High-quality Si_3N_4 circuits as a platform for graphene-based nanophotonic devices

Abstract

Hybrid circuits combining traditional nanophotonic components with carbon-based materials are emerging as a promising platform for optoelectronic devices. We demonstrate such circuits by integrating singlelayer graphene films with silicon nitride waveguides as a new architecture for broadband optical operation. Using high-quality microring resonators and Mach-Zehnder interferometers with extinction ratios beyond 40 dB we realize flexible circuits for phase-sensitive detection on chip. Hybrid graphene-photonic devices are fabricated via mechanical transfer and lithographic structuring, allowing for prolonged light-matter interactions. Our approach holds promise for studying optical processes in lowdimensional physical systems and for realizing electrically tunable photonic circuits. ©2013 Optical Society of America

Optical Absorption in Graphene-on-Silicon Nitride Microring Resonators

“…1(b), under an input power up to 200 mW, waveguides of different lengths had a similar loss factor α ∼25 dB/mm, which agreed quite well with the simulation results. Our achieved loss factor was smaller than that of the previous work (∼67 dB/mm) [14] due to higher TE mode confinement in our waveguides and thus stronger tangential electrical field in our waveguide cores.…”

“…Besides, Si 3 N 4 waveguides have much lower nonlinear loss [13], [14] in the telecommunications band, unlike silicon waveguides. Moreover, Si 3 N 4 waveguides have smaller thermo-optic effects and larger fabrication tolerance compared to silicon waveguides.…”

Sideband pump-probe technique resolves nonlinear modulation response of PbS/CdS quantum dots on a silicon nitride waveguide

“…[30][31][32] Additionally, a range of hybrid photonic devices based on silicon nitride structures has been demonstrated. 10,[33][34][35][36][37] In contrast to pure silicon, the material does not display large intrinsic nonlinearities or a substantial free carrier absorption 38 and therefore allows us to observe the nonlinear response of the QDs without waveguide-induced background. A schematic of the sample is displayed in Fig.…”

Silicon Graphene Reconfigurable CROWS and SCISSORS

“…Intra-band transitions are the dominant source for the overall conductivity in the microwave and terahertz regions of the spectrum that can be expressed in terms of the Kubo's formula [18]:…”

“…In Section 2 we review some basic properties of graphene that are important in the design of tunable integrated photonic components, such as the dependence of its conductivity and dielectric constant on the chemical potential and applied voltage and we briefly describe the silicon photonics waveguide considered for the implementation of the reconfigurable resonant filters. Although graphene can be incorporated into other material platforms including InP [17] and Si 3 N 4 [18] its integration in Silicon waveguides is so far better understood both theoretically and experimentally, and therefore, we consider this option in the paper, although the design procedure can be extended to both of them as well. Section 3 presents the layouts of the CROW and SCISSOR devices and elaborates on the designs of its key component, which is the tunable 2 Â 2 coupler implemented by means of a graphene based Mach-Zehnder Interferometer (MZI).…”