Saturation and polarization characteristics of 1.56 μm Optical probe pulses in a LTG-GaAs photoconductive antenna terahertz detector

• Main Authors: Estacio, Elmer S., Hibi, Masakazu, Saito, Katsuya, Que, Christopher T., Furuya, Takashi, Miyamaru, Fumiaki, Nishizawa, Seizi, Yamamoto, Kohji, Tani, Masahiko
• Format: text
• Published: Animo Repository 2013
• Subjects: Photoconductivity; Antennas (Electronics); Gallium arsenide; Terahertz spectroscopy; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/4033
• Institution: De La Salle University

The characteristics of low temperature-grown GaAs photoconductive antenna (PCA) terahertz detectors probed by 1.56 μm laser pulses are investigated. The influence of TM and TE polarized probe, as well as the saturation characteristics are studied for 2 μm- and 5 μm-gap PCA's. Different polarization characteristics at low probe powers and at the saturation regimes were observed. Results are explained in terms of the polarization-dependent photocarrier distribution at the PCA gap arising from tight focusing. This work also demonstrates using a 1.56 μm probe for a GaAs PCA to achieve ∼60 dB SNR; matching its performance characteristics for above-bandgap probes. © 2013 Springer Science+Business Media New York.