Ronaldo Celso Viscovini

CHD/sub 2/OH optically pumped by a waveguide CO/sub 2/ laser: new far-infrared laser lines from the CD/sub 2/ wagging vibrational mode

For the first time, a wide tunability waveguide CO/sub 2/ laser was used to pump the CHD/sub 2/OH molecule for the generation of new FIR laser lines with a large offset. Optoacoustic signals associated with the infrared absorbing transitions of the CD/sub 2/ wagging vibrational mode served as a guide for finding new laser lines. All lines were characterized in wavelength, relative polarization, intensity, optimum pressure of operation, and precise offset measurements.

Characterization of new FIR laser lines from CHD/sub 2/OH

In this work, we report new optically pumped far-infrared (FIR) laser lines from CHD/sub 2/OH. A waveguide CO/sub 2/ laser of wide tunability (290 MHz) was used as pump source, and a Fabry-Pe/spl acute/rot open cavity was used as a FIR laser resonator. Optoacoustic absorption spectra were used as a guide to search for new FIR laser lines. We could observe 15 new laser lines in the range from 116.4 to 401.4 /spl mu/m. The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred Lamb-dip technique was used to measure the frequency absorption transition both for the new and previously reported laser lines.

Frequency Stabilization of Waveguide CO2 Laser by a Digital Technique

In this work we present a simple technique for laser frequency stabilization, based on Digital signal processing. The technique is used to stabilize a waveguide CO2 laser of wide tunability by using three kinds of reference signals: the CO2 laser ouptut power, an infrared absorption optoacoustic signal and the output power of a Far-Infrared optically pumped molecular laser.

/sup 13/CD/sub 3/OD optically pumped by a waveguide CO/sub 2/ laser: new FIR laser lines

A waveguide CO/sub 2/ laser of wide tunability was used to pump infrared transitions of the /sup 13/CD/sub 3/OD C-O stretching vibrational mode. The optoacoustic signal associated with the absorbing transitions served as a guide to search for new laser lines. We could observe 36 new far-infrared laser lines ranging from 57 to 1192 /spl mu/m. All lines were characterized in wavelength, relative polarization, intensity, optimum pressure of operation, and precise offset measurements.

Infrared optoacoustic spectroscopy of13CD3OD around the 10R and 10P CO2 laser lines

In this work we present the results of an investigation about Doppler limited infrared absorbing transitions of the C-O stretching vibrational mode of13CD3OD by means of optoacoustic detection. This technique is an alternative, more sensitive and of higher resolution than the Fourier transform spectroscopy which is applied to this methanol isotopomer, due to the contamination problem associated with the fast exchange of OD by OH in the molecule. Using a waveguide CO2 laser of 290 MHz tunability on each line we were able to observe 69 absorptions, most of then of large offset. The data will be useful in theoretical analysis of this sample, as well as a guide in the search for new FIR laser lines.

Vibrational and Rotational Spectroscopy of 13CD3OD

We have used Fourier Transform spectral data on the C-O stretching mode of 13CD3OD in order to perform a vibro-rotational analysis for this molecule. We have estimated a few molecular parameters of the ground and C-O stretching vibrational modes. Based on these parameters, and by using the Kwan-Dennison model, we propose assignments for a number of far-infrared laser transitions of 13CD3OD.

Characterization of new FIR laser lines from CD/sub 3/-rocking and asymmetric CD/sub 3/ deformation modes of /sup 13/CD/sub 3/OD

In this paper, we report new optically pumped far-infrared (FIR) laser lines from the in-plane CD/sub 3/-rocking and asymmetric CD/sub 3/ deformation absorption vibrational bands of /sup 13/CD/sub 3/OD. A waveguide CO/sub 2/ laser of wide tunability (290 MHz) was used as the pump source, and a Fabry-Perot open cavity as the FIR laser resonator. Optoacoustic absorption spectrum was used as a guide to search for new FIR laser lines. We could observe 13 new laser lines in the range 103-491 /spl mu/m. The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred lamb-dip technique was used to measure the frequency absorption transition for both new and previously reported laser lines.

An enhanced parallel port interface for controlling and monitoring experiments

In this paper we present a circuit for enhanced parallel port (EPP) interfacing that is of low cost and great versatility for general use for data communication in research laboratories. The communication is bi-directional and its speed is higher than 500 Kbytes s-1 . This circuit has an address decoder, which permits individual communication with eight items of equipment of 8 and 16 bits, with an extra status bit. The addressing system also allows insertion of up to 16 such interfacing circuits into the same computer EPP output, each of which can be independently reached.

Infrared Optoacoustic Spectroscopy of 13CD3OD Around 9P CO2 Laser Lines

In this work we present the results of an investigation about Doppler limited infrared absorbing transitions of the in-plane methyl-rocking and the asymmetric methyl deformation modes of 13CD3OD by means of optoacoustic detection. This is an alternative and attractive technique to be applied to this methanol isotopomer, in comparison to Fourier transform spectroscopy. In fact the contamination problem associated with the fast exchange of OD by OH in the molecule limits the use of the Fourier transform technique. Using a waveguide CO2 laser of 290 MHz tunability on each line we were able to observe 20 IR absorptions, most of them of large offset. The data will be useful in theoretical analysis of this molecule, as well as in the generation of FIR laser radiation in optically pumped molecular laser.

DCOOD Optically Pumped by a 13CO2 Laser: New Terahertz Laser Lines

In this work, we report new optically pumped terahertz laser lines from DCOOD. An isotopic 13CO2 laser was used for first time as pump source, and a Fabry–Perot open cavity was used as a terahertz laser resonator. Optoacoustic absorption spectra were used as a guide to search for new terahertz laser lines. We could observe six new laser lines in the range from 303.8 μm (0.987 THz) to 725.l μm (0.413 THz). The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred Lamb‐dip technique was used to measure the frequency absorption transition both for this laser lines.