Low coherence interferometry for mid-IR precision optics manufacturing

Paul M. Thomas; Chris Cotton; Don Gibson; John Hart; Mike Marcus; John Pietruszka; David Rigolo; Richard St. Louis

doi:10.1117/12.2690583

29 November 2023 Low coherence interferometry for mid-IR precision optics manufacturing

Paul M. Thomas, Chris Cotton, Don Gibson, John Hart, Mike Marcus, John Pietruszka, David Rigolo, Richard St. Louis

Proceedings Volume 12778, Optifab 2023; 127780M (2023) https://doi.org/10.1117/12.2690583
Event: SPIE Optifab, 2023, Rochester, New York, United States

Abstract

We report on an optical, non-contact, thickness measurement system for materials that are opaque in the Near infrared (NIR) through ultraviolet (UV) wavelength range. While measurement options do exist, they must either physically touch the sample or rely on an assumed bulk distribution of material. In addition, optical and semiconductor materials are often highly sensitive to contamination and greatly benefit from noncontact metrology. The authors have adapted techniques used for the Lumetrics Optigauge 2000 low coherence interferometry (LCI) system to build a 2.8 μm LCI system using non-silica optical fibers to direct the probe signal. A (100) Silicon (Si) test sample was selected as a control because it can be measured by both an Optigauge II and the MIR-LCI system. In this work, the authors successfully measured materials that are transparent in the midinfrared (MIR) range, such as Germanium. The authors speculate that MIR-LCI will enable wedge, thickness, flatness, and other measurements performed using an Optigauge II system for MIR transparent materials.

Conference Presentation

(2023) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

Paul M. Thomas, Chris Cotton, Don Gibson, John Hart, Mike Marcus, John Pietruszka, David Rigolo, and Richard St. Louis "Low coherence interferometry for mid-IR precision optics manufacturing", Proc. SPIE 12778, Optifab 2023, 127780M (29 November 2023); https://doi.org/10.1117/12.2690583

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