Laser action in hydrazine: observation and characterization of newlarge offset FIR laser lines

Using for the first time a waveguide CO₂ laser with a tunability of 300 MHz, in order to pump large offset infrared absorptions, we obtained 34 new far-infrared laser lines from the hydrazine molecule; their wavelengths range from 155.2 to 669.3 μm. All of the new lines and some other already known laser emissions are characterized in the wavelength, the polarization relative to that of the pumping CO₂ laser, the optimum pressure of operation, relative intensity, and the offset relative to the CO₂ center frequency     

Compact pulsed deuterium fluoride laser

Several new laser lines corresponding to 1-0 transitions of deuterium fluoride (DF) have been observed in a small pulsed laser operated on He, SF6, and D2mixtures.     

The water-vapor laser

Water-vapor lasers oscillate on more than a hundred pulsed lines and over a dozen CW lines over the wavelength range from 7 to 220 μ (1300-45 cm^-1). Nearly eighty of these lines are now identified as vibrational-rotational and pure rotational transition in the low-lying vibrational states of the water-vapor molecule. The structure of the water-vapor molecule is reviewed, and the mechanisms responsible for creating population inversions in water-vapor discharges are discussed. It is shown how a model, based on perturbations between rotational levels of different vibrational states, can be used to explain the laser action and to predict new laser lines. Detailed summaries of data on all observed laser lines in H2O¹⁶, H2O¹⁸, and D2O¹⁶and their identifications are presented. Some of the lines are newly reported, and more accurate wavelength measurements have been made for many of the lines. The observation of predicted laser lines in H2O¹⁸is shown to be a strong confirmation of the perturbation model. The list of references contains a fairly complete bibliography of previous work on the water-vapor laser, and a representative bibliography of work on the energy-level structure of the water-vapor molecule.     

New CW FIR laser action by Stark tuning from optically pumped CH3OH and CH3OD

Fifteen new CW FIR laser lines are reported from Stark tuned CO2optically pumped CH3OH and CH3OD. Four new CW laser lines have also been observed from zero field optically pumped CH3OD, three with a CO2laser, and one with an N2O laser.     

New CW lines from a submillimeter waveguide laser

Sixty-one new CW laser lines with wavelengths between 0.1 and 1.5 mm have been observed with a waveguide laser optically pumped by a CO2laser.     

Characteristics of a Raman laser excited by an ordinary ruby laser

The stimulated Raman effect of benzene has been observed using an ordinary (nongiant) ruby laser. The build-up of oscillation at the v2, 2v2, 3v2and 4v2Stokes lines and also at the first v1Stokes line have been observed. The threshold exciting power for laser action in the v2Stokes line has been measured to be 9.5 kW. A rate equation for the Raman laser has been given, and the total scattering cross section for the v2Raman line of benzene has been determined as σ = 0.46×10^-28cm². The estimation based on the results of this investigation indicates that it is possible to construct a Raman laser of benzene using an Ar gas laser.     

New CW far-infrared laser lines from CO2laser-pumped CD3OH

Twenty-one new CW far-infrared laser lines have been observed from the CD3OH molecule pumped by a CO2laser. The wavelengths of these new lines fall in the short wavelength range from 34.5 to 287 μm.     

New CW CO2 laser lines: the 9-μm hot band

We have made what we think is the first observation of the oscillation of the 9-μm hot-band lines 01¹1→[11¹ 0,03¹0]_II of CO₂. We have observed 40 lines with a maximum power of 8 W. They will provide a new source of laser radiation for spectroscopy. The set of lines has been positively identified by directly measuring the frequencies of two of the lines with a heterodyne technique using a CO₂ laser standard     

Methanol and the optically pumped far-infrared laser

New results on the generation and spectroscopic analysis of optically pumped far-infrared (FIR) laser emission from CH₃OH have been obtained as part of a systematic study of methanol isotopomers as FIR laser sources utilizing the extended line coverage available from a recently developed high-resolution CO₂ laser of high efficiency. For normal CH₃OH, six new short-wavelength lines have been found using a 2 m long Fabry-Perot FIR laser cavity. Accurate heterodyne frequency measurements are reported for 14 CH₃OH FIR laser lines, nearly all above 100 cm^-1, as well as accurate frequency offsets for most of the corresponding CO₂ pump lines. Spectroscopic assignments are presented for nine high-frequency FIR laser lines in four pump systems     

New FIR laser lines from optically pumped CH3OH: Measurements and assignments

26 new FIR laser lines have been observed in CO2laser pumped CH3OH, and together with some previously observed lines their wavelengths have been measured with a relative accuracy of3 times 10^{-4}by using the FIR resonator as a scanning Fabry-Perot interferometer. Based on the internal consistency of the data, it is suggested that a number of the lines originate from combination bands involving simultaneous excitation of the CO stretch mode and a different vibrational mode.     

New frequency measurements and laser lines of optically pumped12CH3OH

The frequencies of 70 optically pumped CW FIR¹²CH3OH laser lines have been measured relative to stabilized CO2lasers. Fifteen new laser lines together with the relative output powers and polarizations for most of the 104 known lines pumped by laser lines in the normal 9 and 10 μm bands of¹²C¹⁶O2are also reported.     

Far-infrared laser oscillations from H2CO

Lasting laser oscillation was obtained from H2CO vapor with a longitudinal-flow tube. Ten lasing lines, including six new lines, have been observed in the pressure range of 0.18-0.35 torr. The optimum conditions were 2.5-7.1 kV and 2.5 Hz for excitation voltage and pulse repetition rate, respectively. The pulse shape of the lines was observed by an Ni-W diode.     

New CO2 laser lines in the 11-μm wavelength region:new hot bands

Nineteen new laser lines in the 11-μm wavelength region have been observed in CW oscillation from a CO₂ laser with a high-Q, high-resolution cavity at a higher than usual current density. The frequency of each line has been measured using heterodyne frequency measurement techniques. Analysis of the frequencies shows that 15 lines are rotation-vibration transitions of the 01¹2-[11¹1,03¹1]_I band (the first sequence hot band) of the CO₂ molecule and four lines belong to the rotation-vibration transitions of the 02²1-[12 ²0, 04²0]_I band of CO₂     

New far-infrared laser lines from CO2-laser-pumped CH3OH gas by using a copper waveguide cavity

Eleven new far-infrared (FIR) laser lines have been observed from CH3OH pumped by a CO2laser. These lines are ranged from 78 to 694 μm and are obtained by using a copper waveguide cavity.     

Narrow-band CO2-TEA laser for efficient FIR laser pumping

To reduce the linewidth mismatch between the emission lines of a CO2-TEA laser and the absorption lines of a low-pressure FIR gain medium a tiltable Ge etalon has been introduced into the TEA resonator. The resulting spectral compression and tunability increase the energy conversion efficiency in a TEA laser pumped CH3OH laser by as much as a factor of 37 and has led to the observation of 14 new FIR laser lines.     

Millimeter and submillimeter-wave laser action in symmetric top molecules optically pumped via perpendicular absorption bands

Ninety-nine new far infrared (FIR) laser lines from 227 μm to 1.965 mm have been observed in CH3CN, CH3CCH, CH3Cl, CH3Br,and CH3I by optically pumping these gases with CO2-laser pulses of 150-μs duration.     

A 500 MHz tunable CO2waveguide laser for optical pumping

A long-pulse CO2waveguide laser is described, which can be single frequency tuned over 500 MHz in about 80 lines. A peak power reaching 125 W at line center and 85 W at the tuning edge in the strongest lines makes the laser ideally suited for optically pumped FIR lasers. New FIR lines have been observed by pumping CH3OH in absorptions located up to 268 MHz from the CO2line center. FIR wavelengths have been measured, identified, and compared to calculations at a level of relative accuracy of5 cdot 10^{-5}.     

New laser lines with wavelengths from λ = 61.7 µm down to λ = 27.7 µm in optically pumped CH3OH and CD3OH

25 new CW far infrared laser lines have been observed with wavelengths fromlambda = 61.7 mum down tolambda = 27.7 mum. We have significantly increased the number of known short wavelength laser lines and extended the laser line spectrum to the 30 μm region by using a BaF2outcoupling system.     

CW iodine-ion laser in a positive-column discharge

In a positive-column He-I2discharge of a cataphoresis-type, CW laser oscillation of an output power around 10 mW for five visible lines has been first observed and output characteristics of three lines have been studied.     

Observation and assignment of D218O FIR laserlines optically pumped by a waveguide CO2 laser

By means of a detailed analysis of the v₂ infrared band of D₂¹⁸O, it has been possible to assign most of the FIR emissions reported in the literature. Moreover, two FIR laser lines which fall in the range of tunability of the CW waveguide CO₂ laser have been predicted and observed. The frequency of the stronger line was measured and found to be 2611.4185(10) GHz, thus filling a gap in the presently available comb of FIR laser lines whose frequencies have been measured. The wavelength precision of the assigned lines was improved by about two orders of magnitude