Patent ID: 6304237
Filing Date: 2001-10-16
Classification: G02F,H04N

Abstract:
An R,G,B pulsed laser light source with reduced speckle noise adapted for use with a display system, which light source generates R, G and B beams and comprises:a laser with a laser medium producing a pulsed laser output beam of selected pulse width and wavelength;an R-channel receiving a first portion of the output beam and generating the R beam, with the R-channel including a resonant cavity with a first nonlinear crystal producing optical radiation having a first wavelength that is greater than the wavelength of the output beam and a spectral width that is greater than a spectral width of the output beam, and a second nonlinear crystal that combines the radiation of the first wavelength with the first portion of the output beam to generate the R beam by sum frequency mixing, said R-beam having a spectral width determined by the spectral width of the optical radiation of the first wavelength;a G-channel receiving a second portion of the output beam and generating the G beam, with the G-channel including a resonant cavity with a third nonlinear crystal producing second harmonic optical radiation of the output beam, with the cavity of the G-channel further including an etalon that produces a plurality of longitudinal G-channel resonant cavity modes which define a spectral width of the G-channel; anda B-channel receiving a third portion of the output beam and generating the B beam, with the B-channel including a fourth nonlinear crystal that frequency-doubles the third portion of the output beam, and a lasing cavity having a Ti:S laser crystal pumped with the frequency-doubled output beam and producing a lasing wavelength that is twice the wavelength of the B-beam, said lasing wavelength being frequency-doubled by a fifth nonlinear crystal located in the lasing cavity and producing the B-beam;with the spectral width of the R-channel and the G-channel reducing the speckle noise of the R,G,B pulsed laser light source.