Second harmonic generation of metal nanoparticles under tightly focused illumination
Sun Jing-Wei1, Wang Xiang-Hui1, †, , Chang Sheng-Jiang1, Zeng Ming2, Zhang Na1
       

Far-field radiation patterns of SHG under (a) PW and (b) focused field illuminations; (c) SH radiation diagrams as a function of Θ at Φ = 0°.