The word laser now has a strong emo-I tional impact, conjuring up images of I space-battles anil high-tech surgery. There was a time when this strange acronym, as yet unloved by science-fiction writers, conjured up nothing at all to a general audience. What is more, scientists thought of the laser as nothing more than a curiosity brought forth by optical physicists and engineers, fascinating perhaps, but little more. It was termed, admittedly by the unkind, 'a solution in search of a problem". We now have the beginnings of a new type of solution — a new type of laser. This is not a source of light but of matter, in the form of alkali atoms. In the 27 January issue of Physical Review Letters, a group at MIT led by Wolfgang Ketterle describe an 'output coupler' that allows pulses of matter to escape in a narrow beam from a trapped Bose-Einstein condensate (Figs 1 and 2). In the 31 January edition of Science, the same group show that this beam is coherent, an essential test of laser behaviour.
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