Integrated solid immersion grating microspectrometer with wedge prism correction for visible and near-infrared...

Area of Science:

• Optical Engineering
• Spectroscopy
• Microsystems

Background:

• Miniaturization of spectrometers presents a significant challenge in balancing optical performance with reduced size.
• Existing compact spectrometers often compromise spectral resolution or operational range.

Purpose of the Study:

• To develop a highly compact spectrometer with high spectral resolution and a broad spectral range.
• To demonstrate the utility of the developed spectrometer in agricultural applications.

Main Methods:

• Integration of a solid immersion grating (SIG), wedge prism, planar reflectors, microslit, and CMOS sensor into a single module.
• Utilizing a wedge prism for focal plane tilt compensation and optical path length compression.
• High-precision encapsulation for device stability.

Main Results:

• Achieved an average spectral resolution of 4.4 nm in the 600-1000 nm range.
• The spectrometer has an ultra-compact volume of 0.63 cm³.
• Demonstrated high correlation (R²=0.941) for predicting soluble solids content in fruits using reflectance spectra.

Conclusions:

• The SIG-W-µSPEC offers a breakthrough in compact spectrometer design, merging high performance with miniaturization.
• The device shows significant potential for on-site, non-invasive detection in agriculture, biomedical sensing, and other fields.