Imaging of an adipose cell using ~5 GHz phonons.
(a) Optical picture taken with a conventional brightfield microscope showing an adipose cell. Fat droplets are clearly visible. (b) The Brillouin frequency map of the area shown in (a). This map was obtained using the complete temporal extent of the detected signals. (c–e) Subsections of the measured volume. The central position of the windows in the z direction are 0.6,1 and 1.4 μm to figures (c–e) respectively. The fat droplet marked with a circle appears and disappears within the measured volume. (f) Typical time trace observed from the cell cytoplasm shown as a star in (a). (g) Fourier transform of the time trace presented in (f) showing the Brillouin frequency peak.