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Microwatts continuous-wave pumped second harmonic generation in few- and mono-layer GaSe.

ABSTRACT: We demonstrate the first achievement of continuous-wave (CW) pumped second harmonic generation (SHG) in few- and mono-layer gallium selenide (GaSe) flakes, which are coated on silicon photonic crystal (PC) cavities. Because of ultrahigh second order nonlinearity of the two-dimensional (2D) GaSe and localized resonant mode in the PC cavity, SHG's pump power is greatly reduced to microwatts. In a nine-layer GaSe coated PC cavity, while the optical power inside the GaSe flake is only 1.5% of that in the silicon PC slab, the SHG in GaSe is more than 650 times stronger than the third harmonic generation in silicon slab, indicating 2D GaSe's great potentials to strengthen nonlinear processes in silicon photonics. Our study opens up a new view to expand 2D materials' optoelectronic applications in nonlinear regime and chip-integrated active devices.

SUBMITTER: Gan XT

PROVIDER: S-EPMC6107046 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

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Microwatts continuous-wave pumped second harmonic generation in few- and mono-layer GaSe.

Gan Xue-Tao XT Zhao Chen-Yang CY Hu Si-Qi SQ Wang Tao T Song Yu Y Li Jie J Zhao Qing-Hua QH Jie Wan-Qi WQ Zhao Jian-Lin JL

Light, science & applications 20180112

We demonstrate the first achievement of continuous-wave (CW) pumped second harmonic generation (SHG) in few- and mono-layer gallium selenide (GaSe) flakes, which are coated on silicon photonic crystal (PC) cavities. Because of ultrahigh second order nonlinearity of the two-dimensional (2D) GaSe and localized resonant mode in the PC cavity, SHG's pump power is greatly reduced to microwatts. In a nine-layer GaSe coated PC cavity, while the optical power inside the GaSe flake is only 1.5% of that i ...[more]

PMID: 30839631

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