Differential schlieren-interferometry with a simple adjustable Wollaston-like prism.
An adjustable Wollaston-like prism is characterized for use in shearing- and differential schlieren-interferometry with laser and white-light illumination. We demonstrate that a polycarbonate prism under mechanical loading behaves identically to Wollaston's classical birefringent beam splitter. A linear relationship is found between the pure bending moment applied to the polycarbonate prism and the resulting light-beam-divergence angle. The utility of this prism in shearing-interferometry is shown by using it in place of the knife-edge in small and large schlieren optical systems. It is inexpensive to fabricate, and it yields adjustable beam-divergence angles over a range of at least 0-24 arc min.
Biss
Matthew M
MM
Gas Dynamics Laboratory, Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802, USA. mmb290@psu.edu
Settles
Gary S
GS
Staymates
Matthew E
ME
Sanderson
Simon R
SR