  In recent years resonant semiconductor and all-dielectric nanophotonics
offered a lot of possibilities for thermally-induced light manipulation at the
nanoscale. Owing to high-quality resonant states, such nanostructures allow for
efficient light-to-heat conversion supported by various temperature detection
approaches based on thermally sensitive intrinsic optical responses
(photoluminescence, Raman scattering, thermorefraction etc.). In this work, we
study theoretically a phenomenon of the photothermal reshaping of the radiation
pattern of second-harmonic generation (SHG) that occurs in resonant
all-dielectric systems. In the suggested geometry near-IR pulsed laser is
utilized for excitation of SHG while simultaneous continuous wave visible laser
heats the structure. The thermooptical switching of the resonant optical states
in the nanostructures governs the reconfiguration of the emission pattern,
without significant loss in the magnitude of the SHG. We believe, that our
findings will pave the way for subwavelength-size near-IR thermally switchable
nonlinear optical devices.
