This invention greatly improves the quality of images obtained using optical
systems illuminated by coherent light. It does so by removing the undesirable psuedo-random
variations in the final image due to interference speckle and inhomogeneities in
the spatial intensity distribution of the light source. A bundle of light-guiding
fibers is interposed between the illumination source and the imaging system. Non-uniform
propagation within the fiber bundle creates a psuedo-random phase variation across
the illumination beam, which gives rise to a dynamic interference speckle pattern
superimposed upon the desired image acquired by the optical system. Rotating the
fiber bundle around the axis of propagation, whilst simultaneously integrating
the output of the photosensitive detector over a period of time, substantially
removes variations due to source inhomogeneities and coherent interference.
