OPTICAL SIGNAL GENERATING DEVICE

摘要

PROBLEM TO BE SOLVED: To normally fix the whole input optical power of an optical amplifier means by multiplexing two signal light with mutually different wave lengths which are modulated by complementary modulating the signals. SOLUTION: A semi-conductor laser 2-1 is coupled with an electric field absorption-type optical modulator 3-1, the semi-conductor laser 2-2 is coupled with the electric field absorption-type optical modulator 3-2 and the electric field absorption-type optical modulators 3-1 and 3-2 are coupled with a semi-conductor optical amplifier 4 with a Y-branch waveguide 5. The semi-conductor optical lasers 2-1 and 2-2 output oscillation lights with the mutually different wave lengths λ1 and λ2, the modulating signals to be impressed on the two electric field absorption-type optical modulators 3-1 and 3-2 are the complementary signals where on/off is inverted and they respectively modulates the oscillation signals with the wave lengths λ1 and λ2. The signal light with the wave lengths γ1 and λ2 from the electric field absorption-type optical modulators 3-1 and 3-2 is multiplexed with the Y-branch waveguide 5, inputted to the semi- conductor optical amplifier 4 by fixed power and amplified so that only the wave length λ1 is outputted from an optical filter 6.