Raman despeckling with spectral control

摘要

An apparatus and method for controlling the spectrum of stimulated Raman scattering that is used for despeckling of digitally projected images. The stimulated Raman scattering is utilized to add wavelength diversity for reduced speckle and to change the color of the light to a more desirable combination of wavelengths. Digital projection with color-sequential projectors may be enabled by alternately switching the Raman spectrum between green and red. Improved projector transmission may be achieved by minimizing the amount of yellow light generated in the Raman spectrum.

主权项

1. An optical apparatus comprising:
a pulsed green laser; a Raman-shifting device; and a digital projector;
wherein the pulsed green laser generates a green light with a light pulse that illuminates the Raman-shifting device;the light pulse is shaped in time to generate a desired spectrum from the Raman-shifting device,the desired spectrum illuminates the digital projector;the light pulse is shaped in time to be a square shape;the desired spectrum is red; andthe light pulse is shaped in time to alternate between a square shape of a first amplitude and a square shape of a second amplitude; the first amplitude is different than the second amplitude; and the desired spectrum alternates between green light and red light.