A BIT
OF THE PHYSICS:
A single beam of tightly focused
laser light creates an extremely high electric field gradient in the vicinity
of the focus. Similar to the force which draws a dielectric into the high
field region of a capacitor, a dielectric particle falling within the laser
beam will experience a force which is directed towards the focus of the
beam. Provided the numerical aperture of the focusing optics is high, the
so called "optical tweezers" give rise to a 3-dimensional trap. The force
due to the field gradient is sufficiently high to overcome the forces due
to both gravity and radiation pressure. The particles can be moved
around in three dimensions.
MY OPTICAL
TWEEZERS:
I'll tell you more when I
have time!
OT WORLD:
Other
people's sites can be found here!
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