Intense terahertz emission from undoped GaAs/n-type GaAs and InAs/AlSb structures grown on Si substrates in the transmission-geometry excitation

• Main Authors: Estacio, E., Takatori, S., Pham, M. H., Yoshioka, T., Nakazato, T., Raduban, M. Cadatal, Shimizu, T., Sarukura, N., Hangyo, Masanori, Que, Christopher T., Tani, Masahiko, Edamura, Tadataka, Nakajima, Makoto, Misa, J. V., Jaculbia, R., Somintac, A., Salvador, A.
• Format: text
• Published: Animo Repository 2011
• Subjects: Terahertz technology; Gallium arsenide; Indium arsenide; Transmission electron microscopy; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/11908
• Institution: De La Salle University

Intense terahertz radiation was generated from femtosecond laser-irradiated InAs and GaAs layers on Si substrates. Results show that InAs/Si and GaAs/Si films can be excited in reflection and transmission geometries. The InAs/Si film exhibited weaker emission for both excitation cases but it will be more feasible as a spectroscopic THz source due to the absence of complex spectral features in its emission spectrum. The GaAs/Si emission is characterized by Fabry–Perot oscillations but it is 90% of that of p-InAs bulk crystal emission intensity in the reflection geometry. Excitation fluence measurements showed that the InAs/Si film saturates easily due to the laser’s shallow penetration depth in InAs.