摘要
Ge-on-Si p-i-n diodes are fabricated by using two-step Ge film epitaxial technology on Si substrates.A remarkable Franz-Keldysh effect is observed in the wavelength range of 1620-1640nm with a largestΔα/αof 2.8 at 1640nm by optical responsivity measurement.The remarkable change of absorption coefficient in the considerable large wavelength range makes Ge-on-silicon a promising candidate for Si-based electro-absorption modulators.The initial design predicts a modulator of bandwidth~50 GHz,and the extinction ratio>7dB by the measured parameter.
基金
Supported by the National Natural Science Foundation of China under Grant Nos 61036003,61176013,60906035
and 61177038,the National High-Technology and Research Development Program of China under Grant No 2011AA010302
the Tsinghua National Laboratory for Information Science and Technology(TNList)Cross-discipline Foundation.
