Patent ID: 8854710

Claim:
A method of laser illumination with reduced speckling in the light field or light spot produced by the laser illumination comprising the steps of: providing a laser illumination device comprising: at least one laser light source, a flat substrate, at least one planar ridge waveguide that has a plane and a longitudinal direction and is formed into an arbitrary configuration that is supported on the flat substrate and is coupled to the at least one laser light source for transmitting the laser light from the laser light source to the at least one planar ridge waveguide that comprises a cladding and a core, and a plurality of light-emitting holograms formed on the at least one planar ridge waveguide; arranging the light-emitting holograms in sequence one after another, wherein all or at least a part of the light-emitting holograms of said plurality are spaced from each other at a distance that is equal to or exceeds the coherence length; providing each hologram with a plurality of light-emitting holographic elements that have a predetermined organization defined by the shape of a given light field or light spot which is to be formed by light beams emitted from said plurality of the holograms in a given position and at a given distance from the at least one planar ridge waveguide; forming the given light spot in the given position and at a given distance from the at least one planar ridge waveguide by emitting the light from the light-emitting holographic elements; the holographic elements being made by forming grooves in the core in predetermined directions thus forming grooves and projections that have a projection direction at an angle α relative to the longitudinal direction of the planar ridge waveguide for defining a side beam tilt angle φ of inclination of the light beams emitted from the respective holographic elements relative to the plane of the at least one ridge waveguide, wherein for a given α the side beam tilt angle φ is given by the following relation: sin φ=n tan α, where n is the effective index of refraction in the ridge waveguide.