Optimal condition for full-field heterodyne interferometry

Jian, Zhi-Cheng; Chen, Yen-Liang; Hsieh, Hung-Chih; Hsieh, Po-Jen; Su, Der‐Chin

doi:10.1117/1.2802095

Cited by 12 publications

(11 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The phase error originated from the sampling error, which depends on the frequency and the visibility of the heterodyne interference signal, the camera recording time, the frame exposure time, the frame period, and the number of gray levels. 23 Considering the related experimental conditions and the visibility of the moiré fringes with a value of 0.3, the phase error Δθ can be evaluated with a value of 0.32 deg.…”

Section: Resultsmentioning

confidence: 99%

Stress measurement of thin film on flexible substrate by using projection moiré method and heterodyne interferometry

Chen

Tseng

et al. 2016

Opt. Eng

View full text Add to dashboard Cite

, "Stress measurement of thin film on flexible substrate by using projection moiré method and heterodyne interferometry," Opt. Eng. 55(6), 064102 (2016), doi: 10.1117/1.OE.55.6.064102. Abstract. We propose a stress measurement system based on a projection moiré method and heterodyne interferometry for thin films on a flexible substrate. In the measurement setup, a CMOS camera in which every pixel can receive a series of heterodyne moiré signals by using a continuously relative displacement with a constant velocity is used. Furthermore, the phase of the optimized sinusoidal curve and the surface profile of the flexible substrate are determined using a least-squares sine fitting algorithm. The thin-film stress is obtained by representing the cross-sectional curve of the surface profile by using a polynomial fitting method, estimating the resultant curvature radii of the uncoated and coated substrates, and using these two radii in the corrected Stoney formula. The proposed measurement system has the advantages of high accuracy, high resolution, and high capacity for substrates with high flexibility and a large measurement depth. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

Section: Resultsmentioning

confidence: 99%

Stress measurement of thin film on flexible substrate by using projection moiré method and heterodyne interferometry

Chen

Tseng

et al. 2016

Opt. Eng

View full text Add to dashboard Cite

show abstract

“…To demonstrate the validity of this method, an He-Ne laser with 632.8 nm wavelength, an EO modulator (New Focus/Model 4002), and a CMOS camera (Basler/A504 K) with 8-bit gray level and 320 Â 256 pixel image resolution are used to test a commercial zero-order quartz quarter-wave plate (Union Optic/WPF4125) condition f c ¼ 1499.3 frames/s is chosen based on the optimal condition proposed by Jian et al [17] to decrease the measurement error. Next, a least-square sine fitting algorithm on IEEE 1241 Standards in a MATLAB program is utilized to estimate the data of c of every pixel.…”

Section: Experiments and Resultsmentioning

confidence: 99%

“…(2) Sampling error It depends on the frequency of the heterodyne interference signal, the camera recording time, the frame period, the frame exposure time and the number of gray levels. The optimal condition presented by Jian et al [17] is used in our tests, so the sampling error Df s is about 0.0361.…”

Section: Article In Pressmentioning

confidence: 99%

Full-field measurement of the phase retardation for birefringent elements by using common path heterodyne interferometry

Chen

2009

Optics and Lasers in Engineering

View full text Add to dashboard Cite

“…The phase error from the sampling processes can also be estimated and it is given Δφ s = 0.036° [17].…”

Section: B Sampling Errormentioning

confidence: 99%

Full-field absolute phase measurements in the heterodyne interferometer with an electro-optic modulator

Chen

Hsieh

et al. 2009

Modeling Aspects in Optical Metrology II

View full text Add to dashboard Cite

A novel method for full-field absolute phase measurements in the heterodyne interferometer with an electro-optic modulator is proposed in this paper. Instead of the commonly-used half-wave voltage to drive the electro-optic modulator, a saw-tooth voltage signal with the amplitude being lower than its half-wave voltage is used. The interference signals become a group of periodical sinusoidal segments. The initial phase of each sinusoidal segment depends on the phase difference induced by the test sample. In real measurements, each segment is taken by a fast camera and becomes discrete digital points. After a series of operations, the starting point of the sampled sinusoidal segment can be determined accurately. Next, the period of the sampled sinusoidal segments is lengthened and they can be modified to a continuous sinusoidal wave by using a least-square sine fitting algorithm. The initial phase of the continuous sinusoidal wave can also be estimated. Subtracting the characteristic phase of the modulator from the initial phase, the absolute phase measured at the pixel can be obtained without the conventional reference signals. These operations are applied to other pixels, and the full-field absolute phase measurements can be achieved. The phase retardation of a quarter-wave plate is measured to show the validity of this method.

show abstract

Optimal condition for full-field heterodyne interferometry

Cited by 12 publications

References 8 publications

Stress measurement of thin film on flexible substrate by using projection moiré method and heterodyne interferometry

Stress measurement of thin film on flexible substrate by using projection moiré method and heterodyne interferometry

Full-field measurement of the phase retardation for birefringent elements by using common path heterodyne interferometry

Full-field absolute phase measurements in the heterodyne interferometer with an electro-optic modulator

Contact Info

Product

Resources

About