| abstract |
(57) [Problem] To improve the optical gain of each wavelength even if the number of wavelengths is increased, there is no limitation on the wavelength used due to the nonlinear optical effect, the output level can be controlled for each wavelength, and the noise figure Provided is an optical modulation device that does not cause an increase in pattern or a pattern effect. SOLUTION: A semiconductor optical amplifier (SOA) 11 and an optical modulator 12 are provided, and the optical modulator 12 is arranged at a subsequent stage of the semiconductor optical amplifier 11, so that the semiconductor optical amplifier 11 first has a single wavelength λ 1. After optical amplification of the CW light, the semiconductor optical modulator 11 modulates the CW light. |