(a) Schematic of the photo-induced chiral force microscopy (PiCFM) concept, enabling the detection of chirality of a sample based on differential force measurement. (b) Photo-induced differential force exerted on the tip (represented by the yellow nanosphere), from two incident scenarios of RCP and LCP light versus chirality parameter of the sample [48]. Differential time-average force can be positive or negative, depending on the chiral parameter κ of the material in the sample (represented by the blue sphere).