US 5,329,601 A · Semiconductor optical waveguide type switch including light control means

Abstract

A semiconductor waveguide type all-optical switch of a simple structure which can switch at high speed with low switching energy. A waveguide is formed within a core layer made of a semiconductor for absorbing controlling light when an electric field is applied, and a pair of electrodes are formed for applying a voltage to a waveguide part where a refractive index change is to be caused. The controlling light together with controlled light is entered in the waveguide. When a voltage is applied, Franz-Keldysh effect causes the wavelength at the optical absorption spectrum edge in the refractive index change part to shift to the long wavelength side. If light of a wavelength satisfying a predetermined condition is used as the controlling light, the controlling light is absorbed only in the refractive index change part for changing the refractive index in the part, thus the controlled light is switched. Preferably, a p-i-n structure is adopted.

Claims18

Dependent claims

A semiconductor waveguide type optical switch comprising:

at least one optical waveguide formed within a core layer made of a semiconductor for absorbing controlling light;
and
a pair of electrodes for applying a static electric field to a part of said waveguide where a refractive index change is to be caused by absorbing said controlling light;
said controlling light being entered into said waveguide together with light to be controlled wherein said controlling light is selectively absorbed at said part and said light to be controlled is propagated through said part, resulting in a switching operation of said light to be controlled.

1 more element

A semiconductor waveguide type optical switch comprising:

a semiconductor substrate;
a first semiconductor cladding layer formed on said substrate;
a semiconductor core layer formed on said first cladding layer;
a second semiconductor cladding layer formed on said core layer, said second cladding layer having a first rib and a second rib disposed on a surface of said second cladding layer;
said core layer having inside thereof a first optical waveguide and a second optical waveguide disposed under said first and second ribs, respectively;
said first and second waveguides having a couple portion where refractive index change is to be caused;
and
a pair of electrodes for applying a static electric field to said couple portion,
wherein a DC voltage is applied between said pair of electrodes, controlling light is entered into at least one of said first and second waveguides together with light to be controlled, and said controlling light is selectively absorbed at said couple portion and said light to be controlled is propagated through said couple portion, resulting in a switching operation of said light to be controlled.

6 more elements

A semiconductor waveguide type optical switch comprising:

a semiconductor substrate;
a first semiconductor cladding layer formed on said substrate;
a semiconductor core layer formed on said first cladding layer;
a second semiconductor cladding layer formed on said core layer, said second cladding layer having a first rib and a second rib disposed on a surface of said second cladding layer;
said core layer having inside thereof a first optical waveguide and a second optical waveguide disposed under said first and second ribs, respectively;
said first and second waveguides having a couple portion where refractive index change is to be caused;
and
a pair of first electrodes for applying a static electric field to said couple portion;
said pair of first electrodes being formed on a surface of said second cladding layer and each of said first electrodes being disposed at each respective side of said couple portion;
and
a second electrode for applying said static electric field to said couple portion;
said second electrode being formed on a back surface of said substrate;
wherein a DC voltage is applied between said pair of first electrodes and said second electrode, controlling light is entered into at least one of said first and second waveguides together with light to be controlled, and said controlling light is selectively absorbed at said couple portion and said light to be controlled is propagated through said couple portion, resulting in a switching operation of said light to be controlled.

10 more elements

Dependencies are inferred from the claim text.

Semiconductor optical waveguide type switch including light control means

Life of this patent

Semiconductor optical waveguide type switch including light control means

Life of this patent

Abstract

Claims18