Optical regenerative-repeater system

Claim 2

An optical regenerative-repeater system, comprising: a first optical amplifier for amplifying an input optical signal; a first injection current supply circuit for supplying a driving current to said first optical amplifier; an optical branch device for branching a signal supplied from said first optical amplifier through an optical isolator; an optical latch for latching a main optical signal supplied from said optical branch device; a photodiode for converting said branched signal supplied from said optical branch device to electric signal; a wide-band amplifier for amplifying an output signal of said photodiode; a differentiating circuit for detecting a level change point in an output signal of said wide-band amplifier; a full-wave rectification circuit for generating line spectrum from an output signal of said differentiating circuit; a timing tank for generating a timing signal in accordance with an output signal of said full-wave rectification circuit; a narrow-band amplifier for amplifying an output signal of said timing tank; a driving current supply circuit for supplying timing current to said optical latch in accordance with an output signal of said narrow-band amplifier; a peak detector for detecting a peak value of said output signal of said full-wave rectification circuit; a direct current (DC) amplifier for generating a control voltage to be supplied to said first injection current supply circuit in accordance with an output signal of said peak detector; a second optical amplifier for amplifying an output signal of said optical latch; and a second injection current supply circuit for supplying a driving current to said second optical amplifier; wherein, gain of said first optical amplifier can be changed by output current of said first injection current supply circuit.

Claim 3

An optical regenerative-repeater system, comprising: a first optical amplifier for amplifying an input optical signal; a first injection current supply circuit for supplying a driving current to said first optical amplifier; an optical branch device for branching a signal supplied from said first optical amplifier through an optical isolator; an optical latch for latching a main optical signal supplied from said optical branch device; a photodiode for converting said branched signal supplied from said optical branch device to electric signal; a wide-band amplifier for amplifying an output signal of said photodiode; a differentiating circuit for detecting a level change point in an output signal of said wide-band amplifier; a full-wave rectification circuit for generating line spectrum from an output signal of said differentiating circuit; a timing tank for generating a timing signal in accordance with an output signal of said full-wave rectification circuit; a narrow-band amplifier for amplifying an output signal of said timing tank; a first peak detector for detecting a peak value of an output signal of said narrow-band amplifier; a first direct current (DC) amplifier for amplifying an output signal of said first peak detector to a predetermined level, comparing said amplified signal with a reference voltage, and generating an error message signal when said amplified signal is equal to said reference voltage; a driving current supply circuit for supplying a timing current to said optical latch in accordance with output signals of said narrow-band amplifier and said first DC amplifier; a second optical amplifier for amplifying an output signal of said optical latch; a second injection current supply circuit for supplying a driving current to said second optical amplifier; a second peak detector for detecting a peak value of said output signal of said full-wave rectification circuit; and a second direct current (DC) amplifier for generating a control voltage to be supplied to said first injection current supply circuit in accordance with an output signal of said second peak detector; wherein, gain of said first optical amplifier can be changed by output current of said first injection current supply circuit; and said output current of said driving current supply circuit is prohibited from supplying output current by an output signal of said first DC amplifier.

Claim 4

An optical regenerative-repeater system, comprising: a first optical amplifier for amplifying an input optical signal; a first injection current supply circuit for supplying a driving current to said first optical amplifier; an optical branch device for branching a signal supplied from said first optical amplifier through an optical isolator; an optical latch for latching a main optical signal supplied from said optical branch device; a photodiode for converting said branched signal supplied from said optical branch device to electric signal; a wide-band amplifier for amplifying an output signal of said photodiode; a differentiating circuit for detecting a level change point in an output signal of said wide-band amplifier; a full-wave rectification circuit for generating line spectrum from an output signal of said differentiating circuit; a timing tank for generating a timing signal in accordance with an output signal of said full-wave rectification circuit; a narrow-band amplifier for amplifying an output signal of said timing tank; a first peak detector for detecting a peak value of an output signal of said narrow-band amplifier; a first direct current (DC) amplifier for amplifying an output signal of said first peak detector to a predetermined level, comparing said amplified signal with a reference voltage, and generating an error message signal when said amplified signal is equal to said reference voltage; a driving current supply circuit for supplying a timing current to said optical latch in accordance with output signals of said narrow-band amplifier and said first DC amplifier; a second optical amplifier for amplifying an output signal of said optical latch; a second injection current supply circuit for supplying a driving current to said second optical amplifier; a second peak detector for detecting a peak value of said output signal of said full-wave rectification circuit; and a second direct current (DC) amplifier for generating a control voltage to be supplied to said first injection current supply circuit in accordance with an output signal of said second peak detector; wherein, gain of said first optical amplifier can be changed by output current of said first injection current supply circuit; and said driving current supply circuit and said second injection current supply circuit are prohibited from supplying output current by an output signal of said first DC amplifier.

Claim 5

An optical regenerative-repeater system, comprising: a first optical branch device for branching an input optical signal; a first optical amplifier for amplifying a main optical signal supplied from said first optical branch device; a first injection current supply circuit for supplying a driving current to said first optical amplifier; a second optical branch device for branching an optical signal supplied from said first optical amplifier through an optical isolator; an optical latch for latching a main optical signal supplied from said second optical branch device; a first photodiode for converting said branched signal supplied from said optical branch device to an electric signal; a wide-band amplifier for amplifying an output signal of said first photodiode; a differentiating circuit for detecting a level change point in an output signal of said wide-band amplifier; a full-wave rectification circuit for generating line spectrum from an output signal of said differentiating circuit; a timing tank for generating a timing signal in accordance with an output signal of said full-wave rectification circuit; a narrow-band amplifier for amplifying an output signal of said timing tank; a first peak detector for detecting a peak value of an output signal of said narrow-band amplifier; a first direct current (DC) amplifier for amplifying an output signal of said first peak detector to a predetermined level, comparing said amplified signal with a first reference voltage, and generating an error message signal when said amplified signal is equal to said first reference voltage; an AND circuit which is supplied with an output signal of said first DC amplifier at one of input terminals; a driving current supply circuit for supplying a timing current to said optical latch in accordance with output signals of said narrow-band amplifier and said AND circuit; a second optical amplifier for amplifying an output signal of said optical latch; a second injection current supply circuit for supplying a driving current to said second optical amplifier; a second peak detector for detecting a peak value of said output signal of said full-wave rectification circuit; a second direct current (DC) amplifier for generating a control voltage to be supplied to said first injection current supply circuit in accordance with an output signal of said second peak detector; a second photodiode which is supplied with said branched signal supplied from said first optical branch device; and a third direct current (DC) amplifier for comparing a voltage signal corresponding to an average light current supplied to said second photodiode with a second reference voltage, and supplying an alarm signal to said AND circuit when they are equalized; wherein, gain of said first optical amplifier can be changed by output current of said first injection current supply circuit; and output current signals of said driving current supply circuit and second current supply circuit are prohibited from supplying output current in accordance with an output signal of said AND circuit.

Claim 6

An optical regenerative-repeater system, comprising: a first optical branch device for branching an input optical signal; a first optical amplifier for amplifying a main optical signal supplied from said first optical branch device; a first injection current supply circuit for supplying a driving current to said first optical amplifier; a second optical branch device for branching an optical signal supplied from said first optical amplifier through an optical isolator; an optical latch for latching a main optical signal supplied from said second optical branch device; a first photodiode for converting said branched signal supplied from said optical branch device to an electric signal; a wide-band amplifier for amplifying an output signal of said first photodiode; a differentiating circuit for detecting a level change point in an output signal of said wide-band amplifier; a full-wave rectification circuit for generating line spectrum from an output signal of said differentiating circuit; a timing tank for generating a timing signal in accordance with an output signal of said full-wave rectification circuit; a narrow-band amplifier for amplifying an output signal of said timing tank; a first peak detector for detecting a peak value of an output signal of said narrow-band amplifier; a first direct current (DC) amplifier for amplifying an output signal of said first peak detector to a predetermined level, comparing said amplified signal with a first reference voltage, and generating an error message signal when said amplified signal is equal to said first reference voltage; an AND circuit which is supplied with an output signal of said first DC amplifier at one of input terminals; a driving current supply circuit for supplying a timing current to said optical latch in accordance with output signals of said narrow-band amplifier and said AND circuit; a second optical amplifier for amplifying an output signal of said optical latch; a second injection current supply circuit for supplying a driving current to said second optical amplifier; a second peak detector for detecting a peak value of said output signal of said full-wave rectification circuit; a second direct current (DC) amplifier for generating a control voltage to be supplied to said first injection current supply circuit in accordance with an output signal of said second peak detector; a second photodiode which is supplied with said branched signal supplied from said first optical branch device; and a third direct current (DC) amplifier for comparing a voltage signal corresponding to an average light current supplied to said second photodiode with a second reference voltage, and supplying an alarm signal to said AND circuit and first current supply circuit when they are equalized; wherein, gain of said first optical amplifier can be changed by output current of said first injection current supply circuit; said first current supply circuit is prohibited from supplying output current in accordance with an output signal of said third DC amplifier; and said driving current supply circuit and second current supply circuit are prohibited from supplying output current in accordance with an output signal of said AND circuit.

Claim 7

An optical regenerative-repeater system, comprising: a first optical branch device for branching an input optical signal; a first optical amplifier for amplifying a main optical signal supplied from said first optical branch device; a first injection current supply circuit for supplying a driving current to said first optical amplifier; a second optical branch device for branching an optical signal supplied from said first optical amplifier through an optical isolator; an optical latch for latching a main optical signal supplied from said second optical branch device; a first photodiode for converting said branched signal supplied from said optical branch device to an electric signal; a wide-band amplifier for amplifying an output signal of said first photodiode; a differentiating circuit for detecting a level change point in an output signal of said wide-band amplifier; a full-wave rectification circuit for generating line spectrum from an output signal of said differentiating circuit; a timing tank for generating a timing signal in accordance with an output signal of said full-wave rectification circuit; a narrow-band amplifier for amplifying an output signal of said timing tank; a first peak detector for detecting a peak value of an output signal of said narrow-band amplifier; a first direct current (DC) amplifier for amplifying an output signal of said first peak detector to a predetermined level, comparing said amplified signal with a first reference voltage, and generating an error message signal when said amplified signal is equal to said first reference voltage; an AND circuit which is supplied with an output signal of said first DC amplifier at one of input terminals; a driving current supply circuit for supplying a timing current to said optical latch in accordance with output signals of said narrow-band amplifier and said AND circuit; a second optical amplifier for amplifying an output signal of said optical latch; a second injection current supply circuit for supplying a driving current to said second optical amplifier; a second peak detector for detecting a peak value of said output signal of said full-wave rectification circuit; a second direct current (DC) amplifier for generating a control voltage to be supplied to said first injection current supply circuit in accordance with an output signal of said second peak detector; a second photodiode which is supplied with said branched signal supplied from said first optical branch device; a third direct current (DC) amplifier for comparing a voltage signal corresponding to an average light current supplied to said second photodiode with a second reference voltage, and supplying an alarm signal to said AND circuit and first current supply circuit when they are equalized; a fourth direct current amplifier for comparing an output signal of said peak detecting circuit with a third reference voltage, and generating an alarm signal when they are equalized; a first alarm circuit which is supplied with an output signal of said third DC amplifier; a second alarm circuit which is supplied with output signals of said first alarm circuit and fourth DC amplifier; and a third alarm circuit which is supplied with output signals of said second alarm circuit and first DC amplifier; wherein, gain of said first optical amplifier can be changed by output current of said first injection current supply circuit; said first current supply circuit is prohibited from supplying output current by an output signal of said third DC amplifier; said driving current supply circuit and said second current supply circuit are prohibited from supplying output current by an output signal of said AND circuit, and abnormality is monitored in accordance with output signals of said first to third alarm circuits.

Claim 8

An optical regenerative-repeater system, comprising: a first optical branch device for branching an input optical signal; a first optical amplifier for amplifying a main optical signal supplied from said first optical branch device; a first injection current supply circuit for supplying a driving current to said first optical amplifier; a second optical branch device for branching an optical signal supplied from said first optical amplifier through an optical isolator; an optical latch for latching a main optical signal supplied from said second optical branch device; a first photodiode for converting said branched signal supplied from said optical branch device to an electric signal; a wide-band amplifier for amplifying an output signal of said first photodiode; a differentiating circuit for detecting a level change point in an output signal of said wide-band amplifier; a full-wave rectification circuit for generating line spectrum from an output signal of said differentiating circuit; a timing tank for generating a timing signal in accordance with an output signal of said full-wave rectification circuit; a narrow-band amplifier for amplifying an output signal of said timing tank; a first peak detector for detecting a peak value of an output signal of said narrow-band amplifier; a first direct current (DC) amplifier for amplifying an output signal of said first peak detector to a predetermined level, comparing said amplified signal with a first reference voltage, and generating an error message signal when said amplified signal is equal to said first reference voltage; an AND circuit which is supplied with an output signal of said first DC amplifier at one of input terminals; a driving current supply circuit for supplying a timing current to said optical latch in accordance with output signals of said narrow-band amplifier and said AND circuit; a second optical amplifier for amplifying an output signal of said optical latch; a second injection current supply circuit for supplying a driving current to said second optical amplifier; a second peak detector for detecting a peak value of said output signal of said full-wave rectification circuit; a second direct current (DC) amplifier for generating a control voltage to be supplied to said first injection current supply circuit in accordance with an output signal of said second peak detector; a second photodiode which is supplied with said branched signal supplied from said first optical branch device; a third direct current (DC) amplifier for comparing a voltage signal corresponding to an average light current supplied to said second photodiode with a second reference voltage, and supplying an alarm signal to said AND circuit and first current supply circuit when they are equalized; a fourth direct current amplifier for comparing an output signal of said peak detecting circuit with a third reference voltage, and generating an alarm signal when they are equalized; a first alarm circuit which is supplied with an output signal of said third DC amplifier; a second alarm circuit which is supplied with output signals of said first alarm circuit and fourth DC amplifier; a third alarm circuit which is supplied with output signals of said second alarm circuit and first DC amplifier; a third optical branch device for branching an output signal of said second optical amplifier and supplying a main optical signal to a transfer line; a third photodiode for converting a branched signal supplied from said third optical branch device to an electric signal; and a fifth DC amplifier for being supplied with a voltage signal having a level corresponding to average current supplied to said third photodiode, and supplying a control signal to said second current supply circuit to stabilize said level of supplied voltage signal; wherein, gain of said first optical amplifier can be changed by output current of said first injection current supply circuit; said first current supply circuit is prohibited from supplying output current by an output signal of said third DC amplifier; said driving current supply circuit and said second current supply circuit are prohibited from supplying output current by an output signal of said AND circuit, gain of said second optical amplifier is controlled by an output signal of said fifth DC amplifier in order to effect stabilizing an output level of said second optical amplifier; and abnormality is monitored in accordance with output signals of said first to third alarm circuits.

Claim 9

An optical regenerative-repeater system, comprising: a first optical branch device for branching an input optical signal; a first optical amplifier for amplifying a main optical signal supplied from said first optical branch device; a first injection current supply circuit for supplying a driving current to said first optical amplifier; a second optical branch device for branching an optical signal supplied from said first optical amplifier through an optical isolator; an optical latch for latching a main optical signal supplied from said second optical branch device; a first photodiode for converting said branched signal supplied from said optical branch device to an electric signal; a wide-band amplifier for amplifying an output signal of said first photodiode; a differentiating circuit for detecting a level change point in an output signal of said wide-band amplifier; a full-wave rectification circuit for generating line spectrum from an output signal of said differentiating circuit; a timing tank for generating a timing signal in accordance with an output signal of said full-wave rectification circuit; a narrow-band amplifier for amplifying an output signal of said timing tank; a first peak detector for detecting a peak value of an output signal of said narrow-band amplifier; a first direct current (DC) amplifier for amplifying an output signal of said first peak detector to a predetermined level, comparing said amplified signal with a first reference voltage, and generating an error message signal when said amplified signal is equal to said first reference voltage; an AND circuit which is supplied with an output signal of said first DC amplifier at one of input terminals; a driving current supply circuit for supplying a timing current to said optical latch in accordance with output signals of said narrow-band amplifier and said AND circuit; a second optical amplifier for amplifying an output signal of said optical latch; a second injection current supply circuit for supplying a driving current to said second optical amplifier; a second peak detector for detecting a peak value of said output signal of said full-wave rectification circuit; a second direct current (DC) amplifier for generating a control voltage to be supplied to said first injection current supply circuit in accordance with an output signal of said second peak detector; a second photodiode which is supplied with said branched signal supplied from said first optical branch device; a third direct current (DC) amplifier for comparing a voltage signal corresponding to an average light current supplied to said second photodiode with a second reference voltage, and supplying an alarm signal to said AND circuit and first current supply circuit when they are equalized; a fourth direct current amplifier for comparing an output signal of said peak detecting circuit with a third reference voltage, and generating an alarm signal when they are equalized; a first alarm circuit which is supplied with an output signal of said third DC amplifier; a second alarm circuit which is supplied with output signals of said first alarm circuit and fourth DC amplifier; a third alarm circuit which is supplied with output signals of said second alarm circuit and first DC amplifier; a third optical branch device for branching an output signal of said second optical amplifier and supplying a main optical signal to a transfer line; a third photodiode for converting a branched signal supplied from said third optical branch device to an electric signal; a fifth DC amplifier for being supplied with a voltage signal having a level corresponding to average current supplied to said third photodiode, and supplying a control signal to said second current supply circuit to stabilize said level of supplied voltage signal; a sixth DC amplifier for comparing said voltage signal corresponding to said average optical current received by said third photodiode with a fourth reference voltage, and generating an alarm signal when they are equalized; and a fourth alarm circuit which is supplied with an output signal of said sixth DC amplifier; wherein, gain of said first optical amplifier can be changed by output current of said first injection current supply circuit; said first current supply circuit is prohibited from supplying output current by an output signal of said third DC amplifier; said driving current supply circuit and said second current supply circuit are prohibited from supplying output current by an output signal of said AND circuit, said second current supply circuit is prohibited from supplying output current by an output signal of said sixth DC amplifier, gain of said second optical amplifier is controlled by an output signal of said fifth DC amplifier in order to effect stabilizing an output level of said second optical amplifier; and abnormality is monitored in accordance with output signals of said first to fourth alarm circuits.