Photoconductive Antennas (PCA) are widely used for terahertz (THz) generation and detection. These PCAs build the basis for future 6G communication as they provide a high data rate and broad bandwidth. In this work, interdigitated photoconductive antenna (IPCA) has been designed and optimized for better performance in terms of THz radiation. The proposed IPCA is made of LT-GaAs substrate material deposited on SI-GaAs. Silver material has been assumed for the IPCA electrode structure. Moreover, the dependence of IPCA on the incident laser parameters such as its wavelength (λ = 800, 1060, and 1550 nm) and pulse duration (100–500 fs) has been investigated theoretically for different teeth widths (W_e = 500, 100, 50, and 20 nm). The performance of the IPCA with various parameters such as average carrier density, conductance, total photocurrent, THz radiated power, and electric field strength, has been analyzed. The results show maximum THz electric field strength of 20.85 V/m for a photo-generated current of 1.887 A and enormous bandwidth beyond 14.9 THz with 20 nm teeth-width-based IPCA when illuminated with 100 fs 800 nm laser pulses. The proposed IPCA structure provides enhanced THz radiation compared to conventional PCA. This investigation helps the researchers to develop and integrate IPCA for future wireless communications as well as for a variety of applications, such as time-domain spectroscopy (THz-TDS), medical imaging, sensing, and security-related applications.