OPTICAL TRANSMISSION APPARATUS AND CONTROL METHOD OF OPTICAL TRANSMISSION SIGNAL

PROBLEM TO BE SOLVED: To control extinction ratio without using a pilot signal.SOLUTION: An optical transmission apparatus 10 comprises: an LDD 12 for generating driving current on the basis of modulation current modulated in accordance with transmission information; an LD 14 for receiving input of the driving current and transmitting an optical signal; an MPD 16 for receiving the optical signal transmitted from the LD 14; a filter for extracting a certain frequency band from a voltage signal obtained on the basis of the optical signal received by the MPD 16; and means for controlling an amplitude of the modulation current on the basis of comparing an amplitude of the voltage signal extracted by the filter with a reference amplitude.