Gravitationally Squeezed Light
General Relativity & Gravitation
Normally, pure states of coherent light have equal uncertainties for pairs of conjugate variables. In recent years, however, it has become possible to produce and detect light in which fluctuations of one of the quadrature components are suppressed below the corresponding flutuations of a coherent state. Such radiation is said to be in a squeezed state. We explore the possibility that a strong gravitational field can produce a squeezed state of light. Such squeezing does in fact occur, and we derive an expression for the resulting uncertainties in a high frequency or long time limit. These results comprise a new, testable prediction of general relativity.
Wheeler, J. T., Gravitationally squeezed light, General Relativity & Gravitation, Vol 21,No 3, March (1989) 293 - 305.