Chalcogenide glass-on-graphene photonics

Abstract

Two-dimensional (2-D) materials are of tremendous interest to integrated photonics given their singular optical characteristics spanning light emission, modulation, saturable absorption, and nonlinear optics. To harness their optical properties, these atomically thin materials are usually attached onto prefabricated devices via a transfer process. In this paper, we present a new route for 2-D material integration with planar photonics. Central to this approach is the use of chalcogenide glass, a multifunctional material which can be directly deposited and patterned on a wide variety of 2-D materials and can simultaneously function as the light guiding medium, a gate dielectric, and a passivation layer for 2-D materials. Besides claiming improved fabrication yield and throughput compared to the traditional transfer process, our technique also enables unconventional multilayer device geometries optimally designed for enhancing light-matter interactions in the 2-D layers. Capitalizing on this facile integration method, we demonstrate a series of highperformance glass-on-graphene devices including ultra-broadband on-chip polarizers, energyefficient thermo-optic switches, as well as graphene-based mid-infrared (mid-IR) waveguideintegrated photodetectors and modulators.

Mid-infrared integrated photonics on silicon: a perspective

“…We also note that slow light designs (large n g ) are an effective route to enhance the FOM, as previously validated in near-IR devices [143]. In a resonator-based thermo-optic switch, analysis yields [142]:…”

“…State-of-the-art graphene waveguide modulators have reached a remarkable 3-dB bandwidth of 35 GHz and a modulation depth of 70 dB/mm near the 1550-nm telecom band [165]. In the mid-IR, our group has recently demonstrated the first graphene-based waveguide modulator [142]. Figure 11A sketches the device layout, which comprises a ChG waveguide and two embedded graphene layers.…”

“…To examine the influence of wavelength scaling on thermo-optic devices, we consider the thermo-optic figure of merit (FOM) defined as the inverse of the product of 10-90% rise time (t r ) and power consumption to turn on or off the switch (P ϕ ), a parameter often cited when drawing a comparison between different thermo-optic switching technologies. For a device based on the Mach Zehnder interferometer (MZI) configuration, the FOM is given as [142]: …”

Graphene Oxide Waveguide and Micro‐Ring Resonator Polarizers

“…Although high polarization‐dependent loss (PDL) has been achieved for these polarizers, it usually comes at the expense of high overall propagation loss and requires complicated buffer layers to achieve broadband operation. Recently, the huge optical anisotropy and broadband response of 2D materials such as graphene and transition metal dichalcogenides have been widely recognized and exploited to implement polarization‐selective devices, including an in‐line fiber polarizer with graphene, graphene–polymer waveguide polarizers, and chalcogenide glass‐on‐graphene waveguide polarizers . However, none of these demonstrations were based on CMOS compatible platforms.…”

High‐density WGM probes generated by a ChG ring resonator for high‐density 3D imaging and applications

“…Chalcogenide glass (ChG) material has shown very interesting aspect that the propagation of light within a certain chalcogenide length changes due to the change in the refractive index . Several investigations have confirmed this observation .…”