English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Mid-infrared (mid-IR) integrated photonics are expected to provide key advances for the demonstration of chip-scale spectroscopic systems. It has been recently reported that Ge-rich SiGe alloy-based photonic structures can provide broadband operation for a wavelength range spanning from 5.5 to 8.5 µm, thus holding great potential for mid-IR applications. In this paper, the Ge-rich SiGe platform is considered for a mid-IR photonic chip-scale sensor, based on the use of the evanescent component of the guided optical mode to probe specific molecular absorption features of the surrounding cladding environment. As a proof of concept, we monitored the absorption spectral patterns of a standalone photoresist spin-coated onto spiral Ge-rich SiGe waveguides. A significant increase of the waveguide optical loss at the spectral window of 5.8-6.2 µm is identified and correlated with the inherent photoresist absorption. The ability of this platform to sense small concentrations of methane gas is also discussed. These results pave the way towards the demonstration of compact, portable, label-free and highly sensitive photonic integrated sensors based on Ge-rich SiGe circuits.

Mid-infrared sensing between 52 and 66 µm wavelengths using Ge-rich SiGe waveguides [Invited]