Optical Molasses
Optical molasses is a laser cooling technique that can cool down neutral atoms to temperatures colder than a magneto-optical trap (MOT). An optical molasses consists of 3 pairs of counter-propagating circularly polarized laser beams intersecting in the region where the atoms are present. The main difference between optical molasses and a MOT is the absence of magnetic field in the former. While a typical Sodium MOT can cool atoms down to 300μK, optical molasses can cool the atoms down to 40μK, an order of magnitude colder.
Famous quotes containing the word optical:
“People who have realized that this is a dream imagine that it is easy to wake up, and are angry with those who continue sleeping, not considering that the whole world that environs them does not permit them to wake. Life proceeds as a series of optical illusions, artificial needs and imaginary sensations.”
—Alexander Herzen (1812–1870)