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

► Eu3+/Sm3+ doped waveguides are identified as a potential medical light source. ► Orangish-red fluorescence holds great promise for photodynamic therapy. ► Energy transfer probability and efficiency of Sm3+→Eu3+ are 151.2 s−1 and 25.3%. ► Energy is efficiently utilized due to the large emission probabilities of Eu3+.