Tm3+/Er3+/Yb3+-codoped oxyhalide tellurite glasses as materials for three-dimensional display

Blue, green and red emissions through frequency upconversion and energy transfer processes in Tm3+/Er3+/Yb3+-codoped oxyhalide tellurite glass under 980 nm excitation are investigated. The intense blue (476 nm), green (530 and 545 nm) and red (656 nm) emissions are simultaneously observed at room temperature. The blue (476 nm) emission was originated from the (1)G(4)->H-3(6) transition of Tm3+. The green (530 and 545 nm), and red (656 nm) upconversion luminescences were identified from the H-2(11/2)->I-4(15/2), S-4(3/2)->I-4(15/2), and F-4(9/2)->I-4(15/2) transitions of Er3+, respectively. The energy transfer processes and possible upconversion mechanisms are evaluated. (C) 2005 Elsevier B.V. All rights reserved.

Transparent colloid containing upconverting nanocrystals: An alternative medium for three-dimensional volumetric display

We report an alternative medium of transparent upconverting colloid containing lanthanide ion doped NaYF4 nanocrystals for three-dimensional (3D) volumetric display. The colloids exhibit tunable upconversion luminescence with a wide spectrum of colors by adjusting the doping concentrations of the nanocrystals and the compositions of the colloids. Our preliminary experimental result indicates that an upconverting colloid-based 3D volumetric display using a convergent, near infrared laser beam to induce a localized luminescent spot near the focus is technically feasible. Therefore arbitrary 3D objects can be created inside the upconverting colloid by use of computer controlled 3D scanning systems. (C) 2008 Optical Society of America

Design and fabrication of color filters for projection display system

Color filters are key components in an optical engine projection display system. In this paper, a new admittance-matching method for designing and fabricating the high performance filters is described, in which the optimized layers are limited to the interfaces between the stack (each combination of quarter-wave-optical-thickness film layers is called a stack) and stack, or between stack and substrate, or between stack and incident medium. This method works well in designing filters containing multiple stacks such as UV-IR cut and broadband filters. The tolerance and angle sensitivity for the designed film stacks are analyzed. The thermal stability of the sample color filters was measured. A good result in optical performance and thermal stability was obtained through the new design approach. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

Design and fabrication of color filters for projection display system

Color filters are key components in an optical engine projection display system. In this paper, a new admittance-matching method for designing and fabricating the high performance filters is described, in which the optimized layers are limited to the interfaces between the stack (each combination of quarter-wave-optical-thickness film layers is called a stack) and stack, or between stack and substrate, or between stack and incident medium. This method works well in designing filters containing multiple stacks such as UV-IR cut and broadband filters. The tolerance and angle sensitivity for the designed film stacks are analyzed. The thermal stability of the sample color filters was measured. A good result in optical performance and thermal stability was obtained through the new design approach. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

Sex-change rules, stock dynamics, and the performance of spawning-per-recruit measures in protogynous stocks

Predicting and under-standing the dynamics of a population requires knowledge of vital rates such as survival, growth, and reproduction. However, these variables are influenced by individual behavior, and when managing exploited populations, it is now generally realized that knowledge of a species’ behavior and life history strategies is required. However, predicting and understanding a response to novel conditions—such as increased fishing-induced mortality, changes in environmental conditions, or specific management strategies—also require knowing the endogenous or exogenous cues that induce phenotypic changes and knowing whether these behaviors and life history patterns are plastic. Although a wide variety of patterns of sex change have been observed in the wild, it is not known how the specific sex-change rule and cues that induce sex change affect stock dynamics. Using an individual based model, we examined the effect of the sex-change rule on the predicted stock dynamics, the effect of mating group size, and the performance of traditional spawning-per-recruit (SPR) measures in a protogynous stock. We considered four different patterns of sex change in which the probability of sex change is determined by 1) the absolute size of the individual, 2) the relative length of individuals at the mating site, 3) the frequency of smaller individuals at the mating site, and 4) expected reproductive success. All four pat-terns of sex change have distinct stock dynamics. Although each sex-change rule leads to the prediction that the stock will be sensitive to the size-selective fishing pattern and may crash if too many reproductive size classes are fished, the performance of traditional spawning-per-recruit measures, the fishing pattern that leads to the greatest yield, and the effect of mating group size all differ distinctly for the four sex-change rules. These results indicate that the management of individual species requires knowledge of whether sex change occurs, as well as an understanding of the endogenous or exogenous cues that induce sex change.