Patent ID: 11942998
Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 17:
18. A PON system comprising:
a plurality of optical network units;
an optical transmission line formed by an optical fiber; and
an optical line terminal configured to communicate with the plurality of optical network units via the optical transmission line, wherein
an optical reception device installed at least to the optical line terminal among the optical network units and the optical line terminal includes
a light receiving element configured to receive an optical signal in a burst state from each optical network unit,
an amplifier configured to receive and amplify a current based on an input current from the light receiving element,
a direct-current adjustment circuit connected to an input electric path extending from the light receiving element to the amplifier, the direct-current adjustment circuit being configured to remove an offset current included in the input current,
an alternating-current adjustment circuit connected to the input electric path and configured to cause a part of the input current to flow therein, and
a controller configured to control the direct-current adjustment circuit and the alternating-current adjustment circuit on the basis of an output of the amplifier and a reference voltage, and

the controller includes
an integrator configured to integrate the output of the amplifier and output a resultant output to two electric paths of a positive phase and a negative phase, and
an inversion suppression circuit configured to operate so as to inject a current to the positive phase and extract a current from the negative phase when a negative phase potential of the output of the integrator is higher than a positive phase potential thereof.