Optical properties of chromium-doped fluoroindate glasses

This work reports on the optical properties of Cr³⁺ ions in the pseudoternary system InF₃-GdF₃-GaF₃. Linear properties, investigated through absorption and emission spectra, provide information on the crystal field, the frequency, and number of phonons emitted during the absorption to the ⁴T₂ band and the emission to the ⁴A₂ ground state, and the Fano antiresonance line shape in the vicinity of the ⁴A₂→²E transition. A study of the nonlinear refractive index as a function of the wavelength, carried out with the Z-scan technique, provides spectroscopic data about electronic transitions starting from the excited state.