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arXiv · 1805.09489

Second harmonic generation in atomically thin MoTe2

Yu Song·Ruijuan Tian·Jiulong Yang·Rui Yin·Jianlin Zhao·Xuetao Gan
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Abstract

We have studied on optical second harmonic generations (SHGs) from atomically thin MoTe2 flakes with 2H and 1T' phases. From 2H-MoTe2 samples with odd (even) numbers of layers, strong (negligible) SHGs are observed due to the layer-dependent broken inversion symmetry. When pumped by a telecom-band laser, SHG from a monolayer 2H-MoTe2 is about one order of magnitude stronger than that from a monolayer WS2; an extremely high second-order nonlinear susceptibility of 2.5 nm/V is estimated, presenting the highest value among those reported in two-dimensional materials. SHG measurements in MoTe2 are also demonstrated as an efficient way to distinguish the 2H-to-1T' phase transition. Comparing to the SHG in 2H-MoTe2, 1T'-MoTe2's SHG has much lower efficiency and the polarization dependence is changed from six-fold to two-lobe pattern.

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Yu Song, Ruijuan Tian, Jiulong Yang, Rui Yin, Jianlin Zhao, Xuetao Gan. 2018-05-24. Second harmonic generation in atomically thin MoTe2. https://arxiv.org/abs/1805.09489

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