Waveguide optical switches
AssigneeHitachi, Ltd.
InventorsHitoshi Nakamura, Tadashi Fukuzawa, Koji Ishida, Hiroyoshi Matumura, Kenji Hiruma, Hiroaki Inoue
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Abstract
The present invention provides a waveguide type optical switch which has a high extinction ratio and can be driven efficiently at a low voltage or a low current injection. Where the waveguide type optical switch is used as a reflection type optical switch, the switch section is of current confinement structure, and where it is used as a directional coupler type optical switch, the pn junction is formed in the position where the optical electric field takes the maximum value for the fundamental mode of the light propagating in the waveguide.
Claims8
A reflection type optical switch comprising:
- a semiconductor substrate;
- a plurality of semiconductor layers formed on said semiconductor substrate;
- including an optical waveguide layer having a plurality of optical waveguide paths to propagate light;
- a switching region in at least one of said optical waveguide paths wherein switching is accomplished when a refractive index at said switching region is changed by carrier injection;
- and a path region for injecting carriers by said carrier injection;
- a current confinement structure formed in at least one of said path region and said semiconductor substrate and formed to be separate from said optical waveguide layer, said current confinement structure allowing said carriers to be injected only into said switching region;
- and
- a pair of electrodes for injecting the carriers into the switching region.
Dependencies are inferred from the claim text.