Imaging at terahertz frequencies (0.1-10 THz, wavelengths 3 mm-30 µm) has proven to be useful in the biomedical field. Still, the acquisition time is an important hurdle. Here, we discuss recent developments toward achieving real-time THz imaging. First, we demonstrate a spectral encoding algorithm to reconstruct a 4500-pixels image with 45 measurements. Second, we improve the image resolution using a super-resolution algorithm specifically developed for the THz. Third, we discuss our most recent work on the fabrication of an THz photoconductive antenna array for imaging. These works pave the way for future applications of THz imaging in biomedical science.
Terahertz (THz) technology is promising in several applications such as imaging, spectroscopy and communications. Among several methods in the generation and detection of THz waves, a THz time-domain system that is developed using photoconductive antennas (PCA) as emitter and detector presents several advantages such as simple alignment, low cost, high performance etc. In this work, we report the design, fabrication and characterization of a 2-D PCA array that is capable of detecting both the amplitude and phase of the THz pulse. The PCA array is fabricated using LT-GaAs and has 8 channels with 64 pixels ( $8 \times 8$ ). A novel approach using a spatial light modulator (SLM) to steer and focus the infrared probe beam towards pixels of the PCA array is presented. Each channel records the photocurrent generated by the THz signal (amplitude and phase) separately and frequencies up to 1.4 THz can be detected. Furthermore, the parameters such as directional time delay of the THz pulse, crosstalk between the channels etc., were characterized. Finally, we show that the proposed 2D PCA array design is flexible and can be used for accelerated THz spectral image acquisition.