RE: [escepticos] Luz lenta

["Pedro J. Hernández" <phgt@...>]

Javier Susaeta escribió:

> En el condensado ése de Bose-Einstein, y para que la noticia fuera cierta,
>el índice de refracción tendría que alcanzar valores altísimos (n=17665022,
>si no me he equivocado) pero claro, el tal condensado es un estado atípico
>de la materia, y a lo mejor es así.
>
> Supongo que no, que se tratará de un malentendido...

Pues ahí va otra fuente supuestamente fiable

PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News
Number 415 February 18, 1999   by Phillip F. Schewe and Ben
Stein

LIGHT HAS BEEN SLOWED TO A SPEED OF 17 m/sec by
passing it through a Bose-Einstein condensate (BEC) of sodium
atoms at nK temperatures.  In general light is slowed in certain
materials, a property exploited in making optical lenses.  As the
index of refraction of these materials gets higher, however,
absorption increasingly takes its toll on the light beam.  In an
experiment at Harvard (Lene Vestergaard Hau, hau en rowland.org),
physicists have used a BEC (and its enormous index of refraction)
as the optical medium, but with the following important
modification.  They contrived a system of laser beams whose
pattern of interference created an effect called electromagnetically
induced transparency, allowing light to propagate unabsorbed but
at greatly reduced speeds, in this case a factor of twenty million
compared to the speed of light in vacuum; greater light-speed slow
downs are expected, to as low as cm/sec.  The researchers also
observed unprecedentedly large intensity-dependent light
transmission.  Such an extreme nonlinear effect can perhaps be
used in a number of opto-electronic components (switches,
memory, delay lines) and in converting light from one wavelength
to another.  (Hau et al., Nature, 18 February 1999.)

un saludo
Pedro J. Hernández
phgt en correo.rcanaria.es
**La web de Pedro J**
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