WAVEGUIDE TYPE OPTICAL MODULATOR

摘要

PURPOSE:To obtain an optical switch (optical modulator) which is driven by a low voltage in a waveguide type optical modulator for which a semiconductor waveguide is used by providing a trap for capturing electrons or holes into a semiconductor which acts as the optical waveguide. CONSTITUTION:The n-type GaAs for an n-type GaAs substrate 1 and an optical waveguide layer 2 is formed of an LPE method. A ridge type optical waveguide 3 is the waveguide layer which is formed by the LPE method and is worked by a photolithographic method and dry etching method. Signal light 9 is made incident on the ridge type optical waveguide. Exit light 10 is from the optical waveguide. The release of the electrons from the electron trap is proportional to the number of photons of the incident excitation light when the relation between the irradiation time and the attenuation quantity of the signal light on the incident side is obtd. and therefore the quantity of the electrons to be released from the trap is larger and the attenuation quantity of the signal light on the exit side is larger as the power of the excitation light is higher. The electrons released from the electron trap and the electrons captured again in the trap are balanced with each other and the stationary stage is attained when the excitation light is irradiated for the specified time.