Resolution of self-images in planar optical waveguides*

A multimode planar optical waveguide of homogeneous refractive index can produce real one-dimensional self-images by interference of the waveguide modes. We discuss the image formation, the linespread function, and its apodisation and optimization. Under optimum conditions, the theoretical linear resolution can reach 0.25(W λf)1/2, where W is the slab thickness and λf is the wavelength in the slab material.