Patent ID: 6337935
Filing Date: 2002-01-08
Classification: G02B

Abstract:
An apparatus for separating wavelengths by dispersion comprising:a) one or more input/output combinations, each of said combinations comprising: 1) an input portion comprising an input waveguide having an opening through which a light signal containing multiple wavelengths is introduced; and 2) an output portion comprising one or more output waveguides each of said output waveguides having an opening through which light signals of one or more wavelengths are received, and wherein for each of said input/output combinations said input waveguide opening and said output waveguide openings are collinear, and wherein for each of said input/output combinations said input waveguide opening and said output waveguides openings contact an output plane which is orthogonal to the direction of travel of said introduced light signals; and wherein said input waveguide openings and said output waveguide openings for all input/output combinations are all parallel to the direction of dispersion and are all parallel to each other; andb) a lens for collimating said introduced signals; c) a planar diffraction grating for dispersing said collimated, introduced signals and reflecting said dispersed signals so that said reflected, dispersed signals are imaged by said lens; and d) a device which 1) spatially transforms the field positions of said multiple wavelengths of said imaged signals by inverting said field positions about one or more axes which are orthogonal to the direction of dispersion; and 2) reflects said spatially transformed signals so that said reflected, spatially transformed signals are collimated a second time by said lens, then dispersed a second time and reflected by said diffraction grating, then imaged a second time by said lens so that each twice imaged signal creates an optical focal spot on one of said openings of said output waveguides.