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Observation of Second Harmonic Generation in Lightning-BoltLike Shaped Nanostructured Metasurface


Khai Q. Le

Source title: 
Journal of Electronic Materials, 48(8): 5119-5124, 2019 (ISI)
Academic year of acceptance: 

Second harmonic generation (SHG) was observed on irradiation of a symmetry-broken gold nanostructured surface with an ultrashort pulse of low input power. A metasurface consisting of lightning-bolt-like shaped gold (Au) nanostructures in a periodic arrangement was fabricated on a glass substrate and utilized to excite surface plasmons. The measured extinction spectrum had a dual band maximized at approximately 605 nm and 786 nm under illumination with linearly polarized light. The two-photon induced photoluminescence and SHG intensity were dependent on the polarization states and wavelength of the femtosecond laser pulse irradiation. Furthermore, the SHG intensity peak was linearly dependent on the input power of the incident laser beam, and the spectral property of the emitted second harmonic was correlated to the extinction spectrum of the nanostructured metasurface. The SHG peak over the pumping wavelengths was resonant with a transverse multipolar plasmon mode. The findings provide useful guidelines for efficient production of second harmonic luminescence.