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US 2018/0294889 A1Published application
Optical receiver and method of controlling optical receiver
AssigneeSumitomo Electric Industries, Ltd.
InventorHideki Oe
Life of this patent
Estimating the term…
Abstract
In an optical receiver, a control unit determines an SOA current set value such that an SOA current becomes a maximum value ISOA_MAX when a VOA voltage is smaller than a first threshold value VVOA_LOW, determines the SOA current set value such that the SOA current becomes smaller than the maximum value ISOA_MAX and larger than a minimum value ISOA_MIN when the VOA voltage is equal to or larger than the first threshold value VVOA_LOW and is smaller than a second threshold value VVOA HIGH, and determines the SOA current set value such that the SOA current is fixed to the minimum value ISOA_MIN when the VOA voltage is equal to or larger than the second threshold value VVOA_HIGH.
Claims14
An optical receiver for receiving an optical reception signal, the optical receiver comprising:
- a variable optical attenuator configured to output a first optical signal obtained by attenuating the optical reception signal with an attenuation amount increasing or decreasing in accordance with a first control signal;
- a semiconductor optical amplifier configured to output a second optical signal obtained by amplifying the first optical signal with a gain increasing or decreasing in accordance with a second control signal;
- an optical receiving unit configured to convert the second optical signal into an electrical signal and output a monitor signal in accordance with the electrical signal;
- a comparison circuit configured to compare the monitor signal with an output set signal and generate the first control signal in accordance with a result of the comparison;
- and
- a control unit configured to generate the second control signal and the output set signal in accordance with the first control signal, wherein
- the comparison circuit makes the first control signal larger as a difference between the monitor signal and the output set signal becomes larger when the monitor signal is larger than the output set signal, and outputs an output value within a predetermined range as the first control signal when the monitor signal is smaller than the output set signal,
- the variable optical attenuator makes the attenuation amount larger when the first control signal becomes larger and makes the attenuation amount smaller when the first control signal becomes smaller,
- the semiconductor optical amplifier makes the gain larger when the second control signal becomes larger and makes the gain smaller when the second control signal becomes smaller, and
- the control unit
- increases the second control signal by a first increase value within a range smaller than a first upper limit value, and increases the output set signal in accordance with the first increase value within a range smaller than a second upper limit value set in accordance with the first upper limit value, when the first control signal is smaller than a first threshold value,
- decreases the second control signal by a first decrease value within a range larger than a first lower limit value smaller than the first upper limit value, and decreases the output set signal in accordance with the first decrease value within a range larger than a second lower limit value set in accordance with the first lower limit value, when the first control signal is larger than a second threshold value larger than the first threshold value, and
- maintains the second control signal and the output set signal when the first control signal falls within a range equal to or larger than the first threshold value and equal to or smaller than the second threshold value.
10 more elements
A method of controlling an optical receiver, the optical receiver being configured to receive an optical reception signal, and
- the optical receiver including
- a variable optical attenuator configured to output, in response to a first control signal, a first optical signal obtained by attenuating the optical reception signal with an attenuation amount becoming larger as the first control signal is larger and becoming smaller as the first control signal is smaller,
- a semiconductor optical amplifier configured to output, in response to a second control signal, a second optical signal obtained by amplifying the first optical signal with a gain becoming larger as the second control signal is larger and becoming smaller as the second control signal is smaller,
- an optical receiving unit configured to convert the second optical signal into an electrical signal and output a monitor signal in accordance with the electrical signal,
- a comparison circuit configured to compare the monitor signal with an output set signal and generate the first control signal in accordance with a result of the comparison, and
- a control unit configured to generate the second control signal and the output set signal in accordance with the first control signal,
- the method comprising:
- making the first control signal larger as a difference between the monitor signal and the output set signal becomes larger when the monitor signal is larger than the output set signal, and outputting an output value within a predetermined range as the first control signal when the monitor signal is smaller than the output set signal;
- increasing the second control signal by a first increase value within a range smaller than a first upper limit value and increasing the output set signal in accordance with the first increase value within a range smaller than a second upper limit value set in accordance with the first upper limit value when the first control signal is smaller than a first threshold value;
- decreasing the second control signal by a first decrease value within a range larger than a first lower limit value smaller than the first upper limit value and decreasing the output set signal in accordance with the first decrease value within a range larger than a second lower limit value set in accordance with the first lower limit value when the first control signal is larger than a second threshold value larger than the first threshold value;
- and
- maintaining the second control signal and the output set signal when the first control signal falls within a range equal to or larger than the first threshold value and equal to or smaller than the second threshold value.
9 more elements
Dependencies are inferred from the claim text.