Bi-directional optical-amplifier module

A bi-directional optical-amplifier module having first and second input/output ports to amplify downward/upward optical signals traveling bi-directionally, comprising:

• a first wavelength-selective coupler connected at a common terminal thereof to the first input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a first unidirectional optical amplifier connected at an input terminal thereof to an output terminal of the first wavelength-selective coupler;
• a fourth uni-directional optical amplifier connected at an output terminal thereof to an input terminal of the first wavelength-selective coupler;
• a first circulator connected to an output terminal of the first uni-directional optical amplifier and an input terminal of the fourth unidirectional optical amplifier at input and output terminals thereof, respectively;
• a second wavelength-selective coupler connected at a common terminal thereof to the second input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a second unidirectional optical amplifier connected at an input terminal thereof to an output terminal of the second wavelength-selective coupler;
• a third uni-directional optical amplifier connected at an output terminal thereof to an input terminal of the second wavelength-selective coupler;
• a second circulator connected to an output terminal of the second uni-directional optical amplifier and an input terminal of the third uni-directional optical amplifier at input and output terminals thereof, respectively;
• and,
• a mid-stage device connected between the common terminals of the first and second circulators, the mid-stage device comprising at least one of dispersion-compensating means, optical-fiber-gain flattening means, and means for removing accumulated noise of optical amplifiers and controlling power of optical signals.

A bi-directional optical-amplifier module having first and second input/output ports to amplify downward/upward optical signals traveling bi-directionally, comprising:

• a first circulator connected at a common terminal thereof to the first input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a first uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the first circulator;
• a fourth uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the first circulator;
• a first wavelength-selective coupler connected to an output terminal of the first unidirectional optical amplifier and an input terminal of the fourth unidirectional optical amplifier to input and output terminals thereof, respectively;
• a second wavelength-selective coupler connected to a common terminal thereof to the second input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a second unidirectional optical amplifier connected at an input terminal thereof to an output terminal of the second wavelength-selective coupler;
• a third uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the second wavelength-selective coupler;
• a second circulator connected to an output terminal of the second uni-directional optical amplifier and an input terminal of the third uni-directional optical amplifier at input and output terminals thereof, respectively;
• and,
• a mid-stage device connected between the common terminal of the first wavelength-selective coupler and the common terminal of the second circulator, the mid-stage device comprising at least one of dispersion-compensating means, optical-fiber-gain flattening means, and means for removing accumulated noise of optical amplifiers and controlling power of optical signals.

A bi-directional optical-amplifier module having first and second input/output ports to amplify downward/upward optical signals traveling bi-directionally, comprising:

• a first circulator connected to a common terminal thereof to the first input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a first uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the first circulator;
• a fourth unidirectional optical amplifier connected to an output terminal thereof to an input terminal of the first circulator;
• a first wavelength-selective coupler connected to an output terminal of the first unidirectional optical amplifier and an input terminal of the fourth uni-directional optical amplifier to input and output terminals thereof, respectively;
• a second circulator connected to a common terminal thereof to the second input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a second unidirectional optical amplifier connected to an input terminal thereof to an output terminal of the second circulator;
• a third unidirectional optical amplifier connected to an output terminal thereof to an input terminal of the second circulator;
• a second wavelength selective coupler connected to an output terminal of the second unidirectional optical amplifier and an input terminal of the third uni-directional optical amplifier at input and output terminals thereof, respectively;
• and,
• a mid-stage device connected between the common terminals of the first and second wavelength-selective couplers, the mid-stage device comprising at least one of dispersion-compensating means, optical-fiber-gain flattening means, and means for removing accumulated noise of optical amplifiers and controlling power of optical signals.

A bi-directional optical-amplifier module having first and second input/output ports to amplify downward/upward optical signals traveling bi-directionally, comprising:

• a first wavelength-selective coupler connected to a common terminal thereof to the first input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a first uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the first-wavelength selective coupler;
• a fourth uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the first wavelength-selective coupler;
• a third wavelength-selective coupler connected to an output terminal of the first uni-directional optical amplifier and an input terminal of the fourth uni-directional optical amplifier to input and output terminals thereof, respectively;
• a second wavelength-selective coupler connected to a common terminal thereof to the second input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a second uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the second wavelength-selective coupler;
• a third uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the second wavelength-selective coupler;
• a fourth wavelength-selective coupler connected to an output terminal of the second uni-directional optical amplifier and an input terminal of the third unidirectional optical amplifier at input and output terminals thereof, respectively;
• and,
• a mid-stage device connected between the common terminals of the third and fourth wavelength-selective couplers, the mid-stage device comprising at least one of dispersion compensating means, optical-fiber-gain flattening means, and means for removing accumulated noise of optical amplifiers and controlling power of optical signals.

A bi-directional optical-amplifier module having first and second input/output ports to amplify downward/upward optical signals traveling bi-directionally, comprising:

• a circulator connected to a common terminal thereof to the first input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a first uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the circulator;
• a fourth uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the circulator;
• a first wavelength-selective coupler connected to an output terminal of the first uni-directional optical amplifier and an input terminal of the fourth uni-directional optical amplifier to input and output terminals thereof, respectively;
• a second wavelength-selective coupler connected to a common terminal thereof to the second input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a second uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the second wavelength-selective coupler;
• a third uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the second wavelength-selective coupler;
• a third wavelength-selective coupler connected to an output terminal of the second uni-directional optical amplifier and an input terminal of the third uni-directional optical amplifier to input and output terminals thereof, respectively;
• and,
• a mid-stage device connected between the common terminals of the first and third wavelength-selective couplers, the mid-stage device comprising at least one of dispersion-compensating means, optical-fiber-gain flattening means, and means for removing accumulated noise of optical amplifiers and controlling power of optical signals.

A bi-directional optical-amplifier module having first and second input/output ports to amplify downward/upward optical signals traveling bi-directionally, comprising:

• a first wavelength-selective coupler connected to a common terminal thereof to the first input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a first uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the first wavelength-selective coupler;
• a fourth uni-directional optical amplifier connected at an output terminal thereof to an input terminal of the first wavelength-selective coupler;
• a circulator connected to an output terminal of the first unidirectional optical amplifier and an input terminal of the fourth unidirectional optical amplifier at input and output terminals thereof, respectively;
• a second wavelength-selective coupler connected to a common terminal thereof to the second input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a second uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the second wavelength-selective coupler;
• a third uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the second wavelength-selective coupler;
• a third wavelength-selective coupler connected to an output terminal of the second uni-directional optical amplifier and an input terminal of the third unidirectional optical amplifier to input and output terminals thereof, respectively;
• and,
• a mid-stage device connected between the common terminal of the circulator and the common terminal of the third wavelength-selective coupler, the mid-stage device comprising at least one of dispersion compensating means, optical-fibe-gain flattening means, and means for removing accumulated noise of optical amplifiers and controlling power of optical signals.

A bi-directional optical-amplifier module having first and second input/output ports to amplify downward/upward optical signals traveling bi-directionally, comprising:

• a first wavelength-selective coupler connected to a common terminal thereof to the first input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a first uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the first wavelength-selective coupler;
• a fourth uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the first wavelength-selective coupler;
• a second wavelength-selective coupler connected to a common terminal thereof to the second input/output port and adapted to perform a separation/combination of optical signals passing therethrough bi-directionally;
• a second uni-directional optical amplifier connected to an input terminal thereof to an output terminal of the second wavelength-selective coupler;
• a third uni-directional optical amplifier connected to an output terminal thereof to an input terminal of the second wavelength-selective coupler;
• a third wavelength-selective coupler connected to respective output terminals of the first and second unidirectional optical amplifiers to first and second input terminals thereof;
• a fourth wavelength-selective coupler connected to respective output terminals of the third and fourth uni-directional optical amplifiers to first and second input terminals thereof;
• and,
• a mid-stage device connected between the common terminals of the third and fourth wavelength-selective couplers, the mid-stage device comprising at least one of dispersion-compensating means, optical-fiber-gain flattening means, and means for removing accumulated noise of optical amplifiers and controlling power of optical signals.