An upconversion random laser (RL) operating in the ultraviolet is reported for Nd3+ doped fluoroindate glass powder pumped at 575 nm. The RL is obtained by the resonant excitation of the Nd3+ state 2G7/2 followed by energy transfer among two excited ions such that one ion in the pair decays to a lower energy state and the other is promoted to state 4D7/2 from where it decays emitting light at 3...

We present new high-resolution coronographic imaging and medium-resolution spectroscopy of the circumstellar region around S 61 and BE 381, two Ofpe/WN9 stars in the Large Magellanic Cloud. The observations were carried out at the ESO/NTT (La Silla) in January 1996 and July 1998. The excellent seeing conditions allowed the circumstellar nebulae associated with both S 61 and BE 381 to be spatial...

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