Fast single-photon avalanche diode arrays for laser Raman spectroscopy

Area of Science:

• Spectroscopy
• Solid-state physics
• Planetary science

Background:

• Fluorescence interference is a significant challenge in Raman spectroscopy, particularly for in situ applications.
• Traditional methods for fluorescence rejection often involve complex instrumentation.
• Solid-state detector technology offers potential for miniaturized and robust spectroscopic instruments.

Purpose of the Study:

• To demonstrate the use of single-photon avalanche diode (SPAD) arrays in time-resolved laser Raman spectroscopy for fluorescence rejection.
• To evaluate the sensitivity and performance of this new instrument architecture.
• To assess the suitability of SPAD arrays for in situ planetary missions.

Main Methods:

• Incorporation of a 128x128 SPAD array into a time-resolved laser Raman spectroscopy setup.
• Testing with highly fluorescent mineral samples (willemite and spodumene).
• Measurement of photon detection efficiency and comparison with traditional imagers.

Main Results:

• Successful distinction between Raman and fluorescence spectra.
• Demonstrated effective fluorescence rejection on mineral samples.
• Achieved sensitivity comparable to more complex traditional systems.

Conclusions:

• Newly developed solid-state detector technology, specifically SPAD arrays, is effective for fluorescence rejection in Raman spectroscopy.
• This technology shows promise for developing sensitive, portable, and radiation-hardened in situ planetary instruments.
• Potential for large-scale manufacturability makes SPAD arrays suitable for future Raman applications facing fluorescence interference.