Structure of the R1 and R2 Bands of Isotopes of Cr3+ Ion in a Single Crystal of Ruby at Room Temperature

Room-temperature absorption and luminescence spectra of the R1 and R2 bands in a single crystal of Ruby Al2O3:Cr3+ (0.05%) are analyzed. The luminescence in these bands was induced both by crystal excitation by radiation of a halogen lamp and by selective excitation of two upper levels of the 2T1 state by radiation of a tunable laser diode (656–662 nm). Four different shifts of the R1 and R2 bands and four different distances between these bands the change in which is a multiple of ~0.52 cm–1 are discovered in spectra of se-lectively excited luminescence bands. Detailed comparative analysis of the obtained spectral bands of luminescence and corresponding absorption spectra allowed determining combined structure of each of the R1 and R2 bands formed by satellite doublets of these bands associated with all four stable isotopes 50Cr3+, 52Cr3+, 53Cr3+, and 54Cr3– of chromium ions. Splitting of these doublets varies from 7.04 to 9.14 сm–1 depending on the isotope mass.