Optical network employing erbium-doped fiber amplifiers

• US 20020141020A1
• Filed: 05/28/2002
• Published: 10/03/2002
• Est. Priority Date: 03/29/1996
• Status: Active Grant

• Current Assignee: Seafort International Trading, S.r.l.
• Original Assignee: Dominion Lasercom, Inc., A Nevada Corporation
• Inventors: Panak, David L., Doucet, Mark A.
• Granted Patent: US 7,092,636 B2
• Time in Patent Office: Days
• US Class Current: 398/121
• CPC Class Codes: G02B 6/4405 with longitudinally spaced waveguide clamping G02B6/4429, G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: G02B 6/4411 Matrix structure
• CPC Class Codes: G02B 6/4416 Heterogeneous cables
• CPC Class Codes: G02B 6/44265 Fibre-to-antenna cables; Auxiliary devices thereof
• CPC Class Codes: G02B 6/4459 Ducts; Conduits; Hollow tubes for air blown fibres
• CPC Class Codes: H01B 11/22 Cables including at least one electrical conductor together with optical fibres
• CPC Class Codes: H04B 10/1121 One-way transmission
• CPC Class Codes: H04B 10/1125 using a single common optical path
• CPC Class Codes: H04B 10/1127 using two distinct parallel optical paths
• CPC Class Codes: H04L 5/16 Half-duplex systems; Simplex/duplex switching; Transmission of break signals non-automatically inverting the direction of transmission

Abstract

A point-to-multipoint bi-directional wide area telecommunications network employing atmospheric optical communication. The network comprises a primary transceiver unit, a plurality of subscriber transceiver units and an optical router. The primary transceiver unit may send data destined for the subscriber transceiver units through the optical router, and the subscriber transceiver units may send data destined for the primary transceiver unit through the optical router. The primary transceiver unit and optical router communicate by means of light beams which are transmitted through the atmosphere. Similarly, the optical router and the subscriber transceiver units communicate by means of light beams which are transmitted through the atmosphere.

Claims

1. A terrestrial optical communication network comprising a plurality of fiber optic links and free-space links between which optical signals are optically coupled by erbium doped fiber amplifiers (EDFAs), wherein a power gain of at least one of the EDFAs is operable to be controlled in response to one or more factors.

2. A terrestrial optical communication network as defined in claim 1 wherein the one or more factors comprise weather conditions.

3. A terrestrial optical communication network as defined in claim 1 wherein the one or more factors comprise an optical signal received over one of the free-space links.

4. A terrestrial optical communication network as defined in claim 1, further comprising a control system for controlling the power gain of at least one of the EDFAs.

5. A terrestrial optical, communication network as defined in claim 4, wherein the control system is a beam deflector control system.

6. A terrestrial optical communication network as defined in claim 4, wherein the control system is an active optics control system.

7. A terrestrial optical communication network as defined in claim 1 further including at least one optical router connected to a plurality of links, wherein the optical router includes one or more EDFAs to optically couple the optical signals from one of the links connected to the optical router to another one of the links connected to the optical router.

8. A terrestrial optical communication network as defined in claim 1, wherein the EDFAs include a transmitting EDFA, wherein the transmitting EDFA amplifies one of the optical signals before its transmission over at least one of the free-space links, and further comprising a controller connected to the transmitting EDFA to control the optical power gain of the transmitting EDFA to adjust the optical power of the optical signal transmitted over the one free-space link.

9. A terrestrial optical communication network as defined in claim 1, wherein the EDFAs include a receiving EDFA, wherein the receiving EDFA amplifies one of the optical signals after its reception over at least one of the free-space links, and further comprising a controller connected to the receiving EDFA to control the optical power gain of the receiving EDFA to adjust the optical power of the optical signal delivered by the receiving EDFA.

10. A terrestrial optical communication network comprising a plurality of fiber optic links and free-space links between which optical signals are optically coupled by erbium doped fiber amplifiers (EDFAs), and further comprising transceivers which transmit and receive the optical signals over the free-space links, wherein at least a first of said transceivers includes an active optics control system configured to adjust a first beam transmitted by the first transceiver through one of said free-space links so as to stabilize the first beam on an optical antenna of a second of said transceivers.

11. A terrestrial optical communication network comprising a plurality of fiber optic links and free-space links between which optical signals are optically coupled by erbium doped fiber amplifiers (EDFAs), and further comprising transceivers which transmit and receive the optical signals over the free-space links, wherein at least a first of said transceivers includes an active optics control system and a beam demodulator, wherein the first transceiver is configured to receive a first optical signal transferred through one of said free-space links, wherein the active optics control system is configured to adjust a first optical signal to optimize an amount of power in said first optical signal delivered to the beam demodulator.

13. The network of claim 12, wherein the signal power of the one or more light beams is adjusted to achieve a proper fade margin.

16. The network of claim 15, wherein the at least one of said EFDAs is configured to amplify the power of a first of said one or more light beams after said first light beam has been transmitted through the atmosphere.

17. The network of claim 15, wherein the at least one of said EFDAs is configured to amplify the power of a first of said one or more light beams before said first light beam is transmitted through the atmosphere.

12. A terrestrial optical communication network comprising a plurality of fiber optic links, free-space links, and one or more erbium doped fiber amplifiers (EDFAs), wherein the one or more EDFAs operate to amplify signal power of one or more light beams within the network.

14. A point-to-multipoint communications network employing atmospheric optical communication, comprising:

a primary transceiver unit, an optical router, and a plurality of subscriber transceiver units and one or more erbium-doped fiber amplifiers (EDFAs), wherein the primary transceiver unit is configured to communicate with the plurality of subscriber transceiver units through the optical router, wherein the primary transceiver unit is configured to communicate with the optical router using transfer of light through the atmosphere, and wherein the optical router is configured to communicate with the plurality of subscriber transceiver units using transfer of light through the atmosphere, wherein the one or more EDFAs are configured to amplify the power of one or more beams of said light transferred through the atmosphere.

15. A point-to-multipoint communications network employing atmospheric optical communication, comprising a primary transceiver unit, a plurality of subscriber transceiver units and one or more erbium-doped fiber amplifiers (EDFAs), wherein the primary transceiver unit is configured to communicate with the plurality of subscriber transceiver units in a point-to-multipoint fashion using transfer of light beams through the atmosphere, wherein the one or more EDFAs are configured to amplify the power of one or more of said light beams.

18. A point-to-multipoint bi-directional wide area communications network employing atmospheric optical communication, comprising:

a primary transceiver unit comprising a primary light source configured to generate a first light beam, wherein said primary transceiver unit is configured to modulate first data on said first light beam, wherein said primary transceiver unit atmospherically transmits said first light beam including said first data;

an optical router configured to receive said first light beam including said first data from said primary transceiver unit; and

a plurality of subscriber transceiver units; and

one or more erbium-doped fiber amplifiers (EDFAs);

wherein said optical router is configured to receive said first light beam including said first data from said primary transceiver unit and redirect said first light beam to said plurality of subscriber transceiver units;

wherein each of said plurality of subscriber transceiver units is configured to atmospherically receive said first light beam from said optical router, wherein each of said plurality of subscriber transceiver units is configured to demodulate at least a portion of said first data from said first light beam;

wherein each of said plurality of subscriber transceiver units is configured to modulate respective second data on a second light beam, wherein each of said plurality of subscriber transceiver units atmospherically transmits said second light beam including said respective second data;

wherein said optical router is configured to receive a plurality of said second light beams including said respective second data from said plurality of subscriber transceiver units and redirect said second light beams to said primary transceiver unit;

wherein said primary transceiver unit atmospherically receives said second light beams including said respective second data, wherein said primary transceiver unit is configured to demodulate said respective second data from said second light beams; and

wherein said primary transceiver unit, said optical router and said plurality of subscriber transceiver units comprise a wide area optical telecommunications network;

wherein said one or more EDFAs are configured amplify the power of at least one of the first light beam and the second light beams.