Tunable IR sensing based on a plasmonic NMEMS platform
Abstract
This program proposes the development of miniaturized, silicon-compatible, and spectrally selective infrared (IR) detectors operating at room temperature able to provide electrically tunable IR responses and to outperform competing sensing technologies in terms of noise and signal to noise ratio. The devices merge nanomechanical (NMEMS) resonators with nanopatterned surfaces made of gold/graphene composites to absorb IR light with desired wavelength and to quickly translate it into a DC voltage. Two different types of ultrathin metasurface absorbers will be explored to decorate NMEMS: (i) hybrid gold-graphene absorbers to provide electrical tunability of the IR absorption while preserving the full-width half maximum (FWHM); and (ii) extremely thin absorbers based on graphene nanostructures that do not mechanically load the NMEMS, aiming to reduce the IR sensor thermal mass and noise. In addition, a phase-differential interrogation scheme is proposed by exploiting a reference and a sensing unit within the same chip. This approach reduces all components of the noise (thermal, optical, mechanical, and electrical) and provides enhanced resilience to environmental factors such as temperature variations and mechanical vibrations, thus enabling the use of this technology in wearable embodiments. This program will demonstrate spectrally selectively IR detectors with a full width half maximum (FWHM)=0.25ÀÀÀÀm located at desired wavelengths in the 1-15ÀÀÀÀm range of the IR band, electrical tunability of the IR absorption up to 15%, noise equivalent power (NEP) in the 10-11-10-12 WHz-1/2 range, and speed of 100s of ÀÀÀÀs. Secondary objectives include: ¥ To unveil and assess the fundamental limits of the proposed platform in terms of responsivity, noise, power consumption/handling, and resilience to environmental factors (thermal variations, mechanical vibrations, and unwanted light). ¥ To manipulate IR light-matter interactions beyond the diffraction limit. ¥ To identify tradeoffs between device complexity and NEP, and to define a clear roadmap in the development of this emerging technology for specific applications. Advances in this technology will result in a reconfigurable, low-cost platform in which multiplexed detection is enabled by gathering dozens/hundreds of miniaturized sensors within the same chip and tailoring each of them to a different IR band. This platform can easily take advantage of neural networks and enable a wide range of applications, including the real-time tracking and analysis of substances with specific IR spectral fingerprints such as gases, metabolites, and a variety of chemicals and biological threats.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2022
- Source ID
- W911NF2210067
Entities
People
- J. S. Gómez‐Díaz
Organizations
- Army Contracting Command
- United States Army
- University of California, Davis