| US 7,379,236 B2 | ||
| Optical fiber communication system using remote pumping | ||
| Hiroji Masuda, Yokosuka (Japan); Hiroto Kawakami, Yokosuka (Japan); and Yutaka Miyamoto, Yokohama (Japan) | ||
| Assigned to Nippon Telegraph and Telephone Corporation, Tokyo (Japan) | ||
| Appl. No. 10/552,554 PCT Filed Jul. 05, 2004, PCT No. PCT/JP2004/009878 § 371(c)(1), (2), (4) Date Oct. 12, 2005, PCT Pub. No. WO2005/004356, PCT Pub. Date Jan. 13, 2005. |
||
| Claims priority of application No. 2003-271157 (JP), filed on Jul. 04, 2003. | ||
| Prior Publication US 2007/0003286 A1, Jan. 04, 2007 | ||
| Int. Cl. H01S 4/00 (2006.01); H04B 10/12 (2006.01) | ||
| U.S. Cl. 359—341.32 [359/341.3] | 3 Claims |
| 1. An optical fiber communication system comprising:
a signal light output device which outputs signal light having a wavelength in a wavelength band of 1570 nm to 1600 nm;
a plurality of transmission fibers which transmit the signal light outputted from the signal light output device;
an erbium-doped fiber module which is positioned between the transmission fibers; and
a signal light reception device which comprises: a pumping light source which outputs pumping light; and a coupler which couples
the pumping light to the signal light which is outputted from the signal light output device and which passes through the
transmission fibers and the erbium-doped fiber module, and outputs the pumping light in a direction opposite to that in which
the signal light is outputted,
wherein the erbium-doped fiber module comprises:
a divider which divides the pumping light propagated in the direction opposite to that in which the signal light is propagated
in the transmission fibers, from the signal light;
a branch which branches the pumping light divided by the divider, with a branching ratio of 33% to 67%, and outputs a first
pumping light beam which is proximately 33% of the pumping light and a second pumping light beam which is proximately 67%
of the pumping light;
an erbium-doped fiber to which the signal light is inputted;
a first coupling device which supplies the first pumping light beam branching off from the branch, to the erbium-doped fiber
from a signal-light outputting end of the erbium-doped fiber; and
a second coupling device which couples the signal light to the second pumping light beam branching off from the branch, and
supplies the signal light and the second pumping light beam to the erbium-doped fiber from a signal-light inputting end of
the erbium-doped fiber.
|