EKHI

Curve 1

Temperature, K: ~298 Wavelength Range, µm: 34.8-40.8 Geometry θ θ': 30° 30° Composition (weight percent), Specifications, and Remarks: NaCl (1.35 µm thick); aluminum mirror substrate; NaCl evaporated on substrate; measured relative to aluminum mirror.

Wavelength / 𝜇m	Reflectance /
34.8	0.996
35.3	0.928
35.8	0.848
36.3	0.823
36.9	0.811
37.3	0.794
37.8	0.834
38.4	0.847
38.9	0.88
39.5	0.89
40.0	0.916
40.8	0.973

Curve 2

Temperature, K: ~298 Wavelength Range, µm: 34.0-41.8 Geometry θ θ': 30° 30° Composition (weight percent), Specifications, and Remarks: Similar to the above specimen and conditions except NaCl 2.34 µm thick.

Wavelength / 𝜇m	Reflectance /
34.0	0.965
34.9	0.959
35.3	0.946
35.8	0.818
36.3	0.813
36.7	0.73
37.3	0.712
37.8	0.752
38.3	0.752
38.9	0.743
39.3	0.768
39.8	0.821
40.9	0.956
41.8	0.959

Curve 3

Temperature, K: ~298 Wavelength Range, µm: 25.9-41.8 Geometry θ θ': 30° 30° Composition (weight percent), Specifications, and Remarks: Similar to the above specimen and conditions except NaCl 5.51 µm thick.

Wavelength / 𝜇m	Reflectance /
25.9	0.95
27.9	0.921
28.9	0.849
29.4	0.834
29.9	0.841
30.4	0.817
30.9	0.804
31.4	0.791
31.9	0.778
32.4	0.776
32.8	0.743
33.4	0.714
33.8	0.69
34.3	0.668
34.9	0.656
35.4	0.656
35.8	0.637
36.3	0.613
36.9	0.584
37.4	0.595
37.8	0.617
38.4	0.621
38.7	0.614
39.3	0.65
40.0	0.699
40.3	0.84
40.8	0.871
41.8	0.919

Far-Infrared Absorption Due to the Virtual Modes in NaCl