Multiphoton absorption in europium(iii) doped YVO4 nanoparticles

Abstract

We report the synthesis and physicochemical characterization of YVO₄ nanocrystals doped with Eu³⁺ ions. The adopted solvothermal synthesis procedure rendered YVO₄ nanoparticles with tetragonal crystal structure and rod-like morphology. The absorption and excitation spectra of the studied nanoparticles showed UV bands which were attributed to the ¹A₁ → ¹T₂ and ¹A₁ → ¹T₁ electronic transitions in the vanadate group, respectively. The nonlinear optical properties of both undoped YVO₄ nanocrystals and those doped with Eu³⁺ ions were studied by wide wavelength range (600–1600 nm) femtosecond Z-scan measurements. The experiments revealed strong multiphoton absorption in the wavelengths around 650 and 1300 nm, within the first and second biological window. This nonlinear absorption results in multiphoton excitation of red europium emission from the nanoparticles, making them potential candidates for application as markers in nonlinear microscopy imaging techniques.