Fresnel lenses in optical waveguides

Fresnel lenses in optical waveguides have been designed, analyzed, and experimentally fabricated and evaluated in BaO waveguides. Diffraction limited spot size, 18 dB of the signal-to-noise ratio, angular field of view of 15°, and 23 percent diffraction efficiency have been observed experimentally. Limitations of and methods for improving its performanee are discussed.