A new guided-wave lens structure

A guided-wave lens is reported. The present lens structure is realized by embedding a low-index lens-shaped waveguide region in a surrounding higher-index planar waveguide. Very large index differences between the lens region and host waveguide are realizable using this technique, making it possible to fabricate low f-number lenses with low spherical aberration. The lens exhibits excellent off-axis performance, low chromatic aberration, and high polarization independence. A prototype f/2 lens in a GaAs/Ga/sub 0.97/Al/sub 0.03/As waveguide has been designed and fabricated using Corning 7059 glass and SiO/sub 2/ for the lens waveguide structure.<
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