Ultra-strong nonlinear optical processes and trigonal warping in MoS₂ layers.

ABSTRACT: Nonlinear optical processes, such as harmonic generation, are of great interest for various applications, e.g., microscopy, therapy, and frequency conversion. However, high-order harmonic conversion is typically much less efficient than low-order, due to the weak intrinsic response of the higher-order nonlinear processes. Here we report ultra-strong optical nonlinearities in monolayer MoS₂ (1L-MoS₂): the third harmonic is 30 times stronger than the second, and the fourth is comparable to the second. The third harmonic generation efficiency for 1L-MoS₂ is approximately three times higher than that for graphene, which was reported to have a large χ ⁽³⁾. We explain this by calculating the nonlinear response functions of 1L-MoS₂ with a con

SUBMITTER: Saynatjoki A 

PROVIDER: S-EPMC5715017 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature