Patent ID: 8197068

Claim:
A laser projection system comprising a light source, a phase retarding element, and a beam scanning element, wherein: the beam scanning element is configured to scan a light beam emanating from the light source across a 2D image frame; the light source comprises at least one frequency-converted laser source comprising a wavelength-tunable laser diode and a wavelength conversion device; the wavelength conversion device of the frequency-converted laser source is configured such that a frequency-converted laser beam emanating along an optical axis from an output of the wavelength conversion device is characterized by a high degree of polarization, relative to a degree of polarization of an input laser beam entering an input of the wavelength conversion device, and wavelength variations in an output of the wavelength-tunable laser diode are manifested as frequency-converted wavelength variations in the frequency-converted laser beam; the phase retarding element is further configured to resolve the polarization of the frequency-converted laser beam into two orthogonal linearly polarized components such that one component of polarization is phase delayed relative to the other; frequency-converted laser beam polarization in the 2D image frame is a function of the degree to which the respective components of polarization are delayed relative to each other and varies with wavelength variations in the output of the wavelength-tunable laser diode; and the polarization variations of the frequency-converted laser beam in the 2D image frame are sufficient to scramble image speckle patterns across the 2D image frame.