Search

Your search keyword '"Zhao, Yuan"' showing total 33 results
Start Over Author "Zhao, Yuan" Journal optics express
33 results on '"Zhao, Yuan"'

31. Surface damage induced by micropores in transparent ceramics under nanosecond laser irradiation.

Author

Chen Y, Feng T, Zhao YA, Jiang BX, and Zhang L

Abstract

The increasing use of transparent ceramics in laser systems presents a challenge; their low damage threshold has become a significant impediment to the development of powerful laser systems. Consequently, it is imperative to undertake research into the damage sustained by these materials. Micropores, the most common structural defects in transparent ceramics, inevitably remain within the material during its preparation process. However, the relationship between the density and size of these micropores and their impact on nanosecond laser damage threshold and damage evolution remains unclear. In this study, we utilize the annealing process to effectively manage the density and size of micropores, establishing a correlation between micropores in relation to damage thresholds. This study confirms for the first time that micropores significantly contribute to laser damage, comparing and analyzing the damage morphology characteristics of both front and rear surfaces of transparent ceramics. It also presents, potential mechanisms that may contribute to these differences in damage. This paper offers guidance for controlling micropores during the preparation and processing of transparent ceramics with high laser damage thresholds. The findings are expected to further improve the anti-nanosecond laser damage capabilities of transparent ceramics.

Published
2024
Full Text
View/download PDF

32. Radiation effect on silicon photonics chips for space quantum key distribution.

Author

Chen ZY, Liu YF, Chen C, Gao Y, and Zheng H

Abstract

Quantum communication satellites have potential for applications in future quantum networks. Photonics integrated chips, due to their compact and lightweight nature, are well-suited for satellite deployment. However, the harsh radiation environment of space can cause permanent damage to these chips, resulting in degraded performance or complete loss of functionality. In this work, we conducted a series of radiation experiments to evaluate the effects of γ rays and high energy protons on quantum key distribution transmitter chips. The results suggest that the insertion loss of the chip is slightly reduced by about 1.5 dB after 100 krad (Si) γ ray irradiation, and further reduced by about 0.5 to 1 dB after 2.39 × 10 11 /cm 2 proton radiation. The half-wave voltages, extinction ratios, and polarization angles are not changed significantly within the measurement error range. Our work proves the feasibility of deploying quantum constellations utilizing terminals based on photonics chips.

Published
2024
Full Text
View/download PDF

33. A solar photovoltaic system with ideal efficiency close to the theoretical limit.

Author

Zhao Y, Sheng MY, Zhou WX, Shen Y, Hu ET, Chen JB, Xu M, Zheng YX, Lee YP, Lynch DW, and Chen LY

Subjects
Computer Simulation, Equipment Design, Equipment Failure Analysis, Light, Scattering, Radiation, Computer-Aided Design, Electric Power Supplies, Filtration instrumentation, Models, Theoretical, Solar Energy
Abstract

In order to overcome some physical limits, a solar system consisting of five single-junction photocells with four optical filters is studied. The four filters divide the solar spectrum into five spectral regions. Each single-junction photocell with the highest photovoltaic efficiency in a narrower spectral region is chosen to optimally fit into the bandwidth of that spectral region. Under the condition of solar radiation ranging from 2.4 SUN to 3.8 SUN (AM1.5G), the measured peak efficiency under 2.8 SUN radiation reaches about 35.6%, corresponding to an ideal efficiency of about 42.7%, achieved for the photocell system with a perfect diode structure. Based on the detailed-balance model, the calculated theoretical efficiency limit for the system consisting of 5 single-junction photocells can be about 52.9% under 2.8 SUN (AM1.5G) radiation, implying that the ratio of the highest photovoltaic conversion efficiency for the ideal photodiode structure to the theoretical efficiency limit can reach about 80.7%. The results of this work will provide a way to further enhance the photovoltaic conversion efficiency for solar cell systems in future applications.

Published
2012
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results