Conventional photonic integration technologies are inevitably substrate-dependent, as different substrate platforms stipulate vastly different device fabrication methods and processing compatibility requirements. Here we capitalize on the unique monolithic integration capacity of composition-engineered non-silicate glass materials (amorphous chalcogenides and transition metal oxides) to enable multifunctional, multi-layer photonic integration on virtually any technically important substrate platforms. We show that high-index glass film deposition and device fabrication can be performed at low temperatures (< 250 °C) without compromising their low loss characteristics, and is thus fully compatible with monolithic integration on a broad range of substrates including semiconductors, plastics, textiles, and metals. Application of the technology is highlighted through three examples: demonstration of high-performance mid-IR photonic sensors on fluoride crystals, direct fabrication of photonic structures on graphene, and 3-D photonic integration on flexible plastic substrates.
High-index-contrast optical devices form the backbone of densely integrated photonic circuits. While these devices are
traditionally fabricated using lithography and etching, their performance is often limited by defects and sidewall
roughness arising from fabrication imperfections. This paper reports a versatile, roll-to-roll and backend compatible
technique for the fabrication of high-performance, high-index-contrast photonic structures in composition-engineered
chalcogenide glass (ChG) thin films. Thin film ChG have emerged as important materials for photonic applications due
to their high refractive index, excellent transparency in the infrared and large Kerr non-linearity. Both thermally
evaporated and solution processed As-Se thin films are successfully employed to imprint waveguides and micro-ring
resonators with high replicability and low surface roughness (0.9 nm). The micro-ring resonators exhibit an ultra-high
quality-factor of 4 × 105 near 1550 nm wavelength, which represents the highest value reported in ChG micro-ring
resonators. Furthermore, sub-micron nanoimprint of ChG films on non-planar plastic substrates is demonstrated, which
establishes the method as a facile route for monolithic fabrication of high-index-contrast devices on a wide array of
A high bandwidth density chip-to-chip optical interconnect architecture is analyzed. The interconnect design leverages
our recently developed flexible substrate integration technology to circumvent the optical alignment requirement during
packaging. Initial experimental results on fabrication and characterization of the flexible photonic platform are also
Chalcogenide glasses, namely the amorphous compounds containing sulfur, selenium, and/or tellurium, have emerged as a promising material candidate for mid-infrared integrated photonics given their wide optical transparency window, high linear and nonlinear indices, as well as their capacity for monolithic integration on a wide array of substrates. Exploiting these unique features of the material, we demonstrated high-index-contrast, waveguide-coupled As2Se3 chalcogenide glass resonators monolithically integrated on silicon with a high intrinsic quality factor of 2 × 105 at 5.2 micron wavelength, and what we believe to be the first waveguide photonic crystal cavity operating in the mid-infrared.
Here we show our ability to fabricate two-dimensional (2D) gratings on chalcogenide glasses with peak-to-valley amplitude of ~200 nm. The fabrication method relies on the thermal nano-imprinting of the glass substrate or film in direct contact with a patterned stamp. Stamping experiments are carried out using a bench-top precision glass-molding machine, both on As2Se3 optically-polished bulk samples and thermally-evaporated thin films. The stamps consist of silicon wafers patterned with sub-micron lithographically defined features. We demonstrate that the fabrication method described here enables precise control of the glass’ viscosity, mitigates risks associated with internal structural damages such as dewetting, or parasitic crystallization. The stamping fidelity as a function of the Time-Force-Temperature regime is discussed, and further developments and potential applications are presented.
Chalcogenide glasses, namely the amorphous compounds containing sulfur, selenium, and/or tellurium, have emerged as a promising material candidate for integrated photonics given their wide infrared transparency window, low processing temperature, almost infinite capacity for composition alloying, as well as high linear and nonlinear indices. Here we present the fabrication and characterization of chalcogenide glass based photonic devices integrated on silicon as well as on flexible polymer substrates for mid-IR sensing, optical interconnect and nonlinear optics applications.
Chalcogenide glasses, namely the amorphous compounds containing sulfur, selenium, and/or tellurium, have emerged as
a promising material candidate for integrated photonics given their wide infrared transparency window, low processing
temperature, almost infinite capacity for composition alloying, as well as high linear and nonlinear indices. Here we
present the fabrication and characterization of chalcogenide glass based photonic devices integrated on silicon as well as
on flexible polymer substrates for sensing, optical interconnect and nonlinear optics applications.