Mid-infrared Spectrally Pure Single-Photon States Generation from 22 Nonlinear Optical Crystals

Figure 5

The result of all the QPM crystals for three kinds of GVM conditions. can achieve a purity of 0.97. can achieve a purity of 0.82. The wavelength versus achievable maximal spectral purity and poling period can be reflected on the scale of the left and right Y-axis. The wavelength range is from 1,224 nm to 7,944 nm, and the poling period is from 6.1 m to 1,301.38 m.