共查询到20条相似文献,搜索用时 15 毫秒
1.
J-M. Lourtioz J. Pontnau M. Morillon-Chapey J-C. Deroche 《Journal of Infrared, Millimeter and Terahertz Waves》1981,2(1):49-63
Eleven new CW far infrared (FIR) laser lines have been observed in the 600 μm–1200 μm range from the CF2Cl2 (Fluorocarbon 12) molecule optically pumped by a CO2 laser. A 510?4–10?3 accuracy is achieved in the measurement of the FIR wavelengths. The frequency offset between the CO2 pump center and the absorption line centers are measured using the transferred Lamb dip technique. Owing to a recent spectroscopic study of the CF2 35Cl2 molecule three lines may be assigned with great confidence as rotational transitions in thev 6 vibrational band 923 cm?1 of this main isotope. 相似文献
2.
Six FIR laser lines from CD3OH pumped by the 10R(36) and the 10R(18) CO2 laser lines are assigned to specific rotational energy levels in the excited C?0 stretch state. It is found that their upper laser levels are shifted by a Fermi resonance between the C?0 stretch vibration and the third and forth harmonics of the torsional mode. The Fermi resonance shifts are +0.332 cm?1 and +2.251 cm?1 for the upper laser levels pumped by the 10R(36) and the 10R(18) CO2 laser lines, respectively. Calculated frequencies of the pump and the laser transitions agree with those of the pump CO2 laser lines and the observed FIR laser lines within estimated accuracy. 相似文献
3.
Ninety-seven new far-infrared (FIR) laser transitions have been observed in optically pumped ethylene glycol, dimethyl ether, formic acid, and monomethyl amine, all excited by a pulsed CO2 laser. 相似文献
4.
D. Pereira C. A. Ferrari A. Scalabrin 《Journal of Infrared, Millimeter and Terahertz Waves》1986,7(8):1241-1250
In this work we report laser action in 69 new FIR laser lines in CD3OH optically pumped by a regular cw CO2 laser. We have performed measurements of laser wavelength, optimum pressure of the gas, relative polarization and intensity on all lines, including some previously known. 相似文献
5.
Di Forte M. Papuchon M. Puech C. Lallemand P. Ostrowsky D. 《Quantum Electronics, IEEE Journal of》1978,14(8):560-562
A new wavelength tuning effect in optically pumped GaAs-GaAlAs distributed-feedback lasers is presented. It is shown that it is possible to tune the emitted wavelength of the laser by changing the angle between the direction of the pumping line and the normal to the grooves of the periodic structure. The results could be applied to injection DFB lasers to achieve frequency multiplexing for optical communications. 相似文献
6.
Theoretical models of the operating characteristics of both pulsed and CW optically pumped submillimeter (SMM) lasers are reviewed. The SMM laser gain is discussed for both pressure and Doppler broadened transitions. A review is given of expressions for SMM laser gain based on quantum mechanical calculations in a three-level molecular system. 相似文献
7.
J. Pujol R. Vilaseca R. Corbalán F. Laguarta 《Journal of Infrared, Millimeter and Terahertz Waves》1987,8(3):299-305
The unstable emission of an optically pumped FIR gas laser is theoretically analysed through numerical resolution of the associated Maxwell-Bloch equations. The instability domain in the main control parameters space is determined and an example of chaotic behaviour is examined. 相似文献
8.
We study mode competition in optically pumped lasers with one active laser line. The stability of single-mode operation under one mode pumping (both fields arbitrarily intense) is determined by calculating the saturated laser gain using either a mono- or bichromatic probe. The probe spectra differ dramatically from the single-mode, intense field gain curves occasionally exploited in this context in earlier works. Some features in the spectra are interpreted with the dressed atom picture. The mathematically simpler single probe gain is shown to be a good approximation for large mode spacings. When the strong field induced Rabi flipping is comparable to the mode spacing, however, a bichromatic probe containing two frequencies which are symmetric with respect to the intense mode is usually needed. Typical mono- and bichromatic probe spectra are discussed and parameter regions are explored which give stable single-mode operation. The results are also relevant in general laser instability studies: some aspects due to the strong field induced coherences will be pointed out. 相似文献
9.
T. A. DeTemple H. K. Chung S. J. Petuchowski 《Journal of Infrared, Millimeter and Terahertz Waves》1980,1(1):27-44
A signal flow graph representation of the density matrix equations appropriate to a serial three-wave interaction is introduced, from which perturbation theory and AC Stark shift information may be extracted. The conditions for a large interaction cross section for the three-photon transition are deduced and applied to selected experimental situations with the main conclusion being that the effect may be present in a large number of CW and pulsed experiments. 相似文献
10.
Diffraction limited CW optically pumped lasers 总被引:1,自引:0,他引:1
The far infrared spectral characteristics of inductive metal mesh dielectric hybrid mirrors were investigated. From experimental and theoretical studies, the mirrors were found to exhibit etalon effects due to the finite Si substrate thickness and to have two separate diffraction conditions. With grid spacingg and substrate index of refractionn , forn^{-1} < g/lambda < 1 the mirrors diffract in transmission while forg/lambda > 1 the mirrors diffract both in transmission and reflection. Using both inductive and capacitive mesh mirrors, EH11 outputs have been obtained at the milliwatt level in the range 70 μm to 1.2 mm. Powers in excess of 10 mW were obtained from CH3 OH at 96 and 118 μm, HCOOH at 393 μm, CH3 I at 447 μm, and CH3 F at 496μm. 相似文献
11.
A. Bertolini G. Carelli N. Ioli C. A. Massa J. C. S. Moraes A. Moretti F. Strumia 《Journal of Infrared, Millimeter and Terahertz Waves》1997,18(4):779-783
Twenty-five new laser lines have been obtained in the wavelength region from 155 to 830 µm by optically pumping the CD2Cl2 (deuterated dichloromethane) molecule with a CW CO2 laser having a tunability range of 300 MHz. The wavelength, polarization relative to that of CO2 pumping radiation, and offset relative to the CO2 center frequency were determined for all of the new lines and some other already known laser emissions. For all of them we give also the relative intensity and the optimum pressure of operation. 相似文献
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13.
Near-millimeter-wave (NMMW) gas lasers, which are optically excited with a CO2 pump laser, are currently the major sources of coherent radiation in the NMMW region (100 to 1000 GHz). These molecular sources are especially useful at NMMW frequencies > 300 GHz where conventional millimeter-wave sources have serious disadvantages. Optically pumped NMMW lasers can provide tens of milliwatts of CW power of very high spectral purity or megawatts of pulsed power with a broader spectral bandwidth. The state of the art of these lasers, with an emphasis on CW operation, is reviewed. Included are discussions of basic principles of operation, design, and approaches to building laser systems with sufficient power and stability for useful application. Some of the uses of NMMW lasers and some current research efforts on these sources are described. 相似文献
14.
F. R. Petersen A. Scalabrin K. M. Evenson 《Journal of Infrared, Millimeter and Terahertz Waves》1980,1(1):111-115
The frequencies of 48 optically pumped cw FIR CH2F2 laser lines have been measured relative to stabilized CO2 lasers. Uncertainties are estimated to be about 5 parts in 107. 相似文献
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The emission frequency of an amplified spontaneous emission (ASE), optically pumped submillimeter (SMM) laser has been studied as a function of laser gas pressure for several different gases and SMM laser lines. For off resonant pumping, Fabry-Perot interfetometer scans indicate a shift in emission frequency between high- and low-pressure laser operation. In high-pressure operation, emission occurs via a Raman type, two-photon process with some additional frequency offset due to the ac Stark effect. The Raman process is favored by its higher quantum efficiency over a two-step process involving single-photon transitions at the pump and SMM wavelengths. In low-pressure operation, the SMM laser emission is found to be delayed in time with respect to the pump pulse. The Raman process thus cannot occur and the two-step process is favored. This results in a shift in the SMM laser emission frequency from the Raman line to the line center frequency of the SMM laser transition. The Raman emission gain bandwidth appears to be broadened by the CO2 pump laser bandwidth. 相似文献
18.
We report the observation of relaxation oscillations in both the C13H3 F and C12H3 F optically pumped lasers. Expressions are derived for the oscillation frequency and its temperature and pressure dependences using a four-level rate equation model. We observe excellent agreement between measured frequencies and the theory presented. Models are considered for using this phenomenon to determine the rotational and vibrational relaxation mechanisms of the laser gases. 相似文献
19.
A. R. Calloway E. J. Danielewicz 《Journal of Infrared, Millimeter and Terahertz Waves》1981,2(5):933-942
A total of nine cw FIR laser lines are reported from two new FIR laser molecules; CH2CHF and S18O2. These two are from a list of twelve candidate molecules that were predicted using a set of selection criteria. The candidate D2 18O was tested, but did not lase. Combining these results with independent studies on other candidates, brings the number of proven laser molecules to 4 out of 5 that were tested. These results confirm the value of the selection criteria as a guideline for predicting new optically pumped FIR laser molecules. 相似文献
20.
Respectively, three and eight laser lines have been precisely measured and assigned in asymmetric-top molecules HDCO and D2 CO. Frequency calculations of rotational transitions use parameters obtained from microwave studies. For frequency calculations of rovibrational transitions, vibrational energies derived from infrared band analysis have been also taken into account. The assignment is confirmed by infrared radio frequency double resonance experiments inside the submillimeter laser cavity. 相似文献