Spectral analysis of 1G4 level in the Pr3+:YLF crystal

Abstract

The spectral measurement and energy level analysis of 1G4 are performed. Based on the absorption characteristics of the 1G4 level with different concentrations of Pr3+:YLF，the modified J-O theory was introduced to calculate the main spectral parameters. The emission cross-section spectra with two polarizations of the 1G4→3H5 transition excited by 1028 nm pumping and the fluorescence lifetime at the target wavelength (1322 nm) were measured. At the doping concentration of 1.0 at.%, the calculated peak emission cross section is close to the order of ∼1 × 10−20 cm2. Furthermore, we also discuss the energy level scheme of 1G4 in detail and proposed a cascade mechanism，which allows to further improve the output performance of the 915 nm (3P0→1G4) laser. For the first time, we propose a new approach to generate the fluorescence of 1322 nm by using 1G4 as an upper level.