Laser emission analysis is an efficient method used for determination of quantitative and qualitative composition of chemical elements in materials. For the analyser designs a proper choice of a laser type, stabilisation of its pulse parameters and performance of a high-resolution spectrometer of sufficient responsivity are crucial problems. The correlation-based method of laser induced breakdown spectrometry for soil contamination was presented. A system of laser induced breakdown spectroanalyser and the investigation of a portable laser emission spectro-analyser for analysis of chemical composition of soil samples are described. The results and examples of its applications are given.
The paper presents results of application of the free particles method for computer modelling of a phenomenon of laser interaction with matter. Alterations made to the method relies on a procedure for modelling of laser radiation absorption and determination of boundary conditions. Computation results for some initial-boundary conditions are presented.
The results of experimental studies on shock wave propagation in plexiglass are discussed. The wave was generated by a single laser pulse of 3 ns and 30 ns duration and of energy from 2 to 30 J. The characteristics of velocity variations of shock wave front propagation are presented in this paper.
The optical method for document protection against counterfeit has been proposed. It is based on the use of optically variable graphics. For the security device design the numerical computation algorithm has been formulated. The algorithm is founded on the coupled-waves theory of the light diffraction by gratings. The computation example for the holographic foil design is demonstrated.
The method for evaluation of holographic security effectiveness has been developed. The use of the Wiener filter based method allows the holograms patterns to be identified from a printed page. Due to elimination of background influence on a correlation function of two analysed images it is possible to estimate a quality factor of a holographic device. The Wiener filter algorithm for numerical analysis of digital images has been proposed. On the basis of correlation analysis the quantitative quality coefficient of the holographic security has been defined.
Laser emission analysis is an efficient method used for determination of quantitative and qualitative composition of chemical elements in materials. For the analyzer designs a proper choice of a laser type, stabilization of its pulse parameters and performance of a high-resolution spectrometer of sufficient responsivity are crucial problems. The correlation-based method of laser induced breakdown spectrometry for soil contamination was presented. A system of laser induced breakdown spectroanalyzer and the investigation of a portable laser emission spectro-analyzer for analysis of chemical composition of materials are described. The results and examples of its applications and optimizations are given.
Characteristics of a quality system accredited in optoelectronic testing laboratory are presented. The scope of accreditation is shown and all measurement procedures are listed. Performing with measuring equipment and basic measurement instruments are given. Some details of calibration laboratory and main characteristics of two standards of Joule and Watt of laser radiation are also presented.
The 3 mJ output energy for Nd:YAG, 1.6 mJ for Nd:YVO4 were obtained in free running mode. Above 170 kW peak power in 5.6 ns pulse duration was achieved in electrooptic Q- switched Nd:YVO4 laser. The lower threshold, near diffraction limited output, shorter cavity length advantage Nd:YVO4 for low energy, high pulse power applications.
Optoelectronic sensor of 2D angular displacements consists of transmitter head with diode lasers as a light source and detection head. The detection head consists of focusing lens, and, placed in its focal plane, 2D position sensitive detector. The current signals collected by electrodes of detector are transformed in analog signal processor to obtain the x and y coordinates of spot center position signals with respect to the center of photosensitive area. The x and y position values divided by focal length represent the coordinates of angular displacement of detection head with respect to the axis of transmitter beam. There was determined the calibration curve of the sensor. The typical results of angular displacement measurements were presented and discussed.
The triangulation method of range and displacement measurements using position sensitive detectors (PSD) is discussed in this paper. The laboratory model of laser triangulation range and displacement sensor built in the Institute of Optoelectronics has been examined and compared with theoretical predictions. The range and resolution of measurements of this sensor dependent on geometrical parameters of the sensor head can be varied in this model. The resolution of 0.5 micrometers of displacement measurement was achieved experimentally in laboratory conditions. The influence of light and electrical noises on linearity and resolution of measurements is discussed.
The paper presents the LL-59 set with Nd:YAG laser used for otorhinolaryngological operations. The set enables the user to apply a new treatment method in otorhinolaryngology. The interaction effects between radiation and tympanic membrane are described.
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