Giant photothermal modulation depth of amorphous silicon nanostructures with resonant lattice Kerker effect

Hao-Yu Cheng^1,2,3*, Chi-Yin Yang⁴, Min-Wen Yu⁴, Wei-Ruei Chen⁴, Shi-Wei Chu², Kuo-Ping Chen⁴, Kung-Hsuan Lin³

¹Nano-Science and Technology in Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
²Department of Physics, National Taiwan University, Taipei, Taiwan
³Institute of Physics, Academia Sinica, Taipei, Taiwan
⁴Institute of Imaging and Biomedical Photonics, National Yang Ming Chiao Tung University, Tainan, Taiwan

* Presenter:Hao-Yu Cheng, email:D10222023@ntu.edu.tw

Mie resonance of high-refractive-index materials with nanostructures has attracted much attention recently. The changes of their spectral response under photoexcitation demonstrate the potential applications of all-optical switch, for which the modulation depth is a key parameter. In this work, we first theoretically demonstrate giant optical modulation depth can be achieved in Mie resonators by using resonant lattice Kerker effect. Following, we used amorphous silicon nanostructure as an example material to experimentally investigate the Mie resonators with and without resonant lattice Kerker effects. We demonstrated modulation depth of ~ 100% at the wavelength of the resonant lattice Kerker effect, which is the highest among the literature of all-optical modulation measurements of Mie resonators

Keywords: photothermal effects, silicon nanostructures, Q factors, Mie resonances, KerKer effects