<p>An optical modulation processor (10) has a Mach-Zender interferometer (MZI) optical modulator (2) which modulates the pulse of the light signal of a laser source (1). An optical phase modulator (3) modulates a phase of a data signal based on a carrier-suppressed-return-to-zero signal from the MZI optical modulator to convert the data signal into a phase-modulated signal. The optical modulation processor has an optical filter (4) that removes the redundant frequency components included in the phase-modulated signal from the optical phase modulator.</p>
