Steven Chu, along with Claude Cohen-Tannoudji and William D. Phillips, were awarded the Nobel Prize in Physics in 1997 for their groundbreaking contributions to the development of methods to laser cool and trap atoms with laser light. Chu and his colleagues developed a technique called "optical molasses," which involved using carefully tuned laser beams to slow down and cool atoms in three dimensions. This process was akin to slowing down the atoms and confining them using an "optical trap."