Superposition and Interference
Conditions for Wave Interference: Reflection due to Phase...
Interference is a phenomenon in which two waves superimpose to form a resultant wave of greater or lesser amplitude.
An air wedge is a simple interferometer used to visualize the disturbance of the wave front after propagation through a test object.
Newton's rings are a series of concentric circles centered at the point of contact between a spherical and a flat surface.