Blue laser diode (LD) and light emitting diode (LED) applications

Abstract

The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high‐resolution photo‐lithography. As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back‐lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc. Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity. Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Preparation, Characterization and Photoluminescence Properties of Ca1-xSrxS:Eu Red-emitting Phosphors for a White LED

“…The development of white LEDs as a cost-competitive, energy-efficient alternative to conventional electrical lightning is very important for expanding LED applications toward general white lightning. [5][6][7] The first reported white light LEDs were based on blue InGaN technology, which uses a combination of blue emission from a blue LED and yellow emission from Y 3 Al 5 O 12 :Ce. However, these two-band white LEDs suffer from limited color rendering and color temperature, and are unable to produce all nature-equivalent colors, especially in the red region.…”

Progress and challenges in electrically pumped GaN-based VCSELs

“…Chemical tracking and biological agent detection is enabled by exciting fluorescent dyes and proteins. 17 In dentistry, low power lasers are used to detect caries, using fluorescence from hydroxyapatite or bacterial by-products. Moreover, photochemical reactions based on photoactivated dye techniques can be used to disinfect root canals, periodontal pockets, cavity preparations and sites of peri-implantitis.…”

Rare Earth Doped Alkali Earth Sulfide Phosphors for White-Light LEDs

“…Traditional colored LEDs have proven effective in signal applications, as indicator lights, and in automotive lightning. The development of white LEDs as a cost-competitive, energy-efficient alternative to conventional electrical lightning is very important for expanding LED applications toward general white lightning [5][6][7]. Phosphors activated with rare earth metal have been widely investigated in the past few decades on account of their technological importance [8].…”