Claims
- 1. A rare earth element-doped multiple-core optical fiber amplifier, comprising: a rare earth element-doped multiple-core optical fiber, comprising: a plurality of cores each having a refractive index of n.sub.w doped with at least one rare earth element therein; and an outer cladding layer having a refractive index of n.sub.c (n.sub.w >n.sub.c), and covering said cores; wherein said cores are positioned substantially on a central axis of said outer cladding layer, at least one of which is surrounded by remaining cores having a larger core diameter than said surrounded core,
- at least one pumping light source;
- at least one wavelength division multiplexing circuit for coupling an pumping light with one end of said rare earth element-doped multiple-core optical fiber; and
- an isolator disposed between said wavelength division multiplexing circuit and said one end of said rare earth element-doped multiple-core optical fiber.
- 2. A rare earth element-doped multiple-core optical fiber amplifier, comprising: a rare earth element-doped multiple-core optical fiber, comprising: a plurality of cores each doped with at least one rare earth element therein; and an outer cladding layer having a lower refractive index than said cores, and covering said cores; wherein said cores are positioned substantially on a central axis of said outer cladding layer, at least one of which is surrounded by remaining cores having a higher refractive index than said surrounded core,
- at least one pumping light source;
- at least one wavelength division multiplexing circuit for coupling an pumping light with one end of said rare earth element-doped multiple-core optical fiber; and
- an isolator disposed between said wavelength division multiplexing circuit and said one end of said rare earth element-doped multiple-core optical fiber.
- 3. A rare earth element-doped multiple-core optical fiber amplifier, comprising: a rare earth element-doped multiple-core optical fiber, comprising: a plurality of cores each doped with at least one rare earth element therein; and an outer cladding layer having a lower refractive index than said cores, and covering said cores; wherein said cores are positioned substantially on a central axis of said outer cladding layer, at least one of which is surrounded by remaining cores containing a larger amount of rare earth element than said surrounded core,
- at least one pumping light source;
- at least one wavelength division multiplexing circuit for coupling an pumping light with one end of said rare earth element-doped multiple-core optical fiber; and
- an isolator disposed between said wavelength division multiplexing circuit and said one end of said rare earth element-doped multiple-core optical fiber.
- 4. A rare earth element-doped multiple-core optical fiber system, comprising:
- a plurality of cores each having a first refractive index doped with at least one rare earth element;
- a cladding layer having a second refractive index lower than said first refractive index for surrounding said plurality of cores, said plurality of cores being positioned in a central region of said cladding layer;
- at least one rare earth element-doped multiple-core optical fiber amplifier for amplifying a signal light by stimulated emission; and
- at least one dispersion-shifted optical fiber connected to an input end and/or an output end of said rare earth element-doped multiple-core optical fiber amplifier,
- wherein said plurality of cores comprises a first group of one or more cores, and a second group of cores, such that said second group of cores surrounds a periphery of said first group of one or more cores to equalize powers propagated through each core of said first and second groups.
- 5. A rare earth element-doped multiple-core optical fiber system according to claim 4, wherein:
- an optical multiplexer/demultiplexer is connected to an input end and/or an output end of said rare earth element-doped multiple-core optical fiber system.
- 6. A rare earth element-doped multiple-core optical fiber system according to claim 4, wherein:
- an optical star coupler for distributing amplified signal lights of different wavelength is connected to an input end and/or an output end of said rare earth element-doped multiple-core optical fiber system.
Priority Claims (2)
Number |
Date |
Country |
Kind |
8-035262 |
Feb 1996 |
JPX |
|
8-074793 |
Mar 1996 |
JPX |
|
Parent Case Info
This application is a division of application Ser. No. 08/695,493 filed Aug. 12, 1996 pending.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
5570448 |
Imoto et al. |
Oct 1996 |
|
Foreign Referenced Citations (6)
Number |
Date |
Country |
5-299733 |
Nov 1993 |
JPX |
5-345632 |
Dec 1993 |
JPX |
6-37385 |
Feb 1994 |
JPX |
6-216441 |
Aug 1994 |
JPX |
8-43644 |
Feb 1996 |
JPX |
8-43668 |
Feb 1996 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
695493 |
Aug 1996 |
|