Design and optimization of optical modulators based on graphene-on-silicon nitride microring resonators

Abstract

In order to overcome the challenge of obtaining high modulation depth due to weak graphene-light interaction, a graphene-on-silicon nitride (SiN x ) microring resonator based on graphene's gate-tunable optical conductivity is proposed and studied. Geometrical parameters of graphene-on-SiN x waveguide are systematically analyzed and optimized, yielding a loss tunability of 0.04 dB/μm and an effective index variation of 0.0022. We explicitly study the interaction between graphene and a 40-μm-radius microring resonator, where electro-absorptive and electro-refractive modulation are both taken into account. By choosing appropriate graphene coverage and coupling coefficient, a high modulation depth of over 40 dB with large fabrication tolerance is obtained.

Waveguide-Integrated van der Waals Heterostructure Mid-Infrared Photodetector with High Performance

“…35−38 In addition, integrating the thicker BP flake might further increase the absorption of the evanescent field and thus enhance the responsivity of the hybrid detector, but such an approach might also lead to a higher noise level. 10,18,19 Alternatively, higher responsivity can be achieved by increasing the optical field at the surface of the waveguide via further reducing the thickness of the waveguide 39 or exploiting the advanced waveguide structures, such as the slot-waveguide and slow-waveguide designs. 40−42 It is also noteworthy that several works have already demonstrated waveguide-integrated BP modulators and BP light-emitting diodes.…”

“…VdW material engineering and fabrication optimization could further enhance the performance of the device. For instance, air-stable hybrid detectors can be made via replacing BP with tellurium and the dark current of the detector can be suppressed by incorporating unipolar barriers into vdW heterostructures. , The cutoff wavelength of the hybrid detector can extend up to 8 μm by integrating the narrow-gap arsenic- or carbon-doped black phosphorus with silicon waveguides. − In addition, integrating the thicker BP flake might further increase the absorption of the evanescent field and thus enhance the responsivity of the hybrid detector, but such an approach might also lead to a higher noise level. ,, Alternatively, higher responsivity can be achieved by increasing the optical field at the surface of the waveguide via further reducing the thickness of the waveguide or exploiting the advanced waveguide structures, such as the slot-waveguide and slow-waveguide designs. − It is also noteworthy that several works have already demonstrated waveguide-integrated BP modulators and BP light-emitting diodes. ,,, These, together with our results, could constitute an important step forward in employing BP-based vdW heterostructures for the mid-infrared silicon photonics.…”

Applications Of Tunable Mid-Infrared Plasmonic Square-Nanoring Resonator Based On Graphene Nanoribbon

“…Over the two past decades, there has been extensive research into a variety of graphenebased plasmonic devices such as modulators [17,18], switches [19,20], filters [21][22][23],…”

Applications of Tunable Mid-Infrared Plasmonic Square-Nanoring Resonator Based on Graphene Nanoribbon

“…Over the two past decades, there has been extensive research into a variety of graphenebased plasmonic devices such as modulators [17,18], switches [19,20], filters [21][22][23], power splitter [24,25], metamaterials [26,27], metasurfaces [28,29], as well as graphenebased plasmonic induced transparency (PIT) and reflection-induced (PIR) effects [30][31][32].…”