| 摘要 |
<p>This invention relates to an optical limiting amplifier which provides an optical output signal of substantially constant power for an optical input signal of varying power which is simple to construct and economical to build. In this invention, an optical signal whose power can fluctuate over a wide range is split into two signals. The first signal is applied to an optical fiber amplifier (84) in the forward feed direction. The second signal is passed through a saturable absorber (86) and then applied to the optical fiber amplifier in the backward feed direction. The signal from the saturable absorber varies at a rate which is greater than the rate at which the signal to the saturable absorber varies. Thus, as the signal to the saturable absorber increases, the signal from the saturable absorber will increase at a greater rate; and, as the signal to the saturable absorber decreases, the signal from the saturable absorber will decrease at a greater rate. The backward feed signal affects the gain saturation of the optical fiber amplifier in such a way as to cause the output power of the optical fiber amplifier to be constant regardless of variations to the input signal power. <IMAGE></p> |
