[en] Two thirds of human body consists of water and the absorption of laser by water is an important factor in medical laser treatment. Er medical lasers have been used in the dermatology, ophthalmology and dental treatments due to its highest absorption by water. However, 2.9 um Er laser can not be transmitted through an optical fiber. On the other hand, Tm laser can be transmitted through an fiber and also has very high absorption by water. Therefore, Tm lasers are used in ophthalmology and heart treatment wherein the fiber delivery is very important for the treatment. Until now, mainly lamp-pumped solid-state lasers have been used in medical treatments, but the lamp-pumped solid-state lasers are being replaced with the diode-pumped solid-state lasers because the diode-pumped solid-state lasers are more compact and much easier to maintain. Following this trend, end-pumped Er and side-pumped Tm lasers have been developed and the output power of 1 W was obtained for Er and Tm respectively

[en] For the first year plan of this program, we developed the power control system for semiconductor lasers. We applied the high-current switching mode techniques to fabricating a power control system. Then, we investigated the direct side pumping techniques with GaA1As diode laser bars to laser crystal without pumping optics. We obtained 0.5W average output power from this DPSSL. (author). 54 refs., 3 tabs., 18 figs

[en] The demands for infrared laser which shows a good water absorption have been increased continuously in the field of medical area. The purpose of this project is development of the excitation system and optical delivery for Er : YAG laser. Therefore, we are trying to optimize the excitation spectrum of flashlamp to match the absorption spectrum of laser material well. More than 500mJ of pulse energy has been obtained with an excitation diffusive chamber. We investigated several parameters of laser transmission with 7 knuckles articulated arm. (author). 4 refs., 13 figs

[en] High-power COIL(Chemical Oxygen Iodine Laser) has been becoming more efficient tool in laser materials processing. The reason for the interest stems from the possibility of getting more than tens of kW output power and minimal loss in optical fiber beam delivery. We developed the design technology of high-power COIL and singlet oxygen generator (Jet type SOG), and evaluated durability of laser mirrors under laser operation in this project. (author). 47 refs., 3 tabs., 13 figs

[en] The laser welding monitoring system was developed to inspect PWR space grid welding for KNFC. The demands for this optical monitoring system were applied to Q.C. and process control in space grid welding. The thermal radiation signal from weld pool can be get the variation of weld pool size. The weld pool size and depth are verified by analyzed wavelength signals from weld pool. Applied this monitoring system in space grid weld, improved the weld productivity. (author). 4 refs., 5 tabs., 31 figs

[en] We discuss the theories in the generation and detection of laser-ultrasonics and present the results obtained from the numerical calculations based on the theories. We carry out the computation of the spatial and temporal distributions of the temperature inside the material. Calculating the displacement of the surface at the epicenter, we make discussions on the characteristics of the ultrasonic wave propagation in the thermoelastic and ablation regions. The speed and the surface motion of the material element are investigated from the solution of the Rayleigh equation. We present the results obtained from the numerical computations based on the theories. The Rayleigh waves generated by the irradiation of the pulsed laser beam in the thermoelastic region and the ablation region are discussed. Also the discussions on the heat wave propagation caused by irradiations of the ultra-short laser pulses are included in the appendix

[en] The stable laser isotope facility will supply raw stable isotope material to produce radioisotope elements for medical and industrial applications. The medical stable isotope, Tl-203 was separated by the isotope selective optical pumping (ISOP) method native to the laboratory for quantum optics, KAERI. The extraction rate of 10 mg/hr was achieved from the separation chamber of 80cm x 80cm x 100cm dimension. The Yb-168 separation facility was improved in stability, durability, and efficiency. The old copper vapor pumping laser system was replaced with two 40W green DPSSL's. The tunable dye laser system was also improved in stability. The extraction rate was measured as 1.5 mg/hr in the improved system. The 200W infrared DPSSL system was also developed and used for photoionization of thallium isotopes. The adaptive optics and beam path control system was applied to the isotope separation facilities. Also the beam quality of the lasers was monitored and improved. To maintain constant isotope composition during reaction process, the wavelengths of tunable lasers are locked by being the mass composition information fed back into the oscillator control unit of the lasers. To optimize isotope separation process timely, the extractor surface is directly analyzed by laser irradiation and TOF mass spectrometer. And the final products in high purity is recovered in maximum by solution chemistry

[en] KAERI has obtained an advanced technology with singular originality for laser stable isotope separation. Objectives for this project are to get production technology of Tl-203 stable isotope used for medical application and are to establish the foundation of the pilot system, while we are taking aim at 'Laser Isotope Separation Technology to make resistance to the nuclear proliferation'. And we will contribute to ensuring a nuclear transparency in the world society by taking part in a practical group of NSG and being collaboration with various international groups related to stable isotope separation technology

[en] The main objectives of this project are to establish the internatinal collaboration basis of optical technolgies between Korean and China through the combination of the Chinese advanced fundamental technologies with the Korea industrialization and commercialization infrastructures, by ways of exchanging scientist and informations, holding joint seminars, cooperative utilization of research resources. On the ground of this establishment, the optical technologies of Korea are supposed to be leveled up to that of the world-most advanced. At the same time, for the improvement of mutual benefit and financial profit of both of the countries, technical support for the investment on the optical industries in the two countries and establishment of foundation for the venture capitals are also the purpose of this project. Because the state-of-the-arts of the Chinese technologies such as aerospace engineering, military defense technology, applications to medical treatments, laser fusion research, and so on, are known to be far above those of Korean and upto one of the most advanced in the world, it is necessary that the acquisition of these technologies, resulting in the enhancement of the levels of domestic technologies in these fields, implementation of joint research projects for technology development as well as the balanced opportunities for commercial product/sales and cooperation should be actively pursued

[en] Optogalvanic spectra have been recorded by axially irradiating hollow uranium cathode glow discharge with a single-mode diode laser. Fifty uranium transitions have been tabulated with optogalvanic signal magnitudes in the 662-680, 774-792, 834-862 nm region for wavelength calibration. Atomic excitation temperature has been determined by the measured signal magnitudes