Distributed Feedback Semiconductor Laser Device

• US 20100074291A1
• Filed: 02/07/2008
• Published: 03/25/2010
• Est. Priority Date: 03/15/2007
• Status: Abandoned Application

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Nakamura, Koji
• Application Number:
  US12/529,029
• Publication Number:
  US 20100074291A1
• Time in Patent Office: Days
• US Class Current: 372/45.10
• CPC Class Codes: H01S 5/06226 Modulation at ultra-high frequencies
• CPC Class Codes: H01S 5/12 the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers comprising a photonic bandgap structure H01S5/11; surface-emitting lasers H01S5/18
• CPC Class Codes: H01S 5/2275 mesa created by etching

Abstract

A DFB laser device which can reduce influence of reflected return light and improve output characteristics and can provide a small-sized and inexpensive optical module when mounted on the optical module. The GC-DFB laser device (10) includes a semiconductor substrate (100), a waveguide layer (104) and an active layer (106) formed on one surface side of the semiconductor substrate, and a diffraction grating structure (102) which is formed on one surface of the waveguide layer and has a gain periodically varying in an optical waveguiding direction; wherein the active layer is disposed so as to adjoin the waveguide layer, a band gap wavelength of the waveguide layer is within ±0.1 μm of an oscillation wavelength of the active layer, a thickness of the waveguide layer is in a range of 5 to 30 nm, and a width of the active layer is in a range of 0.7 to 1.0 μm.

Claims

1. A gain coupled distributed feedback semiconductor laser device comprising:

a semiconductor substrate;

a waveguide layer and an active layer which are formed on one surface side of the semiconductor substrate; and

a diffraction grating structure provided on one surface of the waveguide layer and having a gain periodically varying in an optical waveguiding direction;

wherein;

the active layer is disposed so as to adjoin the waveguide layer;

a band gap wavelength of the waveguide layer is within ±

0.1 μ

m of an oscillation wavelength of the active layer;

a thickness of the waveguide layer is in a range of 5 nm to 30 nm; and

a width of the active layer is in a range of 0.7 μ

m to 1.0 μ

m.

2. The distributed feedback semiconductor laser device according to claim 1, wherein:

the waveguide layer is formed on the semiconductor substrate;

the active layer is formed on the waveguide layer; and

the diffraction grating structure is a structure including a boundary between the semiconductor substrate and the waveguide layer.

3. The distributed feedback semiconductor laser device according to claim 2, wherein:

the semiconductor substrate is an InP substrate;

the waveguide layer is an InGaAsP waveguide layer; and

the active layer is composed of alternately laminated layers of an InGaAsP barrier layer and an InGaAsP well layer.

4. The distributed feedback semiconductor laser device according to claim 1, wherein:

the active layer is formed on the semiconductor substrate; and

the waveguide layer is formed on the active layer;

the distributed feedback semiconductor laser device further comprising a semiconductor layer disposed on the waveguide layer;

wherein the diffraction grating structure is a structure including a boundary between the waveguide layer and the semiconductor layer.

5. The distributed feedback semiconductor laser device according to claim 4, wherein:

the active layer is composed of alternately laminated layers of an InGaAsP barrier layer and an InGaAsP well layer;

the waveguide layer is an InGaAsP waveguide layer; and

the semiconductor layer is an InP semiconductor layer.