Chromatic confocal phase stepping interferometer

Joseph Cohen-Sabban

doi:10.1117/12.681677

14 August 2006 Chromatic confocal phase stepping interferometer

Joseph Cohen-Sabban

Proceedings Volume 6292, Interferometry XIII: Techniques and Analysis; 629216 (2006) https://doi.org/10.1117/12.681677
Event: SPIE Optics + Photonics, 2006, San Diego, California, United States

Abstract

The idea which initiated this work is to adapt the principle of phase coding to a Confocal Chromatic type sensor in order to enhance the dynamic range and the axial resolution of height measuring systems. When using a classical Confocal chromatic type measurement, we obtain a "coarse" value of the distance. Then by the means of a spectrally adjustable light source and a chromatic objective, we choose the wave length in order to focus in the plane of the object. Next, by measuring the phase coding, we can precisely define the profile of the object. So, in the end, we obtain the subnanometric preciseness of the phase coding while clearing up the ambiguity that is inherent to interferometric methods thanks to the confocal chromatic measurement. The initial idea is to use a Linnik interferometer, with a dedicated chromatic objective in the object arm, and an achromatic objective in the reference arm. A change of the wave length leads to a variation of the focus plane in relation to the object. This equivalence between a variation in wave length and a variation in distance, caused by the axial chromatism, leads us to imagine a system of phase coding in which the usual movement of the reference mirror is replaced by a variation of the wave length. We then obtain an interferometer without any moving part, which produces the extensive depth of field that is peculiar to chromatic systems.

Citation Download Citation

Joseph Cohen-Sabban "Chromatic confocal phase stepping interferometer", Proc. SPIE 6292, Interferometry XIII: Techniques and Analysis, 629216 (14 August 2006); https://doi.org/10.1117/12.681677

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
7 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Colorimetry

Confocal microscopy

Interferometers

Phase interferometry

Interferometry

Imaging systems

Glasses

Show All Keywords

Keywords/Phrases

Search In:

Publication Years