Abstract: The present invention relates to an apparatus and a method for realizing all-optical NOR logic device using the gain saturation characteristics of a semiconductor optical amplifier (SOA). More particularly, the invention relates to a 10 Gbit/s all-optical NOR logic device among all-optical logic devices, in which a signal transmitted from a given point of an optical circuit such as an optical computing circuit is used as a pump signal and a probe signal.

Abstract: The present invention relates to a fabrication method of an epilayer structure for InGaAsP/InP ridge waveguide phase modulator with high phase modulation efficiency. In more detail, it relates to a P-p-n-N InGaAsP/InP ridge waveguide phase modulator fabricated to be that the phase change of the TE-mode is linearly proportional to the reverse bias voltage at 1.55 ?m wavelength. The present invention presents a method for fabricating an epilayer structure for achieving the optical confinement in the vertical direction of an InGaAsP/InP waveguide phase modulator, characterized by comprising the steps of: forming a first cladding layer of N-InP on an N+-InP substrate; forming a first waveguide layer of n-InGaAsP and a second waveguide layer of p-InGaAsP in sequence on the first cladding layer; forming a second cladding layer of P-InP and a third cladding layer of P-InP in sequence on the second waveguide layer; and forming an electrode layer of p+-InGaAs on the third cladding layer.