• Proceedings of the Optical Society of Korea Conference
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• 1996.09a
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• pp.12-12
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• 1996

• The Journal of the Korean dental association
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• v.47 no.8
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• pp.479-486
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• 2009

Purpose: The aim of this study was to show the clinical results of combination of Nd-YAP (1340nm) laser therapy with conventional endodontic and periodontal treatment. Materials and Methods: Four patients with chronic advanced periodontitis and endodontic infection were treated with conventional treatment and Nd-YAP laser therapy. Occlusal adjustment and splinting were done for stabilization of the teeth with severe horizontal and vertical mobility. The protocol for periodontal treatment was followed as scaling and root planing, pocket irrigation with 3% $H_2O_2$ and exposure of Nd-YAP laser using 320${\mu}m$ optical fiber with 160mJ/pluse, 30Hz. The other protocol for endodontic treatment was followed as access opening, canal preparation by hand and rotary instrument, canal filling, and exposure of Nd-YAP laser using 200${\mu}m$ optical fiber with 200mJ/pluse, 10Hz and 180mJ/pluse, 5Hz which were used respectively for disinfection and canal filling. The assessments of probing depth, mobility, and radiography were made prior to and after treatment. Result: All of these four clinical cases showed good healing of periodontium, which presented decrease of mobility and pocket depth, and increase of bone regeneration and bone density on the radiography. Conclusion: The bactericidal effect of Nd-YAP laser would provide benefits for improving clinical results that are obtained from conventional therapy.

• Korean Journal of Optics and Photonics
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• v.10 no.3
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• pp.233-236
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• 1999

We have constructed a narrow-linewidth single-longitudinal-mode unidirectional $Er^{3+}$ -doped fiber laser using a fiber Bragg grating incorporated by a three port optical circulator with a compact configuration. Using a conventional delayed self-heterodyne detection technique with Mach-Zehnder interferometer a linewidth of 5 kHz was measured. In a single-longitudinal-mode operation, output power of up to 2.7 mW at 1548 nm were obtained for a launched pump power of 43 mW at 980 nm.

• Korean Journal of Optics and Photonics
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• v.5 no.1
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• pp.125-130
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• 1994

A new cavity configuration for passive mode locking of fiber laser is proposed and demonstrated. It consists of a dichroic mirror at one end of the cavity, and a nonlinear loop mirror, which is a Sagnac loop, at the other end. The experimental observations are described for both Er-doped fiber laser and Nd-doped fiber laser. laser.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.6_2
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• pp.943-948
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• 2020

In this paper, we developed a fiber optic interferometer system based on frequency-swept laser. This frequency-swept laser with an external-cavity structure can generate a high coherent light with a linewidth of 132 kHz at 1552 nm. It also shows a superior swept linearity of R2 = 0.99995 under repetition rate of 200 kHz due to absence of mechanical moving parts in the laser cavity. By using a piezoelectric fiber optic stretcher, various vibration experiments were implemented, such as 0.5 to 2.0 kHz vibration signals with intervals of 0.5 kHz, with a sampling rate of 7 kHz. Real-time peak tracking can be successfully recovered according to the applied vibration frequency with high linearity of R2 = 0.99983.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.16-24
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• 1998

In a high speed long haul fiber optic communication system using modulation, fiber chromatic dispersion and laser chirping can cause serious performance degradations. In this paper, the combined effect of laser chirping and chromatic dispersion on the per- formance of 2.5[Gbps] rate lightwave systems operating at a wavelength of 1550[nm] was investigated. Also we used an optical equalizer to compensate the laser chirping and fiber dispersion, and knew that the receiver sensitivity was improved by about 2 ~ 4[dB].

• Korean Journal of Optics and Photonics
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• v.1 no.1
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• pp.107-113
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• 1990

Characteristics and applications of three major types of lasers are discussed. They are chemical-metabolic, thermal destructive, and nonthermal mechanical lasers. The thermal destructive lasers ($CO_2$, Argon, and Nd:YAG) are especially explained in detail with regard to energy density, wavelength, fluence, stage of thermal destruction, and advantages of laser surgery. Excimer and Q-swiched lasers are discussed as nonthermal mechanical ones. Delivery system, optical fiber and articulated arm, is also discussed. Finally, recent advancements of medical laser are included in the conclusion.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.192-193
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.78-79
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 1996.09a
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• pp.93-93
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• 1996