Pseudo-random Path Generation Algorithms and Strategies for the Surface Quality Improvement of Optical Aspherical Components

Zha, Jun; Zhang, Hangcheng; Li, Yipeng; Chen, Yaolong

doi:10.3390/ma13051216

Cited by 8 publications

(3 citation statements)

References 36 publications

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“…For this analysis, the raster scanning and Archimedes-type paths will be considered. The pseudo-random path is omitted from this analysis due to the direct dependence on the particular path generation algorithm selected [18,19]. This would lend a parametric model to be specific to a single algorithm rather than a more generalized formulation as is being explored.…”

Section: Sub-aperture Tool Polishingmentioning

confidence: 99%

Parametric Mid-Spatial Frequency Surface Error Synthesis

Hefferan

Graves²,

Trumper³

et al. 2021

Photonics

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Standard mid-spatial frequency tooling mark errors were parameterized into a series of characteristic features and systematically investigated. Diffraction encircled and ensquared energy radii at the 90% levels from an unpowered optical surface were determined as a function of the root-mean-square surface irregularity, characteristic tooling mark parameters, fold mirror rotation angle, and incident beam f-number. Tooling mark frequencies on the order of 20 cycles per aperture or less were considered. This subset encompasses small footprints on single-point diamond turned optics or large footprints on sub-aperture tool polished optics. Of the characteristic features, off-axis fabrication distance held the highest impact to encircled and ensquared energy radii. The transverse oscillation of a tooling path was found to be the second highest contributor. Both impacts increased with radial tooling mark frequency.

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Section: Sub-aperture Tool Polishingmentioning

confidence: 99%

Parametric Mid-Spatial Frequency Surface Error Synthesis

Hefferan

Graves²,

Trumper³

et al. 2021

Photonics

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show abstract

“…Conventionally, surface finishing process [10][11][12] followed by machining process is considered as one of the standard procedures to improve the surface quality of optical elements. Further, the ultraprecision machining technology has been rapidly developed through numerous studies, such as parameter optimization [13][14][15][16][17] and random path generation [18,19]. Although the surface finishing process has been developed as a way to indisputably improve the quality of optical surfaces, it is time-consuming and less economical owing to the additional efforts that are required after the machining process.…”

Section: Introductionmentioning

confidence: 99%

Novel Approach to Improve the Optical Performance by Machining Process Without Surface Finishing

Park

Lee

Kim

et al. 2021

Int. J. of Precis. Eng. and Manuf.-Green Tech.

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With the increase in dimensions of optical elements in addition to ever rising demand for aspherical optics, the millimeter-scale periodic waviness that is naturally produced by machining (such as diamond turning) process in precision optical engineering has been one of the most crucial issues in the development of high surface quality optical elements. Even an extremely small waviness can affect the laser beam profile significantly through interference caused by Bragg scattering. This paper presents a novel method for improving a laser beam profile by utilizing the characteristics of Bragg scattering without requiring established final surface finishing processes such as optical polishing. By engraving an artificial periodic structure with a period of a few hundred microns, the Bragg scattering angle that influences the formation of interference fringes in the laser beam profile was drastically enlarged. Consequently, the quality of the beam profile was improved at a propagation distance where the 0th and 1st (− 1st) order beam modes are spatially separated, only by diamond turning machining without the surface finishing process. In addition, this approach represents an important contribution to green technology, which seeks energy saving and waste reduction in the optical surface manufacturing process.

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“…Takizawa et al [11] used a pseudo-random path based on circular elements to suppress repetitive patterns on polished surfaces, and the surface ripple obtained using this path was significantly better than other pseudo-random paths. Zha et al [12] used two methods, changing the path formation direction and changing the path interval, to avoid the superposition of convolution effect during polishing. Huang et al [13] proposed a pseudo-random based on the traveling salesman problem to reduce the impact of periodic polishing paths.…”

mentioning

confidence: 99%

A mid-high spatial frequency error suppression method based on the pseudo-random path with spatial MABF mapping for complex surface

Wang,

Ji,

Zhao

et al. 2023

Preprint

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Optical lenses, mirrors and other precision optical components will inevitably produce mid-high spatial frequency errors in polishing, which will cause light scattering in different degrees, and seriously affect the imaging performance of the optical system such as contrast and reflectivity. The pseudo-random path has high direction randomness, effectively suppressing the machined surface's periodic polishing marks. In this study, a mesh surface pseudo-random path planning method based on the Matrix Angle Based Flattening (MABF) algorithm is proposed to suppress the mid-high spatial frequency errors generated in the polishing process of free-form surface, and it extended the application scope of the pseudo-random path planning method from the plane to the complex surface. Firstly, to improve the computational efficiency and reduce the deformation of the mesh in the parameterization process, an improved Angle-based Flattening (ABF) algorithm called the MABF algorithm is proposed. Then, a pseudo-random path planning method for complex surfaces is proposed based on spatial mapping. This method mainly includes pseudo-random path planning in the parameterized plane, path inverse mapping and NURBS smoothing processing. The pseudo-random path obtained by this method has the advantages of smooth and uniform distribution. Simulation results show that the MABF algorithm is superior to the ABF algorithm in computing efficiency and error control. Simulations and experiments are conducted to verify the feasibility of the proposed path planning method in complex surface polishing and the effectiveness of suppressing mid-high spatial frequency errors.

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Pseudo-random Path Generation Algorithms and Strategies for the Surface Quality Improvement of Optical Aspherical Components

Cited by 8 publications

References 36 publications

Parametric Mid-Spatial Frequency Surface Error Synthesis

Parametric Mid-Spatial Frequency Surface Error Synthesis

Novel Approach to Improve the Optical Performance by Machining Process Without Surface Finishing

A mid-high spatial frequency error suppression method based on the pseudo-random path with spatial MABF mapping for complex surface

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