Accession Number:

AD1096652

Title:

Determining the Out-of-Plane Thermal Expansion Coefficient by Analyzing the Temperature Dependence of Thin-Film Interference Fringes

Descriptive Note:

Journal Article - Open Access

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC WASHINGTON United States

Personal Author(s):

• Beadie,G
• Rosenberg,A
• Shirk,James S

Report Date:

2019-02-25

Pagination or Media Count:

11.0

Abstract:

We analyze a new method for determining the out-of-plane coefficient of thermal expansion for thin films of transparent materials. The method is based on the measurement of interference peaks recorded in transmission spectra as a function of sample temperature. The locations of interference peaks depend on the optical path. We show how a consideration of Lorentz-Lorenz equation, in addition to the transmission peak equation, can separate the different contributions of index and physical pathlength to the optical path. The analysis is generalized to include the effects of uniaxial material properties such as anisotropic linear thermal expansion and birefringence. By applying this method of analysis to recent data, we demonstrate the importance of including the effect of the thermo-optic coefficient in interpreting observed data

Descriptors:

• amorphous materials
• molecular weight
• polymeric films
• measurement
• physical properties
• thermal expansion
• thin films
• refractive index
• anisotropy
• POLYIMIDE RESINS

Subject Categories:

• Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE