyzed. The shortest DFB-laser pulses obtained have a duration of 11 ps. After the emission of 350000 pulses the intensity
of the DFB-laser output has decreased by a factor of two and the pulse duration has increased by a factor of 1.2. For single
DFB-laser pulses of 20-ps duration the spectral bandwidth is measured to be Δλ=0.03 nm, which is only 0.005 nm above the calculated
Fourier limit assuming a Gaussian profile for the temporal shape of the pulses. Coarse wavelength tuning of the DFB laser
between 590 and 619 nm is done by turning the prism. Additionally, a fine tuning of the DFB-polymer-laser wavelength is achieved
by changing the temperature of the polymer/dye layer (=-0.05 nm/°C) in the range from 20 to 40 °C.
Received: 1 March 2001 / Revised version: 23 May 2001 / Published online: 18 July 2001 相似文献
15.
A rate-equation model for the laser action of infrared dyes is introduced. An extended four-level scheme is used to describe the photophysical processes in the dye molecules. The dye is excited by a single picosecond pulse in the traveling-wave geometry. The spectral and temporal properties of the picosecond dye-laser emission and the gain curve of the system are calculated. The numerical results are compared to experimental data. The theoretical model is in good quantitative agreement with the experiment. 相似文献
16.
A distributed feedback dye laser arrangement is described which can generate pulses at the subharmonic wavelengths of the main excimer laser lines (308 nm, 248 nm, 193 nm, etc.). The laser can be pumped with broadband lasers, such as the XeCl* laserpumped dye laser with competing cavities. The laser is designed to be used as a part of a femtosecond, terawatt excimer laser system. 相似文献
17.
J. Hebling 《Applied physics. B, Lasers and optics》1988,47(3):267-272
The behaviour of an excimer-laser-pumped distributed feedback dye laser (ELP DFDL) using a mixture of saturable absorber and laser dye as an active medium was studied. In a DFDL self-Q-switching occurs because of the population inversion dependence of the feedback. If the DFDL contains absorber saturation of the absorption by the leading edge of the created laser pulse also causes Q-switching. As a result of this double self-Q-switching, mixing a saturable absorber into the laser dye, the laser pulses become shorter and more stable. This was demonstrated experimentally. Mixing Rhodamine B into the dye solution of a Coumarin 153 ELP DFDL, a six-fold reduction in the pulse duration and a more than two-fold reduction in the pulse energy instability were observed. The experimental results were in good qualitative agreement with the predictions of a simple rate equation model. 相似文献
18.
Analysis of tunable picosecond pulse generation from a distributed feedback Ti:sapphire laser 下载免费PDF全文
A distributed feedback Ti:sapphire laser (DFTL) pumped by a 532nm Q-switched pulse is proposed for the generation of tunable picosecond pulses. With coupled rate equation model, the temporal characteristics of DFTL are obtained. The numerical solutions show that the DFTL pulse with a 50-ps pulse duration and as much as 3.SmJ pulse energy can be obtained under 40-m J, 5-ns pulse pumping. The dependence of output pulse width on the laser crystal‘s length, pumping pulse duration, and pumping rate is also discussed in detail. 相似文献
19.
20.
A simple 10 ps KrF laser system consisting of quenched dye laser oscillator pumped by a XeCl laser, a distributed feedback dye laser (DFDL), a three-stage dye amplifier and a two-stage KrF amplifier are described. The output of the laser system is 140 mJ with 10 ps pulse width by using polarization-multiplexing amplification. A focused output laser intensity of about 4×1015 W/cm2 is obtained. The saturation fluence for KrF laser is obtained with this laser. 相似文献