Laser selective spectromicroscopy of myriad single molecules: tool for far-field multicolour materials nanodiagnostics

In this Colloquium, we discuss the main principles, achievements and perspectives in the field of highly parallel luminescence spectroscopy and imaging of single molecules (SM) in transparent solids. Special attention will be given to SM detection at low temperatures, where ultranarrow and bright zero-phonon lines (ZPL) of emitting centres are achievable for observation. Frequency of ZPL can be used as an additional property for separation of multiple SM images within diffraction limited volume, thus realising "multicolour" super-resolution microscopy. The extreme sensitivity of ZPL parameters to SM local environment allows application of SM spectromicroscopy for the study of structure and dynamics of doped solids on the nanometre scale. We show that the way to "bridge" the accidental rare events detected by SM probes to general material properties is a statistical analysis of spectral-spatial data obtained by a separated detection of all effectively fluorescing dye centres in a bulk sample. First experimental realisation of three-dimensional phononless luminescence SM spectromicroscopy with modification of SM point-spread function is demonstrated.