• Laser Solutions
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• v.3 no.1
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• pp.2-11
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• 2000

Laser cleaning has begun to attract a considerable amount of interest recently as a new cleaning technique among scientists and engineers. The unique characteristics of laser cleaning are currently finding successful applications in industry, in medicine as well as in the world of art conservation. This paper takes an overview of the laser cleaning technique itself including basic principles and characteristics, and provides an account of current trends especially with regard to practical applications. Experience with its successful applications in various fields shows that laser cleaning may be about to emerge as a real alternative to conventional cleaning methods.

• Korean Journal of Optics and Photonics
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• v.5 no.1
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• pp.182-188
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• 1994

We review the basic principles of laser speckle photography and its applications to the measurement of surface displacement and deformation and to flow velocimetry. metry.

• Proceedings of the Optical Society of Korea Conference
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• 1988.06a
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• pp.33-36
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• 1988

The distributed feedback dye laser is a source of single picosecond pulses tunable in a very wide wavelength range. Operational principles, experimental arrangements, and recent applications are reviewed.

• Laser Solutions
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• v.5 no.2
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• pp.9-15
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• 2002

Basic principles and unique characteristics of laser-induced shock cleaning have been described compared to a conventional laser cleaning method and the removal of small tungsten particles from silicon wafer surfaces was attempted using both methods. It was found that the conventional laser cleaning was not feasible to remove the tungsten particles whereas a successful removal of the particles was carried out by the laser-induced shock waves. From the quantitative analysis using a surface scanner, the average removal efficiency of the particles was more than 98% where smaller particles were slightly more difficult to remove probably due to the increased adhesion force with a decrease of the particle size. It was also seen that the gap distance between the laser focus and the wafer surface is an important processing parameter since the removal efficiency is strongly dependent on the gap distance.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.1-8
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• 2020

In this paper, the principles, characteristics and recent studies of the laser micro soldering are reviewed. The factors which influence laser micro welding and soldering are also included. Laser soldering is a non-contact process that transfers energy to solder joint by a precisely controlled laser beam. In recent electronics industry, the demands for laser soldering are increasing due to bonding for complex circuits and local heating in micro-joint. In laser soldering, there are several important factors like laser absorption, laser power, laser scanning speed, and etc, which affect laser solderability. The laser absorption ratio depends on materials, and each material has different absorption or reflectivity for the laser beam, which requires fine adjustment of the laser beam. Laser types and operating conditions are also important factors for laser soldering performance, and these are also reviewed.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.3
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• pp.7-13
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• 2019

In this paper, the principles, types and characteristics of the laser and laser soldering are introduced. Laser soldering methods for electronics, metals, semiconductors are also presented. Laser soldering is a non-contact process that transfers energy to solder joint by a precisely controlled beam. Demands for laser soldering are increasing due to bonding for complex circuits and local heating in micro joint. Laser absorption ratio depends on materials, and each material has different absorption or reflectivity of the laser beam, which requires fine adjustment of the laser beam. Laser types and operating conditions are also important factors for laser soldering performance. In this paper, the performance of Nd:YAG laser soldering is compared to the hot blast reflow. Meanwhile, a diode laser gives different wavelength and smaller parts with high performance, but it has various reliability issues such as heat loss, high power, and cooling technology. These issues need to be improved in the future, and further studies for laser micro-joining and soldering are required.

• Korean Journal of Optics and Photonics
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• v.13 no.1
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• pp.73-78
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• 2002

We have investigated the lasing characteristics of intracavity second harmonics of a Nd:YAG laser pumped by a laser diode. Through the analysis of the scalings of laminar phases, we verify that the second harmonics are generated through on-off intermittency. The intermittent behavior can be reproduced by a numerical simulation with rate equations.

• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.211-220
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• 1991

The relief of pain by laser therapy in useful in the treatment of ulcers burn, tenosynovitis, tendinitis, bursitis, neuritis, rheumatism, chilblains, herpes, zoster. The degenerative cells probiferate to replace by the active vigorous cells by laser rays and suppressed the growth of cell in pathological lesion or condition laser rays promote healing by stimulating growth of celt or tissue The purpose of this study was to introduce about the principles of therapeutic laser ray, characteristics, indication, contraindication, technique, therapeutic effect or clinical effect throughout refference books. The author believe that therapeutic laser rays will contribute grently toward over coming the difficulties of physical therapy.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.24 no.1
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• pp.13-17
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• 2013

Laser laryngeal microsurgery is currently the primary method of treatment of various laryngeal diseases. The development of laryngeal microsurgery came from the introduction of a small spot $CO_2$ laser micromanipulator and more precise microlaryngeal instruments. $CO_2$ laser laryngeal microsurgery has enabled very precise surgery because it has small focus size and hemostatic effect. There are some limitations to the use of the $CO_2$ Laser such as adjacent tissue damage and vocal fold scarring. These problems can be minimized through understanding the mechanisms by which lasers function and correctly manipulating the parameters under a surgeon's control. We should also recognize the safety of $CO_2$ laser for the surgeon to precisely perform the procedure.

• Medical Lasers
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• v.10 no.2
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• pp.76-81
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• 2021

Biological tissues and organs are composed of different arrays of cells, biochemical cues, and extracellular matrices arranged in a complex microarchitecture. Laser-Assisted Bioprinting (LAB) is an emerging and promising technology that is reproducible with high accuracy that can be used for fabricating complex bioengineered scaffolds that mimic tissues and organs. The LAB process allows researchers to print intricate structural scaffolds using cells and different biomaterials essential for facilitating cell-scaffold interaction and to induce tissue and organ regeneration which cannot be achieved in a traditional scaffold fabrication. This process can fabricate artificial cell niches or architecture without affecting cellular viability and material integrity. This review tackles the basic principles and key aspects of Laser-Assisted Bioprinting. Recent advances, limitations, and future perspectives are also discussed.