In this paper we report TE-mode phase modulation obtained by inducing a capacitive charge on graphene layers embedded in the core of a waveguide.There is a biasing regime in which graphene absorption is negligible but...In this paper we report TE-mode phase modulation obtained by inducing a capacitive charge on graphene layers embedded in the core of a waveguide.There is a biasing regime in which graphene absorption is negligible but large index variations can be achieved with a voltage–length product as small as V_(π)L_(π)≃0.07 V cm for straight waveguides and V_(π)L_(π)≃0.0024 V cm for 12μm radius microring resonators.This phase modulation device uniquely enables a small signal amplitude<1 V with a micrometer-sized footprint for compatibility with CMOS circuit integration.Examples of phase-induced changes are computed for straight waveguides and for microring resonators,showing the possibility of implementing several optoelectronic functionalities as modulators,tunable filters,and switches.展开更多
We propose and experimentally demonstrate capacitive actuation of a graphene–silicon micro-ring add/drop filter. The mechanism is based on a silicon–SiO_2–graphene capacitor on top of the ring waveguide. We show th...We propose and experimentally demonstrate capacitive actuation of a graphene–silicon micro-ring add/drop filter. The mechanism is based on a silicon–SiO_2–graphene capacitor on top of the ring waveguide. We show the capacitive actuation of the add/drop functionality by a voltage-driven change of the graphene optical absorption. The proposed capacitive solution overcomes the need for continuous heating to keep tuned the filter's in/out resonance and therefore eliminates "in operation" energy consumption.展开更多
Prom Maxwell's equations, we compute the speed and the direction of propagation of active power refracted from air into a negative index material. We prove, both analytically and numerically that the power may ref...Prom Maxwell's equations, we compute the speed and the direction of propagation of active power refracted from air into a negative index material. We prove, both analytically and numerically that the power may refract positively even if phase fronts refract negatively. Considerations on the usage of ray optics in problems involving negative index materials are drawn.展开更多
文摘In this paper we report TE-mode phase modulation obtained by inducing a capacitive charge on graphene layers embedded in the core of a waveguide.There is a biasing regime in which graphene absorption is negligible but large index variations can be achieved with a voltage–length product as small as V_(π)L_(π)≃0.07 V cm for straight waveguides and V_(π)L_(π)≃0.0024 V cm for 12μm radius microring resonators.This phase modulation device uniquely enables a small signal amplitude<1 V with a micrometer-sized footprint for compatibility with CMOS circuit integration.Examples of phase-induced changes are computed for straight waveguides and for microring resonators,showing the possibility of implementing several optoelectronic functionalities as modulators,tunable filters,and switches.
文摘We propose and experimentally demonstrate capacitive actuation of a graphene–silicon micro-ring add/drop filter. The mechanism is based on a silicon–SiO_2–graphene capacitor on top of the ring waveguide. We show the capacitive actuation of the add/drop functionality by a voltage-driven change of the graphene optical absorption. The proposed capacitive solution overcomes the need for continuous heating to keep tuned the filter's in/out resonance and therefore eliminates "in operation" energy consumption.
文摘Prom Maxwell's equations, we compute the speed and the direction of propagation of active power refracted from air into a negative index material. We prove, both analytically and numerically that the power may refract positively even if phase fronts refract negatively. Considerations on the usage of ray optics in problems involving negative index materials are drawn.
