Optical splitter, slave gateway, detection method and optical communication system

The invention provides an optical splitter which is applied to the field of optical communication. The optical splitter comprises a light splitting unit, a control unit and a photoelectric composite unit. The light splitting unit is used for receiving a downlink optical signal from the main gateway and transmitting N downlink sub optical signals to the photoelectric composite unit. The control unit is used for transmitting N first electric signals with different frequencies to the photoelectric composite unit. The photoelectric composite unit comprises N ports. The N ports are used for being connected with N slave gateways through photoelectric composite cables respectively. The photoelectric composite unit is used for respectively outputting N downlink sub-optical signals through the N ports and respectively outputting N first electric signals with different frequencies through the N ports. According to the invention, the operation and maintenance information can be transmitted to the slave gateway through t