Suspended waveguide-enhanced near-infrared photothermal spectroscopy for ppb-level molecular gas sensing on a chalcogenide chip.

ABSTRACT: On-chip waveguide sensors have attracted significant attention recently due to their potential for high-level integration. However, so far, on-chip gas sensing based on traditional laser absorption spectroscopy has demonstrated low detection sensitivity, due to weak light-gas interaction over a limited interaction distance. On-chip photothermal spectroscopy (PTS) appears to be a powerful technique to achieve higher sensitivity; its performance is yet constrained to parts-per-million (ppm)-level due to a small fraction of evanescent field in the light-gas interaction zone and fast thermal dissipation through the solid substrate. Herein, we demonstrated suspended chalcogenide glass waveguide (ChGW)-enhanced PTS that overcomes these limitations, enabling highly sensitive parts-per-billion (pp

SUBMITTER: Zheng K 

PROVIDER: S-EPMC12914002 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature