Semiconductor device

• US 7,808,698 B2
• Filed: 10/25/2005
• Issued: 10/05/2010
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Akiyama, Tomoyuki
• Primary Examiner(s): BOLDA, ERIC L
• Application Number:
  US11/257,145
• Publication Number:
  US 20060221438A1
• Time in Patent Office: 1,806 Days
• Field of Search: 359/344
• US Class Current: 359/344
• CPC Class Codes: H01S 5/026 Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers stabilisation of output H01S5/06
• CPC Class Codes: H01S 5/0262 Photo-diodes, e.g. transceiver devices, bidirectional devices H01S5/0265 takes precedence
• CPC Class Codes: H01S 5/0264 for monitoring the laser-output
• CPC Class Codes: H01S 5/1085 Oblique facets
• CPC Class Codes: H01S 5/2022 Absorbing region or layer parallel to the active layer, e.g. to influence transverse modes
• CPC Class Codes: H01S 5/2206 based on III-V materials
• CPC Class Codes: H01S 5/227 Buried mesa structure ; Striped active layer
• CPC Class Codes: H01S 5/50 Amplifier structures not provided for in groups H01S5/02 - H01S5/30

Abstract

A semiconductor device including a semiconductor optical amplifier in which a photodetector is integrated without causing power loss at a low cost. The semiconductor device includes a semiconductor substrate, a semiconductor optical waveguide, at least partly capable of functioning as a semiconductor optical amplifier, to guide signal light, and a photodetector provided in a region other than a region where the semiconductor optical waveguide is provided, wherein the semiconductor optical waveguide and the photodetector are integrated on the semiconductor substrate.

Claims

1. A semiconductor device comprising:

a semiconductor substrate;

a semiconductor optical waveguide to guide signal light from an input-side end face to an output-side end face of said semiconductor device;

a photodetector to detect part of light laterally radiated from a side wall face which defines said semiconductor optical waveguide and passing through a region, which does not have a waveguide structure to confine light in lateral direction, of said semiconductor device, the radiated light being part of the signal light;

an output photodetector provided at a position where light reflected on the output side can be detected, and

said semiconductor optical waveguide and said photodetector integrated on said semiconductor substrate.

2. A semiconductor device according to claim 1, wherein said output photodetector is provided at a position where light reflected on the output-side end face of said device can be detected.

3. A semiconductor device according to claim 1, further comprising an optical waveguide for detecting output light, adapted to guide light reflected on the output side to said output photodetector.

4. A semiconductor device according to claim 1, comprising, as said photodetector,

an input photodetector provided at a position where light radiated from the wall face of said semiconductor optical waveguide without being coupled to said semiconductor optical waveguide on the input side can be detected.

5. A semiconductor device according to claim 4, further comprising an optical waveguide for detecting input light, adapted to guide non-guided radiated light from the wall face of said semiconductor optical waveguide to said input photodetector on the input side.

6. A semiconductor device according to claim 1, comprising, as said photodetector,

an input photodetector provided along an input side portion of said semiconductor optical waveguide in such a manner as to enable the detection of non-guided radiated light from the wall face of said semiconductor optical waveguide without being guided by said semiconductor optical waveguide.

8. A semiconductor device according to claim 1, further comprising a light absorbing region capable of absorbing non-guided radiated light from the wall face of said semiconductor optical waveguide without being guided by said semiconductor optical waveguide.

9. A semiconductor device according to claim 8, wherein said light absorbing region has the same waveguide structure as said semiconductor optical waveguide, and said semiconductor device is configured such that a forward bias voltage is applied to the semiconductor optical amplifier portion of said semiconductor optical waveguide and a reverse bias voltage is applied to said light absorbing region or no bias voltage is applied thereto.

10. A semiconductor device according to claim 1, further comprising an amplifying region for amplifying light guided to said photodetector.

11. A semiconductor device according to claim 10, wherein said amplifying region has the same waveguide structure as said semiconductor optical waveguide.

12. A semiconductor device according to claim 1, further comprising an semiconductor optical amplifier provided in at least part of a region where said semiconductor optical waveguide is provided.

7. A semiconductor device comprising,

a semiconductor substrate;

a semiconductor optical waveguide to guide signal light from an input-side end face to an output-side end face of said semiconductor device;

a photodetector to detect part of light laterally radiated from a side wall face which defines said semiconductor optical waveguide and passing through a region, which does not have a waveguide structure to confine light in lateral direction, of said semiconductor device, the radiated light being part of the signal light;

a semiconductor optical amplifier provided in at least part of a region where said semiconductor optical waveguide is provided, and

said semiconductor optical waveguide and said photodetector integrated on said semiconductor substrate,

wherein said photodetector has the same waveguide structure as said semiconductor optical waveguide, and said semiconductor device is configured such that a forward bias voltage is applied to the semiconductor optical amplifier portion of said semiconductor optical waveguide and a reverse bias voltage is applied to said photodetector.

13. A semiconductor device comprising:

a semiconductor substrate;

a semiconductor optical waveguide adapted to guide signal light from an input-side end face to an output-side end face of said semiconductor device;

a photodetector detecting light radiated from a side wall face of said semiconductor optical waveguide, the radiated light being part of the signal light; and

an output photodetector provided at a position where light reflected on the output side can be detected,

wherein an entire length of said semiconductor optical waveguide is formed obliquely to an end face of said device.

14. A semiconductor device according to claim 13, comprising as said photodetector,

an input photodetector provided at a position where light radiated from the wall face of said semiconductor optical waveguide without being couple to said semiconductor optical waveguide on the input side can be detected.

15. A semiconductor device according to claim 13, further comprising a semiconductor optical amplifier provided in at least part of a region where said semiconductor optical waveguide is provided,

Wherein said photodetector has the same waveguide structure as said semiconductor optical waveguide, and said semiconductor device is configured such that a forward bias voltage is applied to the semiconductor optical amplifier portion of said semiconductor optical waveguide and a reverse bias voltage is applied to said photodetector.

16. A semiconductor device according to claim 13, further comprising a semiconductor optical amplifier provided in at least part of a region where said semiconductor optical waveguide is provided.