Random error analysis of profile measurement of large aspheric optical surface using scanning deflectometry with rotation stage

Xiao, Muzheng; Takamura, Tomohiko; Takahashi, Satoru; Takamasu, Kiyoshi

doi:10.1016/j.precisioneng.2013.01.005

Cited by 11 publications

(5 citation statements)

References 5 publications

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“…3.1. Propagation from the angle error to profile error [14] We performed an error analysis to check what factors were sensitive to the measurement results. This was necessary before setting up the experimental device.…”

Section: Error Analysis and Simulation Of Measuring Errormentioning

confidence: 99%

Profile measurement of aspheric surfaces using scanning deflectometry and rotating autocollimator with wide measuring range

Ishikawa

Takamura

Xiao

et al. 2014

Meas. Sci. Technol.

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High-accuracy aspherical mirrors and lenses with large dimensions are widely used in large telescopes and other industry fields. However, the measurement methods for large aspherical optical surfaces are not well established. Scanning deflectometry is used for measuring optical signals near flat surfaces with uncertainties on subnanometer scales. A critical issue regarding scanning deflectometry is that high-accuracy autocollimators (AC) have narrow angular measuring ranges and are not suitable for measuring surfaces with large slopes and angular changes. The goal of our study is to measure the profile of large aspherical optical surfaces with an accuracy of approximately 10 nm. We have proposed a new method to measure optical surfaces with large aspherical dimensions and large angular changes by using a scanning deflectometry method. A rotating AC was used to increase the allowable measuring range. Error analysis showed that the rotating AC reduces the accuracy of the measurements. In this study, we developed a new AC with complementary metal-oxide semiconductor (CMOS) as a light-receiving element (CMOS-type AC). The CMOS-type AC can measure wider ranges of angular changes, with a maximum range of 21 500 μrad (4500 arcsec) and a stability (standard deviation) of 0.1 μrad (0.02 arcsec). We conducted an experiment to verify the effectivity of the wide measuring range AC by the measurement of a spherical mirror with a curvature radius of 500 mm. Furthermore, we conducted an experiment to measure an aspherical optical surface (an off-axis parabolic mirror) and found an angular change of 0.07 rad (4 arcdegrees). The repeatability (average standard deviation) for ten measurements of the off-axis parabolic mirror was less than 4 nm.

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Section: Error Analysis and Simulation Of Measuring Errormentioning

confidence: 99%

Profile measurement of aspheric surfaces using scanning deflectometry and rotating autocollimator with wide measuring range

Ishikawa

Takamura

Xiao

et al. 2014

Meas. Sci. Technol.

Self Cite

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“…In the method proposed in [10][11][12][13], the angle of the specimen, which might be large and heavy, is adjusted using a piezoelectric transducer (PZT) to maintain the null angle. In [14], in order to enlarge the angle measurement range, a rotating stage is installed for adjusting the angle of the measurement beam from the autocollimator. On the other hand, the angles of the specimen and the measurement beam used to illuminate the SUT are fixed in the proposed method.…”

Section: Exprimental Setupmentioning

confidence: 99%

High-lateral-resolution scanning deflectometric profiler using a commercially available autocollimator

Bitou¹,

Kondo²

2014

Meas. Sci. Technol.

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The lateral resolution of the angle-based deflectometric surface profiler using a commercially available autocollimator has been improved by introducing a novel null instrument. The proposed null instrument is simple, inexpensive, and has a short response time. High-accuracy flatness measurements of low-reflective surfaces have been successfully demonstrated using a laser beam with a spot size of 1 mm. The repeatability of the surface profile measurement is better than ±0.6 nm.

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“…is instrument provided a ∼500 um spatial resolution of the measured topography. Other methods such as de ectometry [4,5], Hartman test [6], or Sagnac interferometer [7] are available for large surfaces but they do not provide the same bene ts. Whatever, all the optical measurement techniques are a ected by both thermal and structural performances of the test system.…”

Section: Introductionmentioning

confidence: 99%

“…e FE results enabled the determination of the dynamic range and suitable locations of accelerometers that were mounted onto the OTS (Section 3.2) for the experimental validation and furthermore for carrying out the transmissibility study (Section 3. 4). e present study aims to assess, predict, and investigate the performance of this unique system within the framework of the optical measurements for providing a reference benchmark study.…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Modal Analysis Applied to an Optical Test System Designed for the Form Measurements of Metre‐Scale Optics

Golanó

Fragonara

Morantz

et al. 2018

Shock and Vibration

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The work focuses on the structural design and performances of a unique optical test system (OTS) used for measuring metre-scale optical surfaces. The investigation was carried out through a modal analysis. Two sets of results are presented. Both modal analysis of the entire OTS and transmissibility function related to its use as an optical system are carried out and analysed. The OTS is used for the measurements of the form accuracy at nanometre level of metre-scale concave surfaces. The OTS is a four and half-metre-tall mechanical structure made of bolted aluminium profiles, two structural platens, two dedicated precision positioning supports, a test piece, and a state-of-the-art laser interferometer. The OTS was numerically modelled and fully instrumented with triaxial accelerometers. The results of the modal analysis highlight the natural modes of the entire OTS. Both numerical and experimental methods are designed. The investigation methods are iterative. Indeed, a preliminary numerical model is created using finite element analysis (FEA). FEA results enable the determination of the dynamic range and suitable locations of accelerometers that are mounted onto the OTS for the experimental validation of the FEA model and further to carry out the transmissibility study. Natural frequencies, damping ratios, and mode shape values are obtained and scrutinized. These results are used for refining the FEA model. In fact, the lack of symmetry and the use of feet are identified as the key design feature that affects the OTS. The correlation between experimental and numerical results is within five percent for the first four modes. The results of the transmissibility study highlight the specific natural modes that influence the OTS measurement capability. Overall, the study enables to guide engineers and researchers towards a robust design using a validated and methodical approach.

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Random error analysis of profile measurement of large aspheric optical surface using scanning deflectometry with rotation stage

Cited by 11 publications

References 5 publications

Profile measurement of aspheric surfaces using scanning deflectometry and rotating autocollimator with wide measuring range

Profile measurement of aspheric surfaces using scanning deflectometry and rotating autocollimator with wide measuring range

High-lateral-resolution scanning deflectometric profiler using a commercially available autocollimator

Numerical and Experimental Modal Analysis Applied to an Optical Test System Designed for the Form Measurements of Metre‐Scale Optics

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