Semiconductor optical modulator and semiconductor optical device

A semiconductor optical device comprising:

• a semiconductor optical modulator;
• and
• an excitation light generating semiconductor laser for generating an excitation light beam, said semiconductor optical modulator and said excitation light generating semiconductor laser being integrated on the same semiconductor substrate,
• wherein said semiconductor optical modulator is of an electroabsorption type for modulating an incident light beam by use of changes in absorption coefficient under application of an external voltage, which comprises:
• an incident facet for receiving the incident light beam of a first wavelength to be modulated;
• an output facet, which is opposed to the incident facet, for outputting a modulated light beam;
• a light absorption layer, which is formed on the semiconductor substrate, for absorbing the incident light beam and thereby generating carriers;
• a carrier accumulation portion for accumulating the generated carriers;
• and
• a carrier guide and release portion having a well layer formed in the light absorption layer, for guiding and releasing the accumulated carriers outside,
• wherein said carrier guide and release portion guides and releases the carriers accumulated in said well layer upon receipt of the excitation light beam of a second wavelength corresponding to bandgap energy of said well layer.

A semiconductor optical device, comprising:

• a semiconductor optical modulator;
• and
• a surface-emitting laser for emitting an excitation light beam which is placed on an upper portion of said semiconductor optical modulator,
• wherein said semiconductor optical modulator is of an electroabsorption type for modulating an incident light beam by use of changes in absorption coefficient under application of an external voltage, which comprises:
• an incident facet for receiving the incident light beam of a first wavelength to be modulated;
• an output facet, which is opposed to the incident facet, for outputting a modulated light beam;
• a light absorption layer, which is formed on a semiconductor substrate, for absorbing the incident light beam and thereby generating carriers;
• a carrier accumulation portion for accumulating the generated carriers;
• and
• a carrier release portion having a well layer formed in the light absorption layer, for guiding and releasing the accumulated carriers outside,
• wherein said carrier release portion guides and releases the carriers accumulated in said well layer upon receipt of the emitted excitation light beam of a second wavelength corresponding to bandgap energy of said well layer, and wherein the emitted excitation light beam is applied onto said light absorption layer.