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1.
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
2.
High-efficiency drivenQ switching of the CO2 laser has been observed by the use of the Stark effect in CH3 Cl, CH3 F, CH3 CHF2 , CH2 = CF2 , and C2 H3 Cl on various lines in both the 9.4- and 10.4-μ bands. The effect is observed with both pulsed and sinusoidal electric fields applied to the intracavity modulator. 相似文献
3.
A new emission line has been observed by optically pumping OCS with 9 μm R(8) CO2 laser radiation and has been tentatively assigned. In addition, fourteen new emission lines of CH3 OD and four of CH3 OH have been discovered. 相似文献
4.
We describe the practical performance of a pulsed mirrorless far-infrared gas laser pumped by a TEA CO2 laser. The system is designed to serve as a high-power source for experiments in far-infrared nonlinear optics and saturation spectroscopy of solids. Out of numerous candidates, 11 gases were selected for a careful survey: CH3 F,13CH3 F, NH3 , D2 O, D2 18O, D2 S, HDS, CH3 Cl, CH3 Br, CH3 I, and CH3 CN. With an available pump energy of up to 10 J, a total of 203 far-infrared lines with pulse energies up to 12 mJ were found, covering the wavelength range from 42 μm to 1.2 mm. 78 of these lines had not been observed before. The position of further 39 lines is at variance with former literature reports. 相似文献
5.
PassiveQ switching of the CO2 laser in the 10.6-μ region using C2 H4 gas and in the 9.6-μ region using CH3 OH vapor is reported. 相似文献
6.
Drozdowicz Z. Woskoboinikow P. Isobe K. Cohn D. Temkin R. Button K. Waldman J. 《Quantum Electronics, IEEE Journal of》1977,13(6):413-417
Single mode, 60-80 ns pulse width, 50-70 kW peak power laser oscillators operating on the 384.6 μm line of D2 O have been developed. The characteristic linewidths of these oscillators are less than 25 MHz full width at half maximum which favorably compares with the intrinsic width of 6-8 MHz associated with the pulse length of about 60 ns. A 12.7 mJ, 195 kW, 384.6μm D2 O laser oscillator-amplifier combination has been constructed and tested. Although single longitudinal mode operation is attained from this oscillator-amplifier system, amplified spontaneous emission (superradiance) from the amplifier adds low power level wide-bandwidth background radiation. Studies of far infrared lasing action in CH3 F and CH3 I are also described. 相似文献
7.
Eleven new far-infrared (FIR) laser lines have been observed from CH3 OH pumped by a CO2 laser. These lines are ranged from 78 to 694 μm and are obtained by using a copper waveguide cavity. 相似文献
8.
Simultaneous laser emission at 337 and 118 μ has been observed in a pulsed discharge through a mixture of N2 , O2 , and either CH4 or (C2 H5 )2 O. Earlier observation of a laser line at 469 μ is rejected and explained. 相似文献
9.
Theory and first operation of a distributed feedback gas laser is expanded. This goal has been achieved by an optically pumped 496μm CH3 F laser equipped with a hollow metal waveguide with deep periodic corrugations. The period of corrugations is tuned by temperature variation. Single-mode operation is achieved. The working pressure of CH3 F is up to 10 torr. Propagation of the laser beam is near the diffraction limit. The spectral linewidth of less than 22 MHz corresponds to the transform limit set by the 50 ns pulse duration. Temperature tuning curves of the laser output are in good agreement with theory. 相似文献
10.
The density matrix formalism describing the interaction between a three level molecular system and two nearly resonant laser fields of arbitrary intensity is extended to include the molecularM -level degeneracy. Expressions for gain on the two possible relative polarizations of a laser pumped molecular laser are derived and its saturation behavior discussed. Numerical results for the 385 μm transition in D2 O and 496 μm transition in CH3 F are presented. 相似文献
11.
Low-vibrational-levelP(J)_{upsilon,upsilon'} CO laser emissions have been measured from He-air-CH4 mixtures. The CW lines below 5.0μ were measured in air to occur at 4.8836, 4.8935, 4.8974, 4.9072, 4.9366, 4.9466, 4.9670, and 4.9778μ. These emissions are tentatively identified to result from transitions as low asupsilon = 3 : 2 . Such emissions were relatively more frequent with CH4 than with CO specifically. 相似文献
12.
Petersen F. Evenson K. Jennings D. Wells J. Goto K. Jimenez J. 《Quantum Electronics, IEEE Journal of》1975,11(10):838-843
A far infrared (FIR) frequency synthesis technique using saturated-absorption stabilized CO2 lasers and a point-contact diode has been used to measure frequencies of a number of strong CW H2 O, D2 O, and CH3 OH laser lines. The first frequency measurements of the 79-μm H2 O, the 73- and 108-μm D2 O, and 11 CO2 -pumped CW12CH2 16OH laser lines are reported. This measurement is the first demonstration of the general usefulness of CO2 lasers for accurate synthesis of FIR frequencies. 相似文献
13.
The effect of low electric field Stark tuning on the absorption of CH3 OH gas at theP(12) 9.4-mu CO2 laser line has been studied. At the 220-mtorr CH3 OH pressure optimal for CH3 OH far-infrared (FIR) laser operation, the line center absorption coefficient increases by a factor of 5 with a Stark field of 2.3 kV/cm. 相似文献
14.
Henningsen J. Inguscio M. Moretti A. Strumia F. 《Quantum Electronics, IEEE Journal of》1982,18(6):1004-1008
Four new FIR laser lines at 62.98, 48.77, 224.53, and 190.65 μm are reported from CH3 OH, optically pumped by the 10R34 and 9R10 lines of a waveguide CO2 laser. Measurements performed by several techniques confirm that the pump offsets are outside the tuning range of conventional CO2 lasers. Two of the lines are assigned as highJ transitions within the torsional ground state of the CO stretch. 相似文献
15.
Bluyssen H. Van Etteger A. Maan J. Wyder P. 《Quantum Electronics, IEEE Journal of》1980,16(12):1347-1351
Very short far-infrared (FIR) pulses were generated from optically pumped CH3 F, CH3 OH/D, and HCOOH lasers using aQ - switched, current pulsed (200 mA, 100 μs), low pressure (20 torr) CO2 laser as a pump source. Values of 20 ns for the rise time and 50 ns for the decay time of the FIR pulses have been observed. The dependence of the FIR pulse shape parameters, i.e., rise time, decay time, and pulse buildup time, on the width of the pump pulse and the pressure of the molecular gas have been investigated experimentally. Due to the regular pulse shape, high repetition rate (350 Hz), high peak power (≳1 W), and broad spectral range (lambda = 100-500 mu m), the pulses are very useful for purposes of solid-state and molecular time resolved spectroscopy. 相似文献
16.
A CH3 F laser oscillator producing between 0.5 and 1 kW pulses lasting 400 ns and confined to less than 27-MHz bandwidth at 496 μm is the basis of an injection laser assembly which generates up to 250 kW of far-infrared (FIR) output within a bandwidth of 55 MHz. 相似文献
17.
Thirteen far IR laser lines in CH3 OH, optically pumped by a CO2 laser, have been assigned toa - andb -type transitions in ν5 CO-stretch band. Identification procedures used were: a frequency match between the CO2 pump and CH3 OH absorption, frequency match of laser lines and CH3 OH ν5 transitions, polarization of far IR radiation, cascade and competition effects between far IR laser lines, and frequency consistencies. An improved set of molecular constants for ν5 transitions were also obtained. 相似文献
18.
Gastaud C. Sentz A. Redon M. Fourrier M. 《Quantum Electronics, IEEE Journal of》1980,16(12):1285-1287
Fifteen new CW FIR laser lines are reported from Stark tuned CO2 optically pumped CH3 OH and CH3 OD. Four new CW laser lines have also been observed from zero field optically pumped CH3 OD, three with a CO2 laser, and one with an N2 O laser. 相似文献
19.
More than 30 laser lines, several of them with an intensity in the order of mW have been obtained in the submillimeter wavelength range from 100 to 900 μm by optically pumping the deuterated molecules of dichloromethane (CD2 Cl2 ) and methanol (CD2 HOH, CH2 DOH) with a step tunable CO2 laser. 相似文献
20.
A long-distance low-loss silica optical-fiber link connected to a compact absorption cell was employed to realize a fully optical highly sensitive fiber gas sensor for low-level CH4 gas in conjunction with a highly radiant InGaAsP light-emitting diode (LED) at 1.66 μm. By using a dielectric interference filter which replaces a monochromator to simplify the system configuration and operation, a 2-km-long silica fiber link was demonstrated to be capable of achieving reproducibly the detection sensitivity of nearly 700 ppm for CH4 gas in air, i.e., 1.3 percent of the lower explosion limit of CH4 density. This high sensitivity verifies a potential for major applications to strategic points within the environment, like industrial and mining complexes as well as urban and residential areas. This result also indicates that the purely optical gas-sensor system based on ultralow loss optical-fiber networks, incorporating LED's or laser diodes, can be extensively utilized for the real-time remote measurement and surveillance of a number of dangerous, explosive, and toxic gases in the near-infrared region. 相似文献