Toward video-rate compressive spontaneous Raman imaging via single-photon avalanche diode arrays

Area of Science:

• Spectroscopy
• Microscopy
• Photonics

Background:

• Spontaneous Raman microscopy offers excellent chemical contrast but is limited by slow imaging speeds.
• Compressive Raman microspectroscopy utilizes single-photon avalanche diodes (SPADs) for enhanced speed, yet is constrained by SPAD sensitivity and dead time.

Purpose of the Study:

• To develop an efficient and scalable parallelization scheme for compressive Raman microspectroscopy.
• To overcome the limitations of current SPAD-based compressive Raman architectures for faster chemical imaging.

Main Methods:

• Implementation of a compressive Raman parallelization scheme utilizing SPAD arrays.
• Employing line excitation instead of spatial multiplexing for enhanced data acquisition.
• Achieving effective pixel dwell times of 0.8 µs.

Main Results:

• Demonstrated over a tenfold speed-up in imaging speed compared to previous methods.
• Achieved unprecedented chemical imaging speeds using spontaneous Raman scattering.
• The parallelization scheme significantly reduces effective pixel dwell times.

Conclusions:

• The developed parallelization scheme enhances compressive Raman microspectroscopy speed efficiently and scalably.
• This advancement enables high-speed chemical imaging and opens possibilities for video-rate molecular spectroscopy.
• The method paves the way for inexpensive, real-time molecular analysis.