Optical communication system

• US 20030039002A1
• Filed: 08/12/2002
• Published: 02/27/2003
• Est. Priority Date: 08/14/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Toriumi, Yoichi, Shino, Kuninori
• Granted Patent: US 7,062,170 B2
• Time in Patent Office: Days
• US Class Current: 398/41
• CPC Class Codes: H04B 10/40 Transceivers

Abstract

An optical communication system suitable for full duplex optical communication between a first and a second optical transceiver units. connected with each other by a single-core optical fiber. The first and second transceiver units may have different types of light emitting elements emitting light having different loss rates in the single-core optical fiber. The system enables stable full duplex communication without setting up large scale or costly transmission units by relatively reducing the optical crosstalk involved. The first optical transceiver unit provides transmission light to be coupled with the single-core optical fiber with the intensity in the range of TAmin-TAmax. The amount of light emitted from the light emitting element of the optical transceiver unit to be coupled with the single-core optical fiber is in the range TBmin-TBmax, which amount may be adjusted by a light emission adjusting unit provided in the optical transceiver unit.

Claims

1. A full duplex optical communication system, comprising a first and a second optical transceiver units connected with each other by means of a single-core optical fiber,

said first optical transceiver unit including:

a first light emitting element for emitting transmission light;

a first light receiving element for receiving signal light; and

first guiding means for guiding said transmission light from said first light emitting element to said single-core optical fiber and for guiding received signal light from said single-core optical fiber to said first light emitting element, and said second optical transceiver unit including;

a second light emitting element for emitting transmission light;

a second light receiving element for receiving signal light; and

second guiding means for guiding said transmission light from said second light emitting element to said single-core optical fiber and for guiding received signal light from said single-core optical fiber to said second light receiving element,

said optical communication system further comprising means for reducing optical crosstalk component relatively, said optical crosstalk component being at least one of the optical crosstalk component originating from said first light emitting element and contained in said signal light received by said first light receiving element and the optical crosstalk component originating from said second light emitting element and contained in said signal light received by said second light receiving element, by adjusting at least one of the amounts of transmission light emitted from said first and second light emitting elements to said single-core optical fiber.

2. The optical communication system according to claim 1, wherein said first and second light emitting elements emit the transmission light which has different transmission loss rates in said single-core optical fiber.

3. The optical communication system according to claim 2, wherein said first and second light emitting elements emit the transmission light having different spectral widths in wavelength.

4. The optical communication system according to claim 2, wherein said first and second light emitting elements emit the transmission light having different wavelength variations.

5. The optical communication system according to claim 2, wherein said first and second light emitting elements emit the transmission light having different wavelengths.

6. The optical communication system according to claim 2, wherein the launched numerical aperture (LNA) of said single-core optical fiber for the transmission light emitted from said first light emitting element differs from that for said second light emitting element.

7. The optical communication system according to claim 1, wherein said first light emitting element is a light emitting diode and said second light emitting element is a laser diode.

8. The optical communication system according to claim 1, wherein when transmission loss of the transmission light emitted from the light emitting element of one of said first and second optical transceiver units in said single-core optical fiber is larger than the corresponding loss of light emitted from the light emitting element of the other optical transceiver unit, said means for reducing optical crosstalk component is adapted to reduce the amount of light emitted from said light emitting element of said other optical transceiver unit to relatively reduce the amount of crosstalk component in the signal light received by the light receiving element of said other optical transceiver unit.

9. The optical communication system according to claim 8, wherein an amount of the transmission light emitted from said light emitting element of said other optical transceiver unit to said single-core optical fiber is variable;

and

wherein said means for reducing optical crosstalk component is adapted to reduce only the maximum amount of light emitted from said light emitting element of said other optical transceiver unit to thereby relatively reduce said crosstalk component in the light received by said light receiving element of said other optical transceiver unit.

10. The optical communication system according to claim 1, wherein when transmission loss of the transmission light emitted from the light emitting element of one of said first and second optical transceiver units in said single-core optical fiber is larger than the corresponding loss of light emitted from the light emitting element of the other optical transceiver unit, said means for reducing crosstalk component is adapted to increase the amount of light emitted from said light emitting element of said one optical transceiver unit to relatively reduce the amount of crosstalk component in the light received by said light receiving element of said other optical transceiver unit.

11. The optical communication system according to claim 10, wherein an amount of the transmission light emitted from said light emitting element of said other optical transceiver unit to said single-core optical fiber is variable;

and

wherein said means for reducing crosstalk component is adapted to increase only the minimum amount of light emitted from said light emitting element of said one optical transceiver unit to thereby relatively reduce said crosstalk component in the light received by said light receiving element of said other optical transceiver unit.