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US 5,471,490 AGranted
Device in which electromagnetic radiation is raised in frequency and apparatus for optically scanning an information plane, comprising such a device
AssigneeU.S. Philips Corporation
InventorsCoen T. H. F. Liedenbaum, Arnoldus L. G. J. Severens, Ronald R. Drenten, Michiel J. Jongerius
Life of this patent
Estimating the term…
Abstract
A doubler for a pulsed multimode laser diode. A controllable feedback loop controls the laser output such that one of the output wavelengths, or the average of two of them, fall within the acceptance bandwidth of a non-linear optical medium. Alternatively, radiation emitted from the pulsed laser is reflected over a path length such that reflected energy reenters the laser during the build-up of a following pulse.
Claims37
A device for generating a beam of radiation, comprising:
- a non-linear optical medium having an acceptance bandwidth,
- a multimode pulsed laser producing radiation at a plurality of wavelengths,
- means for directing said radiation into said medium, and
- feedback means having an active control system comprising a detector producing an output signal responsive to frequency-raised radiation from said medium, and a control unit responsive to said output signal for controlling at least one parameter affecting said pulsed laser so that at least one of said wavelengths or an average value of two of said wavelengths falls within said acceptance bandwidth, and for influencing the quantity of said frequency-raised radiation.
1 more element
A device for generating a beam of radiation, comprising:
- a non-linear optical medium having an acceptance bandwidth,
- a multimode pulsed laser producing radiation at a plurality of wavelengths,
- means for directing said radiation into said medium, and
- optical wavelength-selective feedback means, receiving frequency-raised radiation from said medium, for controlling at least one of said wavelengths or an average value of two of said wavelengths to fall within said acceptance bandwidth, by reflecting a portion of one pulse of radiation to reenter the laser during the build-up time of a following pulse of radiation.
1 more element
Dependencies are inferred from the claim text.