Eu3+ and Sm3+ co-activated aluminum germanate glass channel waveguide as irradiation source for photodynamic therapy

A bright and compact orangish-red fluorescence trace is observed in an Eu3+/Sm3+ co-doped K+Na+ ion-exchanged aluminum germanate (NMAG) glass channel waveguide under excitation with a 488 nm Ar+ laser. The excitation wavelength range and the emission intensity of Eu3+ in NMAG glass are remarkably improved by the sensitization of Sm3+, and the energy transfer probability and efficiency are calculated to be 151.2 s−1 and 25.3%, respectively. Meanwhile, the energy transferred from Sm3+ can be efficiently utilized to generate intense fluorescence of Eu3+ due to the large spontaneous emission probabilities of the Eu3+: 5D0→7FJ (J=1, 2, and 4) transitions that reach up to 68.9, 364.7, and 152.6 s−1, respectively. Enhanced fluorescence in the Eu3+/Sm3+-doped NMAG glass channel waveguide, which matches the excitation band of most photosensitizers, holds great promise for photodynamic therapy.