Laser illumination beam generation system employing despeckling of the laser beam using high-frequency modulation of the laser diode current and optical multiplexing of the component laser beams
First Claim
1. A laser illumination beam generation system comprisinga laser diode (LD) for producing a laser beam in response to a diode current supplied to said laser diode, wherein said laser beam has a central characteristic wavelength and a coherence length;
- a diode current drive circuit for generating said diode current and supplying said diode current to said laser diode;
a high frequency modulation (HFM) circuit for modulating said diode current supplied to said laser diode, so as to produce a spectral side-hand components about said central characteristic wavelength, and thereby reducing the coherence length of said laser beam; and
an optical multiplexing (OMUX) device for receiving said laser beam as an input beam and generating multiple laser beams therefrom and recombining said multiple laser beams so as to produce a composite output laser illumination beam having reduced coherence.
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Accused Products
Abstract
A laser illumination beam generation system including a laser diode (LD) for producing a laser beam in response to a diode current supplied thereto, wherein the laser beam has a central characteristic wavelength. Diode current drive circuitry generates the diode current and supplies the same to the VLD. A high frequency modulation (HFM) circuitry modulates the diode current supplied to the laser diode, so as to produce a spectral side-band components about the central characteristic wavelength, and thereby reduces the coherence of the laser illumination beam as well as its coherence length. An optical multiplexing (OMUX) device receives the laser beam as an input beam and generates multiple laser beams therefrom and recombines the multiple laser beams so as to produce a composite output laser illumination beam having reduce coherence.
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Citations
14 Claims
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1. A laser illumination beam generation system comprising
a laser diode (LD) for producing a laser beam in response to a diode current supplied to said laser diode, wherein said laser beam has a central characteristic wavelength and a coherence length; -
a diode current drive circuit for generating said diode current and supplying said diode current to said laser diode; a high frequency modulation (HFM) circuit for modulating said diode current supplied to said laser diode, so as to produce a spectral side-hand components about said central characteristic wavelength, and thereby reducing the coherence length of said laser beam; and an optical multiplexing (OMUX) device for receiving said laser beam as an input beam and generating multiple laser beams therefrom and recombining said multiple laser beams so as to produce a composite output laser illumination beam having reduced coherence. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A laser illumination beam generation system comprising:
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a laser diode for producing a laser beam having a central characteristic wavelength and a coherence length; 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 for modulating said diode drive current at a sufficiently high frequency to cause said laser diode to produce said laser beam having a spectral side-band components about said central characteristic wavelength, and reducing the coherence length of said laser beam; and an optical beam multiplexing (OMUX) module for receiving said laser beam as an input beam, and generating as output, a plurality of laser beam components that are recombined to produce a composite laser beam having substantially reduced coherence length for use in illumination applications where a substantial reduction in speckle pattern noise is achieved. - View Dependent Claims (12, 13, 14)
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Specification