Bridging the scalability gap in van der Waals light guiding with high refractive index MoTe2.

van der Waals transition metal dichalcogenides, distinguished by a high refractive index and giant optical anisotropy, are promising materials for integrated photonic devices. However, their superior optical properties are nowadays limited to exfoliated samples with only a micrometer scale, whereas industrial integration requires at least cm-scale dimensions. Here, we resolve this problem for MoTe2 by demonstrating that chemical vapor deposition synthesis can provide an identical optical response to the benchmark exfoliated samples in a broad spectral range (250-5,000 nm). It allows us to show high-performance waveguiding properties of MoTe2 with a subwavelength footprint of ∼λ/8 for telecommunication wavelengths. Therefore, our findings reveal MoTe2 as an ideal platform for the next-generation nanophotonics.