Polarization selective Dove prism

Quantifying polarization changes induced by rotating Dove prisms and K-mirrors

Dove prisms and K-mirrors are devices extensively used for rotating the wavefront of an optical field. These devices have several applications, including measurement of orbital angular momentum, microscopy, beam steering and pattern recognition. However, the wavefront rotation achieved through these devices is always accompanied by polarization changes in the incident field, which is an undesirable feature in many of these applications. Although the polarization changes induced by a Dove prism have been explored to quite some extent, no such study is available for a K-mirror. In this letter, w…

Can a Dove prism change the past of a single photon?

We reexamine the thought experiment and real experiment of Vaidman et al., by placing Dove prisms in the nested Mach-Zehnder interferometer arms. In those previous works, the criterion of whether a single photon was present, or not, was the presence of a "weak trace", indicating the presence of a nonzero weak value. This was verified by slightly varying the mirror angle at a given frequency, which was then detected on a position sensitive detector at the oscillation frequency. We show the presence of the Dove prisms gives identical weak values everywhere to the previous configuration because t…

Dove prism in single-path Sagnac interferometer for orbital-angular-momentum photon states

The degree of freedom of orbital angular momentum (OAM) is an important resource in high-dimensional quantum information processing, as the quantum number of OAM can be infinite. The Dove prism (DP) is a most common tool to manipulate the OAM light, such as in interferometers. However, the Dove prism does not preserve the polarization of the photon states and decreases the sorting fidelity of the interferometer. In this work, we analyze the polarization-dependent effect of the DP on single-path Sagnac interferometers. The results are instructive to quantum information processing with OAM light…

When photons are lying about where they have been

The past of the photon in a nested Mach-Zehnder interferometer with an inserted Dove prism is analyzed. It is argued that the Dove prism does not change the past of the photon. Alonso and Jordan correctly point out that an experiment by Danan et al. demonstrating the past of the photon in nested interferometer will show different results when the Dove prism is inserted. The reason, however, is not that the past is changed, but that the experimental demonstration becomes incorrect. The explanation of a signal from the place in which the photon was (almost) not present is given. Bohmian trajecto…

一种平均偏振变化近零的波前旋转器

A wavefront rotator with near-zero mean polarization change

本研究提出通过优化折射率的方法，可在任意给定底角下设计平均偏振变化近零的K反射镜，实验验证其偏振变化比商用产品低一个数量级，对OAM相关应用有重要价值。

基于波前扭旋器的OAM模式排序

OAM-mode sorting with a wavefront twister

本文提出一种基于波前扭旋器的OAM模式排序装置，通过该元件与透镜组合，将OAM模式映射到透镜后焦平面的不同半径环内，实现高维OAM模式的高效排序。