Table 1 Naturally occuring hypebolic materials and their operating wavelengths

UV

Graphite (C) [30]

0.24–0.28

Magnesium diboride (\(\text {MgB}_2\)) [32]

0.33–0.42

Bismuth telluride (\(\text {Bi}_2\text {Te}_3\)) [45]

0.31–1.38

VIS-NIR

Bismuth selenide (\(\text {Bi}_2\text {Se}_3\)) [45]

0.709–1.180

Ruthenates (\(\text {Sr}_2\text {RuO}_4\),\(\text {Sr}_3\text {Ru}_2\text {O}_7\)) [33]

1.49

Hexagonal boron nitride (hBN) [31]

6.2–7.3, 12.1–13.2

\(\alpha \text {-MoO}_{3}\) [46, 47]

9.9–18.3

IR

\(\alpha \text {-V}_{2}\text {O}_{5}\) [48]

9.6–19.7

Sapphire(\(\text {Al}_2\text {O}_3\)) [36]

20

Bismuth (Bi) [36]

53.7–63.2

Calcite (\(\text {CaCO}_3\)) [44]

6.45–7.09, 13.99–14.04