Substrate-blind photonic integration based on high-index glass materials

Abstract

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.

A substrate-blind platform for photonic integration

“…8,9 Previous work enabled high-performance glass-based optical devices integrated on substrates of semiconductor and glass, [10][11][12][13][14] and here we extended the substrate-blind integration strategy by realizing photonic integration on three types of emerging substrate platforms: IR optical crystals (calcium fluoride, CaF 2 ), [15][16][17] flexible polymer membranes, 4,18 and 2D materials (graphene). 19 We deposited the glasses on the substrates using thermal evaporation or solution derivation, 20 and then patterned them using photolithography or direct nanoimprinting. 21,22 We demonstrated the procedure in several photonic components, including waveguides, resonators, gratings, and photonic crystals, with outstanding optical performance.…”