Work

Enhanced broadband non-degenerate two-photon absorption in Ga-doped ZnO for ultrafast all-optical switching

Year: 2025

Type: article

Abstract: Zinc oxide (ZnO) plays a crucial role in the application of all-optical devices due to its broadband nonlinear optical response.In this work, the broadband nonlinear optical response of Ga-doped ZnO (GZO) was investigated using femtosecond transient absorption spectroscopy (450-800 nm), revealing an ultrahigh modulation depth (∼86%) and ultrafast response (∼280 fs) at a pump wavelength of 750 nm.Non-degenerate two-photon absorption (TPA) spectra corrected by dispersion revealed significantly stronger TPA in the visible range.An energy level model based on Ga-related defects explained the enhancement mechanism of TPA and the photoluminescence spectrum.This study highlights the significant potential of GZO in future broadband all-optical device applications.

Source: Chinese Optics Letters

DOI: 10.3788/col202523.111901