• Title/Summary/Keyword: Blue laser diode

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High-brightness Phosphor-conversion White Light Source Using InGaN Blue Laser Diode

  • Ryu, Han-Youl;Kim, Dae-Hwan
    • Journal of the Optical Society of Korea
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    • v.14 no.4
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    • pp.415-419
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    • 2010
  • A phosphor-conversion white light source is demonstrated using an InGaN-based blue laser diode (LD) and a yellow-emitting phosphor excited by the blue LD. The photometric and colorimetric properties of this blue-LD-based white light source are characterized. When injection current of the LD is 100 mA, luminous flux and luminous efficiency of the white light are found to be over 5 lm and 10 lm/W, respectively. When injection current is >90 mA, luminance is estimated to be larger than 10 Mcd/$cm^2$. In addition, color characteristics of the white light such as chromaticity coordinates, a correlated color temperature, and a color rendering index are found to be quite stable as current and temperature of the LD varies. The demonstrated LD-based white light source is expected to be used in high-brightness illumination applications with good color stability.

Holographic Data Storage System Using Blue Laser Diode (청색 레이저 다이오드를 이용한 홀로그래픽 데이터 저장장치)

  • Kwak Bong-Sik;Lee Serong-Hun;Ha Sang-Woo;Jung Yung-Woo;Kim Jin-A;Seo Jeong-Kyo;Choi In-Ho
    • 정보저장시스템학회:학술대회논문집
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    • pp.42-43
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    • 2005
  • Higher density in the holographic storage can be obtained by using shorter wavelength laser and higher numerical aperture (NA). In this paper, we adopted a blue laser diode with a wavelength of 405nm and high NA object lens. And the phase conjugation method is applied to prevent image distortion due to high NA. The performance of the system has been shown experimentally.

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A PSPICE Circuit Modeling of Strained AlGaInN Laser Diode Based on the Multilevel Rate Equations

  • Lim, Dong-Wook;Cho, Hyung-Uk;Sung, Hyuk-Kee;Yi, Jong-Chang;Jhon, Young-Min
    • Journal of the Optical Society of Korea
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    • v.13 no.3
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    • pp.386-391
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    • 2009
  • PSPICE circuit parameters of the blue laser diodes grown on wurtzite AlGaInN multiple quantum well structures were extracted directly from the three level rate equations. The relevant optical gain parameters were separately calculated from the self-consistent multiband Hamiltonian. The resulting equivalent circuit model for a blue laser diode was schematically presented, and its modulation characteristics, including the pulse response and the frequency response, have been demonstrated by using a conventional PSPICE.

Effective Annealing and Crystallization of Si Film for Advanced TFT System

  • Noguchi, Takashi
    • Journal of Information Display
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    • v.11 no.1
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    • pp.12-16
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    • 2010
  • The effect of the crystallization and activated annealing of Si films using an excimer laser and the new CW blue laser are described and compared with furnace annealing for application in advanced TFTs and for future applications. Pulsed excimer laser annealing (ELA) is currently being used extensively as a low-temperature poly-silicon (LTPS) process on glass substrates as its efficiency is high in the ultra-violet (UV) region for thin Si films with thickness of 40-60 nm. ELA enables extremely low resistivity relating to high crystallinity for both the n- and p-type Si films. On the other hand, CW blue laser diode annealing (BLDA) enables the smooth Si surface to have arbitral crystal grains from micro-grains to an anisotropic huge grain structure only by controlling its power density. Both annealing techniques are expected to be applied in the future advanced TFT systems.

Study on Dual-Lenses Actuator for HD-DVD System (차세대 DVD 시스템용 Actuator 연구)

  • Kim, Seok-Jung;Lee, Yong-Hoon;Ahn, Young-Man;Chung, Chong-Sam
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.377.1-377
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    • 2002
  • Recently, an optical disc system has been proposed using blue laser diode, high NA objective lens and groove only disc structure. A new method is needed to readout CD and DVD in the blue system. In order to readout CD and DVD in HD-DVD system, we adopted dual-lenses actuator in consideration of optical utilization efficiency, optical performance and insurance of sufficient W.D (working distance). (omitted)

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Development of Twin-Objective Actuator with Radial Tilt Function for Blu-Ray Disc Recorder (BD Recorder용 3축 독립구동 Twin-Objective 액추에이터 개발)

  • Kim, Seok-Jung;Heor, Tae-Youn;Kim, Tae-Kyung;Ahn, Young-Man;Chung, Chong-Sam;Park, Soo-Han
    • Transactions of the Society of Information Storage Systems
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    • v.1 no.2
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    • pp.121-126
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    • 2005
  • Recently, an optical disc system has been proposed using blue laser diode, high NA objective lens and groove only disc structure. A new method is needed to readout CD and DVD in this Blu-Ray Disc Recorder. In order to readout CD and DVD in Blu-Ray Disc Recorder, we adopted dual-lenses actuator in consideration of optical utilization efficiency, optical performance and insurance of sufficient W.D(working distance). This dual-lenses actuator has two objectives in radial direction, one is for CD/DVD and the other is for BD. We had to solve the induced problems of collision between disc and lens, DC tilt increase, AC tilt increase, 2nd resonance deterioration and AC sensitivity drop caused by disposing two lenses in an actuator. Also we developed high response twin- objective actuator with radial tilt function to apply high-speed BD Recorder or BD Player. Consequently we presented that two kinds of dual-lenses actuators for BD Recorder have been possessed good performance in 3 axis directions. And we measured eye patterns of CD, DVD and BD by using one BD optical pick-up with dual-lenses actuator.

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Design of Cover Layer Incident Dual-Layer Near-Field Recording Optics with Hemispherical SIL (반구형 SIL을 이용한 미디어 내부 이층 근접장 광 기록계의 설계)

  • Kim Wan-Chin;Choi Hyun;Song Taesun;Park No-Cheol;Park Young-Pil
    • 정보저장시스템학회:학술대회논문집
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    • pp.4-11
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    • 2005
  • In this paper, we propose novel optics design for media inside near-field recording (NFR) using hemispherical solid immersion lens (HMS). To obtain strong advantage of data protection and high data capacity simultaneously, HMS based near field optics using aplanatic position of super hemisphere is designed. In this design, to improve small optical tolerance of this aplanatic position, additional aspheric lens surface is added on top of the HMS and it is combined with zoom optics which composed of two single lenses having low numerical aperture (NA). Also, to compensate chromatic aberration which happens seriously in optics using blue laser diode, diffractive optical element is used. Using zoom optics, additional aspheric lens surface, and diffractive optical element together, wavefront aberration and chromatic aberration are effectively reduced in broad range of cover layer thickness and wavelength variation. In addition, In this paper, effect of gap induced aberration is investigated by analyzing different behavior of each TM and TE wave for designed media inside dual-layer NFR optics.

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Measurement and Analysis of Phosphor Conversion Efficiency for Color-Matching LCDs (Color-Matching LCD를 위한 형광체 전환효율의 측정과 분석)

  • Jeon, Hwa Jun;Lim, Gyo Sung;Na, Dae Gil;Kwon, Jin Hyuk
    • Korean Journal of Optics and Photonics
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    • v.24 no.5
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    • pp.256-261
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    • 2013
  • Power conversion efficiency of the red and green phosphors was measured and analyzed. Two different samples of phosphors of thickness 50 ${\mu}m$ were prepared: one was the phosphor layer coated on the transparent substrate and the other was prepared on the reflective substrate. The 445 nm blue laser diode beam was used as the exciting beam. The conversion efficiencies of the red and green phosphor layers were 41.4% and 46%, respectively. The quantum efficiencies of the red and green phosphors were 60.4% and 53.5%, respectively.

Design of Cover Layer Incident Dual-Layer Near-Field Recording Optics with Hemispherical SIL (반구형 SIL을 이용한 미디어 내부 이층 근접장 광 기록계의 설계)

  • Choi, Hyun;Kim, Wan-Chin;Song, Tae-Sun;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.1
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    • pp.13-20
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    • 2006
  • In this paper, we propose novel optics design for media inside near-field recording(NFR) using hemispherical solid immersion lens(HMS). To obtain strong advantage of data protection and high data capacity simultaneously, HMS based near field optics using aplanatic position of super hemisphere is designed. In this design, to improve small optical tolerance of this aplanatic position, additional aspheric lens surface is added on top of the HMS and it is combined with zoom optics which composed of two single lenses having low numerical aperture(NA). Also, to compensate chromatic aberration which happens seriously in optics using blue laser diode, diffractive optical element is used. Using zoom optics, additional aspheric lens surface, and diffractive optical element together, wavefront aberration and chromatic aberration are effectively reduced in broad range of cover layer thickness and wavelength variation. In addition, in this paper, effect of gap induced aberration is investigated by analyzing different behavior of each TM and TE wave for designed media inside dual-layer NFR optics.

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Study on Dual-Lenses Actuator for HD-DVD System (차세대 DVD 시스템용 Actuator 연구)

  • Kim, Seok-Jung;Lee, Yong-Hoon;Ahn, Young-Man;Chung, Chong-Sam
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.777-781
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    • 2002
  • Recently, an optical disc system has been proposed using blue laser diode, high NA objective lens and groove only disc structure. A new method is needed to readout CD and DVD in this blue system. In order to readout CD and DVD in HD-DVD system, we adopted dual-lenses actuator in consideration of optical utilization efficiency, optical performance and insurance of sufficient W.D (working distance). This dual-lenses actuator has two objectives in radial direction, one is for CD/DVD and the other is for HD-DVD. We had to solve the induced problems of DC tilt increase, $2^{nd}$ resonance deterioration and AC sensitivity drop caused by disposing two lenses in an actuator. Especially, to solve AC sensitivity drop, we introduced two 2-pole magnets and separated focus and track magnetic circuits. Consequently we presented that dual-lenses actuator has been possessed good performance. And we measured eye patterns of CD, DVD and HD-DVD by using HD-DVD optical pick-up with dual-lenses actuator.

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