Patent ID: 8676063

Claim:
A method of generating correlated photon pairs, comprising: simultaneously inputting excitation light and auxiliary signal light to a nonlinear optical medium, input of the excitation light causing quantum correlated photon pairs to be generated by spontaneous parametric fluorescence, each quantum correlated photon pair including a signal photon and an idler photon, input of the auxiliary signal light and the excitation light causing auxiliary idler light to be generated by a stimulated parametric conversion process; detecting intensities of the auxiliary idler light and the auxiliary signal light output from the nonlinear optical medium; and controlling at least one of an intensity of the excitation light, a wavelength of the excitation light, and a temperature of the nonlinear optical medium according to the detected intensities of the auxiliary idler light and the auxiliary signal light, thereby holding a ratio of the detected intensities at a preset value.