Narrowband plasmonic metamaterial absorber integrated pyroelectric detectors towards infrared gas sensing

Abstract

Non-dispersive infrared (NDIR) gas sensing technique analyses a target gas based on its characteristic absorption wavelengths in the infrared spectrum. In an NDIR gas sensor, infrared radiation from a broadband source passes through and interacts with the sample gases in a chamber. Due to the lack of pixel level spectral selectivity, the optical detector in the NDIR gas sensor has to pair with a bandpass filter to selectively detect the attenuation to the infrared energy caused by the target gas. To measure multiple target gases at the same time, one can simply implement many pairs of "bandpass filter + infrared detector". However, this inevitably increases the overall size and complexity of the gas sensor. In this paper, we propose using narrowband plasmonic metamaterial absorber (PMA) to introduce pixel level spectral selectivity to infrared detectors and thus eliminating the requirement of separate bandpass filters. By inserting the PMA integrated narrowband detector array into the NDIR gas sensor, multiple gases can be analyzed with significantly reduced device footprint. When fully developed, the proposed device platform should be very useful in infrared spectroscopy.