in Slovenia has made a breakthrough that has resulted in the world's
first microlaser that emits in 3D. The new 3D
microlaser was created at the Jožef Stefan Institute in
Ljubljana, Slovenia.The laser that has been developed is
small, tunable, and cheap to build making it the world's first
practical 3D laser. The laser has been described in a recent issue of
Optics Express and was developed by Matjaž Humar and Igor Muševic.
The laser is a microdroplet 3D laser system that allows light to
shine in all directions using a dye molecule lodged inside spherical
drops of helical molecules that are dispersed in a liquid.Muševic
said, "This is the first practical 3-D laser ever produced."
He believes that millions of the microdroplet lasers can be made in
seconds and can then be used in coherent light emitters. The helical
molecules used in the novel lasers are choleric liquid crystals that
are similar to the key molecules used inside LCDs.
molecules don’t mix well with the polymer liquid that surrounds
them. The inability of the two to mix creates an index of refraction
that varies periodically outward through the body of the 15 micron
droplets. The researchers describe the molecules like an onion with
the layers corresponding to materials with different index of
refraction.The active medium inside the new lasers is the
florescent dye molecules that are inside the liquid crystals. The
lasers are very easy to build because the molecules self assemble
according to chemistry meaning that no fabrication process is
needed."Scientists have been trying to make these lasers
from solid state materials, but you can imagine how difficult it is
to make hundreds of alternating shells of optical materials, which
should be very uniform," said Muševic. "The beauty of our
approach is that such a 3-D onion droplet is self-assembled in a
fraction of a second."The scientists also say that the
laser can be tuned without needing to replace the droplets. Tuning
can be done my modifying the temperature of the laser and possibly by
applying an additional electric filed.