| 摘要 |
Methods and apparatus for controlling a bias voltage (20) supplied to an optical modulator that comprises a biasable component configurable to be biased by application of the bias voltage (20), the method comprising: providing a target for the modulator output power; applying, to the biasable component, a bias voltage (20) that biases the biasable component so that the output power is within a pre-defined range of the target; monitoring the output power and, if the output power of the modulator is determined to be outside the pre-defined range, varying the value of the bias voltage (20) to bring the output power back within the pre-defined range; and monitoring the optical input to the modulator and, if it has been disabled, maintaining the bias voltage (20) at its current level for a pre-determined length of time that is dependent upon how long the modulator has been operating at quadrature. |
| 主权项 |
1. A method of controlling an optical modulator, the modulator being configurable to be biased by application of the bias voltage such that the modulator operates at quadrature, the method comprising:
receiving, by the modulator, an optical input; outputting, by the modulator, an optical output having an output power; providing a target for the output power, the target for the output power being an output power corresponding to the modulator operating at quadrature; applying, to the modulator, a bias voltage that biases the modulator so that the output power is within a pre-defined range of the target output power; thereafter, detecting that an optical input to the optical modulator has been disabled; determining a first length of time, the first length of time being a length of time that, prior to the optical input to the optical modulator being disabled, the output power of the modulator was within the pre-defined range of the target output power; and maintaining the bias voltage at its current level for a second length of time, the second length of time being dependent upon the first length of time. |
