The experimental excitations for luminescent glasses are usually monochromatic, but LED chips in applications have an emission bandwidth. In order to investigate the luminescence properties of rare earth ions doped glasses excited by broadband lights, a computational model was presented based on the dependences of excitation wavelengths on emission spectra, chromaticity coordinates and correlated color temperatures (CCTs). The simulations were carried out applying Ce/Tb/Eu co-doped calcium borosilicate glasses as examples. The results show that for the same CCTs, the center wavelengths of chips are different with the excitation wavelengths of fluorescence spectrophotometers.
Quantum efficiency measurement of luminescence glasses for high-power white LED was investigated. Luminescence
glasses have transparent and anisotropic characteristics, for this reason, we adopted an integrating sphere with 20cm
diameter which was connected to a CCD spectrometer to obtain fluorescence spectra of the sample. The relative spectral
intensity distribution of the sample under the light source excited was derived from the measured spectra firstly, then
using the standard halogen lamp to calibrate the system, we got the absolute spectral intensity distribution, finally the
quantum efficiency of the sample can be calculated based on the distribution. It provides an accurate method to measure
the luminescence materials’ emission characters.
Proc. SPIE. 8202, 2011 International Conference on Optical Instruments and Technology: Solid State Lighting and Display Technologies, Holography, Speckle Pattern Interferometry, and Micro/Nano Manufacturing and Metrology
The Eu2+ and Dy3+ co-doped luminescence high silica glass was prepared by combining porous
glass preparation and sintering process. The emission spectra and excitation spectra of luminescence
glasses were measured. With the excitation of ultraviolet (UV) wavelength of 365nm, there were two
emission bands with central wavelength 480nm and 573nm in spectra of samples which presented the
near white light luminescence. The energy transfer process from
Dy3+ to Eu2+ and concentration quench
process of Eu2+ in samples were demonstrated by comparing the relative spectral intensity of emission
spectra and excitation spectra. This type of glass might be an adoptable candidate for white LED
through an appropriate UV chip excitation.