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

TL;DR

This paper introduces a rapid, full-field Brillouin microscopy technique using a custom Fourier-transform spectrometer, enabling high-speed 2D spectral imaging of biological samples with minimal exposure.

Contribution

The authors develop a novel imaging Fourier transform spectrometer that significantly accelerates Brillouin spectral acquisition, enabling real-time 2D imaging of biological samples.

Findings

Achieved up to 40,000 spectra per second over a 300μm field-of-view.

Demonstrated high spatial resolution in biological and phantom samples.

Enabled 3D imaging of photosensitive biological samples with minimal damage.

Abstract

Brillouin microscopy is an emerging optical elastography technique that can be used to assess mechanical properties of biological samples in a 3D, all-optical and hence non-contact fashion. However, the low cross-section of spontaneous Brillouin scattering results in weak signals typically requiring prolonged exposure times or illumination dosages potentially harmful for biological samples. Here, we present a new approach for highly-multiplexed, and therefore rapid, spectral acquisition of the Brillouin scattered light. Specifically, by exploiting a custom-built Fourier-transform imaging spectrometer and the symmetric properties of the Brillouin spectrum, we experimentally demonstrate full-field 2D spectral Brillouin imaging of phantoms as well as biological samples, at a throughput of up to 40,000 spectra per second over a ~300um field-of-view. This represents an approximately three orders of magnitude improvement in speed and throughput compared to standard confocal methods while retaining high spatial resolution and the capability to acquire three-dimensional images of photosensitive samples in biology and medicine.