Broadband electric field absorption forma semiconductor optical modulator

摘要

PROBLEM TO BE SOLVED: To provide a wide band electric field absorption type semiconductor optical modulator excellent in driving voltage and an insertion loss. ;SOLUTION: In the wide band electric field absorption type semiconductor optical modulator provided with a semiconductor core 5 of which wavelength on an absorption end is shorter than the wavelength of an optical signal and a voltage impressing electrode 1 for absorbing an optical signal to the core 5 by moving the absorption end wavelength of the core 5 to the long wavelength side at the time of impressing voltage, an electric signal input part I and an electric signal output part II are arranged so that the electrode 1 forms an advancing waveform electrode and the whole thickness D of a non-doped layer including the core 5 is thinned to reduce driving voltage. The deterioration of an optical modulation band and the reflection of an electric signal due to the mismatch of characteristic impedance between an optical modulator and an external circuit are reduced by shortening the length of a correlation part between an electric signal and an optical signal. The mismatch of characteristic impedance can be corrected by adjusting the doping density of p-type or n-type doping layer 3, 6 arranged on the upper and lower parts of the core 5.;COPYRIGHT: (C)1999,JPO