Laser Interferometry

Laser interferometer schematic

Laser interferometer schematic

Laser Interferometry uses a monochromatic laser as a light source.  A monochromatic and coherent light source is required to generate easily processed interference patterns.  This laser is split via a beam splitter.  One beam reflects off a mirror and goes back to a camera (detector).  The other beam reflects off of a sample and goes back to the camera.  The changes in height along the sample surface change the path distance of the light. When this is combined with the light reflected directly off of a mirror, a pattern is generated based on the different heights of the samples surface.  This pattern is then input into a computer and can be used to reconstruct the surface.