SPATIAL OPTICAL BEAM STEERING WITH AN ALGAAS INTEGRATED PHASED-ARRAY

A passive spatial light beam deflector based on a channel waveguide ph ased-array concept is presented. Diffraction gratings patterned by ele ctron-beam lithography couple light into and out of the device. Phasin g is achieved electro-optically with indium tin oxide/AlGaAs Shottky j unctions. Discrete beam steering is first demonstrated with a 43-eleme nt rib waveguide array at an 850-nm wavelength. A sawtooth electrode k eeps the device length short and the electrode surface small. Continuo us deflection over a +/-7.2 mrad range at a 900-nm wavelength is then reported. A set of seven sawtooth and offset electrodes permits addres sing any point within this range. The beam has a width of 1.5.mrad, an d the maximum modulation voltage is -8.5 V.