Optical force density and surface displacements in transparent dielectrics due to nonionizing sub-picosecond laser excitation

The optical force density acting in transparent dielectric media due to short laser excitation is theoretically analyzed. For typical laser pulses with picosecond duration, the momentum component of the optical force becomes of the same order of magnitude as the stress component, enhancing the overall optomechanical effects. Simulations of the optically induced surface displacements in fused silica glass are also presented. With careful choice of realistic simulation parameters, dispersive and nonlinear effects were shown to be suppressed and displacements of 50 pm were found for single-pulse excitation with 100-fs duration, where the momentum component of the force is dominant. A possibility of measuring these displacements with piezoelectric detection is also discussed, providing a way to attain spatiotemporal characterization of the optical momentum force in continuum media. Such a description would significantly advance our current knowledge of the behavior of optical forces, potentially contributing to more versatile optomechanical applications while also clarifying the ongoing Abraham-Minkowski fundamental problem on the momentum transferred by light.