Abstract
A low-index waveguide of lens shape is embedded in a high-index Ga/sub .72/Al/sub .28/As/Ga/sub .59/Al/sub .41/As host waveguide with anti-reflection layer incorporated at the lens boundaries to reduce reflections. An improvement factor of 1.25 in the throughput efficiency of the lens is achieved by the inclusion of AR layer. At an f-number of 1.8 and a wavelength of 1.152 /spl mu/m, a focal spot size of 2.1 /spl mu/m and a sidelobe level of /spl minus/13 dB were measured. The angular field of view measured in the host waveguide is 11/spl deg/.