PULSED THz GENERATION BASED ON PHOTOCONDUCTIVE ANTENNA FOR THz TIME-DOMAIN SPECTROSCOPY

Abstract

Terahertz (THz) wave is defined as the region of the electromagnetic spectrum with frequencies ranging from 100 GHz to 10 THz. The THz technology has many potential applications. However, it was called the “THz gap” due to the lack of efficient generation of THz waves. Therefore, the development of efficient THz sources plays an important role to close this gap. In this thesis, we investigated the THz pulse generation from a photoconductive antenna (PCA) THz emitter using a 1550 nm femtosecond (fs) laser. The PCA is fabricated based on the InGaAs and InAlAs multilayer structure. The THz signal is measured using the time-domain spectroscopy system. Both the photocurrent and current change are the key determinants of THz amplitude. At least a two-fold increase in the resistance is required for THz emission. In addition, the integration of PCA with a spintronic emitter is proposed for broadband THz emission.