Miniaturized on-chip spectrometer enabled by electrochromic modulation

Area of Science:

• Optoelectronics
• Spectroscopy
• Materials Science

Background:

• Miniaturized spectrometers are crucial for portable sensing but face limitations in spectral resolution due to filter count.
• Current computational spectrometers struggle to improve resolution without increasing the number of spectral response units.

Purpose of the Study:

• To develop a miniaturized computational spectrometer with enhanced spectral resolution using electrochromic filters.
• To demonstrate improved spectral resolution and adaptability for hyperspectral imaging.

Main Methods:

• Integration of electrochromic filters directly onto photodetector pixels.
• Electrochemical modulation of filter spectral response via ion and electron injection.
• Experimental validation of spectral resolution improvement with applied voltages.

Main Results:

• Achieved a significant decrease in average peak wavelength difference from 1.61 nm to 0.29 nm.
• Demonstrated effective operation with as few as two or four filter units.
• Confirmed the electrochromic filter's suitability for hyperspectral imaging due to uniform transparency.

Conclusions:

• Electrochromic filter modulation offers a new strategy for high-resolution miniaturized spectrometers.
• This approach enhances performance for low-cost, portable spectral sensing.
• The concept inspires further research into stimulus-responsive filters for spectrometers.