Beam scattering laser monitor

摘要

New systems for characterizing laser beams, using measurements performed on light which has been Rayleigh scattered from the beam. Different implementations are used for beam profiling, using images of the Rayleigh scattered light, and for laser beam power measurement, using the integrated Rayleigh scattered light. Both of these implementations can be applied to laser beams having high powers, since the measurements do not require insertion of any element into the beam itself, but rather depend on light scattered laterally from the passing beam. The measurements can thus be termed “non contact” measurements, in contrast to prior art methods which require an element inserted into the beam. The systems use Rayleigh scattering from the laser beam passing through ambient air, such that no special scattering chambers or liquids are required for the measurements. Special cancellation algorithms or filters are used to discriminate from light arising from scattering from dust particles.

主权项

1. A method for characterizing a beam of light, said method comprising:
imaging said beam of light while it is propagating in ambient air through a sampling region, such that images can be obtained of light scattered from said sampling region in a generally lateral direction to the direction of said beam propagation; treating image data associated with said images with a pulse discriminator to remove from said image data signals having at least one of intensity, spatial or temporal characteristics outside of predetermined parameters for said image data; and processing said treated image data to determine a characteristic of said beam of light at at least one location in said sampling region.