Devices having low loss curved or tapered optical waveguides
AssigneeAmerican Telephone and Telegraph Company, AT&T Bell Laboratories
InventorsSteven K. Korotky, Enrique A. J. Marcatili
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Abstract
An optical device comprising an optical waveguide having a varying refractive index has low radiation loss. The waveguide may be either curved or tapered.
Claims15
A device comprising, a substrate, an optical waveguide, said waveguide being in said substrate, said device having a cross-sectional profile of refractive index through and in the vicinity of said waveguide which can be represented as a sum of a first profile of refractive index and a second profile of refractive index,
- said first profile of refractive index being such as to result in guidance of an electromagnetic wave at least in the absence of bends or tapers, and
- said second profile of refractive index being such as to essentially equalize optical path length around a bend or through a taper,
- whereby radiation loss at said bend or taper is minimized.
Method for making an optical device, said method comprising establishing a region of raised index of refraction in a body of optically transparent material, said region of raised index of refraction comprising a waveguide, said region of raised refractive index having a cross-sectional profile of refractive index which can be represented as a sum of a first profile of refractive index and a second profile of refractive index, said first profile of refractive index being such as to result in guidance of an electromagnetic wave at least in the absence of bends or tapers, and said second profile of refractive index being chosen so as to essentially equalize optical path lengths along the optical axis and other significant optical paths around a bend or through a taper, whereby radiation loss at said bend or taper is minimized.
Dependencies are inferred from the claim text.