Development of a low-cost, 11 µm spectral domain optical coherence tomography surface profilometry prototype

Nyasha J. Suliali; Peter Baricholo; Pieter H. Neethling; Erich G. Rohwer

doi:10.1117/12.2268064

26 June 2017 Development of a low-cost, 11 µm spectral domain optical coherence tomography surface profilometry prototype

Nyasha J. Suliali, Peter Baricholo, Pieter H. Neethling, Erich G. Rohwer

Author Affiliations +

Proceedings Volume 10329, Optical Measurement Systems for Industrial Inspection X; 103292Q (2017) https://doi.org/10.1117/12.2268064
Event: SPIE Optical Metrology, 2017, Munich, Germany

Abstract

A spectral-domain Optical Coherence Tomography (OCT) surface profilometry prototype has been developed for the purpose of surface metrology of optical elements. The prototype consists of a light source, spectral interferometer, sample fixture and software currently running on Microsoft® Windows platforms. In this system, a broadband light emitting diode beam is focused into a Michelson interferometer with a plane mirror as its sample fixture. At the interferometer output, spectral interferograms of broadband sources were measured using a Czerny-Turner mount monochromator with a 2048-element complementary metal oxide semiconductor linear array as the detector. The software performs importation and interpolation of interferometer spectra to pre-condition the data for image computation. One dimensional axial OCT images were computed by Fourier transformation of the measured spectra. A first reflection surface profilometry (FRSP) algorithm was then formulated to perform imaging of step-function-surfaced samples. The algorithm re-constructs two dimensional colour-scaled slice images by concatenation of 21 and 13 axial scans to form a 10 mm and 3.0 mm slice respectively. Measured spectral interferograms, computed interference fringe signals and depth reflectivity profiles were comparable to simulations and correlated to displacements of a single reflector linearly translated about the arm null-mismatch point. Surface profile images of a double-step-function-surfaced sample, embedded with inclination and crack detail were plotted with an axial resolution of 11 μm. The surface shape, defects and misalignment relative to the incident beam were detected to the order of a micron, confirming high resolution of the developed system as compared to electro-mechanical surface profilometry techniques.

Citation Download Citation

Nyasha J. Suliali, Peter Baricholo, Pieter H. Neethling, and Erich G. Rohwer "Development of a low-cost, 11 µm spectral domain optical coherence tomography surface profilometry prototype", Proc. SPIE 10329, Optical Measurement Systems for Industrial Inspection X, 103292Q (26 June 2017); https://doi.org/10.1117/12.2268064

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
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Optical coherence tomography

Prototyping

Interferometers

Detection and tracking algorithms

Light emitting diodes

Light sources

Metrology

Show All Keywords

Keywords/Phrases

Search In:

Publication Years