Abstract

In this investigation, we propose a polarized dual low-coherence scanning interferometer. The spatial phase-shifting technique and the concept of the dual low coherence are adopted to overcome the scanning conditions of typical low-coherence scanning interferometers and reduce the measurement time. In the proposed interferometer, the scanning interval is not critical because the visibility and the phase are immediately obtained during a scanning procedure, and the whole scanning distance can be significantly reduced by the dual low coherence. To verify the system performance, the surface profiles of a plane mirror and a step height specimen were measured, and it was confirmed that the whole scanning distance was reduced 10 times without any scanning conditions.

© 2022 Optica Publishing Group

Dual low coherence scanning interferometry for rapid large step height and thickness measurements

Hyo Mi Park, Hee Won Jung, and Ki-Nam Joo
Opt. Express 24(25) 28625-28632 (2016)

High-speed polarized low coherence scanning interferometry based on spatial phase shifting

Jun Woo Jeon, Hee Won Jeong, Hyo Bin Jeong, and Ki-Nam Joo
Appl. Opt. 58(20) 5360-5365 (2019)

High-speed combined NIR low-coherence interferometry for wafer metrology

Hyo Mi Park and Ki-Nam Joo
Appl. Opt. 56(31) 8592-8597 (2017)

Sub-sampling low coherence scanning interferometry and its application: refractive index measurements of a silicon wafer

Ki-Nam Joo
Appl. Opt. 52(36) 8644-8649 (2013)

Dual-wavelength heterodyne differential interferometer for high-precision measurements of reflective aspherical surfaces and step heights

H. J. Tiziani, A. Rothe, and N. Maier
Appl. Opt. 35(19) 3525-3533 (1996)