Interaction of Tm3+ ions in calcium-niobium-gallium and yttrium-aluminum garnet laser crystals

The cross relaxation of Tm3+ ions (on the 3H4→3F4, 3H6→3F4 transitions) has been studied in CNGG and YAG laser crystals. The radiationless transfer of energy from Cr3+ ions to Tm3+ ions has been studied in YAG crystals. The interaction between these ions is shown to be due to dipole-dipole and shorter-range quadrupole-quadrupole mechanisms.