“…Hyperbolic metamaterials (HMMs), such as metallic nanowires embedded in dielectric materials [14,15], have shown the potential in numerous applications for far-field radiation [16][17][18][19][20][21], due to the unlimited length of propagating wave vector (i.e., high-k mode) and broadband enhancement on photonic density of state (PDOS) [16,17,[22][23][24][25][26][27][28] in addition to the epsilon-nearzero (ENZ) and epsilon-near-pole (ENP) modes [29]. Recently, nanowire-based HMMs have also been intensively studied for enhancing near-field thermal radiation by several times or even orders of magnitude over that with bulk materials [15,[22][23][24][30][31][32][33][34].…”