Excited state characteristics of the Li2B4O7 and KLiB4O7 glasses activated by Cr3+ ions

•Excited state characteristics by means of ESA, optical gain and ground state bleaching spectra in LBO:Cr and KLBO:Cr glasses are measured.•Interpretation is based on detailed configuration coordinate diagram derived from experimental data.

The excited state characteristics by means of the excited state absorption (ESA), optical gain and bleaching spectra have been measured for prototype glasses with Li2B4O7 (LBO) and KLiB4O7 (KLBO) compositions activated by Cr3+ ions. The work addressed to search for novel attractive media for broadband lasers and amplifiers, is a completion of detailed spectroscopic evaluation described in earlier papers. One of the examined materials (KLBO), in accordance with optimistic comments given in previous work, reveals a very broad gain spectrum in the near IR, which itself is interesting in view of very few reports on glasses showing optical gain for Cr3+ ions in the low-field local environment. The ESA/gain/bleaching spectra, registered with equipment of improved sensitivity, have been reproduced by calculations, and detailed single configuration coordinate diagram, based on experimental data, has been created for interpretation.

Graphical abstractCalculated ESA/gain/bleaching spectrum for the Li2B4O7:Cr (LBO) glass and calculated and observed ESA/gain/bleaching spectrum for the KLi2B4O7:Cr (KLBO) glass (a); and interpretation, by means of the configuration coordinate diagram, of the observed absorption, emission and excited state absorption/gain spectra based on experimental data and simulation of the spectra constituting the observed ESA spectra (b).Figure optionsDownload full-size imageDownload high-quality image (121 K)Download as PowerPoint slide