Patent ID: 8260152
Filing Date: 2012-09-04
Classification: H04B

Abstract:
1. A signal detection method in a light receiving apparatus comprising: detecting a level of an input light input to an optical amplifier; storing the level of the input light detected in a memory; comparing the level of a preceding input light stored in the memory with a current level of the input light; detecting a state of existence or non-existence of an optical signal according to a change, of the input light level, detected in the comparison; dispersion-compensating the input light; and extracting a clock signal from the input light, wherein, when the change in the level of the input light is detected in the comparison, the existence or non-existence of the optical signal in the input light can be distinguished by the presence or absence of the clock signal extracted by the extraction, and further, when any clock signal is not extracted in the extraction, a dispersion amount in the dispersion compensation is swept.