Abstract
<title>Abstract</title> <p>Terahertz time-domain spectroscopy imaging inherently encodes both spectral and depth information within the temporal profile of each pulse, which makes it attractive for non-destructive evaluation. However, the implementation of electrically programmable single-pixel imaging in the THz range has been hindered by the narrowband or discrete-frequency nature of most existing spatial light modulators, leading to a trade-off between modulation flexibility and the preservation of broadband waveform information. Here, we demonstrate an electrically controlled ultrawideband THz spatial light modulator based on a non-resonant GaAs Schottky microslit array, enabling hyperspectral and three-dimensional single-pixel imaging over a ultrawideband spectral range from 0.2 to 1.4 THz. With a 64-pixel effective Hadamard aperture and a Diag-ordered sampling sequence, the system enables hyperspectral spectral-fingerprint imaging, transmission- and reflection-mode three-dimensional reconstruction, and dynamic imaging with a frame acquisition time of approximately 9 s. This work establishes a waveform-preserving, electronically reconfigurable encoding platform that provides a compact solution for multidimensional THz imaging, with potential use in pharmaceutical screening, industrial inspection, biomedical diagnosis, and security screening.</p>