OPTICAL AMPLIFIER, WAVELENGTH MULTIPLEXING OPTICAL TRANSMISSION SYSTEM, AND PROGRAM

摘要

When multiplexed signal lights are amplified by optical amplifiers, a value of a monitor signal is compared with a threshold equivalent to a value of the monitor signal when noise indexes of the multiplexed signal lights start increasing. Next, when the value of the monitor signal is equal to or larger than the threshold, that is, when the powers of the multiplexed signal lights are large, a gain constant control is performed to amplify the multiplexed signal lights. Conversely, when the value of the monitor signal is smaller than the threshold, that is, when the powers of the multiplexed signal lights are small, an output constant control is performed to amplify the multiplexed signal lights.

主权项

1. An optical amplifier including a plurality of multiplexed signal lights of mutually different frequencies as input light, the optical amplifier comprising:
a first detector configured to detect a power of the input light; an excitation light outputter configured to output an excitation light to amplify the input light; a second detector configured to detect the power of the amplified input light; and a controller configured to control the excitation light outputter so as to, upon determination that the power of the input light is high based on the detection result of the first detector, make a ratio of a detection result by the second detector relative to a detection result by the first detector constant, and configured to control the excitation light outputter so as to, upon determining that the power of the input light is low based on the detection result of the first detector, make the detection result by the second detector substantially constant; and a third detector configured to detect a power of the excitation light; wherein the controller is configured so as to: upon the power of the excitation light detected by the third detector being greater than or equal to a first threshold, determine that the power of the input light is large; and upon the power of the excitation light detected by the third detector being smaller than or equal to a second threshold smaller than the first threshold, determine that the power of the input light is small.