Filterless Nondispersive Infrared Sensing using Narrowband Infrared Emitting Metamaterials

• DOI: 10.1021/acsphotonics.0c01432
• Publication Date: 2021-01-15T04:42:51Z
• Authors: Alyssa Livingood; J. Ryan Nolen; Thomas G. Folland; Lauren Potechin; Guanyu Lu; Scott Criswell; Jon-Paul Maria; Christopher T. Sh...; Edward Sachet; Joshua D. Caldwell
• Keywords: Thermopile; Narrowband; Thermophotovoltaic

For many industrial and manufacturing applications, detecting identifying low concentrations of harmful gases byproducts are performed using nondispersive infrared (NDIR) sensors. These simple devices utilize a broadband IR emitter, thermopile detector, spectrally narrow bandpass filter tuned to vibrational resonance the analyte interest. However, such filters expensive fabricate limit NDIR operation at only single frequency, unless wheels employed, which expand size complexity device considerably. Here, we create nanophotonic emitting metamaterial (NIREM) fabricated from thin films doped CdO grown on patterned sapphire substrates (PSS) that exhibit narrowband thermal emission. By coupling sufficiently line width emitter with detector as thermopile, functionality sensor can be replicated without need for filter. Unlike metamaterial-based emitters, our emits both p- s-polarized light near-unity emissivity angles ranging 0° 40° off surface normal complicated lithography steps. As proof concept, implement this NIREM CO2 gas detection within an FTIR spectrometer, demonstrating performance comparable conventional blackbody/filter combination. This demonstrates concept provide suitable plug-and-play replacement they implemented in form-factor commensurate or significantly reduced comparison current state art. In principle, by incorporating multiple dies emit different frequencies, modes could sequentially detected, making approach amenable identification quantification molecules configuration.