Long-wave infrared super-resolution wide-field microscopy using sum-frequency generation

Super-resolution microscopy in the visible is an established powerful tool various disciplines. In long-wave infrared (LWIR) spectral range, however, no comparable schemes have been demonstrated to date. this work, we experimentally demonstrate super-resolution LWIR range ([Formula: see text]m) using IR-visible sum-frequency generation. We operate our microscope a wide-field scheme and image localized surface phonon polaritons 4H-SiC nanostructures as proof-of-concept. With technique, enhanced spatial resolution of [Formula: text], enabling resolve polariton resonances individual sub-diffractional with sub-wavelength spacing. Furthermore, show that allows us differentiate between patterns associated different modes within nanostructures.