Dispersion multiplexing with broadband filtering for miniature spectrometers

Area of Science:

• Optics and Photonics
• Spectroscopy
• Instrument Design

Background:

• Traditional dispersive spectrometers are limited by grating efficiency and spectral range.
• Slit-based designs in spectrometers can limit light throughput, impacting sensitivity.
• Broadband filters in detectors can lead to spectral overlap challenges.

Purpose of the Study:

• To develop a proof-of-concept spectrometer with an expanded spectral range.
• To enhance light throughput compared to traditional spectrometer designs.
• To demonstrate the feasibility of dispersion multiplexing for improved spectral sensing.

Main Methods:

• Replaced traditional grating with a multiplex holographic grating.
• Employed broadband color filters on a digital focal plane array.
• Utilized a computational inversion algorithm to disambiguate spectral bands.
• Incorporated a static coded aperture mask instead of a slit.

Main Results:

• Achieved measurement of three overlapping spectral bands on a single detector.
• Demonstrated an increased spectral bandwidth compared to traditional spectrometers of similar size.
• Showcased enhanced light throughput via the coded aperture mask.
• Verified operational principles through experimental measurements.

Conclusions:

• The dispersion multiplexing spectrometer design successfully expands spectral range and light throughput.
• The combination of multiplex holographic gratings and computational algorithms enables effective spectral disambiguation.
• This novel spectrometer architecture offers a promising alternative for enhanced spectral sensing applications.