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1.
Analysis is given for a possibility of singly resonant parametric oscillation in the submillimeter range at synchronous pumping
of the ZnGeP2 crystal by a train of 100-ps second-harmonic pulses from the CO2 laser with the radiation energy 1.0 J. The calculation shows that using the ZnGeP2 crystal and the second harmonic of the CO2 laser with the energy density 1.8 J cm−2, one can get the peak submillimeter radiation power from 3.6 to 12 MW in the range from 95 to 300 μm (1.0–3.3 THz). The expected
peak power values are larger than the experimental ones obtained by other nonlinear optics methods. 相似文献
2.
N. Ioli V. Panchenko M. Pellegrino F. Strumia 《Applied physics. B, Lasers and optics》1985,38(1):23-30
An ir CO2, dc current pumped, optical waveguide (WG) amplifier has been built, and its active medium optical parameters measured for several CO2 emission lines, and their dependence from active medium total pressure, discharge current and temperature was investigated.High gain is found which, coupled with relatively high saturation power in the WG fundamental mode and ease of fabrication with this technology in long (up to 1.5 m) lengths, indicates promising use to efficiently amplify high spectral and spatial purity output of a short, highly tunable WG laser up to power levels suited for nonlinear spectroscopy and optical pumping. The dependence of the small signal gain coefficient and of the saturation parameter for individual rotational lines on the radiation intensity was computed using experimentally known parameters of the discharge plasma. The computation was carried out using the two mode rate equation approach for CO2–N2–He gas mixtures. A satisfactory agreement between theoretical and experimental results was obtained.Work supported by G.N.S.M.-C.N.R. and M.P.I. 相似文献
3.
Pulsed sealed off CO2 laser operation at 19 atm gas pressure has been demonstrated by pumping DF/CO2/He mixtures with radiation from a pulsed DF laser. DF acts as an absorber for the pumping radiation, and the CO2 upper laser level is populated via subsequent energy transfer. CO2 pulse energy at 19 atm was 0.5 mJ corresponding to a photon conversion efficiency of 4% measured relative to the number of absorbed pumping photons. 相似文献
4.
New aspects of substance separation by the laser driven diffusion of gaseous mixtures through capillaries are presented. By using the chopped radiation of a low power CO2 laser, the experimental dependence of the separation coefficient on the pulse frequency in mixtures containing resonant and non-resonant gases was investigated. The induced effects agree with a model in which the number density of adsorbed molecules should be connected to temporal characteristics of the radiation. By avoiding heating effects, a pulsed laser irradiation may provide a new approach related to the practical purposes of substance separation in metal capillaries. 相似文献
5.
I. G. Koprinkov K. V. Stamenov K. A. Stankov 《Applied physics. B, Lasers and optics》1984,33(4):235-238
An intensive generation of radiation from a discharge-pumped atomic-fluorine gas laser is reported. A peak power exceeding 330 kW and a total energy of more than 2 mJ is obtained for a number of lines in the red, using a NF3He (1100) gas mixture at total pressure of 500 Torr. The circuitry optimization is described and the conditions for effective operation of the atomic-fluorine laser are discussed. The temporal and the spectral characteristics of the laser emission are also presented. 相似文献
6.
Michele A. De Bousbahi K. Carelli G. Moretti A. Moruzzi G. Strumia F. Xu L.-H. 《Applied physics. B, Lasers and optics》2004,78(1):39-42
Our new waveguide pulsed CO2 laser, with peak powers above 1 kW, has allowed us to observe 24 new far-infrared laser lines emitted by hydrazine. Each of them is characterized in wavelength, relative polarization, intensity, optimum operating pressure and pump offset from the center of the exciting CO2 line. These new laser emissions either form pairs sharing the same pump line, or complete such pairs with lines known from the literature. In the latter case, we have measured the relative polarization and offset of the partner lines whenever they were not reported in the literature. The availability of laser systems with two emission lines orthogonally polarized and sharing the same upper level is expected to facilitate the assignment work. We present complete assignments for four FIR laser emissions, and we propose J and K values for 12 further laser systems. PACS 42.55.Lt; 42.62.Fi 相似文献
7.
Coherent terahertz radiation in a widely step-tunable range of 72.3–2706 μm (0.11–4.15 THz) has been generated in GaAs crystal
by difference-frequency generation using one CO2 laser with dual-wavelength output. The peak power of THz pulse reaches 35 W at the wavelength of 236.3 μm, which corresponds
to a pulse energy of 2.1 μJ. An average power of 10 μW has been achieved when working repetitively. This efficient terahertz
radiation source is more compact and widely tunable than other THz sources pumped by CO2 laser. 相似文献
8.
U. Werling K. F. Renk Wan Chong-Yi 《International Journal of Infrared and Millimeter Waves》1986,7(6):881-889
Conclusion We described a CH3F Raman laser pumped by a two stage 20 atmospheres CO2 laser. The emission spectrum of the CH3F laser at 11 Torr extends from 23 cm–1 to 45 cm–1 when the CO2 laser is scanned over the 9R emission branch at a fixed pump power of 180 mJ. The emission spectrum shows a strong structure with large parts where the FIR energy decreases to zero. This fact makes the use of such a laser for spectroscopic scanning experiments in the FIR difficult. The laser is, however, very suited for working at fixed but adjustable FIR frequencies. The pulse energy in the maxima of the emission characteristics at a pump energy of 180 mJ exceeds 300 J, which corresponds a photon conversion coefficient of more than 6%. 相似文献
9.
P. T. Lang F. Sessler U. Werling K. F. Renk 《International Journal of Infrared and Millimeter Waves》1989,10(7):821-828
Summary We described a13CH3F Raman laser pumped by a grating tuned 20 atmospheres CO2 laser. The emission characteristics of the13CH3F laser extends from 14 cm–1–35 cm–1 and from 49 cm–1–72 cm–1; about 65% of these frequency ranges can be covered with tunable radiation. The characteristics shows a strong dependence on the rotaional quantum numbers of the states involved in the Raman laser transitions and, within each tuning interval, on the frequency offset with respect to the frequencies of resonant transitions. We obtained, at 51 cm–1, a maximum FIR laser pulse energy of about 800 J (at a pump energy of 200 mJ), corresponding to a photon conversion of about 8%. In some cases we have observed simultaneous emission at a Raman and a cascade frequency. In addition, FIR emission power dependence on13CH3F gas pressure and pump pulse power were investigated for different J quantum numbers. 相似文献
10.
Lasing and discharge in mixtures of SF6 with hydrogen and hydrocarbons are investigated. If the chemical reaction is initiated by a self-sustained discharge (a generator
with both an inductive and capacitive energy storage can be used), the maximum lasing efficiency is attained at high values
of the ratio E/p (where E is the electric field intensity and p is the pressure in the mixture) if shaped electrodes and preionization of the discharge gap are employed. For the first time,
the lasing efficiency obtained in a nonchain HF laser is as high as 10% of the energy deposit and 4.5% of the stored energy
for a specific radiation energy of ≈140 J/(l atm). At high efficiencies, the emission spectrum of the nonchain HF laser significantly
broadens and cascade lasing at P(3-2) → P(2-1) → P(1-0) vibrational transitions for several rotational lines is realized. 相似文献
11.
A two-pulse two-wave (Nd and CO2 lasers) scheme is proposed for irradiating a laser target, which ensures the highest factor of laser radiation conversion to the X-ray range (13.5 nm ± 1%). Analytic estimates are obtained for parameters of pulses and of the target made of Xe or Li. Numerical optimization is performed for X-ray emission from a spherical Xe target exposed to a CO2 laser pulse. The maximal factor of conversion of laser radiation to X rays is ~1%. Angular and spectral characteristics of X-ray radiation are obtained. The flux of fast Xe ions ejected from the target and damaging the Mo/Si coating of X-ray mirrors is estimated. 相似文献
12.
M. O. Bulanin A. P. Burtsev Yu. M. Ladvishchenko Yu. M. Sveshnikov 《Optics and Spectroscopy》2001,91(1):38-45
The refractivity of gaseous SF6 and NH3 in the region of the intense absorption bands of these compounds was measured by two-beam, two-color interferometry using a He-Ne laser and a CO2 laser tunable throughout its emission lines. Quantitative data on the profiles of the absorption bands of these gases were also obtained by IR Fourier spectroscopy. By using the joint processing of the results of refractometric and spectral measurements on the basis of the Kramers-Krönig formalism, the dispersion dependences of the vibrational polarizabilities of the given molecules were calculated and the integrated intensities of their fundamental vibrational bands were refined. A table of values of total and vibrational polarizabilities at the emission frequencies of the CO2 laser was compiled. 相似文献
13.
The ability of a CO2 laser to oscillate in the range of 16 (14) μm at room temperature was investigated experimentally and theoretically. The output energy per pulse was ~60 mJ at peak power of ~50 kW. It was necessary to minimize not only harmful losses but also useful ones in both channels 0001–0200 and 0200–0110 and to increase the input energy, i.e., the density of free electrons in the discharge, in order to increase the peak power and energy of 16-μm radiation. The highest values of peak power and energy of radiation were reached at different pressures of the active mixture. The rotational bottleneck effect limiting the peak power and energy of oscillation was important at rather low pressures of the active medium. Oscillation at the R12 line is more preferable than that at the P12 line for use as 9.6-μm dumping radiation. 相似文献
14.
This paper presents the results of studies aimed at the creation of a hybrid laser system which is composed of a gas lasers and a nonlinear crystal and appreciably broadens and enriches the radiation spectrum of these lasers. A highly efficient conversion (37%) is attained when generating the second harmonic in a ZnGeP2 crystal owing to an increase in the peak power of CO laser radiation in the mode locking regime. The two-cascade conversion (generation of both sum and difference frequencies) of radiation of a broadband CO laser in the single sample of such nonlinear crystals as ZnGeP2 and AgGaSe2 is demonstrated. In this case, the radiation spectrum is broadened by nearly a factor of two, and the number of detected spectral lines grows by a factor of four. The use of a comparatively simple laser system of gas-discharge CO and CO2 lasers to conversion in AgGaSe2 results in laser radiation tunable over a set of narrow spectral lines within a range from 2.5 to 16.6 μm (more than two and a half octaves). 相似文献
15.
We have measured absorption of emission from a TEA CO2 laser, lasing on hot band lines, in pure CS2 and a mixture of CS2 with air, and we have determined the optimal lines for optical excitation. Numerical modeling has shown that as the peak
intensity of the pump radiation is increased, we observe absorption saturation, the extent of which decreases as the pressure
increases. The major factor responsible for absorption saturation is the “rotational bottleneck” effect. Depending on the
peak intensity of the radiation, addition of a buffer gas can lead to an increase or decrease in the absorption.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 61–66, January–February, 2007. 相似文献
16.
Summary Large helium-free emissions are obtained in two mini-TEA CO2 lasers, by using always a corona preionization without additives and with a maximum energy density of 900J/l in the discharge.
In general, helium-free emissions are more stable, but the best condition in efficiency, energy and peak power is observed
always with a small He content added to the laser mixture.
Riassunto L'uso di una piú efficiente preionizzazione a corona ha permesso l'operazione di un laser a CO2 senza elio a pressione atmosferica con elevate densità di energia nella scarica (900 J/l) e grande efficienza di conversione dell'energia elettrica in radiazione laser.相似文献
17.
Operation of a CH3F laser at 496μ has been obtained in a hemispherical optical cavity pumped by up to 42 J of 9.55μ CO2 TEA laser radiation. Highly modulated 1μ pulses delivering 6 mJ at peak powers greater than 10 kW have been recorded. 相似文献
18.
T. Tillert P. Zimnas K. F. Renk 《International Journal of Infrared and Millimeter Waves》1996,17(6):1011-1021
Using a continously tunable pulsed 20-atmosphere CO2 laser as a pump source, we generated pulses of mid-infrared radiation, partly tunable in frequency intervals in the range between 200 and 900 cm–1 via stimulated Raman scattering in gaseous ammonia. As a Raman cell we used a multiple pass cell. We observed for14NH3 and15NH3 laser lines at 52 different frequencies with 39 lines observed for the first time. Tuning ranges up to 150 GHz and peak powers of several MW were achieved. The quantum efficiency reached 40 %. 相似文献
19.
A. Tönnißen J. Wanner K. W. Rothe H. Walther 《Applied Physics A: Materials Science & Processing》1979,18(3):297-304
The measurement of the concentration of gaseous hydrogen fluoride in the exhaust of an aluminum plant by resonance absorption
of the radiation of a cw chemical HF laser is reported. The HF concentration has been evaluated taking into account the simultaneous
absorption of water vapor and carbon dioxide at the HF laser frequencies. The absorption cross sections for H2O and CO2 at the HF laser lines have been determined in laboratory experiments. 相似文献
20.
N. Beverini G. Carelli A. De Michele M. Finotti N. Ioli A. Moretti 《Applied physics. B, Lasers and optics》2003,77(1):93-95
By means of a new CO2 laser we performed a new investigation of the far-infrared laser emission spectrum of hydrazine excited by the 10P(32) and 10R(8) CO2 laser lines. We found seven new lines and measured the frequency of four of them; moreover we measured the frequencies of two more lines previously reported in the literature with only wavelength measurements. The frequencies of the far-infrared laser emissions have been measured by means of a frequency-synthesis chain based on new InP Schottky diodes. The detected signal was beat-note generated in a Schottky diode between the far-infrared radiation, the harmonics of a 72 GHz frequency reference and a rf signal. We also characterized all of the observed lines by their polarization relative to the pumping CO2 laser, the optimum pressure and the offset relative to the CO2 center frequency. PACS 42.55.Lt; 42.62.Fi 相似文献