Abstract
Shortly after Hawking’s prediction of thermal radiation from black holes, it became apparent that observers in accelerating frames should see a Planck distribution of electromagnetic radiation (Unruh radiation). Since an acceleration g=980 cm/ produces a radiation temperature of only ∼4× K, the detection of such thermal radiation is a major challenge. A nonlinear optical medium whose index of refraction is changing rapidly with time accelerates zero-point quantum fluctuations. The sudden ionization of a gas or a semiconductor crystal to generate a plasma on a subpicosecond time scale can produce a reference frame accelerating at ∼g relative to an inertial frame.
- Received 6 July 1988
DOI:https://doi.org/10.1103/PhysRevLett.62.1742
©1989 American Physical Society