Brillouin Gain Microscopy

Abstract: Optical imaging with mechanical contrast is critical for material and biological discovery since it allows contactless light-radiation force-excitation within the sample, as opposed to traditional mechanical imaging. Whilst optical microscopy based on stimulated Brillouin scattering (SBS) enables mechanical imaging of materials and living biological systems with high spectrospatial resolution, its temporal resolution remains limited. Here, we develop Brillouin gain microscopy (BGM) with a 200-fold higher temporal resolution by detecting the Brillouin gain at a mechanically contrasting frequency in the sample with high sensitivity. Using BGM, we demonstrate mechanical imaging of materials, living organisms and cells at high spectro-spatiotemporal resolution.