3D surface mapping of freeform optics using wavelength scanning lateral shearing interferometry

Ghim, Young-Sik; Rhee, Hyug-Gyo; Davies, Angela; Yang, Ho‐Soon; Lee, Yun-Woo

doi:10.1364/oe.22.005098

Cited by 40 publications

(18 citation statements)

References 17 publications

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“…A freeform surface with sag of a couple of millimeters was measured and the retrieved surface error was comparable with that obtained by a calibrated stylus profilometer. [ 96 ] Commercial wavefront sensors based on the quadriwave LSI are available, e.g., from PHASICS, France.…”

Section: Interferometric Areal Measurementmentioning

confidence: 99%

Measurement of Freeform Optical Surfaces: Trade‐Off between Accuracy and Dynamic Range

Chen

Xue

Zhai

et al. 2020

Laser & Photonics Reviews

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Freeform optical surfaces are advantageous to optical designers, as they provide additional degrees of freedom for optimization. The loss of rotational symmetry, however, makes measurement of freeforms more challenging. Herein, advances in interferometric areal measurement of freeform optical surfaces, including null tests, non-null tests, near-null tests, and adaptive null tests, are reviewed. Some new developments, in the Hartmann test, deflectometry, and phase retrieval, as representatives of non-interferometric areal measurement, are then presented. Overall, the focus is on single-point-probe-based profilometry categorized into coordinate measurements and slope-or curvature-based measurements. Innovative measurement technology is trying to bridge the gap between high accuracy and high dynamic range as freeform optical surfaces are finding more applications in visible and shorter-wavelength optics.

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Section: Interferometric Areal Measurementmentioning

confidence: 99%

Measurement of Freeform Optical Surfaces: Trade‐Off between Accuracy and Dynamic Range

Chen

Xue

Zhai

et al. 2020

Laser & Photonics Reviews

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“…그리고 파면의 기울기를 측정하는 방법으로는 편향법(deflectometry) 및 층밀리기 간섭 계 (shearing interferometry) 방법 등이 있다. 편향법으로 잘 알려진 방법은 론치 와 Shack-Hartmann 방법이 있다 [4][5][6][7][8][9][10][11] . 편 향법은 일반적으로 외부 환경에 덜 민감 하다는 장점이 있고 시료의 크기가 커도 측정에 어려움이 덜한 장점이 있다.…”

Section: Fig 1 Schematic Diagram Of Transmission Deflectometryunclassified

Simultaneous Determination of Both Surface Profiles of a Bifocal Lens Using Dual-Wavelength Transmission Deflectometry With Liquid

Shin¹,

Yu²

2015

Korean Journal of Optics and Photonics

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We propose a method for simultaneously measuring the front and back surface profiles of transparent optical components. The proposed method combines dual-wavelength transmission deflectometry with liquids to record distorted phases at different wavelengths, and then numerically reconstructs the three-dimensional phase information to image the front and back surfaces of the lens. We propose a theoretical model to determine the surface information, and a bifocal lens is experimentally investigated. Unlike conventional transmission deflectometry, our proposed method supports direct observation of the front and back surface profiles of the optical elements.

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“…One caveat is that the stitching errors may significantly increase with the number of sub-apertures. Other non-null interferometric approaches include lateral shearing interferometry [17], Moire interferometry [18], and tilted wave interferometry configured with a two-dimensional point-source array [19]. Extensive calibrations are generally required to mitigate alignment and ray tracing errors.…”

Section: Introductionmentioning

confidence: 99%

Point-cloud noncontact metrology of freeform optical surfaces

2018

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In this paper, we demonstrate the development of a point-cloud metrology method for the noncontact, high resolution, high precision testing of freeform surfaces. The method leverages swept source optical coherence tomography together with a common-path setup in the sample arm configured to mitigate the axial jitter caused by scanning and environmental perturbations. The lateral x-y scanning field was also rigorously evaluated for the sampling step, linearity, straightness, and orthogonality. Based on the finely engineered system hardware, a comprehensive system model was developed capable of characterizing the vertical displacement sensitivity and lateral scanning noise. The model enables predicting the point-cloud surface-metrology uncertainty map of any freeform surface and guiding the selection of optimum experimental conditions. A system was then assembled and experimentally evaluated first with flat and spherical standards to demonstrate the measurement uncertainty. Results of measuring an Alvarez freeform surface with 400-µm peak-to-valley sag show 93 nm (< λ/14) precision and 128 nm (< λ/10) root-mean-square residual from the nominal shape. The high resolution measurements also reveal mid spatial frequency structures on the test part.

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3D surface mapping of freeform optics using wavelength scanning lateral shearing interferometry

Cited by 40 publications

References 17 publications

Measurement of Freeform Optical Surfaces: Trade‐Off between Accuracy and Dynamic Range

Measurement of Freeform Optical Surfaces: Trade‐Off between Accuracy and Dynamic Range

Simultaneous Determination of Both Surface Profiles of a Bifocal Lens Using Dual-Wavelength Transmission Deflectometry With Liquid

Point-cloud noncontact metrology of freeform optical surfaces

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