Optical transmission apparatus and optical systems

• US 6,731,874 B2
• Filed: 06/14/2002
• Issued: 05/04/2004
• Est. Priority Date: 02/25/1997
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tsushima, Hideaki, Sawada, Yasushi, Kitajima, Shigeki
• Primary Examiner(s): Pascal, Leslie
• Assistant Examiner(s): SINGH, DALZID E
• Application Number:
  US10/172,811
• Publication Number:
  US 20020176142A1
• Time in Patent Office: 690 Days
• Field of Search: 359/110, 359/117, 359/124, 359/177, 390/45, 390/48, 390/49, 390/30, 390/50, 390/79, 390/177
• US Class Current: 398/45
• CPC Class Codes: H01S 3/0078 Frequency filtering
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/10015 by monitoring or controlling, e.g. attenuating, the input signal
• CPC Class Codes: H01S 3/13013 by controlling the optical pumping
• CPC Class Codes: H01S 3/2391 emitting at different wavelengths
• CPC Class Codes: H04B 10/0731 Testing or characterisation of optical devices, e.g. amplifiers
• CPC Class Codes: H04Q 11/0001 using optical switching
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget
• CPC Class Codes: H04Q 2011/0069 using dedicated optical channels
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring

Abstract

An optical transmission apparatus, an optical repeater using the optical transmission apparatus, and an optical cross-connect equipment for controlling switches depending on supervisory information, comprising: a doped fiber for amplifying an optical signal of wavelength Od; a wavelength multiplexer for outputting a pumping light to the doped fiber; a wavelength multiplexer for multiplexing an amplified optical signal and a supervisory optical signal to as to output it to an optical fiber at downstream side; a pumping and supervisory light source; an optical coupler for distributing the light from the light source at a ratio of N:1 to the wavelength multiplexers; and a driver for controlling the light source by adding the supervisory information and a direct current signal.

Claims

1. An optical cross-connect equipment comprising:

(1) an optical switch having a plural number of input ports and a plural number of output ports, for exchanging connections between said input ports and said output ports;

(2) a first transmission apparatus, having;

a first wavelength demultiplexer for dividing an input optical signal applied thereto into a supervisory optical signal and a wavelength multiplexed input signal;

a supervisory optical signal receiver for receiving said supervisory optical signal, to extract an input supervisory information therefrom; and

a second wavelength demultiplexer for dividing said wavelength multiplexed input signal into optical signals, each having a separate wavelength, thereby to connect the optical signals to the different input ports of said optical switch, respectively;

(3) a second transmission apparatus, having;

a first wavelength multiplexer for wavelength multiplexing the optical signals from the plural number of output ports of said optical switch, to form a multiplexed waveform output;

a supervisory optical signal transmitter for converting an output supervisory information into the supervisory optical signal; and

a second wavelength multiplexer for multiplexing said wavelength multiplexed output signals and said supervisory optical signal, thereby to provide an output optical signal of the second transmission apparatus; and

(4) a controller for inputting the input supervisory information obtained in said first transmission apparatus and for outputting the output supervisory information to said second transmission apparatus.

2. An optical cross-connect equipment, as defined in the claim 1, wherein said first transmission apparatus further includes an optical amplifier for amplifying said wavelength multiplexed input signal, disposed in a front stage of said second wavelength demultiplexer.

3. An optical cross-connect equipment, as defined in the claim 2, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

4. An optical cross-connect equipment, as defined in the claim 1, wherein said second transmission apparatus further includes an optical amplifier for amplifying said wavelength multiplexed output signal, disposed in a rear stage of said second wavelength multiplexer.

5. An optical cross-connect equipment, as defined in the claim 4, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

6. An optical cross-connect equipment, as defined in the claim 1, wherein,

said first transmission apparatus further includes an optical amplifier for amplifying said wavelength multiplexed input signal, disposed in a front stage of said second wavelength demultiplexer; and

said second transmission apparatus further includes an optical amplifier for amplifying said wavelength multiplexed output signal, disposed in a rear stage of said second wavelength multiplexer.

7. An optical cross-connect equipment, as defined in the claim 6, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

8. An optical cross-connect equipment, as defined in the claim 1, wherein said first transmission apparatus further includes an interface portion for receiving the optical signals, each having the separate wavelength and converting said optical signals into electrical signals and converting said electrical signals into optical signals, said interface portion disposed in a rear stage of said second wavelength demultiplexer.

9. An optical cross-connect equipment, as defined in the claim 8, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

10. An optical cross-connect equipment, as defined in the claim 1, wherein said second transmission apparatus further includes an interface portion for receiving the optical signals, converting said optical signals into the electrical signals and converting said electrical signals into the optical signals, each having the separate wavelength, said interface portion disposed in a front stage of said first wavelength multiplexer.

11. An optical cross-connect equipment, as defined in the claim 10, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

12. An optical cross-connect equipment, as defined in the claim 1, wherein, said first transmission apparatus further includes an interface portion for receiving the optical signals, each having the separate wavelength and converting said optical signals into electrical signals and converting said electrical signals into optical signals, said interface portion disposed in a rear stage of said second wavelength demultiplexer;

and

said second transmission apparatus further includes an interface portion for receiving the optical signals, converting said optical signals into the electrical signals and converting said electrical signals into the optical signals, each having the separate wavelength, said interface portion disposed in a front stage of said first wavelength multiplexer.

13. An optical cross-connect equipment, as defined in the claim 12, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

14. An optical cross-connect equipment, as defined in the claim 1, wherein wavelength of said supervisory optical signal is selected from any one of 1.3 um band, 1.5 um band, and 1.48 um band.

15. An optical cross-connect equipment, as defined in the claim 14, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

16. An optical cross-connect equipment, as defined in the claim 1, wherein the information transmitted by said supervisory optical signals includes at least any one of a network supervisory information, a wavelength multiplex system supervisory information, and an optical switch supervisory information.

17. An optical cross-connect equipment, as defined in the claim 16, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

18. An optical cross-connect equipment, as defined in the claim 1, wherein said controller conducts supervision on said optical switch.

19. An optical cross-connect equipment, as defined in the claim 18, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.

20. An optical cross-connect equipment, as defined in the claim 1, wherein at least one of said first transmission apparatus and said second transmission apparatus are provided in a plural number thereof.