Transport of intensity equation-based terahertz lensless full-field phase imaging.

Terahertz (THz) phase imaging is widely spreading in various scenarios, among which full-field phase distributions are commonly retrieved by digital holography or ptychography. In this Letter, the transport of the intensity equation reconstruction method is applied into the THz band. An algorithm named the lensless US-transport of intensity equation (TIE) is proposed to accommodate to an in-line configuration.

Continuous-wave terahertz reflective ptychography by oblique illumination.

Massive usage scenarios prompt the prosperity of terahertz (THz) reflective imaging methods. In this Letter, we apply ptychography to continuous-wave THz reflective imaging. Our scheme has a compact lensless layout and uses a full-field oblique-illumination recording mode.

Multi-layered full-field phase imaging using continuous-wave terahertz ptychography.

Due to the unique properties of terahertz (THz) waves, THz phase imaging has been widely investigated to retrieve the absorption and phase modulation of dielectric two-dimensional thin samples, as well as multiple stacked samples. In this Letter, we apply the three-dimensional ptychographic iterative engine algorithm for continuous-wave THz full-field multi-layered phase imaging. The complex-valued transmission function of two-layered polypropylene thin plates and the corresponding probe function are reconstructed, respectively, which are immune to crosstalk of different layers.

Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography.

Continuous-wave terahertz ptychography is a promising large field-of-view lensless terahertz phase imaging method. Inaccurate probe positions would severely degrade the reconstruction quality, as compared to other spectral bands. In this paper, we propose a probe position correction method based on cross-correlation registration on overlapped regions of the object wavefront for terahertz ptychography.