title: Folding mirror schlieren diffraction interferometer.
abstract: 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.
authors.affiliation: Coherent Optics Division, Central Instruments Organisation, Chandigarh, India.
authors.forename: Raj
authors.initials: R
authors.lastname: Kumar
authors.forename: D P
authors.initials: DP
authors.lastname: Chhachhia
authors.forename: A K
authors.initials: AK
authors.lastname: Aggarwal