Single-lens integrated miniature Raman spectrometer with fine resolution and high étendue.

Area of Science:

• Spectroscopy
• Optical Engineering
• Materials Science

Background:

• Raman spectroscopy is crucial for chemical analysis and material characterization.
• Miniaturization of spectroscopic instruments is essential for portable and in-situ applications.
• Existing compact spectrometers often face trade-offs between size, resolution, and performance.

Purpose of the Study:

• To develop a highly compact Raman spectrometer with high spectral resolution.
• To demonstrate reliable substance identification using the developed spectrometer prototype.
• To explore novel optical configurations for miniaturized spectroscopic instruments.

Main Methods:

• Designed a compact spectrometer integrating a plano-convex spherical lens, immersed grating, and cylindrical lens.
• Employed optical path folding and sagittal plane pre-collimation to achieve miniaturization.
• Coupled the optical components to achieve a spectral resolution of 1 nm within the 885-950 nm range.

Main Results:

• Achieved a spectral resolution of 1 nm in the 885-950 nm wavelength range.
• The spectrometer prototype has a compact volume of 70×20×5 mm³.
• Successfully accommodated fiber input with a numerical aperture of 0.37.

Conclusions:

• The developed compact Raman spectrometer demonstrates high spectral resolution and reliable substance identification.
• The innovative optical design enables significant miniaturization without compromising performance.
• This compact spectrometer is suitable for portable and field-based chemical analysis applications.