US 7,065,119 B2Granted

Distributed feedback laser with varying electrical resistance for uniform gain inside the optical waveguide

AssigneeTelefonaktiebolaget LM Ericsson (publ)

InventorsKrister Frojdh, Per Granestrand

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Abstract

An electrooptic device (1) such as a distributed feed back semiconductor laser or a semiconductor modulator comprises an optical waveguide. A contact layer (11) is applied to the optical waveguide for conducting electrical current to the device for driving or modulating it. The contact layer is connected to the end of an electrically conducting path (3) and can have a shape, as seen perpendicularly to the surface of the device, to give an electric resistance between the end of the path and different areas at the optical waveguide which resistance is higher for areas located close to the ends of the device than for areas are located at the central region of the device. The shape can be si-milar to a trapezium having concave oblique sides and is selected so that the resulting varying electrical resistance gives a sub-stantially uniform electrical power or gain inside the optical waveguide, taken in the longitudinal direction of the waveguide.

Claims21

Dependent claims

An electrooptic device including an optical waveguide having a longitudinal direction, two opposite ends and a central region, a region of an electrically conducting layer forming a contact layer applied to the length of the optical waveguide for conducting electrical current to the electrooptic device for driving it, wherein

the contact layer extends over the optical waveguide up to said two opposite ends and has a substantially constant or uniform thickness, and
the contact layer is connected to an electrically conducting path at a connection region and has a configuration or pattern in the plane of the electrically conducting layer to give an electric resistance between the connection region and areas at the optical waveguide which is higher for those of the areas which are located close to said two opposite ends than for those of the areas which are located at said central region, so that the contact layer has an electrical resistance varying in the longitudinal direction, the varying electrical resistance adapted to make the electrical power developed in or the gain inside the optical waveguide constant or uniform in the longitudinal direction.

Dependencies are inferred from the claim text.

Facts

Application: 10/433,658Filed 13 Dec 2001
Priority: SE 000461313 Dec 2000
Published: US 2004/0076207 A122 Apr 2004
Granted: 20 Jun 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H01S 5/0421
Electrical excitation ; Circuits therefor: characterised by the semiconducting contacting layers
H01S 5/12
Construction or shape of the optical resonator , e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or…: the…
H01S 5/04254
Electrodes, e.g. characterised by the structure: characterised by the shape
H01S 5/22
Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or…:…