Stress-Induced birefringence
Stress-induced birefringence can be present in a material that does not normally have optical anisotropy. It may be permanently present resulting from stress created during the manufacturing process, such as with injection molded plastics or in polished optical materials or may be temporarily induced by applying a force to a material such as occurs in Hinds photoelastic modulator (PEM) optical assemblies. The stress optic coefficient is a measure of an object’s optical susceptibility to a physical stress.
Stress-induced birefringence can be measured the same way other low-level birefringence is measured. Hinds Instruments supplies components and award winning Exicor® instrumentation for the accurate and precise measurement of stress induced birefringence.
APPLICATIONS
Quality control for optical materials; plastics, flat panel display glass, laser optics, silicon for solar cells
TYPICAL PEM
I/FS50 with NIOOTHER INSTRUMENTATION
Exicor® Birefringence Measurement Systems
FURTHER READING
J. C. Kemp, Basic Laboratory set-up for various measurements possible with the photoelastic modulator, Application note, Hinds Instruments, Inc. (1975)
S. J. Johnson, “Simultaneous dichroism and birefringence measurements of sheared colloidal suspension in polymeric liquids," Ph. D thesis, Stanford Univ. (1985).
T. C. Oakberg, “Measurement of Low-level Strain Birefringence in Optical Elements Using a Photoelastic Modulator,” SPIE, 2873, 17-20 (1996)
Contact us to see how Hinds Instruments works with our customers to solve complex metrology problems.
