Generation of squeezed states in the presence of a frequency difference

Gunnar G. Bjork, Olle Nilsson, Y. Yamamoto +1 more

Rafael Julius, Azrul Nizam Alias, Muhammad Syawal Abd Halim

We report an examination on the possibility of generating enhanced squeezed light over two octaves of frequency difference, with each octave incorporating two-channel nonlinear waveguides suited for the fundamental, second, and fourth harmonic modes. We investigate the behavior of squeezing owing to the presence of evanescent coupling in scenarios for traveling-wave and intracavity cases. We show that the existing technique may generate enhanced squeezing in a frequency range spanning the fourth harmonic.

Paula B. Monteiro, Adriano Aragão, Ardiley Torres Avelar +1 more

Mark S. Hillery

Sum and difference squeezing are both higher-order, two-mode squeezing effects. Sum squeezing is turned into normal squeezing by sum-frequency generation. The operators that are used to define it form a representation of the su(1,1) Lie algebra. Difference squeezing can generate normal squeezing through difference-frequency generation. The operators that characterize it form a representation of the su(2) Lie algebra. Both are nonclassical effects. For uncorrelated modes the presence of squeezing in at least one of the modes is a necessary condition for the existence of either sum or difference squeezing. If the modes are correlated this is no longer true. Both sum and difference squeezing can be generated by combining a squeezed mode with one in a coherent state. Sum squeezing is also produced by a parametric amplifier. In order to better illustrate some of these effects a pictorial representation of sum squeezing is presented.

А. Н. Ораевский

Meijuan Wu, Shiqun Li, Ling-An Wu

We investigate the quantum fluctuations of the fields produced in sum- and difference- frequency generation from light initially in the squeezed state. Under certain conditions the output may also be squeezed.