Optical polarizer
AssigneeBell Telephone Laboratories, Incorporated
InventorsFranz K. Reinhart, James C. Shelton
Life of this patent
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Abstract
An optical polarizer is described in which a propagation layer (14) is covered with a dielectric buffer layer (16) and a metal layer (18). The thickness of the buffer layer is chosen so as to increase the attenuation of TM modes of radiation in the waveguide relative to TE modes. In accordance with the invention, additional discrimination between TM and TE modes is achieved by segmenting the metal layer into a plurality of tandem sections (18.1, 18.2, 18.3), thereby increasing the mode coupling loss for TM modes. A GaAs-AlGaAs rib waveguide polarizer is specifically described.
Claims8
An optical polarizer comprising
- a propagation layer (14) of material for carrying optical radiation (22) in both TE and TM modes,
- a dielectric layer (16) on said propagation layer and having a lower optical dielectric constant than said propagation layer,
- a metal layer (18) on said dielectric layer,
- the thickness (W.sub.ox) of said dielectric layer being chosen so as to increase the attenuation of said TM modes relative to said TE modes, characterized in that
- said metal layer comprises a plurality of separate segments (18.1, 18.2, 18.3) arranged in tandem on said propagation layer so as to increase the coupling loss of said TM modes relative to said TE modes.
Dependencies are inferred from the claim text.