Ultrasmall high efficiency all-optical switch with single silicon nanoparticle

摘要

In this study, we found giant photothermal nonlinearity with n_2 = 10~(-1) μm~2/mW in ～100nm silicon nanoblocks, based on Mie-resonance enhanced absorption and efficient temperature increase via thermal insulation. Through a continuous-wave pump-probe setup, we demonstrated an ultrasmall high-contrast all-optical switch with 90% modulation depth. Due to the 0.001μm~3 small geometrical size, thermal dissipation is as fast as nanosecond, leading to modulation speed at GHz, which is much faster than other thermal optic switches. The large and fast all-optical switching could open the possibility toward high-density integrated photonic nanocircuits based entirely on silicon