Precision optical metrology without lasers

Ralf B. Bergmann; Jan Burke; Claas Falldorf

doi:10.1117/12.2183451

17 July 2015 Precision optical metrology without lasers

Ralf B. Bergmann, Jan Burke, Claas Falldorf

Proceedings Volume 9524, International Conference on Optical and Photonic Engineering (icOPEN 2015); 952403 (2015) https://doi.org/10.1117/12.2183451
Event: International Conference on Optical and Photonic Engineering (icOPEN2015), 2015, Singapore, Singapore

Abstract

Optical metrology is a key technique when it comes to precise and fast measurement with a resolution down to the micrometer or even nanometer regime. The choice of a particular optical metrology technique and the quality of results depends on sample parameters such as size, geometry and surface roughness as well as user requirements such as resolution, measurement time and robustness. Interferometry-based techniques are well known for their low measurement uncertainty in the nm range, but usually require careful isolation against vibration and a laser source that often needs shielding for reasons of eye-safety. In this paper, we concentrate on high precision optical metrology without lasers by using the gradient based measurement technique of deflectometry and the finite difference based technique of shear interferometry. Careful calibration of deflectometry systems allows one to investigate virtually all kinds of reflecting surfaces including aspheres or free-form surfaces with measurement uncertainties below the μm level. Computational Shear Interferometry (CoSI) allows us to combine interferometric accuracy and the possibility to use cheap and eye-safe low-brilliance light sources such as e.g. fiber coupled LEDs or even liquid crystal displays. We use CoSI e.g. for quantitative phase contrast imaging in microscopy. We highlight the advantages of both methods, discuss their transfer functions and present results on the precision of both techniques.

Citation Download Citation

Ralf B. Bergmann, Jan Burke, and Claas Falldorf "Precision optical metrology without lasers", Proc. SPIE 9524, International Conference on Optical and Photonic Engineering (icOPEN 2015), 952403 (17 July 2015); https://doi.org/10.1117/12.2183451

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