||Three-dimensional imaging of biological cells with picosecond ultrasonics
Danworaphong, Sorasak Tomoda, Motonobu ,
Matsumoto, Yuki Matsuda, Osamu ,
Ohashi, Toshiro ,
Watanabe, Hiromu Nagayama, Masafumi ,
Gohara, Kazutoshi ,
Otsuka, Paul H.Wright, Oliver B.
, p.163701 , 2015-04-21 , American Institute of Physics
We use picosecond ultrasonics to image animal cells in vitro-a bovine aortic endothelial cell and a mouse adipose cell-fixed to Ti-coated sapphire. Tightly focused ultrashort laser pulses generate and detect GHz acoustic pulses, allowing three-dimensional imaging (x, y, and t) of the ultrasonic propagation in the cells with similar to 1 mu m lateral and similar to 150 nm depth resolutions. Time-frequency representations of the continuous-wavelet-transform amplitude of the optical reflectivity variations inside and outside the cells show GHz Brillouin oscillations, allowing the average sound velocities of the cells and their ultrasonic attenuation to be obtained as well as the average bulk moduli.