Energy efficiency and lighting quality considerations are driving research into laser-pumped white light sources. Laser diodes as pump sources for downconversion phosphors promise freedom from "droop" that adversely affects the efficiency of light-emitting diodes (LEDs). High-intensity laser diode-pumped light sources for applications such as search lights and automobile headlights have been demonstrated recently. Our paper describes the design and construction of a domestic/office-type solid-state luminaire driven by light from an integrated violet laser-diode module. A trichromatic phosphor made from a blend of separate europium-containing rare-earth phosphors was used as the downconversion medium. Mechanical and optical design of the reflector and the phosphor plate are described. Characteristics of both the pump light and the downconverted light are also described. Our studies also looked at the variation of chromaticity coordinates with variation in pump power and the effect of laser speckle on the lamp's light output. Finally, there is a brief discussion of energy conversion efficiency and longevity considerations, comparing pumping with LEDs versus pumping with laser diodes.

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High quality white light-emitting diodes (LEDs) employ multi-component phosphor mixtures to generate light of a high color rendering index (CRI). The number of distinct components in a typical phosphor mix usually ranges from two to four. Here we describe a systematic experimental technique for starting with phosphors of known chromatic properties and arriving at their respective proportions for creating a blended phosphor to produce light of the desired chromaticity. This method is applicable to both LED pumped and laser diode (LD) pumped white light sources. In this approach, the radiometric power in the down-converted luminescence of each phosphor is determined and that information is used to estimate the CIE chromaticity coordinate of light generated from the mixed phosphor. A suitable method for mixing multi-component phosphors is also described. This paper also examines the effect of light scattering particles in phosphors and their use for altering the spectral characteristics of LD- and LED-generated light. This is the only approach available for making high efficiency phosphor-converted single-color LEDs that emit light of wide spectral width.

In this research, the pure titanium foil was treated in glycerol base electrolyte with 0.7 wt.% NH4F and a small amount of H2O at 17 V for 2 hours by electrochemical anodization process in order to prepare Titania nanotube arrays at room temperature (~25 ºC), different water content was added to the electrolyte as a tube enhancing agent. The high density uniform arrays are prepared by using organized and well aligned these tubes. The average size of tube diameter, ranging from 57 to 92 nm which found it increases with increasing water content, and the length of the tube ranging from 2.76 to 4.12 µm, also found to increase with increasing water content and ranging in size of wall thickness from 23 to 35 nm. A possible growth mechanism is presented. The X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) were utilized to study the structure and morphology of the Titania films.