Low driving voltage band-filling-based III-V-on-silicon electroabsorption modulator

In this paper, a method for realizing a low driving voltage electroabsorption modulator based on the band-filling effect is demonstrated. The InP-based electroabsorption modulator is integrated using divinylsiloxane-bis-benzocyclobutene adhesive bonding on a silicon-on-insulator waveguide platform. When the electroabsorption modulator is forward biased, the band-filling effect occurs, which leads to a blue shift of the exciton absorption spectrum, while the absorption strength stays almost constant. In static operation, an extinction ratio of more than 20 dB with 100 mV bias variation is obtained in an 80 μm long device. In dynamic operation, 1.25 Gbps modulation with a 6.3 dB extinction ratio is obtained using only a 50 mV peak-to-peak driving voltage. The band-filling effect provides a method for realizing ultra-low-driving-voltage electroabsorption modulators.