Thz Wave Emission From The Cu2o/Cu Interface Under Femtosecond Laser Irradiation

Cu or Cu/Au (80 nm thick Cu, 50 nm thick Au) sputtered on Si were kept at 25 degrees C for a week or annealed at a temperature from 80 to 300 degrees C, then tested for THz emission under femtosecond laser irradiation (35 fs-800 nm). THz radiation was detected from samples annealed from 80 to 170 degrees C, which had a Cu2O/Cu interface as the THz source. Cu/Au/Si annealed at 80 degrees C emitted the highest THz radiation because of high laser absorption by the porous Cu2O layer formed at low temperature and the Au film reflected THz radiation and/or increased the laser absorption by the Fabry-Perot effect.