Refractive index of infrared-transparent polycrystalline alumina

Daniel C. Harris; Linda F. Johnson; Lee R. Cambrea; Lawrence Baldwin; Meghan Baronowski; David E. Zelmon; William B. Poston; John D. Kunkel; Mark Parish; Marina R. Pascucci; John J. Gannon Jr.; Tzu-Chien Wen

doi:10.1117/12.2257580

3 May 2017 Refractive index of infrared-transparent polycrystalline alumina

Daniel C. Harris, Linda F. Johnson, Lee R. Cambrea, Lawrence Baldwin, Meghan Baronowski, David E. Zelmon, William B. Poston, John D. Kunkel, Mark Parish, Marina R. Pascucci, John J. Gannon Jr., Tzu-Chien Wen

Author Affiliations +

Proceedings Volume 10179, Window and Dome Technologies and Materials XV; 101790F (2017) https://doi.org/10.1117/12.2257580
Event: SPIE Defense + Security, 2017, Anaheim, CA, United States

Abstract

The refractive index of polycrystalline α-alumina prisms with an average grain size of 0.6 μm is reported for the wavelength range 0.9 to 5.0 and the temperature range 293 to 498K. Results agree within 0.0002 with the refractive index predicted for randomly oriented grains of single-crystal aluminum oxide. This paper provides tutorial background on the behavior of birefringent materials and explains how the refractive index of polycrystalline alumina can be predicted from the ordinary and extraordinary refractive indices of sapphire. The refractive index of polycrystalline alumina is described by

𝑛𝑛² − 1 = (A+B [𝑇𝑇²−𝑇𝑇²₀]) +Dλ² /λ2−(λ₁+C [𝑇𝑇²−𝑇𝑇²₀])² + λ²−λ₂²

where wavelength λ is expressed in μm, T_o = 295.15 K, A = 2.07156, B = 6.273× 10^-8, λ₁ = 0.091293, C = –1.9516 × 10^-8, D = 5.62675, and λ₂ = 18.5533. The slope dn/dT varies with λ and T, but has the approximate value 1.4 × 10^-5 K^-1 in the range 296–498 K.

Citation Download Citation

Daniel C. Harris, Linda F. Johnson, Lee R. Cambrea, Lawrence Baldwin, Meghan Baronowski, David E. Zelmon, William B. Poston, John D. Kunkel, Mark Parish, Marina R. Pascucci, John J. Gannon Jr., and Tzu-Chien Wen "Refractive index of infrared-transparent polycrystalline alumina", Proc. SPIE 10179, Window and Dome Technologies and Materials XV, 101790F (3 May 2017); https://doi.org/10.1117/12.2257580

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