US 5,459,747 A · Semiconductor optical devices

Abstract

A semiconductor optical device includes a first semiconductor layer, and a diffraction grating disposed on the first semiconductor layer. The diffraction grating includes portions of a superlattice layer grown on the first semiconductor layer and including alternatingly arranged second semiconductor layers of a semiconductor material in which mass transport hardly occurs, during growth of other semiconductor layers and third semiconductor layers of a semiconductor material different from the material of the second semiconductor layers. The device includes a fourth semiconductor layer burying the diffraction grating. In this structure, since the second semiconductor layers are included in the diffraction grating, the shape of the diffraction grating is maintained during the vapor phase deposition of the fourth semiconductor layer. Therefore, the thickness, amplitude, and pitch of the diffraction grating that determine the optical coupling constant are controlled with high precision.

Claims13

Dependent claims

A semiconductor optical device including:

a semiconductor substrate of a first conductivity type and having opposite front and rear surfaces;
a first conductivity type active layer disposed on the front surface of the semiconductor substrate;
a first semiconductor layer of a second conductivity type, opposite the first conductivity type, disposed on the active layer;
a diffraction grating comprising portions of a superlattice layer disposed on the first semiconductor layer, said superlattice layer comprising alternatingly arranged second semiconductor layers comprising a semiconductor material in which mass transport during growth of other semiconductor layers hardly occurs and second conductivity type third semiconductor layers comprising a semiconductor material different from the semiconductor material of the second semiconductor layers;
a second conductivity type fourth semiconductor layer burying the diffraction grating;
a second conductivity type contact layer disposed on the fourth semiconductor layer;
and
first and second electrodes respectively disposed on the rear surface of the substrate and the contact layer.

5 more elements

An integrated semiconductor laser diode and light modulator comprising:

a compound semiconductor substrate of a first conductivity type;
a compound semiconductor first cladding layer of the first conductivity type disposed on the semiconductor substrate;
in a first region of the first cladding layer, a compound semiconductor active layer and a compound semiconductor barrier layer successively disposed on the first cladding layer and a plurality of mutually discontinuous stripe-shaped portions of a multiple quantum well structure disposed on the barrier layer, the stripe-shaped portions being periodically arranged parallel to each other and perpendicular to a light guiding direction of the semiconductor laser diode, forming a diffraction grating;
in a second region of the first cladding layer, a light absorption layer having a multiple quantum well structure contiguous with and contacting the active layer and the barrier layer;
a compound semiconductor second cladding layer of a second conductivity type opposite the first conductivity type disposed on and contacting the barrier layer, the stripe-shaped portions of the multiple quantum well structure, and the light absorption layer;
a first electrode in electrical contact with the semiconductor substrate;
a second electrode in electrical contact with the second cladding layer opposite the first region of the first cladding layer;
and
a third electrode spaced from the second electrode and in electrical contact with the second cladding layer opposite the second region of the first cladding layer.

6 more elements

An integrated semiconductor laser diode and light modulator comprising:

a compound semiconductor substrate;
a compound semiconductor light guiding layer disposed on and having an interface with the semiconductor substrate, the interface of the semiconductor substrate and the light guiding layer including a periodic variation forming a diffraction grating in a first region of the semiconductor substrate;
a first layer including a multiple quantum well structure disposed on the light guiding layer and having a first thickness opposite the first region of the semiconductor substrate and a second thickness, larger than the first thickness, opposite a second region of the semiconductor substrate;
a second layer including a multiple quantum structure disposed on the first multiple quantum well structure and having a first thickness opposite the first region of the semiconductor substrate and a second thickness, smaller than the first thickness of the second layer, opposite the second region of the semiconductor substrate;
a compound semiconductor cladding layer disposed on the second layer;
a first electrode disposed on the semiconductor substrate;
a second electrode in electrical contact with the cladding layer opposite the first region of the semiconductor substrate;
and
a third electrode spaced from the second electrode and in electrical contact with the cladding layer opposite the second region of the semiconductor substrate.

6 more elements

Dependencies are inferred from the claim text.

Semiconductor optical devices

Life of this patent

Semiconductor optical devices

Life of this patent

Abstract

Claims13