  We present theoretical formulation and experimental demonstration of a novel
technique for the fast compression-less terahertz imaging based on the
broadband Fourier optics. The technique exploits k-vector/frequency duality in
Fourier optics which allows using a single-pixel detector to perform angular
scan along a circular path, while the broadband spectrum is used to scan along
the radial dimension in Fourier domain. The proposed compression-less image
reconstruction technique (hybrid inverse transform) requires only a small
number of measurements that scales linearly with the image linear size, thus
promising real-time acquisition of high-resolution THz images. Additionally,
our imaging technique handles equally well and on the equal theoretical footing
the amplitude contrast and the phase contrast images, which makes this
technique useful for many practical applications. A detailed analysis of the
novel technique advantages and limitations is presented, as well as its place
among other existing THz imaging techniques is clearly identified
