ELECTRIC-FIELD DEPENDENCE OF OPTICAL-ABSORPTION IN THE 1.55-MU-M BURIED HETEROSTRUCTURE INGAASP INGAASP MULTIPLE-QUANTUM-WELL WAVE-GUIDE ELECTROABSORPTION MODULATOR VIA REGROWTH OF SEMIINSULATING INP AROUND VERTICAL MESAS FABRICATED BY REACTIVE ION ETCHING/

We present experimental studies on the absorption change due to the qu antum-confined Stark effect in the 1.55 mu m wavelength InGaAsP/InGaAs P multiple quantum well electroabsorption waveguide modulator structur e. High quality strained InGaAsP/InGaAsP multiple quantum wells were g rown by MOCVD on InP (100) substrates. Sharp satellite peaks in double -crystal X-ray diffraction are obtained from a p - i - n waveguide str ucture consisting of 6 periods of 80/100 Angstrom InGaAsP/InGaAsP MQWs . The surface-normal electroabsorption exhibits a significant quantum- confined Stark effect (QCSE) near 1.55 mu m wavelength with a field de pendent absorption change. A 38 meV quantum-confined Stark shift has b een attained in an applied electric field of 1.1x10(5) V/cm in this MQ W sample. We also investigated the electric field induced effects on t he exciton absorption in InGaAsP/InGaAsP MQW structure suited for 1.55 pm wavelength and its application to optical modulator incorporating the SI-InP blocking SI-PBH geometry. Electroabsorption waveguide modul ators fabricated using this MQW material exhibit good on-off ratio in excess of 13 dB by applying a 2 V drive voltage to a 200 mu m long mod ulate; chip.