Method for producing a partially coherent beam with fast pattern update rates

A method for producing a partially coherent optical beam with fast update rate, the method comprising:

• sending an input optical beam through an angular beam deflector that imparts a time-dependent angular deflection on the input optical beam;
• sending the optical beam having the time-dependent angular deflection through an optical system that focuses the optical beam and converts the time-dependent angular deflection of the optical beam into a time-dependent spatial, transverse motion;
• sending the focused optical beam having the time-dependent transverse motion into a multimode optical waveguide having an input end, and output end, and a core, the core having a predetermined size, the focused optical beam having a focal spot having a diameter that is much smaller than the core size of the multimode optical waveguide, thereby exciting a plurality of high-order modes of the multimode optical waveguide, the high-order modes intermixing while the beam propagates through the multimode optical waveguide to create a spatially non-uniform intensity and phase distribution at the output end of the multimode optical waveguide;
• allowing the focal spot of the focused optical beam to move transversely across the input end of the multimode optical waveguide in a random or predefined pattern along one or two transverse dimensions, whereby a continuous change of the spatially non-uniform intensity and phase distribution of the optical beam at the output end of the multimode optical waveguide results, thus producing a partially coherent optical beam with a fast update rate that is approximately equal to the angle-deflection rate multiplied by a ratio of the multimode optical waveguide core size to the optical beam focal spot diameter.