Light amplification medium control method, light amplification apparatus and system using the same

摘要

In a light amplification apparatus in which a part of a light output from a light amplification medium is transmitted through a branching means to a light detection means so that light power of the light output is detected by the light detection means whereby at least one of an excitation source and a return means is controlled through a control means so that light branch from a branching means is returned as a return light to the light amplification medium through the branching means again in a state in which light power is adjusted by the return means, and, as a result, the light power of the light output from the light amplification medium can be kept in a desired value while the occurrence of a light surge is suppressed, a light amplification medium control method and a light amplification apparatus wherein a signal light input can be amplified while the occurrence of a light surge is suppressed by a simple structure and with good control response, and a system using the same.