New measurements of MWIR cryogenic refractive indices for silicon and germanium from CHARMS

Douglas B. Leviton; Manuel A. Quijada; Kevin H. Miller

doi:10.1117/12.2631523

29 August 2022 New measurements of MWIR cryogenic refractive indices for silicon and germanium from CHARMS

Douglas B. Leviton, Manuel A. Quijada, Kevin H. Miller

Proceedings Volume 12188, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation V; 121882K (2022) https://doi.org/10.1117/12.2631523
Event: SPIE Astronomical Telescopes + Instrumentation, 2022, Montréal, Québec, Canada

Conference Poster

Abstract

Silicon and germanium are important and popular, transmissive, mid-wave infrared (MWIR) and long-wave-infrared (LWIR) optical materials used in a very wide variety of applications including scientific instruments, thermal imaging, and defense infrared systems. Prior to the present study, accurate, cryogenic, refractive index measurements of these two materials using the Cryogenic High Accuracy Refraction Measuring System (CHARMS) at the Goddard Space Flight Center (GSFC) were last completed for NASA’s James Webb Space Telescope program and published around 2006. Numerous infrared optical systems have since been successfully designed and built based on these previous CHARMS index data. A new, more accurate study of cryogenic refractive indices of silicon and germanium has been carried out for sample materials produced in the 2019-2020 time period. This paper presents findings for about a half dozen samples of each material from different boules and, including results from 2006, represents the first significant study of interspecimen index variability of Si and Ge using CHARMS. These new measurements spanned the wavelength region from 1.11-5.43 μm for Si and 1.90-5.43 μm for Ge over the temperature range from 100-310 K. Updated measurement uncertainties for these materials in CHARMS are presented reflecting improvements made to CHARMS since 2006.

Citation Download Citation

Douglas B. Leviton, Manuel A. Quijada, and Kevin H. Miller "New measurements of MWIR cryogenic refractive indices for silicon and germanium from CHARMS", Proc. SPIE 12188, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation V, 121882K (29 August 2022); https://doi.org/10.1117/12.2631523

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