• Title/Summary/Keyword: Q-switched Er:YAG laser

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Thermomechanical Effect on the Water Wet Dental Hard Tissue by the Q-switched Er : YAG Laser

  • Y. H. Kwon;Ky0-han Kim
    • Journal of Biomedical Engineering Research
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    • v.20 no.2
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    • pp.231-236
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    • 1999
  • Understanding the exgenous water induced thermomechanical effect on the dental hard tissue by the Q-switched Er:YAG laser (1-$mutextrm{s}$-long pulse width) has an important impact on the further understanding of the free-running Er:YAG laser (250-$mutextrm{s}$-long pulse width) ablation on the dental gard tissue because one macroscopic effect in the free-running laser is an accumulation of microscopic effects we investigated in this study. The Q-switched Er:YAG laser with exogenous water on the tooth enhanced ablation rate compared to the case of no water on the tooth. The frequency of exogenous-water jet on the tooth has affected the ablation rate in such a way that as we dispensed water drops less frequently we could get more enhanced ablation rate. The amplitude of the recoil pressure depends on the tooth surface conditions such that as surfaces wet, and as the volume of the exogenous water drop increased, the amplitude of the recoil pressure increased also. From this study we realized that the 1 $mutextrm{s}$ long pulsed induced thermomechanical effect provides us useful information for the understanding of the free-running Er:YAG laser induced ablation with exogenous water.

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High Power Continuous-Wave and Graphene Q-switched Operation of Er:YAG Ceramic Lasers at ~1.6 ㎛

  • Wang, Yong;Chen, Hao;Shen, Deyuan;Zhang, Jian;Tang, Dingyuan
    • Journal of the Optical Society of Korea
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    • v.17 no.1
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    • pp.5-9
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    • 2013
  • We report on high-power continuous-wave operations of an Er:YAG ceramic laser in-band pumped by a cladding-pumped Er,Yb fiber laser at 1532 nm. With an output coupler of 10% transmission, the ceramic laser yielded 16.7 W of continuous-wave output at 1645 nm for 28.8 W of incident pump power, corresponding to a slope efficiency of 61.0% with respect to the incident pump power. The lasing wavelength switched to 1617 nm when output couplers of > 20% transmission were used. Up to 16.2 W of 1617 nm output was generated for 33.0 W of incident pump power, corresponding to a slope efficiency of 51.8%. Graphene Q-switched operation of Er:YAG cermic laser at 1645 nm was also demonstrated with stable pulses of 30-74 kHz repetition rates and 1.5-6.4 ${\mu}s$ pulse widths.

WATER INDUCED MECHANICAL EFFECT ON THE DENTAL HARD TISSUE BY THE SHORT PULSED LASER

  • Kwon,Yong-Hoon;Kim, You-Young
    • Journal of Photoscience
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    • v.5 no.1
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    • pp.33-37
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    • 1998
  • One macroscopic effect in the free-running Er:YAG laser is an accumulation of microscopic effects. Understanding of the exogenous water induced mechanical effect on the dental hard tissue by the Qswitched Er:YAG laser has an important impact on the further understanding of the free-running Er:YAG laser ablation on the dental hard tissue. The Q-switched Er:YAG laser (1-$\mu$s-long pulse width) was used in the recoil pressure measurement with an aid of water-jet system and a pressure transducer. The amplitude of the recoil pressure depends on the tooth surface conditions (dry and wet) and the volume of the water upon it. Wet surfaces yielded higher recoil pressure than that of dry, surface, and as the volume of the exogenous water drop increased, the amplitude of the recoil pressure increased also.

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285 mJ Electro-optically 𝚀-switched Er:YAG Master Oscillator Power Amplifier (MOPA) System with Adjustable Pumping Delay between Flashlamps at 2.94 ㎛

  • Heesuk Jang;Hajun Song;Hae Seog Koh;Han Young Ryu
    • Current Optics and Photonics
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    • v.7 no.3
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    • pp.297-303
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    • 2023
  • In this paper, we demonstrated a high-energy (285 mJ) mid-infrared flashlamp-pumped electro-optically 𝚀-switched Er:YAG master oscillator power amplifier (MOPA) system and comprehensively investigated its temporal, spectral, and spatial characteristics. To increase the output energy, we optimized the delay between the timings at which the flashlamps of the master oscillator and power amplifier were triggered. In addition, the output energy was improved while minimizing thermal effects by cooling the MOPA system to a temperature slightly above the dew point. Consequently, the MOPA structure boosted the output energy without damaging the lithium niobate Pockels cell, which is a crucial element in 𝚀-switching. This design realized pulses with energies up to 0.285 J and pulse durations of approximately 140 ns at a wavelength of 2,936.7 nm. This high-energy mid-IR Er:YAG MOPA system can be used for various scientific, engineering, and military underwater applications.

Characteristics of four-pass Ti:sapphire laser amplifier and amplified spontaneous emission (사중경로 Ti:sapphire 레이저 증폭기의 증폭 특성과 자발방출에 의한 증폭)

  • 김규옥
    • Korean Journal of Optics and Photonics
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    • v.11 no.5
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    • pp.365-370
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    • 2000
  • We have constructed a collinear four pass Ti.sapphire laser amplifier by usmg polmization effect When we pumped the mnplifier with 188 mJ second harmonics of Q-switched Nd:YAG laser, we observed that a 450 mW 1l1cident cw Ti:sapphire laser beam is amphfled to pulse with energy of 34 mJ and pulse width (FWffM) of 25 os. We could mmllmze the a.mplified spontaneous emission by simple method of rotating the Tbapphire amplifier rod er rod

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