Phonon-polaritons are quasiparticles formed by the coupling of photons with optical phonons in polar dielectric materials. They exist predominantly in the mid-infrared to terahertz spectral range, within the so-called Reststrahlen band, where the real part of the permittivity becomes negative due to strong lattice vibrations. In this regime, surface phonon-polaritons or volume-confined hyperbolic phonon-polaritons can be excited. These modes combine the best of two worlds: the long lifetimes and low optical losses of phonons with the strong electromagnetic field confinement of polaritons. As a result, phonon polaritons enable extreme subwavelength light manipulation, long propagation lengths, and novel applications in the mid-IR and THz regimes. In our group, we explore how to tailor and enhance phonon polaritons in polar dielectrics