Semiconductor optical modulator having a quantum well structure for increasing effective photocurrent generating capability

摘要

An optical modulator (100) comprises a first waveguide layer (104) and a barrier layer (108), and a quantum well layer (106) sandwiched between the first waveguide layer (104) and the barrier layer (108), where the quantum well layer (106) has a graded composition that varies the bandgap energy of the quantum well layer (106) between a minimum bandgap energy and the bandgap energy of at least one of the first waveguide layer(104) and the barrier layer (108).