Showing papers by "Abraham Katzir published in 1984"
TL;DR: Flexible, nontoxic infrared optical fibers were used for the transmission of the carbon dioxide laser beam intraarterially for the dissolution of atheromatous plaques and recanalization of obstructed arteries.
54 citations
24 Oct 1984
TL;DR: Preliminary results indicate that a system based on a CO2 laser and an infrared transmitting fiber may be useful in cardiology.
Abstract: Carbon dioxide laser energy was used for the dissolution of atheromatous plaques. Delivery system was based on a AgCl:AgBr fiber which was inserted in a loose teflon tube. The system was used to vaporize human plaques in vitro as well as blocked human arteries which were transplanted in dogs. Preliminary results indicate that a system based on a CO 2 laser and an infrared transmitting fiber may be useful in cardiology.
10 citations
TL;DR: In this article, a distributed Bragg reflector (DBR) lattice matched Pb1−xSnxTe/PbSeyTe1−y diode laser was fabricated using liquid phase epitaxy.
Abstract: Distributed Bragg reflector (DBR) lattice‐matched Pb1−xSnxTe/PbSeyTe1−y diode lasers were fabricated using liquid phase epitaxy. These DBR lasers were operated within a limited range of heat‐sink temperatures 8.5–38 K, and the threshold current density at 20 K was ∼3 kA/cm2. Single longitudinal‐mode operation was obtained up to more than three times the threshold current. The DBR lasers exhibited continuous tuning over a relatively wide range of ∼6 cm−1 near 775 cm−1 (12.9 μm). The average tuning rate was 0.21 cm−1/K, and it was much smaller than the rate for corresponding Fabry–Perot lasers, which was 2.3 cm−1/K.
10 citations
TL;DR: A new method for calculating the heterodyne efficiency of an optical receiver is applied to specific optical systems looking through a turbulent atmosphere.
Abstract: A new method for calculating the heterodyne efficiency of an optical receiver is applied to specific optical systems looking through a turbulent atmosphere. The optical and atmospheric parameters which characterize the system efficiency are considered, and optimization of the performance of an heterodyne receiver is discussed.
8 citations
TL;DR: In this article, the refractive index N of lead-tin-telluride is calculated for frequencies near the fundamental absorption edge and the contribution to N from electron states near the band-edges is calculated more exactly than in previous works.
Abstract: The refractive index N of lead-tin-telluride is calculated for frequencies near the fundamental absorption edge. The contribution to N from electron states near the band-edges is calculated more exactly than in previous works and a new expression for the contribution from the high frequency region is proposed. Good agreement is obtained between our calculations and experimental results. The change of N due to gain in injection laser is also calculated and it is shown that it cannot be neglected.
5 citations
TL;DR: The far field of PbSnTe injection lasers, perpendicular to the junction plane, was measured in this paper, and the results were shown to be in good agreement with theoretical predictions.
Abstract: The far field of PbSnTe injection lasers, perpendicular to the junction plane, was measured. The results are shown to be in good agreement with theoretical predictions. Design considerations are given for constructing laser structures having an improved far-field pattern.
5 citations
TL;DR: In this paper, two stabilized CO2 lasers, of frequencies col and cwt, were coupled into a single infrared fiber, using a Y coupler, with no other optics.
Abstract: Infrared-transmitting silver halide fibers, 0.3 to 1 .0 mm in diameter, were fabricated by extrusion and were found to have losses of about 1 dB/m at X = 10.6 Am. Infrared heterodyne experiments have been carried out using these fibers. Two stabilized CO2 lasers, of frequencies col and cwt, were used. The two laser beams were coupled into a single infrared fiber, using a Y coupler, with no other optics. Both beams were transmitted through this fiber to a fast IR detector. A heterodyne signal at a beat frequency cal - (02 was obtained from the detector.
4 citations
Book•
01 Jan 1984
1 citations
TL;DR: PbSnTe diode lasers with an unpumped section were fabricated in this paper, and it was found that this section was virtually transparent at the lasing frequency, and such unpumped regions can serve as integrated waveguides for integrated optics applications in the midinfrared.
Abstract: PbSnTe diode lasers with an unpumped section were fabricated. It was found that this section was virtually transparent at the lasing frequency. Such unpumped regions can serve as integrated waveguides for integrated optics applications in the midinfrared.
1 citations
01 Jan 1984
TL;DR: In this paper, the authors proposed the use of the heterodyne detection method for the detection of electromagnetic (EM) radiation in the middle spectrum of the spectrum, where 300°K thermal emission peaks.
Abstract: The detection of electromagnetic (EM) radiation is, in general, degraded by noise. This noise may arise from intrinsic fluctuations in the EM signal to be detected, as well as from background emission. In particular, background (thermal) noise becomes important when one considers detection in the middle — infrared, where 300°K thermal emission peaks. If the EM signal has a very narrow spectral line width, it is possible to filter out most of the white noise by employing a narrowband detection system. This suggests the adoption of the heterodyne detection method, which is well known in the radio and microwave regimes, in the infrared wavelength region [1].