No abstract

No abstract

A new optical switch design is reported that consists of two sets of parallel channel waveguides intersecting at right angles. Arrays based on Ti:LiNbO(3) technology, with waveguide intersections iron doped to provide photorefractive sensitivity, have been fabricated. Interfering guided beams are used to write index gratings at the waveguide intersections, which in turn diffract a portion of an incident signal beam into the crossing waveguide. Arrays ranging from 15 x 15 up to 50 x 50 waveguides are constructed in an active area of 5 mm x 5 mm. Diffraction efficiency and writing-time measurements are reported along with a proposal for a practical architecture.

No abstract

A new high density integrated-optical switch design using electrically controlled diffraction gratings formed in the intersection of crossing waveguides is proposed and demonstrated. The gratings are formed, in one implementation, by implanting donor atoms in a periodic pattern. Free carriers from the implanted ions modify the index of refraction resulting in Bragg diffraction between the waveguides. Depletion of the free carriers using a reverse bias voltage switches off the diffraction. High speed switch arrays of 100×100 elements on a single substrate may be feasible. Fabrication and demonstration of a low efficiency proof-of-concept switch array in GaAs for use at 1.55 μm are reported. Other designs capable of much higher diffraction efficiencies are described.