Compact computational spectrometer using a solid wedged low finesse etalon.

Area of Science:

• Optics and Photonics
• Spectroscopy
• Materials Science

Background:

• Traditional spectrometers often face limitations in compactness and spectral resolution.
• Hybrid solid-state etalons offer potential for novel spectroscopic instrumentation.
• Computational imaging techniques are advancing spectral analysis capabilities.

Purpose of the Study:

• To develop and demonstrate a novel compact computational spectrometer.
• To investigate the performance of a two-layer hybrid solid wedged etalon.
• To implement advanced spectral reconstruction algorithms for improved resolution.

Main Methods:

• Fabrication of a two-layer hybrid solid wedged etalon using ${{\rm Nb}_2}{{\rm O}_5}$ and Infrasil 302.
• Integration of the etalon with a complementary metal-oxide semiconductor (CMOS) imager.
• Spectral reconstruction using a non-negative least-squares fitting algorithm with analytically computed wavelength response vectors.

Main Results:

• Demonstrated operation of the compact computational spectrometer from 0.4-0.9 µm.
• Achieved spectral resolutions below 30 cm$^{-1}$ from single snapshots.
• The novel computational technique outperformed conventional Fourier processing methods.

Conclusions:

• The developed hybrid wedged etalon computational spectrometer offers superior performance and spectral resolution.
• The non-negative least-squares fitting algorithm provides an effective approach for spectral reconstruction.
• The system's potential for conversion into a hyperspectral imager highlights its versatility.