High-contrast ratio and high-efficiency anamorphic DLPillumination system design with a freeform surface lens

2021 ◽  
Author(s):  
Wei Chen Ding ◽  
Jui Wen Pan
Keyword(s):  
System Design ◽  
High Efficiency ◽  
Contrast Ratio ◽  
Freeform Surface ◽  
High Contrast

scholarly journals Phase-Change Metasurface by U-Shaped Atoms for Photonic Switch with High Contrast Ratio

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1499
Author(s):  
Xiaoyu Ma ◽  
Ruirui Song ◽  
Zhihua Fan ◽  
Shaolin Zhou
Keyword(s):  
Phase Transition ◽  
Phase Change ◽  
High Efficiency ◽  
Contrast Ratio ◽  
Active Phase ◽  
Hybrid Design ◽  
High Contrast ◽  
Metal Insulator Metal ◽  
Phase Tuning ◽  
Low Efficiency

Currently, diverse metasurfaces act as exotic platforms enabling versatile wave regulations in deep-subwavelength level for ultracompact integration. To address the existing issues of passive nature and low-efficiency in wave controls, one type of metasurface for active phase tuning is proposed in this paper by integrating the phase-change dielectric of Ge2Sb2Te5 into the of U-shaped meta-atoms. Specifically, the phase-change-based hybrid design of Ge2Sb2Te5-integrated metalens switch is demonstrated and numerically confirmed with switchable focusing. The well-defined metal-insulator-metal (MIM) setup is used to enable high-efficiency reflective wavefront tunig and practical Ge2Sb2Te5 phase transition. Upon the phase transition between the amorphous and crystalline states of Ge2Sb2Te5, the cross-polarized component of reflected waves in the given wavelength range is switched “on” (maximized) for as-designed geometric phase plus meta-lensing or “off” (minimized) for no lensing with ultra-high contrast ratio of ~36:1. As a result, such hybrid design of phase-change metasurface may provide a promising route for active photonic device with compact integration.

scholarly journals Patterned waveguide liquid crystal displays

RSC Advances ◽  
2020 ◽  
Vol 10 (68) ◽  
pp. 41693-41702
Author(s):  
Yunho Shin ◽  
Jinghua Jiang ◽  
Guangkui Qin ◽  
Qian Wang ◽  
Ziyuan Zhou ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Switching Time ◽  
Contrast Ratio ◽  
Liquid Crystal Displays ◽  
High Contrast ◽  
High Brightness ◽  
Photo Polymerization ◽  
Ultrafast Switching ◽  
Light Waveguide ◽  
Polymer Stabilized

A polymer stabilized LC based light waveguide display is reported. Performance is improved by patterned photo-polymerization or electrode. It has high brightness, ultrafast switching time, high contrast ratio, and high transmittance for transparent and augmented displays.

scholarly journals Full-frame and high-contrast smart windows from halide-exchanged perovskites

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
You Liu ◽  
Jungan Wang ◽  
Fangfang Wang ◽  
Zhengchun Cheng ◽  
Yinyu Fang ◽  
...  
Keyword(s):  
Contrast Ratio ◽  
High Contrast ◽  
Smart Window ◽  
Frame Size ◽  
Smart Windows ◽  
Ideal Solutions ◽  
Ion Gel ◽  
And Control ◽  
Colour Rendering ◽  
Perovskite Photovoltaic

AbstractWindow glazing plays an essential role to modulate indoor light and heat transmission, which is a prospect to save the energy cost in buildings. The latest photovoltachromic technology has been regarded as one of the most ideal solutions, however, to achieve full-frame size (100% active area) and high-contrast ratio (>30% variable in visible wavelength) for smart window applicability is still a challenge. Here we report a photovoltachromic device combining full-transparent perovskite photovoltaic and ion-gel based electrochromic components in a vertical tandem architecture without any intermediated electrode. Most importantly, by accurately adjusting the halide-exchanging period, this photovoltachromic module can realize a high pristine transmittance up to 76%. Moreover, it possesses excellent colour-rendering index to 96, wide contrast ratio (>30%) on average visible transmittance (400-780 nm), and a self-adaptable transmittance adjustment and control indoor brightness and temperature automatically depending on different solar irradiances.

Stacked metal cathode for high-contrast-ratio polymeric light-emitting devices

2005 ◽  
Vol 86 (14) ◽  
pp. 143514 ◽  
Author(s):  
S. H. Li ◽  
H. Liem ◽  
C. W. Chen ◽  
E. H. Wu ◽  
Z. Xu ◽  
...  
Keyword(s):  
Contrast Ratio ◽  
High Contrast ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Metal Cathode

Extreme Adaptive Optics

2018 ◽  
Vol 56 (1) ◽  
pp. 315-355 ◽  
Author(s):  
Olivier Guyon
Keyword(s):  
Adaptive Optics ◽  
Thermal Emission ◽  
Contrast Ratio ◽  
Angular Separation ◽  
Circumstellar Disks ◽  
Spectroscopic Characterization ◽  
Central Star ◽  
High Contrast ◽  
Direct Imaging ◽  
Segmented Mirror

Over the last two decades, several thousand exoplanets have been identified, and their study has become a high scientific priority. Direct imaging of nearby exoplanets and the circumstellar disks in which they form and evolve is challenging due to the high contrast ratio and small angular separation relative to the central star. Exoplanets are typically within 1 arcsec of, and between 4 and 10 orders of magnitude fainter than, the stars they orbit. To meet these challenges, ground-based telescopes must be equipped with extreme adaptive optics (ExAO) systems optimized to acquire high-contrast images of the immediate surrounding of nearby bright stars. Current ExAO systems have the sensitivity to image thermal emission from young massive planets in near-IR, while future systems deployed on Giant Segmented Mirror Telescopes will image starlight reflected by lower-mass rocky planets. Thanks to rapid progress in optical coronagraphy, wavefront control, and data analysis techniques, direct imaging and spectroscopic characterization of habitable exoplanets will be within reach of the next generation of large ground-based telescopes.

scholarly journals High-fidelity photometry and astrometry of high-contrast imaged companions using LOCI processing.

2013 ◽  
Vol 8 (S299) ◽  
pp. 44-45
Author(s):  
Jérôme Maire ◽  
Jonathan Gagné ◽  
David Lafrenière ◽  
James R. Graham ◽  
René Doyon
Keyword(s):  
Contrast Ratio ◽  
Angular Separation ◽  
Speckle Noise ◽  
High Contrast ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
Suppression Technique ◽  
Imaging And Spectroscopy ◽  
And Migration ◽  
Imaging Performance

RésuméDirect imaging and spectroscopy of exoplanets is a key element for understanding planet formation and migration. Such direct detections and characterizations remains technologically challenging, since a very high contrast ratio and small angular separation are involved, and futhermore speckle noise limits the high-contrast imaging performance. We further discuss a speckle subtraction and suppression technique that fully takes advantage of spectral and time-domain information on quasi-static speckles to measure the highest-fidelity photometry as well as accurate astrometry of detected companions.

Optical System Design for Ultraviolet-LED Curing Based on the Structure of Freeform Surface

2014 ◽  
Vol 34 (12) ◽  
pp. 1222003
Author(s):  
李梦远 Li Mengyuan ◽  
孙伽略 Sun Jialue ◽  
张大伟 Zhang Dawei ◽  
李柏承 Li Baicheng
Keyword(s):  
System Design ◽  
Optical System ◽  
Freeform Surface ◽  
Optical System Design
Sign in / Sign up

Export Citation Format

Share Document