Light-receiving element.

摘要

Most optical communication systems have a function of detecting the presence/absence of a light input. In such an optical communication system, an output optical current generated by a light-receiving element is also consumed by the monitor function. For this reason, when a light input is very weak, a disturbance occurs in an output electrical signal for information transmission. This invention has its object to provide a light-receiving element which can monitor a light signal input without causing a disturbance in an output electrical signal. For this purpose a light-receiving element has the first active area (28) irradiated with a light signal, and the second light-receiving element has a second active area (29) irradiated with a leakage light component of the light signal. An output optical current for information transmission is generated by the light signal radiated on the first active area (28), and a monitor light output current is generated by the leakage light component of the light signal radiated on the second active area (29).