The intrinsic phosphor properties are of significant importance for the performance of phosphor screens used in medical imaging systems. In previous analytical-theoretical and Monte Carlo studies on granular phosphor materials, values of optical properties, and light interaction cross sections were found by fitting to experimental data. These values were then employed for the assessment of phos...

OBJECTIVES To assess the accuracy of NewTom 9000 cone beam CT (CBCT) images for the detection and quantification of periodontal bone defects in three dimensions. METHODS A sample of 146 sites in 5 dry skulls provided the ground truth (GT). Half of the sample had bone loss of at least 3 mm. Two metal spheres at each site ensured correspondence between GT and CBCT measurements. Skulls were subm...

We have successfully demonstrated the enhanced luminous flux and lumen efficiency in white light-emitting diodes by the randomly textured phosphor structure. The textured phosphor structure was fabricated by a simple imprinting technique, which does not need an expensive dry-etching machine or a complex patterned definition. The textured phosphor structure increases luminous flux by 5.4% and 2....

The optical properties of YAG:Ce phosphor were measured by a double-integrating-sphere system and calculated by Mie theory and Monte Carlo ray tracing to provide precise optical characterizations of YAG:Ce phosphor for white light-emitting diode (LED) packaging design. Measurement results showed that the phosphor presents strong absorption for blue light, high reflection for yellow light, and a...

Recently, high-performance color converters excitable by blue laser diode (LD) have been sprung up for projection display. However, thermal accumulation effect of is a non-negligible problem under high-power LD irradiation. Herein, we developed novel opto-functional composite (patterned CaAlSiN3: Eu2+ phosphor-in-glass film-Y3Al5O12: Ce<sup...

Computed radiography (CR) systems have been gaining adoption as digital replacements for film for diagnostic and therapy imaging. As a result, film processors are being removed from service, leaving a void for the medical physicists who use film and processors for two-dimensional mega-voltage beam dosimetry. This is the first report to evaluate the ability of a commercial CR reader and storage ...

A possibility of YVO4:Eu phosphor as a red phosphor for the application to ultraviolet (UV) light emitting diodes (LEDs) was investigated. Bi was used as a sensitizer for Eu to improve photoluminescence (PL) intensity in the longer wavelengths region than 350 nm and Bi-sensitized YVO4:Eu phosphor was characterized in terms of crystal structure, and PL excitation/emission spectra. Addition of Bi...

The performance of a persistent phosphor is often determined by comparing luminance decay curves, expressed in cd/m 2 . However, these photometric units do not enable a straightforward, objective comparison between different phosphors in terms of the total number of emitted photons, as these units are dependent on the emission spectrum of the phosphor. This may lead to incorrect conclusions reg...

High efficiency white light-emitting diodes with superior color-mixing have been investigated. It is suggested that the patterned remote phosphor structure could improve the uniformity of angular-dependent correlated color temperature (CCT) and achieve high chromatic stability in wider operating current range, as compared to the conventional remote phosphor coating structure. In this experiment...