Frequency measurements on far-infrared laser emissions of carbonyl fluoride (COF2)

The frequencies of 9 optically-pumped far-infrared emissions from COF₂ have been measured by harmonic mixing in a Schottky diode with harmonics of 3-and 4-mm band klystron radiation. The measured emissions lie in the wavelength range 1135–358 m. The results are compared with frequencies predicted from mid-infrared spectroscopy.     

Optically pumped submillimeter laser lines from CH2F2 and CD2Cl2 using a12C18O2 CW laser

Thirty-nine new submillimetre laser lines in CH₂F₂ and twelve in CD₂Cl₂ have been obtained in a Fabry-Perot FIR resonator by optically pumping with a CW¹²C¹⁸O₂ laser. The wavelength range obtained for CH₂F₂ is 126m to 1091m and for CD₂Cl₂ 212m to 774m. The wavelength measurements are accurate to within 5.10^–3. The relative polarisations of the pump laser and the FIR laser output were also determined. Tentative assignments of the IR and FIR transitions were made using existing microwave data.     

12CH2F2 and13CH2F2far-infrared lasers: New lines and frequency measurements

We report here the discovery of 13 new far-infrared laser lines from¹²CH₂F₂ and seven new lines from¹³CH₂F₂. Most of the new lines were pumped by high-J lines of the 9R branch of a cw-CO₂ laser. Wavelengths range from 97.6 to 616.18 μm. Frequency, pump offset, relative polarization, and relative intensity were measured for most of the new lines.     

Frequency measurements of far infrared12CH3OH laser lines

We have measured the frequencies of 12 known and 3 new submillimeter laser lines obtained by pumping¹²CH₃OH with a cw waveguide CO₂ laser in a Fabry-Perot far infrared resonator. We have also measured the relative polarization and the pumping CO₂ frequency offset for each line.Supported in part by a joint grant with the U.S. National Science Foundation # INT80-19014 and the Brazilian Conselho Nacional de Pesquisas (CNPq).Work of the U.S. Government; not subject to U.S. copyright.     

New NH2H4 far-infrared laser lines and their frequencies

We report 25 new far-infrared laser lines and 26 heterodyne frequency measurements in hydrazine. The frequencies range from 1.0 to 5.5 THz with most of the frequencies between 2.5 and 4.0 THz. The lines were generated in a high frequency, far-infrared Fabry-Perot laser cavity pumped by a CO₂ laser. The cavity has a high Q for wavelengths below 150 µm and uses variable coupling to optimize the power for each line.This work has been financed by the Brazilian Government - Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), and by the United States Government - NASA grant W-18, 623.Contribution of NIST, not subject to U.S. copyright.     

Frequencies of cw FIR laser lines from optically pumped CH2F2

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.     

Optically pumped CW fir laser: New submillimeter laser emissions from CH2DOH, CH3I, CD3I, and trioxymethylene

We obtained twelve new far infrared laser transitions by optically pumping the CH₂DOH, CH₃I, CD₃I and Trioxymethylene molecules with a CW CO₂ laser having a tunability range of 280 MHz. We measured the wavelength, polarization, relative intensity and pump offset relative to the CO₂ center frequency for all the new lines.     

Far infrared laser frequencies of CH3OD and N2H4

The frequencies of 26 laser lines with wavelengths between 57 and 534 m have been measured in the optically pumped laser gases CH₃OD and N₂H₄. A pair of stabilized cw 12_{CO 2} lasers was used as a frequency standard for the heterodyne frequency measurements. Seven of the 26 lines are new.     

Frequency measurements of CF2CHF and SO2 laser lines and a new far infrared laser line of HDCO

The emission frequencies of several optically pumped far infrared laser lines of CH₂CHF, SO₂ and HDCO molecules have been measured by mixing them with a harmonic of a millimeter-wave synthesizer operating in the range 78–118 GHz. A new line of HDCO at 1886 GHz has been found.     

Heterodyne frequency measurements of COF2, CD3F,13CD3F, and C2H5I lasers

Heterodyne frequency measurements are reported for twenty optically pumped laser lines from various molecules including COF₂, CD₃F,¹³CD₃F, and C₂H₅I.     

New FIR laser lines from optically pumped C2H3F, C2H3Cl, C2H3Br, C2H3CN, C2H5F, CH2CF2, HCOOH and CH3Br

Twenty-seven new cw far infrared laser lines with wavelengths between 137 and 988m have been observed from optically pumping C₂H₃F, C₂H₃Cl, C₂H₃Br, C₂H₅F, C₂H₃CN, CH₂CF₂, HCOOH and CH₃Br with a CO₂ laser. The wavelengths of these FIR laser lines were determined together with their optimum pressures and relative intensities.     

Optically pumped cw CH2DOH fir laser: New lines and frequency measurements

We have measured the output powers and relative polarizations of 66 cw FIR laser lines from CH₂DOH (including 50 not previously reported), which were optically pumped by a CO₂ laser. The frequencies of 43 of these lines were measured relative to stabilized CO₂ lasers.     

Acoustooptic extension of the frequency tunability of CW CO2 lasers: New FIR lasers emissions from CH3OH and13CH3OH

We have increased the frequency tunability of our CW waveguide CO₂ lasers by means of an acoustooptic amplitude modulator, operating at the fixed frequency of 90 MHz. The up-shifted, or down-shifted, laser optical sideband can be generated independently by adjusting the orientation of the modulator. The efficiency is larger than 50%. The frequency tunability of the CO₂ laser around each laser line is thus increased by 180 MHz. To demonstrate the possibilities of this method, a source composed of the above modulator and of a CW, 300 MHz tunable waveguide CO₂ laser has been used for the search of new large offset FIR laser lines from optically pumped CH₃OH and¹³CH₃OH molecules. As a result 15 and 10 new large offset laser lines were discovered respectively. New assignments of some laser lines are also proposed. We have also measured the Stark effect, the offset, and the polarization of other already known lines. In particular a Stark effect frequency tuning of about 1 GHz is demonstrated for a laser line at 208.399 m.     

Frequency measurements of far infrared cw lasing lines in optically pumped CHCl2F

The wavelengths, frequencies, and relative polarizations of 15 FIR cw lasing lines obtained by optically pumping CHCl₂F with a cw CO₂ laser have been measured. The lines are in the wavelength range from 340.3 to 905.4 m and were pumped by P- and R-branch laser lines in the 9 m band of CO₂.Supported in part by a joint grant with the U. S. National Science Foundation grant # INT80-19014 and the Brazilian Consellio Nacional de Pesquisas (CNPq)Contribution of the U. S. Government, not subject to copyright.     

Analysis of far-infrared laser magnetic resonance spectra of CH2Br at 447.3 and 671.1μm

A simple model has been developed to describe the Zeeman patterns of far-infrared laser magnetic resonance spectra of the monobromomethyl radical CH₂Br observed at 447.3 and 671.1μm. A satisfactory agreement between the experimental spectra of the radical and their simulation with this simple model has been achieved. This approach can be used to gain further information about the structure and the spectrum of this interesting radical.     

New Far-Infrared Laser Lines and Frequency Measurements of Acetaldehyde and Vinyl Fluoride

Eight far-infrared laser lines have been obtained by optically pumping acetaldehyde (CH₃CHO) and nine by pumping vinyl fluoride (CH₂CHF) with a cw CO₂ laser. The far-infrared laser structure used a metal-dielectric waveguide cavity. This is the first reported observation of four of the laser lines in acetaldehyde. In this work, we measure the frequency, optimum pressure of operation, relative intensity, relative polarization, and pump offset from CO₂ laser-line center.     

New FIR laser lines and frequency measurements in CD3OD

Twenty-four new submillimeter laser lines in fully deuterated methyl alcohol (CD₃OD) in the wavelength range from 52 to 328 m have been obtained in a Fabry-Perot FIR resonator by optically pumping the methanol with a cw CO₂ laser. We have made accurate wavelength measurements and have determined the relative polarization of most of the known CD₃OD laser lines. The frequencies of 13 of the strongest lines were also measured.Contribution of the U.S. Government, not subject to copyright.     

Frequencies and wavelengths from a new, efficient FIR lasing gas: CD2F2

We report for the first time wavelength, relative polarization, and frequency measurements for 47 new cw FIR laser lines in the wavelength region from 120 to 1714 m, all obtained by optically pumping CD₂F₂ with a CO₂ laser. Relative output powers were also measured. For comparison, the 189.8 m line pumped by R_I(34) is nearly five times as efficient as the 118.8 m methyl alcohol line.Contribution of the U.S. Government, not subject to copyright.     

The effects of power rippling on CO2 laser cutting

A power rippling method was proposed in this study to improve the cut edge quality by disturbing the natural frequency of the periodic striations in high power C0₂ laser cutting. A pilot study was also designed and set up to examine the power responsibility of the laser system, which is externally controlled by a modulated analogue signal from a signal generator. Several aspects were examined in this study. The effects of different power rippling frequencies on the cut surface roughness is the first such aspect, and the different power modulation depth on cut surface roughness is another. The power rippling shape is the third important parameter examined in this study. It was found that the amplitude and frequency of the striation pattern on the cut surface were significantly affected by the characteristics of the rippling power. Cutting quality can be significantly improved by rippling the laser power.