An optical transmission and reception system includes a transmitter and receiver. The transmitter differentially encodes control information to generate a differentially coded signal; uses the differentially coded signal to modulate a signal sequence in which electricity concentrates at a particular frequency; applies time-division multiplexing on the modulated signal sequence and a primary signal in one of two polarized wave components, and applies time-division multiplexing on the other polarized wave components and the signal sequence itself; and polarization-multiplexes the both of the time-division multiplexed polarized waves into an optical signal; and transmits the optical signal to the receiver. The receiver polarization-demultiplexes the received optical signal to generate two polarized wave signals; extracts the signal sequence in which electricity concentrates at the particular frequency from the two polarized wave signals; and applies differential detection on the extracted signal sequence to demodulate the control information.