Amplitude-squared squeezing of coherent light coupled to a driven quantum oscillator with time-dependent mass and frequency
S. K. Singh, Swapan Mandal
The higher order moments and hence the amplitude-squared squeezing of input coherent light coupled to a quantum driven harmonic oscillator with time-dependent mass and frequency (DHTDMF) are investigated. Exact analytical expressions for the purpose of investigating the amplitude-squared squeezing of the input coherent light are exhibited. The squeezing in the normal sense of the input coherent light is independent of the driven term. On the other hand, the higher order (amplitude-squared) squeezing is sensitive to the driven term. In order to realize the flavour of the analytical approach, we give an interesting special case for the DHTDMF having ω(t) = ω(0) = ω, and driven term . It is found that the effects of the driven term are negligible if the oscillator is in the off-resonance situation. The condition of strong input coherent light also ensures the suppression of the effects of driven terms. By using a complete analytical method, we give an approximate analytical form of the relevant equations for investigating the amplitude-squared squeezed states. We carefully examine the special situations when the oscillator is underdamped, overdamped and critically damped (from both directions). The possibility of getting amplitude-squared squeezing of the input vacuum field is also discussed. To provide the feelings of the analytical results and hence the deep realizations of the physical system, we give a few results graphically. The realization of the present model in classical and in quantum mechanical pictures are clearly indicated.
Journal of Modern Optics•May 20, 2008•2 citations