The trend of structured light-induced force microscopy: a review


 Modern nanotechnology demands advanced microscopy with ever finer resolution and detectivity of both explicit and inexplicit features of matter. While typical optical microscopy can only directly observe diffraction-limited sample appearance, a plethora of novel techniques has been presented to interrogate intrinsic nature of matter in super-resolution. In particular, the photo-induced force microscopy (PiFM) attracts intense interest from the optical community due to its unique optical force detection mechanism. Recent works of PiFM suggest that, combined with structured light illumination, the so-called system of structured light-induced force microscopy (SLiFM) can characterize conventionally elusive matter properties with fidelity. In this review, we discuss the origin and state-of-art trend of the SLiFM, including the following sections: 1) the principle of PiFM and how it detects optical forces; 2) the fundamental physics of structured light beams; 3) the fundamental physics of structured light-structured matter interaction; 4) the relation between optical force and local electromagnetic fields. Lastly, we highlight the future industrial and academic inspirational applications of SLiFM in the characterization and manipulation of opto-magnetism and chirality, etc.