Diffuse Laser Illuminator
Original Publication Date: 1985-Jun-01
Included in the Prior Art Database: 2005-Feb-18
The present method produces uniform diffuse illumination with a narrow spectral band and a time averaged speckle pattern by scattering laser light from small particles suspended in a liquid. The time averaging of the speckle pattern results from the Brownian motion of the suspended particles. The figure shows a system for producing uniform diffuse illumination in accordance with the present method. A laser 2 generates a laser beam 4. The laser beam 4 is directed into a container 6 containing a liquid 8 in which small particles 10 are suspended. The particles 10 scatter the laser beam 4, producing scattered light 12. Because of the Brownian motion of the small particles 10, the speckle pattern 14 changes rapidly to produce a uniform field of illumination.