Optical Review

, Volume 17, Issue 3, pp 166–170

Estimation of inner surface profile of a tube by two-wavelength phase-shifting digital holography

Regular Papers

DOI: 10.1007/s10043-010-0029-0

Cite this article as:
Yokota, M. & Ishitobi, N. OPT REV (2010) 17: 166. doi:10.1007/s10043-010-0029-0

Abstract

A novel phase-shifting digital holographic method for estimation of inner surface profiles of tubes is proposed. For surface contouring, a two-wavelength method using injection-current-induced wavelength changes of a laser diode is used. To obtain inner surface information on a tube, a cone-shaped mirror is set inside the tube. Speckle noise occurring in the reconstructed phase difference image is effectively suppressed by an adaptive filtering technique consisting of exponential averaging and masking filtering processes. Distribution of optical path length in the experimental alignment is calculated and well explains the experimental results. It is shown that the calculation of optical path length by a simple model can remove the distortion of profiles occurring in the experimental results and enable the estimation of the inner surface profile of an aluminum tube.

Keywords

phase shiftingdigital holographytwo wavelength methodinner surface profileoptical path lengthadaptive filtering

Copyright information

© The Optical Society of Japan 2010

Authors and Affiliations

  1. 1.Faculty of Science and EngineeringShimane UniversityMatsueJapan
  2. 2.Solution Head QuarterProbizmo Co., Ltd.ShimaneJapan