ИСТИНА

We investigate both theoretically and experimentally the spectral features and correlations in macroscopic (bright) squeezed quantum states of light generated in high-gain parametric down-conversion process. To describe theoretically the spectral features of parametric squeezed light we develop a generalized fully analytical approach, based on the concept of independent collective (Schmidt) modes and valid for the cases of both weak and strong nonlinear interaction. We suggest a method based on two separated crystals which provides control and engineering the spectrum of the generated BSV light by timing of the pump. The obtained results are understood and explained in terms of the introduced Schmidt modes in the frame of our developed theory and a very good agreement between the theoretical predictions and experimentally observed results is found.