Proposed high-speed micron-scale spatial light valve based on a silicon-graphene hybrid structure

We propose a new ultracompact CMOS-compatible variable-transmission spatial light valve based on a silicon-graphene hybrid structure. Normally incident ∼1560  nm light can be coupled to a silicon-graphene-based 1D photonic crystal cavity through a perturbation-based diffractive coupling scheme. The lightwave modulation is achieved by tuning the Fermi level of the graphene, which can change both the loss and the resonant wavelength of the cavity. Based on finite-difference time-domain simulation, the modulation depth is larger than 10 dB with driving voltage of about 4.8  V(pp) while the modulation speed is estimated to be higher than 45 GHz.