Abstract: An optical device comprises a light input, a light modulating means and a light output. The optical device further comprises an optical amplification device arranged to amplify light travelling between said light modulating means and said output. The optical amplification device comprises first and second serially connected post SOA (Semiconductor Optical Amplifier) units, each comprising at least one respective serially connected post SOA segment, which device is arranged to vary a light amplification by varying respective SOA bias voltages across said post SOA segments. A total SOA length of the first post SOA unit is relatively longer than a total SOA length of the second post SOA unit, which is relatively shorter. The optical device is arranged to, during operation using a particular operation program, always keep respective SOA bias voltages across each of the post SOA segments of the first post SOA unit at +0.5 V or more.

Abstract: A method of manufacturing an integrated semiconductor optical waveguiding device comprising an elongated waveguide, the method comprising: providing a material stack comprising a substrate layer, an anisotropically wet etchable conductive layer, a waveguiding core layer, an etch-guiding layer between the substrate layer and the waveguiding core layer, and InP material between the etch-guiding layer and the waveguiding core layer; etching said material stack down to and including said waveguiding core layer, to form an elongated shape of the elongated waveguide together with an etched area laterally beside the waveguide; providing an etch mask material across the formed waveguide; and wet etching parts of said etched areas that are not protected by the etch mask, to remove material of the etch-guiding layer across a lateral direction of the waveguide, forming a laterally extending through tunnel in the etch-guiding layer and in the conductive layer.

Abstract: A method of manufacturing an integrated semiconductor optical waveguiding device comprising an elongated waveguide, the method comprising: providing a material stack comprising a substrate layer, an anisotropically wet etchable conductive layer, a waveguiding core layer, an etch-guiding layer between the substrate layer and the waveguiding core layer, and InP material between the etch-guiding layer and the waveguiding core layer; etching said material stack down to and including said waveguiding core layer, to form an elongated shape of the elongated waveguide together with an etched area laterally beside the waveguide; providing an etch mask material across the formed waveguide; and wet etching parts of said etched areas that are not protected by the etch mask, to remove material of the etch-guiding layer across a lateral direction of the waveguide, forming a laterally extending through tunnel in the etch-guiding layer and in the conductive layer.

Abstract: An optical device comprises a light input, a light modulating means and a light output. The optical device further comprises an optical amplification device arranged to amplify light travelling between said light modulating means and said output. The optical amplification device comprises first and second serially connected post SOA (Semiconductor Optical Amplifier) units, each comprising at least one respective serially connected post SOA segment, which device is arranged to vary a light amplification by varying respective SOA bias voltages across said post SOA segments. A total SOA length of the first post SOA unit is relatively longer than a total SOA length of the second post SOA unit, which is relatively shorter. The optical device is arranged to, during operation using a particular operation program, always keep respective SOA bias voltages across each of the post SOA segments of the first post SOA unit at +0.5 V or more.