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

Table 1

Main properties of the 10 uniaxial birefringent crystals (part I), 4 biaxial birefringent crystals (part II), and 8 periodic poling crystals (part III) discussed in this work, including the chemical formula, the axis (uniaxial, biaxial, or isotropic), the point group, the transparency range , and the maximal nonlinear coefficient at different wavelengths (in m in the bracket). Most of the data were obtained from references [34, 35]. The crystal has different types of point group at different temperatures.  = . The calculated result is from [22] according to the method from [36].

Name (ref.)	Chemical formula	Axis	Point group	(m)	(pm/V)
CMTC		Uniaxial		0.402.35	= 6.2  1.2
THI		Uniaxial	4mm	1.0060.0	Unknown
[37]		Uniaxial	6	0.286.00	= 4.6  0.3
AAS		Uniaxial	3m	0.6113.3	= 16.6  2.5
HGS [38]		Uniaxial		0.5513.0	= 31.5  4.7
CGA [39]		Uniaxial	2m	2.3018.0	= 186  16
TAS		Uniaxial	3m	1.2817.0	= 68  31
AGS		Uniaxial	2m	0.4713.0	= 12.5  2.5
AGSe		Uniaxial	2m	0.7119.0	= 39.5  1.9
GaSe [40]		Uniaxial	2m	0.6220.0	= 54  11 [40]
LIS [41]		Biaxial	mm2	0.3413.2	= 16  4
LISe [42]		Biaxial	mm2	0.4614.0	= 16  4 [43]
LGS [44]		Biaxial	mm2	0.3211.6	= 10.7  2.7 [45]
LGSe [46]		Biaxial	mm2	0.3713.2	= 18.2  4.6 [45]
LT [47]		Uniaxial	3m	0.285.50	= 12.9
LN		Uniaxial	3m	0.405.50	= 25.2
KTP		Biaxial	mm2	0.354.50	= 14.6  0.7
KN		Biaxial	mm2	0.404.50	= 21.9  0.5 [48]
		Uniaxial	4mm (room temp.)	0.409.00	= 14.4  2.5
		Biaxial	mm2	0.1410.0	= 0.039
PMN-0.38PT [49]		Uniaxial	4mm	0.311.0	= 12.6
OP-ZnSe [50]		Isotropic	3m	0.4518.0	= 53.8