Acquisition of an Automated Optical Microscope for Computational Polarized Light Microscopy
Abstract
This proposal requests funds for the acquisition of a computer-controllable optical microscope equipped with a rotatable polarizer/analyzer system, a eucentric sample rotation stage, a multi-wavelength high brightness light source, and a high resolution camera system. This instrument will be used by the PI’s group and other groups within the Department of Materials Science and Engineering at Carnegie Mellon University to study optically uniaxial and biaxial materials and determine the 3D orientation of the principal axis (in uniaxial systems) and both principal axes (in biaxial systems); the materials systems will include hte uniaxial titanium, magnesium, and -TiAl systems, and the orthorhombic compound forsterite (Mg2SiO4) as a representativebiaxial material. This technique, which we call computational polarized light microscopy or CPLM, will be combined with results from density functional theory modeling of the refractive indices as a function of light wavelength. The theory will allow us to create a forward model for the signal formation process, and subsequently a dictionary-based indexing method will be used to determine the grain orientations. This approach will have several benefits over the more traditional EBSD-based methods, including the fact that the electron microscopy based approaches are an order of magnitude more expensive, and the ability to rapidly scan large areas through the use of a precision automated eucentric stage. The requested instrument will be made available to the CMU and external research communities.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 19, 2018
- Source ID
- FA95501810336
Entities
People
- Marc Degraef
Organizations
- Air Force Office of Scientific Research
- Massachusetts Institute of Technology
- United States Air Force