High-brightness laser-based White light sources for automotive lighting applications (Conference Presentation)

2019 ◽  
Author(s):  
Abdelmalek Hanafi ◽  
Helmut Erdl ◽  
Paul Rudy ◽  
James Raring ◽  
Julian A. Carey
Keyword(s):  
White Light ◽  
Light Sources ◽  
High Brightness ◽  
Automotive Lighting

scholarly journals PWM Dimming for High Brightness LED Based Automotive Lighting Applications

2017 ◽  
Vol 7 (5) ◽  
pp. 2434 ◽  
Author(s):  
Muhammad Wasif Umar ◽  
Norzaihar Yahaya ◽  
Zuhairi Baharuddin
Keyword(s):  
Luminous Flux ◽  
Light Sources ◽  
High Brightness ◽  
Pulse Width Modulated ◽  
Design Engineers ◽  
Simulink Simulation ◽  
Automotive Lighting ◽  
Theoretical Predictions ◽  
Dimming Control ◽  
Pwm Dimming

In recent years, the use of high brightness LEDs has become increasingly accepted as light sources in mainstream vehicles. However, they are semiconductor devices and their electrical characteristics are completely different to the traditional lamps. The output luminous flux of an LED is determined by the forward current running through it. Hence they cannot be powered directly from the automotive battery using the conventional driving techniques. They require specialised driving circuits which can respond to the changing needs of the LEDs as their electrical properties change, while maintaining the uniform brightness.<strong> </strong> This paper discusses the importance of dimming for LED based automotive lighting applications. A boost type DC-DC switching converter with pulse width modulated (PWM) dimming control has been proposed. MATLAB/Simulink simulation package has been used to verify the theoretical predictions hence to provide a useful guide for design engineers and researchers.

Crystalline Silicon White Light Sources Driven by Optical Resonances

Nano Letters ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2397-2405
Author(s):  
Jin Xiang ◽  
Mincheng Panmai ◽  
Shuwen Bai ◽  
Yuhao Ren ◽  
Guang-Can Li ◽  
...  
Keyword(s):  
White Light ◽  
Crystalline Silicon ◽  
Light Sources ◽  
Optical Resonances

scholarly journals Photocatalytic Performance of ZnO: Al Films under Different Light Sources

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Prashant Pradhan ◽  
Juan Carlos Alonso ◽  
Monserrat Bizarro
Keyword(s):  
White Light ◽  
Irradiation Time ◽  
Zno Films ◽  
Light Sources ◽  
X Ray Diffraction ◽  
Treatment Processes ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Very High ◽  
High Degradation Rate

ZnO and Al doped ZnO films were produced by spray pyrolysis. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy, and photoluminescence. Their photocatalytic activity was evaluated by the decomposition of the methyl orange dye using different light sources: ultraviolet light, artificial white light, and direct sunlight. The films were also tested under darkness for comparison. The ZnO films were able to degrade the test pollutant under UV and sunlight in more than a 60% after 180 min of irradiation and a scarce degradation was obtained using white light. However, the Al doped ZnO films presented a very high degradation rate not only under UV and sunlight (100% degradation), but also under white light (90% degradation after the same irradiation time). An unexpected high degradation was also obtained in the dark, which indicates that a nonphotonic process is taking place parallel to the photocatalytic process. This can be due to the extra electrons—provided by the aluminum atoms—that migrate to the surface and produce radicals favoring the decomposition process even in the dark. The high activity achieved by the ZnO: Al films under natural conditions can be potentially applied to water treatment processes.

scholarly journals System efficiency of laser-based white light

2014 ◽  
Vol 3 (5-6) ◽  
Author(s):  
Roland Lachmayer ◽  
Alexander Wolf ◽  
Gerolf Kloppenburg
Keyword(s):  
Thermal Management ◽  
White Light ◽  
High Power ◽  
Laser Diodes ◽  
Light Sources ◽  
System Efficiency ◽  
Light Emitting ◽  
Scale Down ◽  
Color Rendering ◽  
Product Weight

AbstractFor many lighting applications, light-emitting diodes (LEDs) are replacing traditional light sources providing the possibility for smart and efficient systems as well as a reduction in the product weight. A next step in this development is the integration of laser-based light sources to increase luminance and to further scale down the optics possibly leading to a reduction of necessary resources. This article reviews the possibilities and challenges arising from the use of laser diodes especially compared to current high-power LED systems in terms of efficiency, color-rendering properties, and thermal management.

>25 Gbit/s LiFi with Dual Wavelength Emission, Eye-safe, Laser Based White Light Collimated and Fiber Delivered Light Sources

2021 ◽  
Author(s):  
James Raring ◽  
Changmin Lee ◽  
Mohamed Sufyan Islim ◽  
Sovan Das ◽  
Adrian Sparks ◽  
...  
Keyword(s):  
White Light ◽  
Dual Wavelength ◽  
Light Sources ◽  
Wavelength Emission

Prospects for 4-laser white-light sources

2018 ◽  
Vol 66 (3) ◽  
pp. 271-280 ◽  
Author(s):  
Snjezana Soltic ◽  
Andrew N. Chalmers
Keyword(s):  
White Light ◽  
Light Sources

scholarly journals Nanophosphors-Based White Light Sources

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1048 ◽  
Author(s):  
Maura Cesaria ◽  
Baldassare Di Bartolo
Keyword(s):  
Rare Earth ◽  
White Light ◽  
Volume Ratio ◽  
Light Sources ◽  
Co Doping ◽  
New Class ◽  
Luminescence Efficiency ◽  
Metal Doped ◽  
The Individual ◽  
The Impact

Miniaturization requests and progress in nanofabrication are prompting worldwide interest in nanophosphors as white-emission mercury-free lighting sources. By comparison with their bulk counterparts, nanophosphors exhibit reduced concentration quenching effects and a great potential to enhance luminescence efficiency and tunability. In this paper, the physics of the nanophoshors is overviewed with a focus on the impact of spatial confinement and surface-to-volume ratio on the luminescence issue, as well as rare earth-activated multicolor emission for white light (WL) output. In this respect, the prominently practiced strategies to achieve WL emission are single nanophosphors directly yielding WL by means of co-doping and superposition of the individual red, green, and blue emissions from different nanophosphors. Recently, a new class of efficient broadband WL emitting nanophosphors has been proposed, i.e., nominally un-doped rare earth free oxide (yttrium oxide, Y2O3) nanopowders and Cr transition metal-doped garnet nanocrystals. In regard to this unconventional WL emission, the main points are: it is strictly a nanoscale phenomenon, the presence of an emitting center may favor WL emission without being necessary for observing it, and, its inherent origin is still unknown. A comparison between such an unconventional WL emission and the existing literature is presented to point out its novelty and superior lighting performances.

scholarly journals Luminous Efficacy of LED White Light Sources

2016 ◽  
Vol 16 (06) ◽  
pp. 64-74
Author(s):  
V Pavlov ◽  
V Pyasetskiy ◽  
A Horohorov ◽  
A Shirankov
Keyword(s):  
White Light ◽  
Light Sources ◽  
Luminous Efficacy
Sign in / Sign up

Export Citation Format

Share Document