Optical receiver, optical terminal, and optical communication system

An optical receiver comprising:

• a pre-amplifier to convert a current signal, into which an input optical signal is converted, into a voltage signal;
• a limiting amplifier to amplify and limit an amplitude of the voltage signal;
• a transmission line connecting the pre-amplifier with the limiting amplifier;
• an alternating current coupling capacitor inserted in a middle of the transmission line or at an end of the transmission line;
• a termination circuit connected with the transmission line, to switch to a first resistance or to a second resistance higher than the first resistance in response to a switching signal;
• and
• an alternating current load connected with the transmission line, the alternating current load being open in a first-frequency range of the voltage signal and having a resistance enabling impedance matching with the pre-amplifier and the transmission line in a second-frequency range of the voltage signal, wherein
• the termination circuit and the alternating current load are electrically connected in parallel, and
• the second-frequency range of the voltage signal is higher than the first-frequency range of the voltage signal.