Directional coupling surface plasmon polariton electro-optic modulator for optical ring networks-on-chip

Electro-optic modulators are essential components of the optical network-on-chip. To resolve the large footprints, poor thermal stability, and low modulation rate of traditional optoelectronic devices such as micro-ring resonators, a directional coupled electro-optic modulator based on surface plasmon polaritons and coupled mode theory is designed. The modulator controls the change in carrier concentration of an indium-tin-oxide-activated material film by applying a voltage to realize electro-optic control. The modulator uses coupled-mode theory to couple the modulated optical signal into a ring waveguide. This type of modulator is suitable for an optical-on-chip network with an optical ring network-on-chip topology. The results show that the device operates at the 1550 nm wavelength with a coupling efficiency of more than 90%, insertion loss of 1.17 dB, extinction ratio of 15.4 dB, modulation rate of up to 0.75 Tbit/s, and size of only 3.8×3.2×1.2µm.