## References

1.Maier, S.A.: Plasmonics: Fundamentals and Applications (Springer, Berlin, 2007).

2.Basov, D.N., Fogler, M.M., and García de Abajo, F.J.: Polaritons in van der Waals materials. Science 354, 195 (2016).

3.Poddubny, A., Iorsh, I., Belov, P., and Kivshar, Y.: Hyperbolic metamaterials. Nat. Photonics 7, 948 (2013).

4.Noginov, M., Lapine, M., Podolskiy, V.A., and Kivshar, Y.: Focus issue: hyperbolic metamaterials. Opt. Express 21, 14895 (2013).

5.Caldwell, J.D., Kretinin, A., Chen, Y., Giannini, V., Fogler, M.M., Francescato, Y., Ellis, C., Tischler, J.G., Woods, C., Giles, A.J., Hong, M., Watanabe, K., Taniguchi, T., Maier, S.A., and Novoselov, K.S.: Sub-diffractional, volume-confined polaritons in the natural hyperbolic material hexagonal boron nitride. Nat. Commun. 5, 5221 (2014).

6.Li, P., Lewin, M., Kretinin, A.V., Caldwell, J.D., Novoselov, K.S., Taniguchi, T., Watanabe, K., Gaussmann, F., and Taubner, T.: Hyperbolic phonon-polaritons in boron nitride for near-field optical imaging and focusing. Nat. Commun. 6, 7507 (2015).

7.Dai, S., Fei, Z., Ma, Q., Rodin, A.S., Wagner, M., McLeod, A.S., Liu, M.K., Gannett, W., Regan, W., Thiemens, M., Dominguez, G., Castro Neto, A.H., Zettl, A., Keilmann, F., Jarillo-Herrero, P., Fogler, M.M., and Basov, D.N.: Tunable phonon polaritons in atomically thin van der Waals crystals of boron nitride. Science *(*Washington*)* 343, 1125 (2014).

8.Dai, S., Ma, Q., Anderson, T., McLeod, A.S., Fei, Z., Liu, M.K., Wagner, M., Watanabe, K., Taniguchi, T., Thiemens, M., Keilmann, F., Jarillo-Herrero, P., Fogler, M.M., and Basov, D.N.: Subdiffractional focusing and guiding of polaritonic rays in a natural hyperbolic material. Nat. Commun. 6, 6963 (2015).

9.Liu, Z., Lee, H., Xiong, Y., Sun, C., and Zhang, X.: Far-field optical hyperlens magnifying sub-diffraction limited objects. Science 315, 1686 (2007).

10.Alfaro-Mozaz, F.J., Alonso-González, P., Vélez, S., Dolado, I., Autore, M., Mastel, S., Casanova, F., Hueso, L.E., Li, P., Nikitin, A.Y., and Hillenbrand, R.: Nanoimaging of resonating hyperbolic polaritons in linear boron nitride antennas. Nat. Commun. 8, 15624 (2017).

11.Folland, T.G., Fali, A., White, S.T., Matson, J.R., Liu, S., Aghamiri, N.A., Edgar, J.H., Haglund, R.F., and Abate, Y. and Caldwell, J.D.: Reconfigurable Mid-Infrared Hyperbolic Metasurfaces using Phase-Change Materials, (arXiv:1805.08292, 2018).

12.Autore, M., Li, P., Dolado, I., Alfaro-Mozaz, F.J., Esteban, R., Atxabal, A., Casanova, F., Hueso, L.E., Alonso-González, P., Aizpurua, J., Nikitin, A.Y., Vélez, S., and Hillenbrand, R.: Boron nitride nanoresonators for phonon-enhanced molecular vibrational spectroscopy at the strong coupling limit. Light: Sci. Appl. 7, 17172 (2018).

13.Sreekanth, K.V., Alapan, Y., ElKabbash, M., Ilker, E., Hinczewski, M., Gurkan, U.A., De Luca, A., and Strangi, G.: Extreme sensitivity biosensing platform based on hyperbolic metamaterials. Nat. Mater. 15, 621 (2016).

14.Hoffman, A.J., Alekseyev, L., Howard, S.S., Franz, K.J., Wasserman, D., Podolskiy, V.A., Narimanov, E.E., Sivco, D.L., and Gmachl, C.: Negative refraction in semiconductor metamaterials. Nat. Mater. 6, 946 (2007).

15.Yao, J., Liu, Z., Liu, Y., Wang, Y., Sun, C., Bartal, G., Stacy, A.M., and Zhang, X.: Optical negative refraction in bulk metamaterials of nanowires. Science 321, 930 (2008).

16.Korzeb, K., Gajc, M., and Pawlak, D.A.: Compendium of natural hyperbolic materials. Opt. Express 23, 25406 (2015).

17.Zebo, Z., Jianing, C., Yu, W., Ximiao, W., Xiaobo, C., Pengyi, L., Jianbin, X., Weiguang, X., Huanjun, C., Shaozhi, D., and Ningsheng, X.: Highly confined and tunable hyperbolic phonon polaritons in van der Waals semiconducting transition metal oxides. Adv. Mater. 30, 1705318 (2018).

18.Caldwell, J.D., Lindsey, L., Giannini, V., Vurgaftman, I., Reinecke, T., Maier, S.A., and Glembocki, O.J.: Low-loss, infrared and terahertz nanophotonics with surface phonon polaritons. Nanophotonics 4, 44 (2015).

19.Brown, L.V., Davanco, M., Sun, Z., Kretinin, A., Chen, Y., Matson, J.R., Vurgaftman, I., Sharac, N., Giles, A.J., Fogler, M.M., Taniguchi, T., Watanabe, K., Novoselov, K.S., Maier, S.A., Centrone, A., and Caldwell, J.D.: Nanoscale mapping and spectroscopy of nonradiative hyperbolic modes in hexagonal boron nitride nanostructures. Nano Lett. 18, 1628 (2018).

20.Giles, A.J., Dai, S., Vurgaftman, I., Hoffman, T., Liu, S., Lindsay, L., Ellis, C.T., Assefa, N., Chatzakis, I., Reinecke, T.L., Tischler, J.G., Fogler, M.M., Edgar, J.H., Basov, D.N., and Caldwell, J.D.: Ultralow-loss polaritons in isotopically pure boron nitride. Nat. Mater. 17, 134 (2018).

21.Li, P., Dolado, I., Alfaro-Mozaz, F.J., Casanova, F., Hueso, L.E., Liu, S., Edgar, J.H., Nikitin, A.Y., Vélez, S., and Hillenbrand, R.: Infrared hyperbolic metasurface based on nanostructured van der Waals materials. Science 359, 892 (2018).

22.Vuong, T., Liu, S., Van der Lee, A., Cuscó, R., Artús, L., Michel, T., Valvin, P., Edgar, J., Cassabois, G., and Gil, B.: Isotope engineering of van der Waals interactions in hexagonal boron nitride. Nat. Mater. 17, 152 (2018).

23.Low, T., Chaves, A., Caldwell, J.D., Kumar, A., Fang, N.X., Avouris, P., Heinz, T.F., Guinea, F., Martin-Moreno, L., and Koppens, F.H.L.: Polaritons in layered two-dimensional materials. Nat. Mater. 16, 182 (2017).

24.Uchida, S.-I. and Tanaka, S.: Optical phonon modes and localized effective charges of transition-metal dichalcogenides. J. Phys. Soc. Jpn. 45, 153 (1978).

25.Raether, H.: Surface Plasmons on Smooth and Rough Surfaces and on Gratings (Springer-Verlag, Berlin, New York, 1988).

26.Dai, X., Jiang, L., and Xiang, Y.: Tunable THz angular/frequency filters in the modified Kretschmann Raether configuration with the insertion of single layer graphene. IEEE Photonics J. 7, 1 (2015).

27.Passler, N.C. and Paarmann, A.: Generalized 4 × 4 matrix formalism for light propagation in anisotropic stratified media: study of surface phonon polaritons in polar dielectric heterostructures. J. Opt. Soc. Am. B 34, 2128 (2017).

28.Maß, T.W.W. and Taubner, T.: Incident angle-tuning of infrared antenna array resonances for molecular sensing. ACS Photonics 2, 1498 (2015).

29.Luo, L. and Tang, T.: Goos-Hänchen effect in Kretschmann configuration with hyperbolic metamaterials. Superlattices Microstruct. 94, 85 (2016).

30.Zhang, C., Hong, N., Ji, C., Zhu, W., Chen, X., Agrawal, A., Zhang, Z., Tiwald, T.E., Schoeche, S., Hilfiker, J.N., Guo, L.J., and Lezec, H.J.: Robust extraction of hyperbolic metamaterial permittivity using total internal reflection ellipsometry. ACS Photonics 5, 2234 (2018).

31.Born, M. and Wolf, E.: Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light (Cambridge University Press, Cambridge, New York, 1999).

32.Taniguchi, T. and Watanabe, K.: Synthesis of high-purity boron nitride single crystals under high pressure by using Ba-BN solvent. J. Cryst. Growth 303, 525 (2007).

33.Liu, S., He, R., Xu, L., Li, J., Liu, B., and Edgar, J.H.: Single Crystal growth of mm-sized monoisotopic hexagonal boron nitride. Chem. Mater. (2018) DOI:10.1021/acs.chemmater.8b02589 34.Yoxall, E., Schnell, M., Nikitin, A.Y., Txoperena, O., Woessner, A., Lundeberg, M.B., Casanova, F., Hueso, L.E., Koppens, F.H.L., and Hillenbrand, R.: Direct observation of ultraslow hyperbolic polariton propagation with negative phase velocity. Nat. Photonics 9, 674 (2015).

35.Schuller, J.A., Zia, R., Taubner, T., and Brongersma, M.L.: Dielectric metamaterials based on electric and magnetic resonances of silicon carbide particles. Phys. Rev. Lett. 99, 107401 (2007).

36.Kuznetsov, A.I., Miroshnichenko, A.E., Brongersma, M.L., Kivshar, Y.S., and Luk'yanchuk, B.: Optically resonant dielectric nanostructures. Science 354, aag2472 (2016).

37.Caldwell, J.D., Glembocki, O.J., Sharac, N., Long, J.P., Owrutsky, J.O., Vurgaftman, I., Tischler, J.G., Bezares, F.J., Wheeler, V., Bassim, N.D., Shirey, L., Francescato, Y., Giannini, V., and Maier, S.A.: Low-loss, extreme sub-diffraction photon confinement via silicon carbide surface phonon polariton nanopillar resonators. Nano Lett. 13, 3690 (2013).

38.Staude, I., and Schilling, J.: Metamaterial-inspired silicon nanophotonics. Nat. Photonics 11, 274 (2017).

39.Ginn, J.C., Brener, I., Peters, D.W., Wendt, J.R., Stevens, J.O., Hines, P.F., Basilio, L.I., Warne, L.K., Ihlefeld, J.F., Clem, P.G., and Sinclair, M.B.: Realizing optical magnetism from dielectric metamaterials. Phys. Rev. Lett. 108, 097402 (2012).

40.Howes, A., Wang, W., Kravchenko, I., and Valentine, J.: Dynamic transmission control based on all-dielectric Huygens metasurfaces. Optica 5, 787 (2018).

41.Li, W. and Valentine, J.: Metamaterial perfect absorber based hot electron photodetection. Nano Lett. 14, 3510 (2014).

42.Giles, A.J., Dai, S., Glembocki, O.J., Kretinin, A.V., Sun, Z., Ellis, C.T., Tischler, J.G., Taniguchi, T., Watanabe, K., Fogler, M.M., Novoselov, K.S., Basov, D.N., and Caldwell, J.D.: Imaging of anomalous internal reflections of hyperbolic phonon-polaritons in hexagonal boron nitride. Nano Lett. 16, 3858 (2016).

43.Ishii, S., Kildishev, A.V., Narimanov, E.E., Shalaev, V.M., and Drachev, V.P.: Sub-wavelength interference pattern from volume plasmon polaritons in a hyperbolic medium. Laser Photonics Rev. 7, 265 (2013).