Fabrication of Solid Wedge Etalon for Computational Spectroscopy

Spectrometry, the study or measurement of spectra produced when material interacts with or emits light, has become essential in numerous fields. Ranging from chemistry to medical diagnostics, there is a demand for compact technologies that can efficiently deliver detailed spectral data. Advanced spectrometers capable of detecting subtle spectral changes could contribute significantly to these varied domains. Current conventional techniques, such as Fourier transform infrared spectroscopy, though widely used, often confront limitations related to size, depth of field, spatial resolution, and spectral range. Over time, users have desired a method to counter this, proposing portable, high-performing spectrometers that can cater to wider spectral ranges ─ an aspect this two-layer hybrid solid wedged etalon aims to address.

Technology Description

The innovation is a compact computational spectrometer that was created by combining a traditional imager with a two-layer hybrid solid wedged etalon. The etalon, made of Nb₂O₅ and Infrasil 302, was designed to operate from 0.4-2.4 μm. The spectrometer’s demonstrated initial usage with a CMOS imager operated from 0.4-0.9 μm, achieving spectral resolutions of 30 cm⁻¹ from single snapshots. A spectral reconstruction technique was also applied using a non-negative least squares fitting algorithm. What sets this technology apart is its advanced computational technique that results in performance and spectral resolutions surpassing Fourier techniques. The technology's versatility is demonstrated by the fact that with the addition of imaging lenses and translational scanning, the system can be converted into a hyperspectral imager. This integration of features in a compact structure signifies a leap forward in the field of spectrometry.