Submillimeter absorption of electrolyte solutions

Absorption coefficients of very absorbing electrolyte solutions have been measured between 20 and 185 cm^?1. Fourier Transform Spectrometry is used together with a Far Infrared laser spectrometer on a discrete serie of lines. Excess absorption of lithium salts solutions, over that of pure solvent is evidenced for tetrahydrofuran and aqueous solutions.     

Further new CW FIR lasting investigations in CH3I,13CH3I and CD3I: New lines and assignments

Forty seven new CW FIR emissions lines have been observed in CH₃I,¹³CH₃I and CD₃I, optically pumped by a CO₂ laser and a N₂ laser, in a metallic waveguide resonator. Assignments are given for a large number of these new lines.     

Far-infrared laser action in vinyl chloride,vinyl bromide,and vinyl fluoride optically pumped by a CW N2O laser

This paper reports the first use of a N₂O laser for optically pumping vinyl halides, to obtain new cw submillimeter laser lines. Eighteen far-infrared (FIR) emissions have been observed in vinyl chloride, twenty five in vinyl bromide and thirty eight in vinyl flouride.     

New CW FIR laser lines obtained in ammonia pumped by a CO2 laser,using the Stark tuning method

We report fifty seven CW FIR emissions observed in NH₃, by resonant pumping with a CO₂ laser. Exact coincidences between IR absorption lines of the gas and emission lines of the CO₂ laser have been carried out by Stark tuning. IR frequency shifts, up to 30 GHz, have allowed the pumping of forty three NH₃ transitions. These FIR emissions correspond to thirty one different wavelengths in the 50–400 μm range; eighteen ones of them are new emitted wavelengths by pumping with the CO₂ laser.     

Operation of a small-scale CW deuterium fluoride chemical laser

We have investigated a small-scale continuous-wave DF chemical laser. Measurements are reported which indicate a multiline output power of 11 W using SF6as the fluorine source. With NF3used as the fluorine source, a multiline output power of more than 20 W was obtained. The degree of SF6dissociation was found to be about 13 percent with O2addition.     

Construction of parallel grids acting as semitransparent flat mirrors in the far infrared

The construction of metallic wired grids used as semitransparent mirrors is described. The reflectance of such grids varies widely with the polarization direction of the beam. The measured characteristics are compared with those calculated. These grids are used in the cavity of an HCN laser and determine the polarization direction of the output beam.     

Mismatch-induced bit error rate in optical chaos communications using semiconductor lasers with electrooptical feedback

We analyze the influence of parameter mismatch between emitter and receiver systems on the bit error rate of an optical chaos communication scheme. Intensity hyperchaos is generated in the system by semiconductor lasers with electrooptical feedback. We find analytical predictions for the dependence of the bit error rate with the amplitude of the various mismatches and the statistical properties of the hyperchaotic carrier. A good concordance is found with numerical and experimental results.     

Surgical treatment of serous detachments of the macular neuroepithelium in diabetics

PURPOSE: Maculopathy in diabetes mellitus represents one of the most serious complications of the diabetic retinopathy. Retinal photocoagulations are often impossible and even dangerous. We propose a new method of surgical treatment for this macular serous detachment. MATERIAL AND METHOD: Thirteen eyes from 11 patients were treated using the same surgical procedure: vitrectomy, aspiration of subretinal liquid through a temporal retinotomy, fragmentation and extraction of the sub and intra retinal exsudates through one or several retinotomies, macular massaging with fluorodecaline, endophotocoagulations (focal on vascular anomalies and macular grid) and fluid-gas exchange (C3F8). RESULTS: Macular serous detachment and subretinal exsudates disappeared in all the cases, the fluorescein leakage decreased. A functional improvement was obtained in 11 eyes, a stabilization in 2. DISCUSSION: The clinical results of this new surgical treatment appear to depend on the preoperative macular ischemia and on the age of the detachment. This surgical procedure is very beneficial but could perhaps be technically improved.