Full-field Brillouin microscopy based on an imaging Fourier-transform spectrometer

Area of Science:

• Biomedical Optics
• Biophysics
• Materials Science

Background:

• Brillouin microscopy is a non-contact optical elastography technique for assessing biological sample mechanical properties in 3D.
• Conventional Brillouin scattering yields weak signals, requiring long exposure times or high illumination doses potentially damaging to samples.

Purpose of the Study:

• To develop a rapid spectral acquisition method for Brillouin-scattered light.
• To enhance the speed and throughput of Brillouin microscopy for biological imaging.

Main Methods:

• Utilized a custom-built Fourier-transform imaging spectrometer for highly multiplexed spectral acquisition.
• Exploited the symmetric properties of the Brillouin spectrum for full-field 2D spectral imaging.
• Demonstrated the technique on phantoms and biological samples.

Main Results:

• Achieved a throughput of up to 40,000 spectra per second with ~70 MHz precision.
• Demonstrated an effective 2D image acquisition speed of 0.1 Hz over a ~300 × 300 µm² field of view.
• Reported a three-orders-of-magnitude improvement in speed and throughput compared to standard confocal methods.

Conclusions:

• The novel approach significantly accelerates Brillouin spectral imaging.
• Enables high-resolution 3D imaging of photosensitive biological samples with reduced exposure.
• Offers a promising tool for non-contact mechanical characterization in biology and medicine.