STTR Phase I: Curved Volume Phase Holographic Gratings: Efficient and High-Resolution Hyperspectral Imaging

Syzygy Optics Llc, Chapel Hill NC

Investigators

Abstract

This Small Business Technology Transfer Phase I project will develop a completely new class of spectrometer, the spherical transmission grating spectrometer (STGS), which utilizes curved volume phase holographic (VPH) gratings coupled with a spherical mirror to deliver aberration-corrected spectral images over the full field of view. The market is projected to reach $35.8 billion by 2026, at an annual growth rate of 18.4%. End-users range from astronomy to agriculture, manufactures, and third-party integrators (e.g., drone companies). Current technologies are too costly or do not possess the size, weight, and power (SWAP) properties required for practical value delivery. Furthermore, in low light conditions or in applications that require aberration-free high-resolution images (e.g., defense-based imaging), current technologies on the market cannot meet customer requirements. This solution promises to solve these issues. Agriculture and defense are the two leading market applications and represent the primary entry points for this technology. The intellectual merit of this project will enable a transformation in the spectroscopy and the hyperspectral imaging (HSI) market by enabling low-cost, superior image quality spectrographs. The product will be a novel spherical transmission grating spectrometer (STGS) for hyperspectral imaging. Preliminary STGS designs, invented in a collaboration with astronomers at the University of North Carolina Chapel Hill and Southern African Large Telescope employ a combination of a spherical mirror and a spherically-curved transmission grating to deliver fully aberration-corrected spectral images with no field distortion. Challenges to their production are the design, fabrication, and testing of this spherical volume phase holographic (VPH) grating. These spectrographs represent a new paradigm in optical spectrometer design, and the team has developed a suite of STGS designs that will allow them to build a new generation of distortion and aberration free spectrographs that are simple, small, and lightweight. The key objectives for this project are: 1) to develop a curved grating manufacturing processes to match design and market goals, 2) to design and fabricate a prototype testbed HSI for design validation and high-throughput quality testing, and 3) to create finalized optical designs for STGSs in the F/2 to F/2.5 range. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.