Optical element power control
AssigneeNorthern Telecom Limited
InventorKim Byron Roberts
Life of this patent
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Abstract
A control system for an optical element such as an optical amplifier in an optical transmission system determines the transmitted optical signal power in each of a plurality of different optical wavelength bands, determines which of the powers is closest to a threshold, and controls an output power of the element, or controls a parameter which affects the threshold, on the basis of the power closest to the threshold. Since there is no longer any need to allow a margin for possible gain variations between different wavelengths, power output can be controlled with reduced upper or lower margins, and thus error rates reduced, or transmission distances increased.
Claims17
A control system for an optical element for an optical transmission system, the optical element being for use in an optical path of the transmission system, downstream of a transmitter, the control system comprising:
- means for determining transmitted optical signal powers in each of a plurality of
- different optical wavelength bands;
- means for determining which of the powers is greatest;
- and
- means for controlling an output power of the element, on the basis of the greatest power.
A control system for an optical transmission system, the transmission system comprising a transmitter, the control system comprising:
- means for determining optical power at a plurality of different optical wavelength bands in the transmission system;
- means for determining which of the powers is greatest;
- and
- means for controlling on the basis of the greatest power a parameter of the transmission system downstream of the transmitter, and which affects a power threshold at which transmission errors may be caused.
A control system for an optical wavelength division multiplexed transmission system, the transmission system comprising a transmitter, the control system comprising:
- means for determining optical powers in a plurality of different optical wavelength bands in the transmission system;
- means for selecting a subset of more than one of the determined powers, the selection being made according to which of the wavelength bands are currently more susceptible to errors;
- and
- means responsive to the selected subset of powers to control a parameter of the transmission system downstream of the transmitter, to maintain at least the subset of determined powers within a given range.
A method of controlling an optical element, the optical element being for use in an optical path of the transmission system, downstream of a transmitter, the method comprising the steps of:
- determining optical powers in each of a plurality of different optical wavelength bands;
- determining which of the powers is greatest;
- and
- controlling an output power of the element on the basis of the greatest output power.
A method of operating an optical transmission system the transmission system comprising a transmitter, the method comprising the steps of:
- determining optical powers in each of a plurality of different optical wavelength bands;
- determining which of the powers is greatest;
- and
- controlling on the basis of the greatest power, a parameter of the system downstream of the transmitter, which affects a threshold power at which transmission errors may be caused.
A method of controlling an optical element in an optical path of the transmission system, downstream of a transmitter, the method comprising the steps of:
- determining optical powers in each of a plurality of different optical wavelength bands;
- selecting a subset of more than one of the determined powers, the selection being made according to which of the wavelength bands are currently more susceptible to errors;
- and
- controlling a parameter of the optical element on the basis of the selected subset of powers.
A method of operating an optical transmission system comprising an optical amplifier, the method comprising the steps of:
- determining optical output powers in each of a plurality of wavelength bands;
- selecting a subset of more than one of the determined powers, the selection being made according to which of the wavelength bands are currently more susceptible to errors;
- and
- controlling the total output power of the amplifier on the basis of the subset.
A control system for an optical element for an optical transmission system, the optical element being for use in an optical path of the transmission system, downstream of a transmitter, the control system comprising:
- circuitry for determining transmitted optical powers in each of a plurality of different optical wavelength bands;
- circuitry for determining which of the powers is greatest;
- and circuitry for controlling an output power of the element, on the basis of the greatest power.
Dependencies are inferred from the claim text.