| 摘要 |
PROBLEM TO BE SOLVED: To provide a method to generate modulated light with chirping substantially reduced, a Mach-Zehnder type optical modulation semiconductor element, and an optical modulator. SOLUTION: Incident light L0 is divided to generate first and second divided light beams (L1 and L2), each provided to first and second waveguides (3, 4). First and second signal voltage is respectively applied to the first and second waveguides to generate third and fourth divided light beams (L3 and L4), and the third and fourth divided light beams are synthesized to generate the modulated light L5. A range of applied voltage to the element 20 includes first and second voltage ranges. The second voltage range is between the first voltage range and zero voltage. The first signal voltage is in the first voltage range, and the second signal voltage has the same phase as the first signal voltage and is in the second voltage range. Voltage dependence of a refractive index of active layers 32 of the first and the second waveguides has negative inclination in the first voltage range and also has positive inclination in the second voltage range. COPYRIGHT: (C)2011,JPO&INPIT |
