Abstract

The uncertainty principle in general requires that "back-action" noise is introduced into an optical field after it has been measured, so that the precision of subsequent measurements is progressively reduced. However, it has been shown that one quadrature component of the field can be measured without changing its quantum state; i.e. a quantum nondemolition, or more precisely, a back-action evasion measurement can be performed.

© 1988 Optical Society of America