Loss induced negative refraction and super-prism effect at highly absorptive interface

It is well-established that waves are inhomogeneous in a lossy isotropic medium, and the validation of the classical Snell's law is still questionable for light refraction at the dissipative and dispersive interface. With high absorption, direct experimental investigation is rather difficult due to the extremely short penetration depth; i.e., the skin depth. In this paper, a simple and unified description of this issue is proposed, which can be applied to both materials with anomalous dispersion and in the Drude region. The gradient ▽_k~ω is found to be incident angle θ_i-dependent, and the direction of the group velocity may deviate significantly from the phase velocity due to the loss induced permittivity structure. The physics behind the negative refraction effect is explained, and a novel loss induced super-prism effect is also predicted.

Propagation dynamics of off-axis noncanonical vortices in a collimated Gaussian beam

It is widely accepted that an off-axis noncanonical vortex moves across the free-space diffracting Gaussian beam without rotation. But our analysis shows that the vortex swirls a while before it approaches infinite. By neglecting the divergence of the host beam, we focus on this rotation characteristics of the vortices in linear homogeneous media. For the symmetrical host beam, it is found that the vortex moves along an elliptical trajectory, while the topological charge and the angular momentum of the vortex core relative to the beam axis are conserved. For the asymmetrical host beam, the vortex trajectory is rather complicated, since the noncanonical parameter varies as the light propagates, resulting in topological charge inversion. But we find that the vortices are always confined in a rectangular area, and the rotation direction is determined by the topological charge.

Highly twisted M-line of a vortex beam due to the coupling of ultrahigh-order modes

In modern optics, particular interest is devoted to the phase singularities that yield complicated and twisted phase structures by photons carrying optical angular momentum.In this paper, the traditional M-line method is applied to a vortex beam(VB) by a symmetric metal cladding waveguide chip, which can host numerous oscillating guided modes via free space coupling.These ultrahigh-order modes(UOMs) result in high angular resolution due to the high finesse of the resonant chip.Experiments show that the reflected pattern of a VB can be divided into a series of inner and outer rings, whilst both of them are highly distorted by the M-lines due to the UOMs’ leakage.Taking the distribution of the energy flux into account, a simple ray-optics-based model is proposed to simulate the reflected pattern by calculating the local incident angle over the cross section of the beam.The theoretical simulations fit well with the experimental results, and the proposed scheme may enable new applications in imaging and sensing of complicated phase structures.

Single-cell detection by enhancement of fluorescence in waveguides for cancer diagnosis and therapy

Cancer is one of the most common diseases to threaten human health.If individuals are diagnosed with malignant tumors via a single cell,medical workers are greatly advantageous to early diagnose and intervene in malignant tumors therapy.In this paper,we propose a fluorescence detection map to rapidly distinguish whether the chromosomes of a cell are normal or abnormal by detecting the fluorescent intensity of a single cell.Herein,we draw a map from a single cell with an abnormal number of chromosomes that is monitored in real time.Moreover,this way offers precise and prompt detection of the surviving of cancer cells at or near the site of the tumor after treatments for cancer,which can achieve personalized cancer diagnosis and therapy.Therefore,cancer recurrences and metastasis can be effectively identified,utilizing this ultrasensitive detection method of an abnormal chromosome number.

一维波动力学进展 通向一种统一的经典观点

经过100多年的发展，量子力学理论经受住了历史的考验。可以说，它所给出的所有结果都得到了精确的实验检验。这些惊人的成功激励着无数忠实的追随者，从而进一步促进量子理论本身发展成了现代物理的基石。然而，量子力学理论本身至今仍然存在许多问题，比如，波函数的概率解释、海森伯不确定性关系、波尔的对应原理、EPR佯谬和薛定谔猫等思想实验、以及测量和波函数坍缩等，在不同程度上引起人们的困惑甚至争议，形成了一些著名的佯谬。