Photo-mixing of Chirped Ultra-short Optical Pulses at 1 μm for the Generation of Broadband Long THz Pulses

Located between microwaves and infrared, the terahertz (THz) frequencies find various applications in recent technologies, notably in non-destructive imaging and telecommunications [1]. The method commonly used for their generation and detection is based on the conversion of infrared ultra-short pulses into THz waves by exciting photoconductive (PC) antennas. While being an efficient process offering a high dynamic range, the ultra-short optical pulse duration and high peak power bring some limitations, particularly for integrating devices toward a high-power level of optical excitation. Here, we present a novel method for photo-mixing generation in PCs using long chirped pulses to reduce peak power, thereby producing broadband, long-duration THz radiation. This approach offers new opportunities for temporal spectroscopy and the development of integrated devices.