US 2003/0142978 A1 · Method for decreasing and compensating the transmission loss at a wavelength-division-multiplexed passive optical network and an apparatus therefor

Abstract

The present invention relates to a wavelength-division multiplexed passive optical network. In particular, it relates to a technology for minimizing the optical loss at a wavelength-division multiplexed passive optical network based on wavelength-locked light source Thereby it improves the transmission quality and increases the transmission distance. A 4-port optical path setting device of the present invention increases the amount of light injected into an optical transmitter and thereby improves the wavelength-locking characteristic of a light source. In addition, it can decrease the optical transmission loss in an optical transmission path, and by an optical amplifier being inserted therein; it can also compensate the optical loss in an optical transmission path. In the present invention, a 4-port optical path setting device having the characteristics described above and a method for fault recovery without an additional optical loss are presented.

Claims11

Dependent claims

A method for decreasing and compensating the optical transmission loss at a wavelength-division multiplexed passive optical network characterized by using a 4-port optical path setting device for handling A-band optical signals and B-band optical signals, wherein numbers of wavelengths are included in each band respectively, characterized in that:

an A-band optical signal inputted through #1 port of said 4-port optical path setting device is outputted through #3 port, an A-band optical signal inputted through #3 port of said 4-port optical path setting device is outputted through #4 port;
and
a B-band optical signal inputted through #2 port of said 4-port optical path setting device is outputted through #4 port and a B-band optical signal inputted through #4 port of said 4-port optical path setting device is outputted through #3 port.

An apparatus for decreasing the transmission loss at a wavelength-division multiplexed passive optical network characterized by using a 4-port optical path setting device for handling A-band optical signals and B-band optical signals, wherein numbers of wavelengths are included in each band respectively, characterized in that said 4-port optical path setting device comprises:

a first optical multiplexer/demultiplexer for multiplexing/demultiplexing A-band and B-band optical signals,
a second optical multiplexer/demultiplexer for multiplexing/demultiplexing A-band and B-band optical signals,
a 3-port optical circulator operated in A-band;
a 3-port optical circulator operated in B-band;
an optical amplifier operated in A-band;
and
an optical amplifier operated in B-band.

4 more elements

A wavelength-division multiplexed passive optical network system using a wavelength-locked optical signal by an injected incoherent light, which has a fault recovery function for the case of a fault being occurred between a central office and a remote distribution node, characterized by comprising:

a central office having a 2×N optical multiplexer/demultiplexer, a first 1×2 optical-spatial switch, a second 1×2 optical spatial switch and a 4-port optical path setting device;
a first optical cable for connecting said central office and said remote distribution node in normal operation state;
a second optical cable for bypassing during a fault recovery;
and
a remote distribution node having a 2×N optical multiplexer/demultiplexer,

2 more elements

Dependencies are inferred from the claim text.

Method for decreasing and compensating the transmission loss at a wavelength-division-multiplexed passive optical network and an apparatus therefor

Life of this patent

Method for decreasing and compensating the transmission loss at a wavelength-division-multiplexed passive optical network and an apparatus therefor

Life of this patent

Abstract

Claims11