Simple and practical method of characterizing the parametric down-conversion source

Wang Dong^{1, 2, †}, Wu Juan^{1, 2, †}, Zhao Liang-Yuan^{1, 2}, An Xue-Bi^{1, 2}, Yin Zhen-Qiang^{1, 2, ‡}, Chen Wei^{1, 2, ‡}, Han Zheng-Fu^{1, 2, ‡}, Wang Qin^{3, ‡}

(color online) (a) The mean photon number per pulse generated by the crystal with increasing pump power. (b) The photon channel transmission with increasing pump power.