Cross-linking and structurable polymer photosensitive materials have been studied for many years and they are widely used for optical recording of information. After the investigation of the photo-chemical and photo-physical processes in various systems, it appears that the chemical structure of the polymer matrix plays an essential role in the process of reaction that takes place upon irradiation by a laser beam. The results of experiments that were conducted to investigate the modification of the absorption with the time of exposure, modification of the degree of photo- structuring with time, the dependence of the photosensitivity of thickness and other characteristics are presented in this paper. Some of the applications of the results concerning the hardening of the cross-linking polymers with the scope to improve the mechanical properties of the surface relief image (hardness, strength, adhesive stability) and the possibilities to make copies by the hot stamping method are also presented.
The medical laser applications use the thermal effects of laser irradiation. The present work contains applications of the thermovision. This method offers the following advantages recording and processing of the thermal distribution on the irradiated zone. The study has in view the development of an algorithm of work for an useful data base regarding the laser application in medicine. The experiments used Ar laser, laser diode and some kinds of biological tissues. The paper presents some thermal distributions before, during and after laser irradiation and the images processing.
This paper reports on the new performance obtained for n-type InSb photoconductive element detectors, made of bulk crystals. It is taken into account the important drop of the electric conductivity, by one magnitude order over the temperature range 77 K - 90 K, that forced us to optimize the heat transfer among the elements of the device. The maximum value obtained for the spectral detectivity is 4 by 10<SUP>12</SUP> cmHz<SUP>1/2</SUP>W<SUP>-1</SUP>, at lambda equals 4.9 micrometer, for a field of view of 60 degrees. The calculations show that the device is limited by the generation-recombination noise.
The paper presents two carbon-dioxide laboratory laser systems that were designed for a large number of heterodyne detection experiments, as small signal detection, target range, and velocity measurements, Doppler shift examination, frequency difference measurement, etc. These systems were performed in cooperation with the Institute of Quantum Electronics from the Military University of Technology, Poland.
The paper proposes an optical arrangement for the control in real-time of the laser spot position in lithography techniques. The arrangement is adequately for the small installation, especially used in research or teaching activities.
As the hazardous waste problem grows and becomes an increasing threat to health, the need for larger volumes of accurate environmental information will expand. During the last year, with the development of satellite and computer technology Earth Science and environmental research have become highly dependent on digital imagery. Landsat, Spot, ERS-1 SAR, NOAA, AVHRR satellite data are processed for detection, extraction and classification for environmental purposes on a global scale based on the spectral information of the imagery. A complete description of an analyzed area from ecological point of view will take account `in situ' measurements of environmental factors. The prediction or assessment of environmental impacts is not an easy task. It must be conducted by an interdisciplinary team, including satellite remote sensing for short term and long term impacts.
The piezoceramic materials are a relatively new field within the ceramic and are of a major interest both for scientific research and for the technological applications promoted. The laboratory research has envisaged the achievement of Pb(Zr<SUB>x</SUB>Ti<SUB>1-x</SUB>)O<SUB>3</SUB> type ceramic masses as well as piezoceramic transducers and ensemble of transducers to be used in a wide range of applications (hydroacoustic systems, micropositioning systems, devices for lasers frequency stabilization, bender systems, etc.). We consider that in the next few years this field will know a great expansion and new multiple applications not only in related sciences, but also in industry and army.
OPTOELECTRONICS -- aborder field of activity between Physics and Electronics represents nowadays a domain of present interest with multiple applications in economy, science and society; it is powerfully outlined and supported financially all over the world