High-power 980-nm pump laser modules for erbium-doped fiber amplifiers.

High-power fiber-coupled pump modules with an emission wavelength of 980 nm and output powers in excess of 200 mW, as measured at the fiber end, have been fabricated. Laser-to-fiber coupling efficiencies in excess of 77% are observed to be in excellent agreement with a mathematical model. Also, the output power stability of these modules has been monitored during severe temperature cycling, and the relative power variation was less than 4% for all the tested modules.

Pattern of efficacy of a musical mnemonic on recall of familiar words over several presentations.

It has been demonstrated that musical accompaniment may aid recall of words. This study examined the mnemonic effect of music on recall of verbal material which contained no unfamiliar words over three presentations. 20 participants (average age 21.9 yr.) were randomly allocated to one of two experimental conditions and heard the to-be-remembered lyrics either being sung or read aloud without musical accompaniment. Analysis of both total number of words correctly recalled and the extent of chunking of recalled material showed better over-all recall in the song condition with evidence of greater chunking of material.