diode

Monolithic Broadband InGaN Light-Emitting Diode

by

Monolithic Broadband InGaN Light-Emitting Diode by Cong Feng, Jian-An Huang, Hoi Wai Choi.

A monolithic nonphosphor broadband-emission light-emitting diode is demonstrated, comprising a combination of high-density microstructured and nanostructured InGaN-GaN quantum wells fabricated using top-down approach. Broadband emission achieved by taking advantage low-dimensional-induced strain-relaxation highly strained wells, combining light emitted from strain-relaxed nanotips at wavelengths shorter than the as-grown as much 80 nm with longer-wavelength larger nonrelaxed microdisks. The localized characteristics have been studied spatially resolved near-field photoluminescence spectroscopy which enabled both intensity spectrum individual to be distinguished larger-dimensioned regions. Distinctive blue-green-yellow can observed electroluminescent device, whose continuous broadband characterized CIE coordinates (0.39, 0.47) color rendering in…

Read Monolithic Broadband InGaN Light-Emitting Diode on OA.mg

Combined Sodium Hypochlorite and 940 nm Diode Laser Treatment Against Mature E. Faecalis Biofilms in-vitro

by

Combined Sodium Hypochlorite and 940 nm Diode Laser Treatment Against Mature E. Faecalis Biofilms in-vitro by Castelo Baz Pablo, Martin Biedma Benjamin, Ruiz Pinon Manuel, Rivas Mundina Berta, Bahillo Jose, Perez Estevez Antonio, Gude Francisco, Moor Roeland De, Varela Patino Purificacion.

Background: Laser irradiation has been introduced in endodontic treatment due to its bactericidal effect. The aim of this study is evaluate the efficacy a 940 nm diode laser alone or combination with 5% sodium hypochlorite (NaOCl) against mature biofilms E. Faecalis. Methods: Sixty-eight (60 for three groups, 4 SEM and as negative controls) single-rooted human central incisors were prepared contaminated After two weeks incubation, specimens randomly divided groups; group 1 (n =20), teeth irradiated laser; 2 (n=20), rinsed NaOCl; 3 NaOCl then laser. Four used observe by SEM. Intracanal bacteria sampling was done, samples plated determinate CFU count. Results: At 24 hours 7 days, showed significant difference (P=0,02; P=0,00) disinfection if compared but did not show (P=1, P=0,66), although obtaining more extensive disinfection. Groups after (P=0,09) days afterwards (P=0,04). Conclusion: light (940 nm)

Read Combined Sodium Hypochlorite and 940 nm Diode Laser Treatment Against Mature E. Faecalis Biofilms in-vitro on OA.mg

Diode laser measurements of concentration and temperature in microgravity combustion

by

Diode laser measurements of concentration and temperature in microgravity combustion by Joel A. Silver, Daniel J. Kane.

Diode laser absorption spectroscopy provides a direct method of determinating species concentration and local gas temperature in combustion flames. Under microgravity conditions, diode lasers are particularly suitable, given their compact size, low mass power requirements. The development laser-based sensors for detection is presented, detailing measurements molecular oxygen. Current progress this work future application possibilities these methods on the International Space Station discussed.

Read Diode laser measurements of concentration and temperature in microgravity combustion on OA.mg

Tuning Superluminescent Diode Characteristics for Optical Coherence Tomography Systems by Utilizing a Multicontact Device Incorporating Wavelength-Modulated Quantum Dots

by

Tuning Superluminescent Diode Characteristics for Optical Coherence Tomography Systems by Utilizing a Multicontact Device Incorporating Wavelength-Modulated Quantum Dots by P. D. L. Greenwood, David T. D. Childs, Kristian M. Groom, Benjamin J. Stevens, Mark Hopkinson, Richard A. Hogg.

This paper details the development of broadband sources at 1050 nm for optical coherence tomography applications. A method obtaining a broad and smooth emission gain spectrum quantum dot (QD) layers is presented. The design, fabrication, operating characteristics multicontact superluminescent diodes are then set out, this device, incorporating QD material, described. It shown that device allows tuning peak position, shape, bandwidth, power, which advantageous imaging simplified utilizing single current source, achieved by resistor network. operation under various drive topologies discussed.

Read Tuning Superluminescent Diode Characteristics for Optical Coherence Tomography Systems by Utilizing a Multicontact Device Incorporating Wavelength-Modulated Quantum Dots on OA.mg

An experimental study of the part played by fluctuations of the electric field in the mechanism of current flow in a magnetron diode under cutoff conditions

by

An experimental study of the part played by fluctuations of the electric field in the mechanism of current flow in a magnetron diode under cutoff conditions by V. A. Berbasov, M. I. Kuznetsov, S. V. Stepanov.

Read An experimental study of the part played by fluctuations of the electric field in the mechanism of current flow in a magnetron diode under cutoff conditions on OA.mg

Miniature Multi-Kilowatt PIN Diode Mic Digital Phase Shifters

by

Miniature Multi-Kilowatt PIN Diode Mic Digital Phase Shifters by P. Onno, A. Plitkins.

A miniature high power, beryllia substrate, lumped element, PIN diode phase shifter has been developed. Design expressions are presented for two UHF models, which operate at kilowatt powers and exhibit 7% bandwidths with low insertion loss.

Read Miniature Multi-Kilowatt PIN Diode Mic Digital Phase Shifters on OA.mg

Photothrombosis of retinal and choroidal vessels in rabbit eyes using chloroaluminum sulfonated phthalocyanine and a diode laser

by

Photothrombosis of retinal and choroidal vessels in rabbit eyes using chloroaluminum sulfonated phthalocyanine and a diode laser by Olga E. Iliaki, Irini I. Naoumidi, Miltiadis K. Tsilimbaris, Ioannis G. Pallikaris.

Background and Objectives Photothrombosis is a relatively new photodynamic application leading to vascular occlusion. In the current work effectiveness of phthalocyanine diode laser in photothrombosis normal retinal choroidal vessels was evaluated. Study design, Materials Methods: Big temporal myelin wing were irradiated using 670 nm (2 mW, 0.5 mm2) after injection chloroaluminum sulfonated (5 mg/kg) twenty albino rabbits. Animals followed up maximum 7 months fundus photography, fluoroangiography, histology. Results underlying resulted all treated eyes 13 17.5 min irradiation. The patent again by 7th day procedure. Choroidal remained closed during whole follow-up period. Light electron microscopy demonstrated occupation platelet thrombi. Damage endothelial cell structure these could be seen. Outer RPE damage localized at irradiation area observed. Conclusion combination with low power simple effective way for induction thrombosis vessels. © 1996 Wiley-Liss, Inc.

3.3.co;2-l”>Read Photothrombosis of retinal and choroidal vessels in rabbit eyes using chloroaluminum sulfonated phthalocyanine and a diode laser on OA.mg

Optimizing spherical light-emitting diode array for highly uniform illumination distribution by employing genetic algorithm

by

Optimizing spherical light-emitting diode array for highly uniform illumination distribution by employing genetic algorithm by Yanxia Shen, Zhicheng Ji, Zhouping Su.

A numerical optimization method (genetic algorithm) is employed to design the spherical light-emitting diode (LED) array for highly uniform illumination distribution. An evaluation function related nonuniformity constructed optimization. With minimum of function, LED produces best uniformity. The genetic algorithm used seek function. By this method, we two arrays. In one case, LEDs are positioned symmetrically on sphere and illuminated target surface a plane. However, in other nonsymmetrically with surface. Both symmetrical nonsymmetrical arrays generate good distribution calculated nonuniformities 6 8%, respectively.

Read Optimizing spherical light-emitting diode array for highly uniform illumination distribution by employing genetic algorithm on OA.mg

Narrow-linewidth, tunable external cavity dual-band diode lasers through InP/GaAs-Si3N4 hybrid integration

by

Narrow-linewidth, tunable external cavity dual-band diode lasers through InP/GaAs-Si3N4 hybrid integration by Yeyu Zhu, Lin Zhu.

We demonstrate hybridly integrated narrow-linewidth, tunable diode lasers in the InP/GaAs-Si3N4 platform. Silicon nitride photonic circuits, instead of silicon waveguides that suffer from high optical loss near 1 µm, are chosen to build a external cavity for both InP and GaAs gain chips at same time. Single frequency lasing 1.55 µm is simultaneously obtained on single chip with spectral linewidths 18-kHz 70-kHz, side mode suppression ratio 52 dB 46 dB, tuning range nm 38 nm, respectively. The resulting dual-band narrow-linewidth have potential use variety novel applications such as difference-frequency generation, quantum photonics, nonlinear optics.

Read Narrow-linewidth, tunable external cavity dual-band diode lasers through InP/GaAs-Si3N4 hybrid integration on OA.mg

Improving carrier transport and light emission in a silicon-nanocrystal based MOS light-emitting diode on silicon nanopillar array

by

Improving carrier transport and light emission in a silicon-nanocrystal based MOS light-emitting diode on silicon nanopillar array by Gong-Ru Lin, Chun-Jung Lin, Hao-Chung Kuo.

A silicon-nanocrystal (nc-Si) based metal-oxide-semiconductor light-emitting diode (MOSLED) on Si nanopillar array with size, height, and density of 30nm, 350nm, 2.8×1010cm−2, respectively, is characterized. The roughened surface contributes to the improved turn-on characteristics by enhancing Fowler-Nordheim tunneling reducing effective barrier providing MOSLED a maximum optical power 0.7μW obtained at biased current 375μA. intensity, current, power-current slope nc-Si high-aspect-ratio are 140μW∕cm2, 5μA, 2±0.8mW∕A, respectively. external quantum efficiency 0.1% reported.

Read Improving carrier transport and light emission in a silicon-nanocrystal based MOS light-emitting diode on silicon nanopillar array on OA.mg