b7 optical constants
nm
NK
300	1.7458	0.10534
310	1.7469	0.094593
320	1.7153	0.086701
330	1.7124	0.075826
340	1.7214	0.067546
350	1.7192	0.060391
360	1.7267	0.052889
370	1.7253	0.046406
380	1.7242	0.041158
390	1.7219	0.036203
400	1.7196	0.031782
410	1.717	0.028392
420	1.7141	0.024741
430	1.7112	0.021775
440	1.7086	0.01932
450	1.7055	0.016471
460	1.7037	0.016648
470	1.7006	0.014353
480	1.6973	0.011895
490	1.6947	0.010253
500	1.6928	0.009957
510	1.6904	0.008809
520	1.6887	0.0078601
530	1.6859	0.0072742
540	1.6842	0.0064531
550	1.6827	0.0063994
560	1.6807	0.0054589
570	1.6791	0.0045879
580	1.6777	0.0042043
590	1.6764	0.0036591
600	1.6753	0.003028
610	1.6742	0.002631
620	1.6726	0.0022877
630	1.6722	0.0022497
640	1.6706	0.0021617
650	1.6702	0.0016218
660	1.6688	0.00136
670	1.6685	0.0013029
680	1.6676	0.00080671
690	1.6669	0.001088
700	1.6666	0.00040265
710	1.6657	0.00026665
720	1.6652	0.0004649
730	1.6648	0.00013828
740	1.6643	0.00011195
750	1.6635	9.9191e-06
760	1.6622	0.00049891
770	1.6628	0.00053963
780	1.6611	0.00015079
790	1.6615	0.00038134
800	1.6612	-8.8567e-05
810	1.662	-0.0014796
820	1.6615	-0.0021474
830	1.6606	-0.00054675
840	1.6595	0.0015394
850	1.66	-0.00068669
860	1.6592	-0.00027604
870	1.6602	-0.0015261
880	1.659	0.0002988
890	1.6607	-0.0080687
900	1.6604	-0.0070926
910	1.66	-0.0078771
920	1.6587	-0.002753
930	1.6577	0.00014529
940	1.6583	-0.0029657
950	1.6581	-0.0017803
960	1.6587	-0.0041463
970	1.6574	-0.001202
980	1.6586	-0.0077938
990	1.6578	-0.0011896
1000	1.6564	0.0036347