A general criterion for non-classical state of light is given, by which two kinds of non-classical single-mode states (antibunching and squeezing) are discussed in detail.
We briefly review the ideas that have shaped modern optics and have led to various applications of light ranging from spectroscopy to astrophysics, and street lights to quantum communication. The review is primarily focused on the modern applications of classical light and nonclassical light. Specific attention has been given to the applications of squeezed, antibunched, and entangled states of radiation field. Applications of Fock states (especially single photon states) in the field of quantum communication are also discussed.
In this paper we discuss the non-classical and noise properties for a beam of coherent light through a nonlinear fibre with gain, and give the exact solutions of the Heisenberg-Langevin equations of motion of the operators, under the condition that the initial state is a two-mode coherent or two-mode squeezing vacuum state. Detailed numerical analysis of the results is performed and presented graphically. We find that squeezing and antibunching for the above mentioned state occur in some conditions, but no sub-Poissonian photon statistics occur. For example, when the average photon number of 1 mode is greater than the average photon number of 2 mode, the 1 mode is bunching, whereas the 2 mode is antibunching; the signal-to-noise ratio for a mode of radiation field can reach maximum values at an average photon number n¯ or at a moment t.
We present a detailed discussion of even and odd coherent states defined as eigenstates of the single mode two-photon annihilation operator a 2. We study the non-classical properties such as squeezing, higher-order squeezing, and photon antibunching. Also discussed are the various quantum quasiprobability distributions, namely the P function, which is shown to be highly singular, the Q function, and the Wigner, which can take on negative values for these states. Finally, we present a discussion of a possible mechanism for the generation of such states based on the competition between parametric amplification and the incoherent losses from two-photon resonant absorption.