The development, by Dr T. Maiman, in the USA in 1960, of the ruby laser caused that many scientific research workers in Poland, fascinated by this outstanding invention, decided to go deeper in this field of science. Owing to intense research works lead in several Polish centres, a whole range of ruby lasers and helium-neon lasers is developed nearly at the same time.

A broad band luminescence was observed by us for Cr3+ in synthetic MgA1204 spinel. Luminescence spectra were strongly dependent on excitation wavelength. This dependence is due to the presence of two different luminescent Cr(III) centres in the spinel. The low value of Dq/B parameter (2.14) for the A site indicates on low ligand field. In view of current in-terest of Cr(III) doped crystals the MgAl204 synthetic spinel displays on attractive material for tunable laser operation.

Lasing properties of 20 new dyes generating in 480-705 nm spectral range under pulsed nitrogen laser exitation are presented. Dyes with donor - acceptor chromogene are of the main importance in the laser techniques. The best known as Coumarines, Rhodamines or Oxazines etc. are widely used for generation of a tunable laser light in a whole visible spectral range. In this paper we would like to present lasing properties of four new groups of this kind of dyes. General structures of presented groups of dyes are shown in Figures 1 (a-d). In Table 1 full chemical names as well as radicals for all the dyes are given. The methods of the chemical synthesis of these dyes were described in our previous papers.

The results of spectral (IR, UV-VIS, H NMR) , gel permeation chromatography and differential thermal analysis investigations of structures of dye foils consisting of bis-(4-dimethyl-amino-dithio-benzil)-nickel dye suspended in polymethylmethacrylate matrix, to be used for passive Q-switching in a 1064 nm laser, are reported. Results of experimental measurements and of numerical calculations of thermal and generating properties, and of the endurance of passive foil type Q-switches in the resona-tor of YAG:Nd3+ laser are also presented. Optimization of polymerization conditions has enabled the production of dye foils with high thermal and photochemical resistance, which give stable operation of a giant pulsed laser.

Single crystals of BaLa1-xNdxGa307 obtained recently by the Czochralski method show a room temperature low threshold laser action associated with the 4F3/2 - 4I11/2 transition of Nd ions. These uniaxial crystals have desired mechanical properties, high thermal conductivity and may be obtained in volumes sufficient to produce the laser rods suitable for conventional sources of optical pumping. Effect of temperature, activator concentration and crystal anisotropy on spectral properties of this new laser active material was studied. Important parameters relative to laser operation of the crystals are reported.

The influence of cyclooctatetraene on the dye laser output energy was examined, It was shown that COT acts not only as a first triplet quencher but also effectively stimulates depopulation of higher triplet states. The importance of such a behaviour of COT in laser generation of a mixture of rhodamine - COT in ethanol is confirmed experimentally and theoretically, basing on the solution of a system of rate equations of a six level model of a dye laser.

The paper presents the results of preliminary investigations both theoretical and experimental of Q-switched and self-injected Nd:YAG oscillator. A new technique is described for producing single nanosecond pulse or trains of them.

A general theoretical model is formulated for the KrF laser with the possibility of excitation by the electron beam, by electric discharge or by electric discharge stabilized by an electron beam. A developed model for electron-vibrational relaxation of states B,C,D of KrF excimer enables investigations the generation or amplification of radiation pulses in the range up to 1011s. Numerical calculation performed for KrF laser pumped by the electric discharge stabilized by an electron beam enabled to obtain the basic characteristics of its work. An interesting result is the obtained increase in the radiation energy in the range of high, ≥80% contents of krypton in the Ar + Kr + F2 mixture.

Large aperture CO2 laser amplifier electron gun produces an electron beam, which should be homogenous in the whole volume to ionize an active medium. - This paper presents experimental investigations how electrode distance, cathode surfaceuvoltage and capacity of supplayer infuance on electrical characteristic of electron gun and measuremant of the speed of cathode plasma.

The paper presents a construction and results of examinations of a small-size nitrogen laser excited by transverse electric discharge. The laser head and a feeder are contained in a common casing. The laser generates UV (λ=337. 1 nm) radiation pulses of up to 75 kW peak power and halfwidth not longer than 0.8 ns.

Results of studies on variations of an absorption coefficient (a) versus time for LiF monocrystals with F2+ color centers, created by 60 Co y-irradiation, at temperatures T1 = 300K, T2 = 250K and T3 = 200K are presented. A LiF crystal with F2+ color centers was applied as a passive modulator of a ruby laser resonator. A giant-pulse generation with a pulse duration of 50 ns was obtained.

In this paper is presented the theoretical analysis of the U-I characteristic for typical for the molecular lasers values of the discharge input power, i.e. when the active medium non-uniformities are important. The analytical results are compared and verified by appropriate experimental investigations.

In this paper is proposed a certain approach to take into account the working medium non-uniformity influence onto the basic characteristic and selection of the TEMoo mode in the sealed-off molecular laser. The analytical results are checked experimentally for the sealed-off CO2 laser giving the output power equal to about 10W.

It is well known, that output power of ion argon laser increases with square of discharge current density. In modern argon ion lasers the density of discharge current reaches 1000 A/cm for the tube of 3 mm internal plasma bore and in such constructions the heat dissipated per 1 cm of the tube lenth is approximately 300 W. This very difficult working conditions have created lots of technological problems which ought to be solved. The laser tube should ensure:- permanent vacuum integrity- ability to disperce high power- high resistance against thermal shocks- high sputter resistance of elements defining discharge bore

The time of duration of the laser pulse generated in TE-0O2 laser is controlled by changing the composition and pressure of the gas mixture and/or the coefficient of the optical resonator useful losses. This paper aim consists in formulating an approximative description of the pulsed TE-0O2 laser allowing for the complex analysis of the pulses longer then lOps. The numerical results of this analysis are presented for two types of the working gas mixture, namely: for the CO2:CO:He, and CO2:N2:He mixture.

The paper contains the results of investigation of the DC transverse discharge in an active region of the CO2 flow laser. The investigations performed concerned the problem of this discharge stability.

We report a significent improvement of the No laser by a wire dc preionisation . The energy generation, pulse to pulse stability and pulse duration have been studied as function of charge voltage and gas pressure . The preionisation was found to increase the energy from 2 to 5 times, depending on the charge voltage and gas pressure. Pulse duration increased by 50%. Simultanously, the instability decrease up to 3 times.

This paper presents results of experimental investigations of radiation output power level of a CO2 molecular laser. This laser works with a simultaneous stabilization of the frequency and of the output radiation power. The frequency of the laser radiation is stabilized by using a frequency stabilization automatic system, whose frequency standard is the maximum of the laser gain curve represented in opto-voltaic signal. The power of the laser output radiation is stabilized by using automatic stabilization system which regulates the output power by changing the intensity of the laser discharge current. The measurements show, that the amplifications and time-constants of both the servo-loops decide about the parameters of power stabilization. The optimal values of amplification and time-constants of these both servo-loops were found experimentally and have been presented in the paper.

Results of investigations of spectral, thermal and laser operation characteristics of crystal Q-switches for the YAG:Nd-5+ laser, which utilize the properties of LiF crystals containing color centres, are reported. Results are also presented of measurements of thermal and photochemical stabilities and of the kinetics of interaction of [F2], [F2+] and [F2-] color centres generated in LiF crystals by means of exposure to γ radiation from Cf-252, Cs-137 and Co-60 sources.

The construction and parameters of picosecond cw dye laser system are described. Due to several new elements introduced into the system excelent stability and very high efficiency are obtained. In order to demonstrate these features an experimental result on transient decay of induced molecular dichroism is presented. It is shown that signal-to-noise ratio greater than 300 can be obtained.

A theoretical model of Ar-N2 laser pumped by high-energy electron or proton beam is characterized. The generation at the wavelength of 357. 7 nm was considered. The most important results of computer calculations are described. Electron and proton beam generated at plasma focus device and 200 keV electron beam were considered as a pump. For pumping by protons the calculated efficiency of generation exceeded 8% and maximum power density of radiation was some hundreds of MW/cm2.

The paper presents a characteristic of plasma focus (PF) devices as new nonclassic sources of charged particles for pumping of gas lasers. The principle of operation of such a source is given and characteristics of generated charged particles are shown. Energy of particles reaches the value of SMeV at supply voltage of 20-40kV. Measure methods of the beam parameters are described and the scheme of the experimental arrangement used to determine the conditions of Ar-N2 laser pumping by ions emitted from a lkJ-PF device is presented.

Basing on numerical calculations carried-out for a simple physical model of the CO, laser, were determined and experimentally checked the optimum ranges of the baser paraneters defining about the applicative properties of the pyrex waveguide CO2 lasers. The optimum, from the point of view of the gain and the generation properties of the active medium, values of parameters were determined. The certain hierarchy of parameters was also determined for those of them which decide about the range of the frequency tuning for a non-dispersive waveguide laser resonator.

The paper contains the review of experiments with a high-power CO2 faow laser. The experiments were carried out for selecting the most effective electric discharge and optical resonator geometries.

The paper presents experiments dealing with interaction of Md:glass laser radiation with plane Al foils. Investigations contained laser simulation of the process of the collisions between macroparticles and target and the measurement of velocity of accelerated foils. glass laser used in the experiment gave 20 J energy in the time of 3 ns. It enabled a simulation of collisions of particles of velocities (2-3)x106 cm/s. Al targets used in the experiment were 4-6 mm in diameter and 12-3000 μm thick. Two variants of the simulated collision of macroparticles with the target were analysed. In the first variant it was assumed that the material of particles-bullets are silicates or Al of the density Q~3 g/cm3 while in the second one - light organic narticles of the density q ~ 1 g/cm3.

An experimental study has been performed of the laser-induced optical birefringence in two different classes of molecular liquids: cyclic alkanes and aromatic-aliphatic ethers. The results obtained enabled the authors to calculate numerically the optical and molar Kerr constants as well as the effective optical polarizability of the molecules. The analysis of our results allowed us moreover to ascertain the predominant role of molecular orientation in the induced optical birefringence in the case of the aromatic ethers, and the existence of weak molecular interaction in the cyclic alkanes studied.

The theoretical principles of an interaction between light waves and the acoustic wave through the photo-acoustic and electro-striction phenomena was presented in the work. A detailed consideration of this non-linear acousto-optical interaction in XY plane of hexagonal system crystals was carried out. An isotropic and colinear anisotropic Stokes's interactions were investigated. Both analytical expressions and nume-rical results of distributions of interacting waves amplitudes were given there.

This paper presents selected problems from the general cycle of investigations concerning laser-matter interaction. These problems are investigations of generation and propagation of shockwave in transparent medium as well as acceleration of thin Al foils. The results of picosecond stroboscopic-differential diagnostic method and shadow diagnostic with the use streak-camera and dye laser as a source of backlighting, were presented. Considering the specifics of each individual experimental system, special attention was put on interpretation of the obtained and presented results. The influence of some parameters of a laser pulse and the used target on the process of laser-matter interaction, was illustrated.

The method of measurement of the attenuation for planar waveguades with metal cover has been presented. The attenuation is found by comparison of the intensity of light leakaged from planar waveguide before and after covered part of waveguide. The method was chequed for the glass waveguide with aluminium cover and the results were in a good agreement with theoretical predictions published previously.

The solution to the boundary-value problem for a simple model of the phase-conjugate mirror is presented. The solution is based on a set of two coupled second-order wave equations and does not assume the slowly varying envelope approximation. The formulae for the amplitudes of the waves generated in the four-wave mixing process are derived and their properties are discussed in detail.

The magnetic garnet monocrystals in the form of thin epitaxial films can be the main elements of various optoelectronic devices such as laser light modulators, switches, deflectors or displays.

A simple analytical model describing a focus of multimode ,different wavelength laser beams is presented in this paper.The cases of partially and completely spatially coherent radiation are considered. In the experimental part, there are presented the results of investigations of focus shifting due to the changes of an argon laser wavelengths in two different optical systems. The results are compared with the theoretical ones.

Modified holographic interferometers are described which enable automatic fringe pattern analysis to be achieved when recording transient events. The introduction of a phase grating enables the method of phase-stepping fringe analysis to be applied to a wide range of metrological problems. The theory of three- and fourchannel holographic interferometers is developed and an analysis of the sources of error is presented with the aid of computer simulations. The adjustment procedure and initial experimental results are shown to confirm the utility of the systems.

A stripe domain grating (SDG) has been theoretically analysed to combine some magnetic field changeable grating parameters with a magnetic sample material parameters. The alterable grating properties were discussed for different types of fiber-optic switch device. The quality and prefered directions of SDG have been quantitatively investigated using unconventional set-up based on the light diffraction effect. The gratings have been induced by the magnetic field with different orientations and values. SDG quality was significantly improved applying nontypically oriented magnetic field. We focused our attention on SDG static properties.

Theoretical possibility of nonlinear TE-TM mode coupling in a thin-film optical waveguide has been examined. Described phenomenon was obtained by third-order nonlinear interaction between two guided modes with different polarizations and two waves falling from outside on the waveguide surface. Phase matching of interacting waves was ensured by choosing proper incidence angles of the falling waves. Effectivity of the interaction depends on the intensity of the external waves and the lenght of the interaction region.

The technical data and parameters of the CO2 surgical laser for gynecology are given. Coagulator was designed and constructed in Institute of Microelectronics and Optoelectronics Warsaw Technical University.

The appliance of a therapeutic laser also known as soft laser has gained wider scope in the latest years. The main characteristics of the laser radiation, namely its monochromatic and coherent nature render the photochemic activity selecive especially on the intracelluar level, stimulating the dynamics of the oxido-reductive changes in a cell. The action of the laser beam upon living tissue depends on the power of the used laser as well as upon the physical properties of the object itself i.e. its optical, mechanical, chemical properties. The use of a high powered laser causes a big rise in the temperature and prescure inside tissue which leads to denaturation of protein and than to evaporation and destruction of the cell. It is possible to gain quite diffrent effects using a soft /or therapeutic/ laser which in the course of stimulating the biological changes in a cell causes its regeneration and not its degradation. There exist three main phenomena on the level of the radiation emition. These are absorption, reflection and penetration. The most important from the medical point of view are penetration and absorption, for the direct biological changes depend upon these very parameters. The action of the laser beam upon tissue in fig. 1.

A method for attachmet of any aminoacid residue to the protoporphyrin (PP) molecule has been developed leading to synthesis of a new class of protoporhyrin derivatives. Photosensitising properties of the new derivatives have been measured under "in vitro" conditions and compared with those of hematoporphyrin (HP). Dimerization constants of the new photosensitizers in aqueous PBS solutions were also determined.

Photosensitizing properties of selected porphyrins: hematoporphyrin (HP). mesoporphyrin (MP), protoporphyrin (PP), coproporphyrin (CP) and hematoporphyrin disuccinate (HPDS) have been investigated "in vitro" as a function of concentration, pH and polarity of the medium. Dimerization constants for the five porphyrins have been determined under analogous experimental conditions and a correlation between the aggregation state and photosensitizing properties was found.

The first part of the paper presents the results of laser •hotocoaculation treatment involving: 141 patients with retinal detachment , 20 with holes in the macula, and 33 with holes at the eye fundus periphery. At estimating the results, the apposition of retina and the observation time have been taken into account. The second part contains the results of observation of 21 patients, in whom, in 26 eyes laser trabeculoplasty was performed. Normalization of intraocular pressure has been obtained in 76.9% of cases. The outflow coefficient after trabeculoplasty has increased in 57.6% of cases.

It has been shown that similar graphical effects can be obtained by means of numerical computer simulation applied to the seismic interferometric analysis of strains and deformations in a rock specimen by suitable choice of parameters involved. The method of seismic interferometry applied to the analysis of strains and deformations in a rock specimen has been described. It has been shown that the graphical effects obtained in this method are similar to those shown in the wires provided that the set of parameters has been chosen properly. It has been also shown that the functions describing surface deformations of wires can be evaluated with a good accuracy from the suitable function in the second process followed by the proper choice of parameters.

A laser scanning system has been described for measurement of optical fibre diameter in course of manufacturing. The principle of operation of the system is based on measurement of time of shading of scanning laser beam by the measured fibre. The criteria have been presented of selection of system optical parameters and their influence has been considered on laser beam shape in measurement space. Metrological properties have been discussed and analysis of systematic and random errors of fibre diameter measurement has been performed.

The paper presents the results of preliminary investigations, both theoretical and experimental, of XeC1 excimer laser pumped by transverse electric discharge with UU preionization. The medium was a mixture of gases He-Xe-HC1. A theoretical model of the XeC1 laser was worked out and a lot of laser parameters calculations were done. In the same time an excimer laser operating on the mixture He-Xe-HC1 was started, the generation of laser radiation was of energy about 20mJ.

A versatile system LSM - 87 have been developed for the investigation of laser micromachining. The system can operate with many types of lasers. Laser trimming of piezoelectric filters is an example of practical application of this system.

A simple system for optical spectra monitoring and measurement for both continuous and pulsed laser emission is presented. The system consists of Fary-Perot interferometer with constant inter-mirror distance, simple CCTV (closed circuit television) camera, sampling unit, multichannel analizer and microcomputer. Interferograms of either single or multiple pulses are recorded and averaged digitally and then processed numerically to yield parameters of spectral distribution.

The un-cooled HgCdTe photoconductive detectors and cooled down to the liquid nitrogen temperature HgCdTe photodiodes were investigated under the conditions of their application to the heterodyne signal detection.

The module of the heterodyne CO2 laser rangefinder with the signal compression has been build up. The analysis of its possibilities was carried out. The results of its experimental investigation are presented.

Method and systems for cloud-base height measurements (based on semiconductor laser) on distance 50-2000 m and visibility (based on He-Cd laser) with measurement base of order of 1 km are presented. Necessity of measurement of refraction index structure function by laser interferometry was indicate. Standard temperature and wind velocity gradients should be measured, too.