Two-photon excited luminescence in POPOP under pulse-periodic laser excitation

摘要： The spectra of two-photon-excited luminescence were registered in a polycrystalline aromatic compound POPOP. The two-photon luminescence in this substance was excited by the second optical harmonic of a solid-state neodymium-doped yttrium lithium fluoride laser (λ = 527 nm) and a copper vapor laser (λ = 510.6 nm). It is shown that the intensity of two-photon-excited luminescence depends nonlinearly on the intensity of an exciting radiation. It has been established that the intensity of the two-photon-excited luminescence is comparable to the intensity of Raman scattering under certain excitation conditions.