Carrier-suppressed optical pulse train generating device and method

A carrier-suppressed optical pulse train generating method comprising:

• a first electric modulation signal generating step generating and outputting, by a first electric modulation signal generator, a first electric modulation signal that is synchronous with a clock signal;
• a second electric modulation signal generating step generating and outputting, by a second electric modulation signal generator, a second electric modulation signal of a same frequency as the first electric modulation signal and having a phase difference of δ radians, where δ is a real number satisfying 0≦δ≦π;
• a two-mode beat light generating step driving a two-mode beat light source by the first electric modulation signal, and generating and outputting two-mode beat light that is synchronous with the clock signal;
• and
• an optical intensity modulating step optical-intensity-modulating the two-mode beat light by an optical intensity modulator that is driven by the second electric modulation signal, and generating and outputting a carrier-suppressed optical pulse train having numerous longitudinal modes whose longitudinal mode spectra are greater than 2.