Abstract

It has long been recognised that the ultimate accuracy of optical measurements is set by the quantum nature of light. The use of coherent laser sources typically provides a limiting resolution that is inversely proportional to the square root of the mean number of photons used in the measurement. This can be improved upon by the use of quantum states of light. Few years ago it was experimentally demonstrated how squeezed light can be used to enhance the resolution of measurements of small displacements in optical images, or beam displacements [1]. In this work we discuss measurements of beam rotations about the optical axis and identify the factors limiting the resolution [2].

© 2007 IEEE