Patent ID: 6472682
Filing Date: 2002-10-29
Classification: B82Y,G02F,H01S

Abstract:
An optical modulator comprising:a semiconductor substrate of a first conductivity type and having a band-gap wavelength; a first light confinement layer of the first conductivity type, on the semiconductor substrate, and having a band-gap wavelength longer than that of the semiconductor substrate; a light absorption layer on the first light confinement layer and having a multiple quantum well structure, the multiple quantum well structure comprising a first well layer and a plurality of second well layers, the first and second well layers having respective absorption spectra with respective peak wavelengths, the peak wavelength of the absorption spectrum of the second well layers being shorter than the peak wavelength of the absorption spectrum of the first well layer; a second light confinement layer of a second conductivity type, having a band-gap wavelength, and disposed on the light absorption layer; and a semiconductor cladding layer of the second conductivity type on the light absorption layer and having a band-gap wavelength shorter than that of the second light confinement layer.