Magnetic-Field-Controlled Photoinduced Thermocapillary Deformation of Magnetic Fluid Surface

The influence of a magnetic field on the features of photoinduced thermocapillary deformation of the free surface of a magnetic fluid layer is considered for the first time. Deformation occurs as a result of local heating of the surface under the action of an incident laser beam and manifests itself as a curvature of the fluid surface profile. The laser beam reflected from the deformed surface exhibits a nonuniform spatial distribution of the radiation intensity in the form of concentric rings. An external magnetic field has an addition effect on the shape of the free surface of the magnetic fluid, thereby making it possible to control the photoinduced thermocapillary deformation. The geometric characteristics and time evolution of the interference pattern of the thermocapillary response are experimentally studied as depending on the strength and orientation of the magnetic field.