The optical properties of Bi3+ ions,with 6s2 electronic configuration,are extensively studied for potential phosphor,scintillator detectors as well as a spectroscopic probe for covalency.Bi3+ can be also used as sensitizer for luminescence of rare earth ions.The enhanced Eu3+ emission together with a red shift of the excitation edge(interesting for NUV pumping)has been reported in various Bi3+-Eu3+ doped inorganic materials.