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. The object phase is retrieved by primarily conducting iterations between the axial intensity derivative and the phase distribution at the recording plane and subsequent backward diffraction propagation. This method is applicable to both isolated and extended weakly absorbing samples with higher reconstruction quality and remarkably less time cost than holographic phase retrieval algorithms. It can also be attempted in other non-interferometric geometries or using low-cost partially coherent THz sources, which significantly broaden the application scope of THz phase imaging.

中文翻译：

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基于强度方程的太赫兹无透镜全场相位成像传输

太赫兹 (THz) 相位成像广泛应用于各种场景，其中全场相位分布通常通过数字全息或 ptychography 来检索。在这封信中，强度方程重建方法的传输应用于太赫兹频段。提出了一种名为无透镜 US 强度传输方程 (TIE) 的算法以适应在线配置。通过主要在轴向强度导数和记录平面处的相位分布之间进行迭代以及随后的后向衍射传播来检索对象相位。该方法适用于孤立的和扩展的弱吸收样本，与全息相位检索算法相比，具有更高的重建质量和明显更少的时间成本。