This paper describes the experimental results in micro-machining technology which were performed by using a 248 nm
KrF excimer laser, beam homogenizers, mask image, projection lens and a five axis computer numerical controlled
(CNC) equipment. The optical system is composed by two beam homogenizers of different focal lengths, a condenser
lens that takes and reshapes the laser beam, the field lens that collimates the beam, the mask that defines the image and
the projection lens. The shape of the mask is kept identical on the target in the micrometric scale. The components which
were manufactured are intended to be used to develop micro-motors and gyroscopes.
The synthesis of bioactive glass from raw materials even during the laser deposition process, could provide
formation of a biocompatible layer on the metallic prosthesis. During the laser irradiation melting and ultrarapid
solidification of ceramic materials occur and glasses controlled by the process parameters (especially laser power
and solidification rate) will be obtained. The aim of the present paper is to study the influence of the processing
parameters on the laser synthesized glasses chemical composition, structure and bioactive behaviour.
A new therapy laser device is presented. The device consists of a central unit and different types of laser probes. The laser probe model SL7-650 delivers seven red (650 nm), 5 mW diode lasers convergent beams. The beams converge at about 30 cm in front of the laser probe and the irradiated area might be varied by simple displacement of the laser probe with respect to the target. The laser probe SL1-808 emits single infrared laser beam up to 500 mW. The efficiency of the use of this device in physiotherapy, and rheumatology, has been put into evidence after years of testing. Dermatology and microsurgery are users of infrared powerful laser probes. The device has successfully passed technical and clinical tests in order to be certified. The laser device design and some medical results are given.
Commercial available red and infrared diode lasers have been tested. A set of ten pieces of red 25 mW nominal output power and five pieces of 0.5 W infrared diode lasers have been investigated. The laser output power has been measured by using an Ophyr power-meter. Ophyr F150 head (3mW noise) was used for power measurements of the infrared diode laser and Ophyr 3A-IS integrated sphere was used in the case of red diode lasers. A Spiricon laser beam analyzer was used to determine the beam intensity distribution. An API wave-check wavelength meter measures the wavelength of the diode lasers. Temporal behavior of the diode lasers over periods of days was recorded. The influence of ambiental conditions is considered. Our study guarantees the proper choice of the diode laser to be used in specific applications such as medical, and industrial applications.
Preliminary studies regarding the interaction of intense short electron beams with different metallic targets are presented. The electron generator consists of a fast filamentary discharge in low-pressure gases. The filling gas is Helium, Argo, or Nitrogen at approximately 0.1 Torr pressure. The target might be easily changed. Also, the beam might be magnetically deflected in order to be properly directed. The interaction of the beam with different targets was investigated by means of a scanning electron microscope. The device is capable to drill holes of several tenths of microns in diameter in metallic targets.
A new application of glass surface treatment is presented here. Fine polishing of optical fiber end, core/cladding surface, is performed. A small power monomode longitudinal 10 W cw CO2 laser is used. A decrease of the roughness form about 5 microns to hundreds of nanometers was achieved. The microstructure of the surfaces has been studied using atomic force microscopy. Applications of polished fiber surfaces are given.
A small average power CO2 laser for some industrial applications is presented. The laser might operate both in a continuous regime and in a pulsed one or in a combination of two. Average power up to 20 W and peak power of several hundreds of kW has been achieved. The advantages of the good optical quality bema of a longitudinal discharge laser and of a high peak power pulsed regime are simultaneously achieved. A high voltage capacitor, which is switched on by means of a rotary spark gap, sustains the pulsed regime. The commutation between the two regimes might be easily done and a mixed operation is obtainable. By superposition of the two regimes, a continuous heating of the materials by the continuous beam as well as an evaporation due to high peak power are obtainable. Drilling, cutting and marking of different types of glasses as well as different plastic materials were performed.
A hybrid with small average power CO2 laser is presented. The laser might operate both in a continuous regime and in a pulsed one. The advantages of the good optical quality beam of a longitudinal discharge laser and of a high power peak pulse are simultaneously achieved. A high voltage capacitor which is switched on by means of a rotary spark gap sustains the pulsed regime. The commutation between the two regimes might be easily done and a hybrid operation is also obtainable. Glass surface treatment using this laser was performed. Fine polishment of the irradiated surface was achieved. The fine structure of the surfaces which were irradiated have been studied using atomic force microscopy.
A comparative study on four groups of patients which have been exposed to laser radiation was performed. Three wavelength were used (633, 670 and 830 nm). The fourth group received only laser placebo. Every group is composed by 20 people homogeneously selected from the point of view of age, sex and clinical and paraclinical parameters. The irradiation dose was kept almost the same, i.e. 15 J/cm2. The dependence of subjective and objective indicators on the laser wavelength were put into evidence.