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2,083 results on '"Shao, Jianda"'

3. Advances in space laser coating for space exploration

Author

WANG Zhihao, WANG Yanzhi, SHEN Zicai, HE Hongbo, and SHAO Jianda

Subjects
space laser, space radiation, laser coating, gravitational wave detection, deep space, Motor vehicles. Aeronautics. Astronautics, TL1-4050
Abstract

With the advancement of space laser technology，laser systems are progressing towards shorter wavelengths，longer lifetimes，and higher orbits. It requires higher performance coatings that can withstand the damage caused by the harsh space environment，such as vacuum，high and low temperatures，proton radiation and Gamma-ray radiation. This paper reviews the development direction of the main space lasers at home and abroad. It also discusses the effects of the space environment on coatings during the development of space laser systems and the evolution mechanism of coating performance under service conditions. It presents the new advances in high-performance space laser coatings and provides insights into future development directions，such as gravitational wave detection in space and deep space exploration.

Published
2024
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28. Motionless and fast measurement technique for obtaining the spectral diffraction efficiencies of a grating

Author

Wang, Shenghao, Liu, Shijie, Shao, Jianda, Wang, Yonglu, Kong, Fanyu, and Jin, Yunxia

Subjects
Physics - Instrumentation and Detectors
Abstract

The measurement of the spectral diffraction efficiencies of a diffraction grating is essential for improving the manufacturing technique and for assessing the grating's function in practical applications. The drawback of the currently popular measurement technique is its slow speed due to the hundreds of repetitions of two kinds of time-consuming mechanical movements during the measuring process (i.e., the rotation of the mechanical arm to capture the light beam, and the mechanical variation of the output wavelength of the grating monochromator). This limitation greatly restricts the usage of this technique in dynamic measurement. In this manuscript, we present a motionless and fast measurement technique for obtaining the spectral diffraction efficiencies of a plane grating, effectively eliminating the aforementioned two kinds of mechanical movement. Herein, the proposed solution for removing the first kind of mechanical movement is tested, and the experimental result shows that the proposed method can be successfully used to measure the plane transmission grating's spectral diffraction efficiencies in the wavelength range of 550-750 nm. The method for eliminating the second kind of mechanical movement is not verified in this manuscript; however, we think that it is very straightforward and commercially available. We estimate that the spectral measurement can be achieved on a millisecond timescale by combining the two solutions. Our motionless and fast measuring technique will find broad applications in dynamic measurement environments and mass industrial testing., Comment: 7 pages, 7 figures,2 tables

Published
2017
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29. Apparatus for measuring the uniformity of the optical transmittance of a semispherical surface at normal incidence

Author

Wang, Shenghao, Liu, Shijie, Shao, Jianda, Xu, Tianzhu, Lu, Qi, Qi, Shen, Feng, Minghui, and Zhang, Long

Subjects
Physics - Optics, Physics - Instrumentation and Detectors
Abstract

In this paper, we build an apparatus for measuring the optical transmittance and its uniformity for a semispherical surface at normal incidence; the system is primarily comprised of a traditional double-beam photometric framework and a novel custom-made mechanical structure with multidimensional degrees of freedom. During the measurement process, a key aligning step is adopted to guarantee that the center point of the semispherical surface stands still in the light beam while scanning the hemispherical optical element point by point around the horizontal and vertical axes, which ensures that the laser beam is always normally incident onto the surface of the hemisphere. The experimental results show that the uniformity of the optical transmittance for a semispherical optical glass can be successfully characterized by the system, with a three-cycle repeatability error of 0.026% being demonstrated. Our system solves the problem of traditional spectrophotometers when measuring the spectral property of a hemispherical surface and thus can be popularized in similar applications., Comment: 6 pages, 10 figures

Published
2017
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33. Setup for measuring the optical propagation time in matter

Author

Wang, Shenghao, Liu, Shijie, Zhou, You, and Shao, Jianda

Subjects
Physics - Instrumentation and Detectors
Abstract

Optical propagation time in matter could reveal fruitful information, such as the velocity of light and the sample's refractive index. In this paper, we build a simple and robust setup for measuring the optical propagation time in matter for a known distance, the system uses high frequency square signal as the signal carrier, and a lock-in amplifier is employed to obtain the phase difference between the reference square signal and the other one penetrating the sample, in this way the optical time of flight in matter can be obtained by a background subtraction process. Primary experimental result confirms the feasibility of the newly proposed measuring theory, which can be used to measure easily in high-speed the speed of light and the refractive index of optical transparent material, compared with the currently popular measuring technique using oscilloscope, potential advantage of our proposed method employing lock-in amplifier is that high accuracy are promising, and in contrast with the presently most popular method for measuring the sample's refractive index based on the minimum deviation angle, superiority of our suggested method is the easy preparation of the sample, the convenient operability and the fast measuring speed., Comment: 10 pages, 3 figures

Published
2017

38. Surface modeling for optical fabrication with linear ion source

Author

Wu, Lixiang, Wei, Chaoyang, and Shao, Jianda

Subjects
Physics - Accelerator Physics, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

We present a concept of surface decomposition extended from double Fourier series to nonnegative sinusoidal wave surfaces, on the basis of which linear ion sources apply to the ultra-precision fabrication of complex surfaces and diffractive optics. It is the first time that we have a surface descriptor for building a relationship between the fabrication process of optical surfaces and the surface characterization based on PSD analysis, which akin to Zernike polynomials used for mapping the relationship between surface errors and Seidel aberrations. Also, we demonstrate that the one-dimensional scanning of linear ion source is applicable to the removal of surface errors caused by small-tool polishing in raster scan mode as well as the fabrication of beam sampling grating of high diffractive uniformity without a post-processing procedure. The simulation results show that, in theory, optical fabrication with linear ion source is feasible and even of higher output efficiency compared with the conventional approach., Comment: 7 pages, 5 figures

Published
2016

46. Tailoring epsilon-near-zero wavelength and nonlinear absorption properties of CdO thin films by Mo doping.

Author

Wu, Yi, Wang, Ying, Wang, Mengxia, Ma, Hao, Jiang, Hang, Yao, Jianke, Zhao, Yuanan, Yu, Kin Man, and Shao, Jianda

Subjects
ABSORPTION coefficients, ABSORPTION, CADMIUM oxide, WAVELENGTHS, OPTOELECTRONIC devices
Abstract

Cadmium oxide (CdO) has recently attracted attention as a material with controllable properties tailored for optoelectronic and nanophotonic devices due to its superior mobility. However, its potential application in near-infrared (NIR) remains to be explored. In this work, we demonstrate that the epsilon-near-zero (ENZ) wavelength and nonlinear optical properties of CdO films can be effectively tuned by Mo doping. The results show that Mo doping increases the electron concentration as well as improve the crystalline quality of CdO. With increasing Mo doping, we achieve blueshifts of the ENZ wavelength from 2.89 to 1.56 μm. The nonlinear absorption (NLA) behavior at 1550 nm changes from reverse saturable absorption to saturable absorption with increasing Mo content. Moreover, significant improvement in NLA performance with nonlinear absorption coefficient β = −72 cm/GW is observed at the highest doping content. Our work shows that doped CdO films with tunable optoelectrical and nonlinear optical properties can be an ideal candidate for optoelectronic and nanophotonic application in the NIR region. [ABSTRACT FROM AUTHOR]

Published
2024
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