Abstract:
A method and device provide efficient wavelength division multiplexing/demultiplexing (WDM) including reduced signal distortion, higher wavelength selectivity, increased light efficiency, reduced cross-talk, and easier integration with other planar devices, and lower cost manufacturing. The method and device include a planar holographic multiplexer/demultiplexer (100) having a planar waveguide (135), the planar waveguide including a holographic element (128) that separates and combines pre-determined (pre-selected) light wavelengths. The holographic element includes a plurality of holograms (105) that reflect pre-determined light wavelengths from an incoming optical beam (121) to a plurality of different focal points, each pre-determined wavelength representing the center wavelength of a distinct channel. Advantageously, a plurality of superposed holograms may be formed by a plurality of structures, each hologram reflecting a distinct center wavelength to represent a distinct channel to provide discrete dispersion. When used as a demultiplexer, the holographic element spatially separates light of different wavelengths and when reversing the direction of light propagation, the holographic element may be used as a demultiplexer to focus several optical beams having different wavelengths into a single beam containing all of the different wavelengths.
Abstract:
A holographic multiplexer/demultiplexer (20) for separating and combining pre-selected wavelengths. Included is a holographic element that contains a specifically written recording of multiple separate focal points (30,32), one for each of a plurality of different pre-selected wavelengths. The holographic multiplexer/demultiplexer separates the different wavelengths contained within a single beam of radiation (12), and focuses each wavelength to a separate pre-recorded focal point. The holographic multiplexer/demultiplexer also multiplexes multiple beams containing a single wavelength of radiation, into a single beam and focuses the single beam to a pre-recorded focal point. The holographic multiplexer/demultiplexer can also be used as a wavelength exchanger.