Detection of dust grains vibrations with a laser heterodyne receiver of scattered light

We present the results of measurement of grains vibrations under external action in gas and liquid with a laser heterodyne receiver of scattered radiation. For investigation of dynamic characteristics of particles we made the laser heterodyne receiver with sensitivity about 2×10−17 W/Hz and source of probing with radiation power 1 mW. In our pilot experiments, measurement of vibration amplitude of nanoparticles in gas (cigarette smoke) and microparticles in fluid (toothpaste in water) was made. We measured values of vibration amplitudes about 20-30 nm.