Calculating the parameters of the biphoton radiation source in a wide wavelength range

In this paper, we develop a constructive algorithm to determine the parameters of a nonlinear crystal for generating correlated photons in a given wavelength range using the effect of spontaneous parametric scattering. The developed method is used to calculate the parameters of a barium beta borate crystal capable of generating biphoton radiation in the wavelength range from 0.548 to 1.55 $\mu$m at a pumping wavelength of 0.405 $\mu$m. The experiment that confirms the method's efficiency is described.