像陡峭山坡上的雪崩一样，一束入射光的脉冲最初仅仅释放少数的电荷载子(charge carrier)，这些电荷载子再轮流释放其他的载子，直到原始信号被放大很多次。

Analogous to a snow avalanche on a steep mountain slope, an incoming light pulse initially frees just a few charge carriers which in turn free others until the original signal is amplified many times.

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