Deflectometry challenges interferometry: the competition gets tougher!

Faber, Christian; Olesch, Evelyn; Krobot, Roman; Häusler, Gerd

doi:10.1117/12.957465

Cited by 89 publications

(44 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the dynamic range of the interferometric testing is quite small, and it can only measure the surface departure within a few wavelengths from reference shape [8,9]. Specifically designed null optics and compensation optics are generally required in the testing of complex surfaces with large aberration, making the testing system very costly and inflexible [10][11][12]. Besides, the interferometry has high requirement on the calibration of testing system [13], which determines its achievable accuracy.…”

Section: Introductionmentioning

confidence: 99%

General testing method for refractive surfaces based on reverse Hartmann test

Wang

Gong

et al. 2017

Applied Optical Metrology II

View full text Add to dashboard Cite

The testing technique with high dynamic range is required to meet the measurement of refractive wavefront with large distortion from test refractive surface. A general deflectometric method based on reverse Hartmann test is proposed to test refractive surfaces. Ray tracing of the modeled testing system is performed to reconstruct the refractive wavefront from test surface, in which computer-aided optimization of system geometry is performed to calibrate the geometrical error. For the refractive wavefront error with RMS 255 μm, the testing precision better than 0.5 μm is achieved.

show abstract

Section: Introductionmentioning

confidence: 99%

General testing method for refractive surfaces based on reverse Hartmann test

Wang

Gong

et al. 2017

Applied Optical Metrology II

View full text Add to dashboard Cite

show abstract

“…The interferometers, such as Fizeau interferometer, TwymanGreen interferometer and point-diffraction interferometer [1][2][3][4][5], have been widely applied as a powerful noncontact testing method. The accuracy of interferometric method can reach the order of nanometers and even subnanometers, however, its dynamic range is quite small [6]. Besides, the interferometric testing has high requirement on the design, fabrication and adjustment of optics in the system [7][8][9], which makes it costly and inflexible.…”

Section: Introductionmentioning

confidence: 99%

“…The calibration determines the achievable accuracy of test system. Various approaches have been proposed to ensure the accurate surface measurement [6,[16][17][18]. In the SCOTS, a laser tracker is used to calibrate geometrical relation between the camera and the illumination screen [19], similar to the alignment process an interferometric testing for aspheric surfaces [20].…”

Section: Introductionmentioning

confidence: 99%

Computer-aided high-accuracy testing of reflective surface with reverse Hartmann test

Wang

Zhang

et al. 2016

Opt. Express

View full text Add to dashboard Cite

Abstract:The deflectometry provides a feasible way for surface testing with a high dynamic range, and the calibration is a key issue in the testing. A computer-aided testing method based on reverse Hartmann test, a fringe-illumination deflectometry, is proposed for high-accuracy testing of reflective surfaces. The virtual "null" testing of surface error is achieved based on ray tracing of the modeled test system. Due to the off-axis configuration in the test system, it places ultra-high requirement on the calibration of system geometry. The system modeling error can introduce significant residual systematic error in the testing results, especially in the cases of convex surface and small working distance. A calibration method based on the computer-aided reverse optimization with iterative ray tracing is proposed for the highaccuracy testing of reflective surface. Both the computer simulation and experiments have been carried out to demonstrate the feasibility of the proposed measurement method, and good measurement accuracy has been achieved. The proposed method can achieve the measurement accuracy comparable to the interferometric method, even with the large system geometry calibration error, providing a feasible way to address the uncertainty on the calibration of system geometry.

show abstract

“…There are a variety of methods for measuring reflective surface profiles, including using a coordinate measuring machine (CMM), a contact-type profilometer, or a computer generated hologram (CGH) interferometric test [2]. Additionally, it has been shown that a phase measuring deflectometry (PMD) system is able to obtain accurate surface profiles with high dynamic range [3][4][5]. This paper deals with implementing a next generation data processingtechnique to the software configurable test system (SCOTS), which is a PMD device.…”

Section: Introductionmentioning

confidence: 99%

Iterative surface construction for blind deflectometry

et al. 2016

View full text Add to dashboard Cite

Freeform optics provide excellent performance for a wide variety of applications. However, obtaining an accurate freeform surface measurement is highly challenging due to its large aspheric/freeform departure. It has been proven that SCOTS (Software Configurable Optical Test System), an advanced deflectometry system developed at the University of Arizona, can measure the departure of a freeform surface from the desired shape with nanometer accuracy. Here, a new data processing technique was used to measure a freeform surface without any prior knowledge of the shape of the surface. Knowing only the geometry of one point on the test surface, this method can take a blind measurement of a freeform surface and arrive at the true surface through iterative construction.

show abstract

Deflectometry challenges interferometry: the competition gets tougher!

Cited by 89 publications

References 0 publications

General testing method for refractive surfaces based on reverse Hartmann test

General testing method for refractive surfaces based on reverse Hartmann test

Computer-aided high-accuracy testing of reflective surface with reverse Hartmann test

Iterative surface construction for blind deflectometry

Contact Info

Product

Resources

About