This is a self-trapped beam of light that creates its own waveguide as it travels through a nematic liquid crystal. The intense electric field of the laser reorients the liquid crystal molecules, locally increasing the refractive index just enough to balance the natural divergence of the beam. Researchers use them to steer light with light or to create reconfigurable optical interconnects.
The nematicon remains stable over several millimeters, acting like a liquid optical fiber for the signal beam.
Related terms
Self-phase modulation
Spectral broadening of an intense pulse caused by its own intensity changing the refractive index it travels through.
Divergence
How fast a laser beam spreads with distance far from its waist, given as an angle in milliradians.
Gaussian beam
A beam whose intensity falls off from the center as a bell curve, the shape of an ideal single-mode laser.