A driving step auto-access method for single-wavelength microscopic interference

Xin Guan; Xuanze Wang; Zhongsheng Zhai; Liangen Yang

doi:10.1117/12.2071581

13 November 2014 A driving step auto-access method for single-wavelength microscopic interference

Xin Guan, Xuanze Wang, Zhongsheng Zhai, Liangen Yang

Proceedings Volume 9276, Optical Metrology and Inspection for Industrial Applications III; 92760U (2014) https://doi.org/10.1117/12.2071581
Event: SPIE/COS Photonics Asia, 2014, Beijing, China

Abstract

Single wavelength microscopic interferometry, driven by the Piezoelectric Transducer (PZT), is a common surface topography measurement method. Its measurement accuracy is directly determined by the original phase acquisition precision of every pixels in area array CCD. Traditional phase identification methods adopt 3 points or 4 points algorithm to obtain the phase. However, they require the displacement step, actuated by the PZT, to strictly keep the same to satisfy the 90° phase condition. Therefore, these methods are only suitable for the strict anti-vibration experimental environment or conditions with high precise closed-loop PZT actuator and strict calibration of interferometric wavelength. An auto-acquisition driving step method for the single wavelength microscopic interferometry is presented in this paper. Firstly, interference sequence diagrams, containing the surface topography information, are gathered by the CCD under open-loop PZT actuating. Next, two pixels whose phase difference is approximate 90° are selected as the calculating center to obtain smoothed gray values with regional gray average algorithm, which can reduce the influence of random noise. Finally, an optimal fitting algorithm for the ellipse, formed by the average gray values, is proposed to obtain the amplitudes and offsets of the two gray values array. According these fitting parameters and gray values, the drive step can be calculated by elliptic equations. Experiments have shown that this method can reduce the requirement conditions of measurement conditions and improve the measurement accuracy.

Citation Download Citation

Xin Guan, Xuanze Wang, Zhongsheng Zhai, and Liangen Yang "A driving step auto-access method for single-wavelength microscopic interference", Proc. SPIE 9276, Optical Metrology and Inspection for Industrial Applications III, 92760U (13 November 2014); https://doi.org/10.1117/12.2071581

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
6 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Ferroelectric materials

Actuators

Interferometry

Charge-coupled devices

Calibration

Data processing

Transducers

Show All Keywords

Keywords/Phrases

Search In:

Publication Years