Fig. 1

Schematic illustration of the 3D orientation mapping (3DOM) microscopy. a Experimental setup of 3DOM. SLM, spatial light modulator; HWP, half-wave plates; PBS, polarizing beam splitter; OBJ, objective; DM, dichroic mirror; EF, emission filter; TL, tube lens. b Polarization modulation depicts the excitation beam (green), p-polarized light (blue), and dipole emitter \(\overrightarrow {\mu }\) (orange). The excitation light converges at the BFP of the objective lens, and different positions of the convergence change in the excitation light’s outgoing direction and polarization state. c Definition of the dipole moment direction \(\overrightarrow {\mu }\) (chemical structure example of a Nile red fluorophore), characterized by its azimuthal angle \(\rho\) and polar angle \(\eta\). The excitation light is a plane wave with a wave vector \(\overrightarrow {k}\), where p-polarized light is defined by \(\alpha\) and \(\beta\). Here, we consider \(\beta \ne\) 0°. d The emission intensity distribution under polarized excitation modulation. e Schematic diagram of dipoles with the same azimuthal angle, different polar angles. f, g Comparison of the emission intensity variations in SDOM and 3DOM at a distance of 250 nm. h 3DOM resolves both azimuthal angle \(\rho\) (indicated by the direction of the rod) and polar angle \(\eta\) (indicated by the color), with length proportional to \(\sin \eta\). In contrast, SDOM only yields an azimuthal angle (indicated by the gray arrow). Scale bar = 200 nm