In this program, we propose to develop a novel hand-held multiplex gas detector platform in the mid-IR range for multiple chemical detection and identification with both high sensitivity and specificity. The sensor technology in this project is based on a lab-on-chip Mid-IR absorption spectrometer incorporating vertical photonic crystal waveguide (VPCW) structures. The VPCW demonstrates significant slow-wave effects leading to enhanced sensitivity within a drastically reduced interaction length. The small geometry of VPCW is an excellent platform for miniaturized sensing and high-resolution on-chip spectroscopy unmatched by any existing technologies. Unlike the conventional approach, the device proposed herein can provide multiple analyte detections in one chip with one broadband LED source and the wavelength indifferent PDs array that offers a cost-effective, compact, and highly sensitive device without compromising the specificity for air-borne and space-borne applications. In the proposed work, our plan is to 1) design three different VPCWs on a Si wafer to exhibit multiplex detection capability with strong confinement of light in the VPCW defect core 2) fabrication and characterization of multiple VPCWs on a Si wafer with minimum interference from adjacent defect holes 3) demonstration of optical detection of CO2, CH4, and N2O with targeted sensitivity of <100ppb and 4) Packaging and integration of one mid-IR LED, VPCW arrays, and matching PD arrays into our hand-held unit.
1. The proposed multiplex sensing system is compact and ideal for in-situ analysis of environmental gases by mounting it on an airborne and space-borne platform
2. Crucial to identifying gases on the earth or at distant planets and moons
3. The proposed platform is fully scalable to a wide range of mid-infrared wavelengths where several important analyses of NASA's interest can be found
4. Discrete component integration in a single package offers a better size, weight, and power (SWaP) advantage over any other existing spectroscopy instrument
1. Human Health and Safety: Ex. Identification of hazardous air pollutants (HAPs) and can be helpful to identify cause of various air borne decease
2. Defense sector: Ex. detection of toxic gases on the battlefield
and volatile organic components (VOCs)
3. Agriculture production and food safety/allergy monitoring
4. Industrial application: Ex. leakage detection of gases in oil storage and tanks