Device for producing a laser beam of reduced coherency using high-frequency modulation of the laser diode current and optical multiplexing of the output laser beam

摘要

A laser beam despeckling device including a laser diode for producing a laser beam having a central characteristic wavelength. The device includes diode current drive circuitry for producing a diode drive current to drive said laser diode and produce said laser beam. High frequency modulation (HFM) circuitry modulates the diode drive current at a sufficiently high frequency to cause said laser diode to produce spectral side-band components about the central characteristic wavelength, and reducing the coherence as well as coherence length of the laser beam. An optical beam multiplexing (OMUX) module is provided for receiving the laser beam as input beam, a generating as output, a plurality of laser beam components that are recombined to produce a composite laser beam having substantially reduced coherence for use in illumination applications where a substantial reduction in speckle pattern noise is achieved.