Hydrazine far-infrared laser lines and assignments: a review (original) (raw)
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Laser action in hydrazine: observation and characterization of new large offset FIR laser lines
IEEE Journal of Quantum Electronics, 1999
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 m. 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 CO 2 laser, the optimum pressure of operation, relative intensity, and the offset relative to the CO 2 center frequency.
IEEE Journal of Quantum Electronics, 2000
A high-peak-power (several hundreds of watts) pulsed CO 2 laser, recently developed in our laboratory, has been used for exciting optically pumped far-infrared laser transitions of N 2 H 4 . A systematic search for N 2 H 4 absorption coincidences with 10P and 10HP CO 2 laser emissions has led to the observation of 27 new far-infrared laser lines, excited by 18 different absorption transitions. All of these new lines have been characterized in wavelength, offset, relative polarization, optimum operation pressure and intensity. Using the LaseRitz program, ten of these lines were assigned, corresponding to five laser systems. For other two laser systems possible and quantum numbers of the energy levels involved in the laser transitions were given.
New far-infrared emissions and frequency measurements in hydrazine
Applied Physics B: Lasers and Optics, 2003
By means of a new CO 2 laser we performed a new investigation of the far-infrared laser emission spectrum of hydrazine excited by the 10P(32) and 10R(8) CO 2 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 CO 2 laser, the optimum pressure and the offset relative to the CO 2 center frequency.
New FIR laser lines from hydrazine and assignments
Applied Physics B: Lasers and Optics, 2004
Our new waveguide pulsed CO 2 laser, with peak powers above 1 kW, has allowed us to observe 24 new farinfrared 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 CO 2 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
Hydrazine (N2H4) and the deuterated isotopes of difluoromethane (CD2F2) and methanol (CH3OD and CD3OH) have been reinvestigated as sources of far-infrared (FIR) laser emissions using an optically pumped molecular laser system designed for wavelengths below 150 microns. With this system, seven FIR laser emissions from optically pumped N2H4, CH3OD and CD3OH were discovered with wavelengths ranging from 54.0 to 185.0 µ m. In addition, the polarizations of eight previously observed laser emissions from optically pumped N2H4, CH3OD and CD2F2 were measured for the first time. All laser emissions are reported with their operating pressures, relative polarizations and wavelengths, measured to ± 0.5 µ m. The effectiveness of this particular system in generating short-wavelength laser emissions has been further demonstrated by the improvement in output power observed from nine known FIR laser emissions.
New far-infrared laser lines and assignments for 13СНзОН methanol
The 13 CH 3 OH isotopomer of methanol has been reinvestigated as a source of far-infrared ( FIR) laser emission by the use of the extended line coverage available from an efficient CO 2 laser recently developed for optical pumping. With this system we have observed 19 new FIR laser lines, pumped by 11 different CO 2 transitions, with five of the pump lines belonging to the new 9HP CO 2 hot band. Accurate heterodyne frequency measurements of the FIR laser and the pump offset have been made for 16 FIR laser lines, including three previously reported in the literature. High-resolution Fourier-transform spectroscopic results for the CO-stretching and the CH 3 -rocking infrared fundamentals of 13 CH 3 OH have been applied to assign the pump and lasing lines for five of the transition systems. One system has the novel feature that two different CO 2 pump lines excite the same upper level, and hence two FIR laser lines of the identical frequency are observed for two different pump lines.
Far infrared laser lines and assignments of CH3OH: a review
International Journal of Infrared and Millimeter Waves, 1992
Methyl alcohol is the most important lasing molecule in the Far-Infrared (FIR) spectral region, and the most widely used for investigation and for applications. Since the last critical review of 1984, over seventy papers have been published dealing with the FIR laser lines and the infrared spectroscopy of CH3OH. In 1984 we could list about 330 FIR laser lines, 98 of which were measured in frequency and 105 assigned. Since then more than 70 papers were published increasing the number of the known laser lines to 575 (103 measured in frequency). Also the FIR and IR spectroscopy was largely improved thanks to the analysis of high resolution FT spectra, and the number of the correctly assigned laser lines has been increased to 224. The wavenumbers of the assigned lines can now be predicted with an accuracy of about 0.001 cmd or better, thus approaching the accuracy of the experimental frequency measurements.
New far-infrared laser lines and assignments for ^13CH_3OH methanol
Journal of the Optical Society of America B, 1995
The 13 CH 3 OH isotopomer of methanol has been reinvestigated as a source of far-infrared ( FIR) laser emission by the use of the extended line coverage available from an efficient CO 2 laser recently developed for optical pumping. With this system we have observed 19 new FIR laser lines, pumped by 11 different CO 2 transitions, with five of the pump lines belonging to the new 9HP CO 2 hot band. Accurate heterodyne frequency measurements of the FIR laser and the pump offset have been made for 16 FIR laser lines, including three previously reported in the literature. High-resolution Fourier-transform spectroscopic results for the CO-stretching and the CH 3 -rocking infrared fundamentals of 13 CH 3 OH have been applied to assign the pump and lasing lines for five of the transition systems. One system has the novel feature that two different CO 2 pump lines excite the same upper level, and hence two FIR laser lines of the identical frequency are observed for two different pump lines.