Laser adaptive holographic system for microweighing of nanoobjects

A system for measuring the mass of micro- and nanoobjects based on resonance microweighing using the principles of adaptive holographic interferometry is proposed and experimentally implemented. The sensitive element of the system is a microcantilever to which the objects to be weighted are attached. The eigenoscillations of the microcantilever are excited with a laser pulse. The detection of oscillations is implemented using the adaptive holographic interferometer, the key element of which, the dynamic hologram, is formed in the photorefractive crystal CdTe. The detected variation in mass of the particles, attached to the microcantilever, amounted to (420 ± 9) × 10^-12 g, the measurement error being 8.5 × 10^-12 g. The sensitivity of the measurement system is 1.7 × 10^-12 Hz g^-1. The possibility of increasing the sensitivity of the system by 6.5 × 10⁶ times and reducing the mass detection threshold by 1.5 × 10⁷ times by microcantilevers of submicron size is experimentally demonstrated.