We demonstrate the use of a mirror as a viewing diaphragm to generate a built-in diffracted reference beam in schlieren diffraction interferometry (SDI). The use of a mirror edge as a diffracting element instead of a conventional knife edge considerably enhances the contrast of the schlieren pattern, and it is shown to be equal to that of a phase knife edge. This increase in contrast is due to the fact that the otherwise unutilized diffracted beam in SDI is recombined in the described folding mirror geometry.
© 2006 Optical Society of America
Original Manuscript: November 28, 2005
Revised Manuscript: March 23, 2006
Manuscript Accepted: April 4, 2006
Raj Kumar, D. P. Chhachhia, and A. K. Aggarwal, "Folding mirror schlieren diffraction interferometer," Appl. Opt. 45, 6708-6711 (2006)