Semiconductor element having opposite signs of .alpha. parameter
AssigneeKokusai Denshin Denwa Kabushiki Kaisha
InventorsHermann A. Haus, Katsuyuki Utaka
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Abstract
A semiconductor optical element comprises a semiconductor substrate, a waveguide, an active layer and a clad layer mounted on said substrate; said active layer comprising first region and second region coupled optically with each other, and having opposite signs of .alpha. parameters with each other, where said parameter is ratio of change of refractive index to change of gain following change of carrier density; a first electrode common to all regions attached on one side of said substrate; and second electrodes for each region attached on the other side of said substrate. The invention is used for an AM modulation laser, or an FM modulation laser.
Claims11
A semiconductor optical element, comprising:
- a semiconductor substrate;
- an active layer comprising a first region and a second region coupled optically with each other, and having at least one of different compositions and different thicknesses with each other,
- a corrugation grating formed along said active layer, said corrugation grating for selecting predetermined wavelengths to make signs of an .alpha. parameter of each region opposite, wherein said .alpha. parameter is a ratio of change of refractive index to change of gain following a change of carrier density;
- said semiconductor optical element further comprising:
- cladding layers disposed on a first and a second side of said active layer, wherein one of said cladding layers is disposed on said semiconductor substrate;
- electrode means disposed on said semiconductor optical element, for injecting current into said semiconductor optical element to vary carrier densities in the active layer.
A semiconductor optical element comprising;
- a semiconductor substrate,
- a wave-guide, an active layer and a clad layer mounted on said semiconductor substrate,
- said active layer comprising first region and second region coupled optically with each other, and having opposite signs of .alpha. parameters with each other, where said parameter is ratio of change of refractive index to change of gain following change of carrier density,
- a first electrode common to all regions attached on one side of said substrate, and
- second electrodes for each region attached on the other side of said substrate.
Dependencies are inferred from the claim text.