Lamp Pumping Research Articles

A proposed 1 kW average power moving slab Nd:Glass laser

The design considerations of a high average power Nd : glass slab laser in which the slab moves between the pumping lamps to distribute the thermal loading over the area of the glass while maintaining high gain in the pumped volume are presented. Continuous wave operation and high repetition rate pulsed operation are projected at the 1kW average power level.

Investigation of absorption from the lower laser level 4I [formula omitted] of the erbium ions in the lutetium garnet

The results of experimental and theoretical investigations of the absorption of the pumping lamp radiation from the excited ( 4I 13 2 ) level of erbium ions in LuAG are presented. It is shown that absorption from this level has the same order of magnitude as from the ground state.

Investigation of the kinetics of intracavity absorption in pulsed dye lasers

In this work the authors studied the kinetics of intracavity absorption in dye lasers pumped with a lamp (lasing pulse duration of 3 musec) and with the second harmonic of the ruby laser (25 nsec). Oscillograms are shown of the lasing pulse of the laser, obtained with single-pulse and lamp pumping, respectively. The results of the studies performed indicate the complicated nature of the process of intracavity absorption in pulsed dye lasers whose lasing duration is equal to 10/sup -8/-10/sup -6/ sec. The use of a recording system with time resolution of the lasing pulse of the laser enables increasing the sensitivity of intracavity measurements. Graphs are included.

Analysis of Na and Ba in an atomic fluorescence method with excitation by a pulsed dye laser with lamp pumping

Analysis of Na and Ba in an atomic fluorescence method with excitation by a pulsed dye laser with lamp pumping

Thermal physics of the BaEr2F8:Tm:Ho active medium

A study was made of the evolution of heat in BaEr2F8:[Tm(5%) + Ho(1%)] as a function of the electrical pump energy. The evolution of heat was resolved into components associated with the delivery of the absorbed energy to the active level and with the dark relaxation of the population of this level. An original method was used to determine the efficiency of utilization of the electrical energy (delivered to the pump lamps) in the active medium and the maximum value of the differential efficiency. Participation of cross-relaxation processes in the conversion of the absorbed energy reduced the heat evolution in the BaEr2F8:Tm:Ho medium by a factor exceeding 3.

Tunable lasers based on organic compounds with lamp pumping

Tunable lasers based on organic compounds with lamp pumping

Participation of singlet oxygen in photodegradation of air-saturated solutions of coumarin dyes

Solutions of coumarin dyes are used to generate stimulated emission in the blue-green region of the spectrum [i]. During irradiation of the active medium by flash pump lamps, the dye becomes degraded~ and this leads to a decrease in the generation energy. The photolysis ofcoumarin dyes has been studied by several authors [2-6]. At present, the photodimerization reaction of coumarins in solutions [2] and photoreduction in deoxygenated ethanol [3] are known, and the opening of the pyrone ring of coumarins by the action of irradiation is suggested in some papers [4, 5]. Dealkylation products of amino groups and oxidation products of the methyl group were isolated as the photolysis products of 7-diethylamino-4methylcoumarin. It was shown that it is oxidation of the methyl group that determines deterioration in the generational characteristics of the laser, since the photoproducts formed absorb emission in the generation region, while the role of the remaining processes is inappreciable [6]. The oxidation mechanism was not studied. To clarify the oxidation mechanism of the photooxidation of coumarin dyes serving as laser media, we studied the regularities of their photolysis in air-saturated solutions.

Influence of the supply conditions of the pumping lamp and its tube diameter upon the efficiency of neodymium glass laser amplifiers

Influence of the supply conditions of the pumping lamp and its tube diameter upon the efficiency of neodymium glass laser amplifiers

Kinetics and operation of the atomic mercury laser

An investigation of the cw atomic mercury laser is reported. The kinetic model developed by earlier workers is extended to include the effect of impurities and allow calculation of the output power over a wide range of parameters. A flowing-gas, multiple-isotope experimental laser is described, having an improved pump lamp design and giving an output power up to 6.5 mW. The output power is measured as a fraction of parameters such as mercury and nitrogen pressures, and lamp current. The nitrogen pressure dependence of the gain is found to be in good agreement with rate equation analysis provided a pressure dependent absorption loss term is taken into account.

Characteristics of K–Rb lamps as the pump sources for YAG:Nd3+lasers

An experimental investigation was made of some characteristics of the operation of Soviet K–Rb pump lamps designed for YAG:Nd3+ lasers. It was found that at low pumping rates these K–Rb lamps are efficient pump sources for YAG:Nd3+ lasers.

Influence of quadratic pump power distribution on hole burning in neodymium lasers

The influence of quadratic pump power distribution on transverse spatial hole burning in homogeneously broadened lasers is analyzed. The optimum relationship between pump size and mode size is given. Theoretical and experimental results are compared for neodymium lasers with helical xenon lamp pumping. From the excellent agreement between theory and experiment we can conclude that the pump intensity radial distribution near axis is close to the quadratic law. The experimental quadratic term is measured. Laser performance as a function of the optical cavity parameters is analyzed.

Effect of nonsteadiness of the pumping power distribution on the generation threshold of a ruby laser

It was established in [i, 2] that the experimental dependences of the threshold pumping energy on losses in the resonator for a ruby laser have a lower slope than a theoretical calculation predicts [3]. The reverse relationship between the experimental and theoretical dependences would be more natural, since heating of the ruby element by the radiation of the pumping lamp and the effect of thermal strains on the size of the losses were not taken into account in the calculation. One can show that nonrectangularity of the pumping pulse shape and the effect of intensified luminescence on the generation threshold also lead to an increase in the slope of the threshold dependence. Thus, taking into account the factors which are usually taken into account offers no qualitative explanation of the observed discrepancy in the behavior of the threshold curve of a ruby laser~ Nonsteadiness of the pumping power distribution is discussed in this paper as a possible cause of the observed effect.

Spectroscopic constants of intercombinational transitions of some laser dyes

In the present work, an original method is used to determine a number of spectroscopic constants for ethanolic solutions of Rhodamine 3B, cresol violet, and oxazine-!7. Possible mechanisms of excitation-energy degradation in these dyes are discussed. The kinetics of the formation and extinction of induced absorption in the given solutions was investigated using an improved method of flash photolysis. A dye laser with lamp pumping was used as the excitation source. A high excitation energy, adequate monochromaticity, and also a comparatively large duration of the laser radiation (comparable with the inverse of the probability of intercombinational transition S~-$TI ) ensured effective population of the metastable T, level of the dyes even with a small quantum yield of particles in the triplet state. At the same time, because the exciting flux is directed and monochromatic, suppression of the scattered radiation in the recording system could readily be eliminated. In addition, selective excitation in the basic absorption band of the dye led to a minimum of undesirable photochemical conversions in the solution. To obtain information on the probabilities of triplet-level deactivation, it is necessary to measure the extinction kinetics of TI§ absorption with fast switching-off of the pumping. Thus, effective population of the TI state requires excitation of the given solution by light pulses of sufficiently long duration (microseconds), while investigation of the deactivation kinetics of the metastable level requires a sharp cutoff of the pumping pulse, i.e., a much shorter trailing edge. The trailing edge was abbreviated using a fastacting electrooptical valve based on a Pockels cell, positioned outside the laser resonator. As a result, for a total excitation-pulse length of (1-4)'10 -6 sec, the duration of the trailing edge was no more than 5'10 -8 sec. The spectral width of the pumping radiation was ~15 nm; variation of the wavelength in the range 460-700 nm was possible; in this spectral range, the output energy of the laser varied from 0.4 to 1.5 Ja Change in transmission of the dye solution after the cessation of the excitation pulse

Excited-state absorption in the pump region of alexandrite

Excited-state absorption in alexandrite has been measured from 420 to 680 nm by using pulsed flash lamp pumping and a dye laser probe. The excited-state absorption cross section is generally of the same order of magnitude as the ground-state absorption cross section (10−19 cm2) and therefore may represent a large loss of energy from the pump source in a laser system. The results were confirmed at two wavelengths with a cw experiment in which 568- or 590-nm radiation was used for pumping and probing.

Investigation of the ultimate conditions for operatring a pump lamp module of the Mikron laser system

The maximum output energies of xenon flashlamps, used to pump large neodymium glass elements, were investigated in the pump pulse duration range 0.1–3 msec. The influence of a Kh-122-PM lamp enclosure on the maximum output energy of the flashlamps was studied. The service life of a multi-lamp module, estimated from our data, was in agreement with the experience gained in operating the Mikron system.

Investigation of the temperature dependence of the lasing characteristics of a dye laser with lamp pumping

Investigation of the temperature dependence of the lasing characteristics of a dye laser with lamp pumping

Effect of intraresonator absorption on the characteristics of a dyestuff laser with forced mode synchronization

It is well-known that theintroduction into the resonator of a broadband dyestuff laser of an absorber with a line spectrum leads to the formation in the laser emission spectrum of gaps at frequencies corresponding to absorption lines [i]. This effect forms the basis of measurements of weak absorptions and the indication of small amounts of a substance by the method of intraresonator spectroscopy. Until recently, pulsed dyestuff lasers with laser and lamp pumping, as well as continuous lasers [2-4], have been used for the purpose of intraresonator spectroscopy.

On the accurate numerical simulation of pulses from dye lasers

A Fourier synthesis for the pumping lamp intensity and the inclusion of shock wave effects enable a set of rate equations to provide an accurate simulation of an output laser pulse. A comparison is made with experimental data from a co-axial flash pumped dye laser using Rh 6G dissolved in methanol.

Stimulated emission spectroscopy of concentrated lithium-neodymium phosphate glasses in4F3/2 →4I11/2 and4F3/2 →4I13/2 transitions

Spectral and laser investigations of concentrated lithium–neodymium phosphate glasses in a wide temperature range from 77 to 500 K are carried out in the 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions. For the first time, using conventional lamp pumping, the laser action in both 4F3/2 → → 4I11/2 and additional 4F3/2 → 4I13/2 transitions of a phosphate glass with 100% concentration of Nd3+ ions is registered as well as for the concentration series of phosphate glasses. A temperature re-switching effect for lines and channels of stimulated emission is found. An explanation of this effect is given. [Russian Text Ignored]

Survival of cryogenic laser fusion fuel configurations in fluorescence energy

The most troublesome factor affecting the survival of a cryogenic fuel configuration in a laser fusion pellet irradiated by high-power laser beams is the fluorescence energy put out by the amplifier system. Prepulses can be blocked, but the incoherent radiation spontaneously emitted and amplified during lamp pump time is an inherent attribute of any optically pumped laser amplifier system and cannot be completely blocked; its effect on the fuel configuration needs to be examined. The effects of this amplified spontaneous emission (ASE) on cryogenic targets have been recorded at various levels using high-speed photomicrography. The results indicate a high probability of the fuel configuration surviving at the present levels of this ASE energy.