| 摘要 |
An optical crosspoint switch module is provided for a matrix of optical sources and receivers. The switch module includes a thin film waveguide atop a substrate, an array of input optical fibers aligned along one edge of the thin film waveguide, and a similar array of output fibers aligned along a second edge of the waveguide. The waveguide and/or the substrate comprise nonlinear optical material. A film containing a grating pattern to be written into the nonlinear medium as persistent but erasable holograms is placed above the waveguide. A spatial light modulator (SLM) is positioned above the patterned film and illuminated from above by either coherent or incoherent light. The SLM functions as a selective mask so that the grating pattern of the film can be written as holograms in selected areas of the nonlinear medium. The holograms written into the nonlinear medium diffract beams from the input fibers along the first edge of the waveguide to the output fibers along the second edge of the waveguide. After holograms have been written in the nonlinear medium to provide an input-to-output light beam distribution scheme, the holograms can be erased by uniform exposure of the nonlinear medium to a light source positioned below the medium. Thereafter, the light beam distribution scheme can be switched by changing the masking pattern of the SLM and writing new holograms in the nonlinear medium.
|
