Squeezing and Sub-Poissonian Effects of Light in Third Harmonic Generation

摘要

The squeezing and sub-Poissonian effects of light in third harmonic generation are investigated based on the fully quantum mechanical approach up to the first order Hamiltonian interaction in gt, where g is the coupling constant between the modes per second and t is the interaction time between the waves during the process in a nonlinear medium. The coupled Heisenberg equations of motion involving real and imaginary parts of the quadrature operators are established. The occurrence of amplitude squeezing effects in both the quadratures of the radiation field in the fundamental mode is investigated and found to be dependent on the selective phase values of the field amplitude. The photon statistics of the pump mode in this process have also been investigated and found to be sub-Poissonian in nature. It is shown that for particular phase values the amplitude squeezing and sub-Poissonian photon statistics of light occur simultaneously. It is observed that there is no possibility to produce squeezed light in the harmonic mode up to first-order interaction in gt. Further, it is found that the normal squeezing in the harmonic mode directly depends upon the amplitude-cubed squeezing of the initial pump field to the case of second-order interaction in gt. This gives a method of converting higher-order (amplitude-cubed) squeezing of the fundamental mode into normal squeezing of the harmonic mode and vice versa.