Yuhang He
China Academy of Engineering Physics
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Yuhang He.
Optics Express | 2014
Yuhang He; Bo Gao; Kaiyuan Xu; Ang Liu; Qiang Li; Liqun Chai
An iterative algorithm is presented to calibrate the shapes of the reference surfaces in three-flat test. Three measurements in three-flat test determine the even part of the flat surfaces. The odd part can be obtained by adding one or more rotation measurements and using analytical recovery algorithm. Here we present an iterative algorithm to obtain the odd part instead of special analytical recovery algorithm. The iterative algorithm is purely numerical, and only involved in data rotation operation. A simulation experiment proves the validity and high accuracy of the proposed algorithm method.
Optical Engineering | 2014
Bo Gao; Qiang Li; Yuhang He; Liqun Chai
Abstract. An iterative algorithm has been successfully used to process data from the three-flat test. On the basis of the iterative algorithm proposed by Vannoni, which is much faster and more effective than the Zernike polynomial fitting method, an improved algorithm is presented. By optimizing the iterative steps and removing the scaling factors, the surface shape can be easily computed in a few iterations. The validity of the method is proved by computer simulation, and the interpolation error and principle error are analyzed.
8th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test, Measurement Technology, and Equipment | 2016
Xiaohong Wei; Yuhang He; Kaiyuan Xu; Bo Gao; Qiang Li; Liqun Chai
Computer generated holograms (CGHs) are state-of-the-art components in optical systems, and are widely used in combination with standard Fizeau interferometers. The primary role of the CGHs is to generate reference wavefront with any desired shape. A method of interferometrically measuring large convex lens with CGHs is adopted, and the results from a set of experiments that demonstrate the accuracy and simplicity of performing the holographic test are presented. A direct comparison of the CGH measurement with results from a compensation method shows excellent agreement. Finally, measurement uncertainty due to substrate error and hologram fabrication processes is analyzed.
8th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test, Measurement Technology, and Equipment | 2016
Yuhang He; Qiang Li; Daoming Wan; Liqun Chai
A new reconstruction algorithm for absolute shape calibration in two-flat test is proposed. The shift-rotation method is applied to absolute shape calibration in two-flat test. Relying on the decomposition of the reconstructed shapes into rotationally asymmetric and symmetric components, an iteration algorithm is presented to reconstruct the rotationally asymmetric components, and Zernike polynomial fitting algorithm is used to calculate rotationally symmetric components. Compared to the traditional algorithms, the proposed algorithm has the characteristics of considerable accuracy and less computational effort. A simulation experiment proves the validity of the presented algorithm.
ieee international conference on photonics | 2015
Ang Liu; Bo Gao; Kaiyuan Xu; Yuhang He; Qiang Li; Liqun Chai
The paper will describe an automated subaperture stitching interferometry for large plano surface based on relevant algorithm, which restruct the whole surface without recording the position of every subaperture. Both correction and data fusion algorithm are used to minimize the stitching error.
Optical Engineering | 2014
Bo Gao; Qiang Li; Yuhang He; Liqun Chai
The corresponding author for this article [Opt. Eng.. 53, (9 ), 092004 (2014)] has been changed from Bo Gao to Liqun Chai. The paper was corrected online on 4 June 2014.
International Symposium on Optoelectronic Technology and Application 2014: Laser and Optical Measurement Technology; and Fiber Optic Sensors | 2014
Bo Gao; Qiang Li; Yuhang He; Liqun Chai; Xiaohong Wei
Zernike Polynomial fitting method is an effective way to reconstruct absolute surface for three-flat test. However, the Zernike circle polynomials are not orthogonal over the circular area, hence they are not suitable for square flat. We present an absolute testing of a square flat with Legendre polynomial fitting method, which relies on calculating the coefficients of the Legendre terms by least-square fitting method. To obtain the three-dimensional surface data, one additional measurement that rotate the test flat through 90° should be introduced. The formulas are derived theoretically in detail, and validity has been proved by simulated experiment. Vertical profiles of the three surfaces are compared with the measurement results obtained by three-flat test. Good agreement validates our method.
International Symposium on Optoelectronic Technology and Application 2014: Laser and Optical Measurement Technology; and Fiber Optic Sensors | 2014
Xiaohong Wei; Bo Gao; Kaiyuan Xu; Qiang Li; Yuhang He; Ang Liu; Liqun Chai
A new technique for precise wavefront measurement of lens with a hologram is presented. In diffraction, the Fresnel-zone plate hologram emulates the reflective properties of a spherical mirror for use during transmission null tests of an optic by use of a phase-shifting interferometer. Experiment shows that the Fresnel-zone hologram method result is quite similar with that of the traditional interferometry testing method, in which retroreflecting spherical surfaces are used as the reference. The benefit of this methodology is the higher degree of precision at lower cost of manufacturing the reflecting hologram, compared with retrospheres capable of delivering similar precision. This technique is widely applicable and is particularly useful for measuring long focus lens.
Optics Communications | 2014
Yuhang He; Qiang Li; Bo Gao; Ang Liu; Kaiyuan Xu; Xiaohong Wei; Liqun Chai
Optik | 2013
Xiaohong Wei; Liqun Chai; Bo Gao; Qiang Li; Yuhang He