• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.2180-2182
• /
• 2000

Laser emission, a part of electromagnetic wave, has short propagation length in water, and the underwater applications of laser are limited. The acquisition of underwater imaging is possible only by using a blue-green laser since the blue-green range has relatively small absorption coefficient in water. We introduce the conditions of the laser required for underwater imaging and the attenuation characteristics of a blue-green laser used in water.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.12 no.1
• /
• pp.11-20
• /
• 2002

The world at the end of the $20^{th}$ Century has become "blue" Indeed, this past decade has witnessed a "blue rush" towards the development of violet-blue-green light emitting diodes (LEDs) and laser diodes (LDs) based on wide bandgap III-Nitride semiconductors. And the hard work has culminated with, first, the demonstration of commercial high brightness blue and green LEDs and of commercial violet LDs, at the very end of this decade. Thanks to their extraordinary properties, these semiconductor materials have generated a plethora of activity in semiconductor science and technology. Novel approaches are explored daily to improve the current optoelectronics state-of-the-art. Such improvements will extend the usage and the efficiency of new light sources (e.g. white LEDs), support the rising information technology age (e.g. high density optical data storage), and enhance the environmental awareness capabilities of humans (ultraviolet and visible photon detectors and sensors). Such opportunities and many others will be reviewed in this presentation.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.110-111
• /
• 2014

RGB laser 를 이용하여 rf-magnetron sputtering 법으로 합성한 a-IGZO 박막의 photoresponse 를 관찰하였다. Air 분위기에서 red 파장을 조사 할 경우 비교적 slow recovery 특성을 보였으며, green 과 blue 파장을 조사 할 경우 red 보다 fast recovery 특성을 나타내었다. 그러나 진공에서 측정할 경우, red 파장에서는 recovery 가 빨라졌으며, green 과 blue 파장의 경우 recovery 가 매우 느려짐을 확인하였다. 이는 passivation 을 하지 않은 소자의 oxygen gas 의 흡/탈착 때문으로 예상할 수 있었으며, red 파장이 gas 탈착에 기여하는 정도가 매우 작고, green 과 blue 파장이 gas 탈착에 기여하는 정도가 매우 크기 때문인 것으로 생각할 수 있었다. 온도를 증가시킬 경우, 모든 경우에서 recovery 가 빠르게 나타났는데 이는 흡/탈착에 필요한 barrier 및 $V_o{^{2+}}$에서 Vo 로 돌아오기 위한 barrier 를 쉽게 넘어갈 수 있기 때문으로 이해 할 수 있었다. 이러한 결과를 stretched exponential equation 을 이용하여 해석하였으며 수치화 하였다.

• Applied Microscopy
• /
• v.27 no.3
• /
• pp.257-263
• /
• 1997

Microstructural characterizations of II-VI blue laser diodes which consist of quaternary $Zn_{1-x}Mg_xS_ySe_{l-y}$ cladding layer, ternary $ZnS_ySe_{l-y}$ guiding layer and $Zn_{0.8}Cd_{0.2}Se$ quantum well as active layer were carried out using the transmission electron microscope working at 300 kV. Even though the entire structure is pseudomorphic to GaAs substrate, the structure had contained numerous extended stacking faults and dislocations which had created at ZnSe/GaAs interfaces and then further grown to the top of the epilayers. These faults might be expected to cause the degradation and shortening the lifetime of laser devices.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.476-477
• /
• 2009

The smallest green laser containing a built-in temperature controlling unit has been demonstrated. The device volume was just 0.5 cubic centimeters, which is nearly the same size as existing red and blue diode lasers, has an electrical-to-optical conversion efficiency of 10% and 150 mW power output. Furthermore as an alternative approach for compact green laser development, a quasi-phase matching method with wide spectral bandwidth for the reduction of speckle noise will be presented.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.1
• /
• pp.139-147
• /
• 1997

Argon laser used in this case report, is special in having two wavelength of 488, 514nm blue-green visible light spectrum. Blue light is used for composite resin polymerization and caries detection. Green light is used for soft tissue surgery and coagulation. Maximum absorption of this laser light occurs in red pigmentation such as hemoglobin. The argon laser may be well-suited for selective destruction of blood clots and hemangioma with minimal damage to adjacent tissues. Argon laser light penetrates tissue to the 1 mm depth, so its thermal intensity is lower than $CO_2$ laser light. Also, due to its short wavelength it can be focused in a small spot and even single gene can be excised by this laser and microscopy. After applicating argon laser to 4 patient for surgical procedure and to 1 patient for curing the composite resin, following results were obtained. 1. Improved visibility were gained due to hemostasis and no specific technique were needed according to easy recontouring of the tissue. 2. Ability to use by contact mode, tactile sense was superior but tissue dragability and accumulation of tissue on the tip needed sweeping motion. 3. Additive local anesthetic procedure was needed. 4. No suture and less curing time reduced chair time, this made argon laser available in pediatric dentistry.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.4
• /
• pp.169-172
• /
• 2003

Silicon nanocrystalline thin films on p-type (100) silicon substrate have been fabricated by pulsed laser deposition technique using a Nd:YAG laser with the wavelength of 355, 532, and 1064 nm. The base vacuum in the chamber was down to $10^-6$ Torr and the laser energy densities were 1.0~3.0 J/$\textrm{cm}^2$ After deposition, silicon nanocrystalline thin films have been annealed at nitrogen gas. Strong Blue and green luminescence from silicon nanocrystalline thin films have been observed at room temperature by photoluminescence and its peak energies shift to green when the wavelength is increased from 355 to 1064 nm.

• Journal of Sensor Science and Technology
• /
• v.28 no.4
• /
• pp.262-265
• /
• 2019

The effect of inter-band transition on surface plasmon resonance in gold thin film was investigated. We induced localized inter-band transition in the film by using incident light on its surface from a green laser (532 nm) source, and the surface plasmon resonance for inter-band transition was investigated at different wavelengths. It was determined that the reflectivity of blue light (450 nm) was significantly reduced in the region where the green laser was incident. We demonstrated that this decrease is mainly due to the coupling between the blue light and the surface plasmon resonance of excited electrons in higher energy states, based on experimental results for the incident and polarization angle-dependent reflectivity of the blue light.

• Applied Chemistry for Engineering
• /
• v.20 no.6
• /
• pp.681-684
• /
• 2009

The turbidity of flow type samples has a nonlinear relation to brightness of laser scattered light, but the shape of images in laser scattered light is different from each turbidity samples. The turbidity measurement will be easy if it uses a pattern of images in laser scattered light. But the excessive analysis load comes from the turbidity measured by red, green, blue intensity (intensity) of all pixels of images in laser scattered light. Therefore the images in laser scattered light were divided by appropriate block to decrease excessive analysis load. The shape of divided images in laser scattered light was different from each turbidity sample. The real turbidity has a linear relation to turbidity measured by the artificial neural network learned with the intensity of divided images in laser scattered light and turbidity.

• Korean Journal of Optics and Photonics
• /
• v.8 no.3
• /
• pp.183-188
• /
• 1997

Cut-off filters would reject all the radiation below and transmit all that above a certain wavelength or vice versa. In this paper, we study design and farbrication of dichroic mirror and broadband high reflective mirror for color separation of white laser beam source to R.G.B color beam source. In laser display system, color separation is very important. We fabricated below specific component for finite color separation of the Kr-Ar laser source. At 45$^{\circ}$ incidence s-polarized light , it is required that - H/R in blue region R>99%, H/T in green and red region T>90% - H/R in green and red region R>99%, H/T in blue region T>90% - H/R in green region R>99%, H/T in red region T>90% We composed the optical system and realize the full color image.