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 interfa...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.展开更多
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. B...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.展开更多
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...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.展开更多
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 malig...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.展开更多
基金Project supported by the China Postdoctoral Science Foundation(Grant No.2016M601586)the National Natural Science Foundation of China(Grant No.11404092)the Opening Funding of Hunan Provincial Key Laboratory of High Energy Laser Technology,China(Grant No.GNJGJS07)
文摘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.
基金supported by the Fundamental Research Funds for the Central Universities,China(Grant No.2017B14914)China Postdoctoral Science Foundation(Grant No.2016M601586)the National Natural Science Foundation of China(Grant Nos.11874140 and 11404092)
文摘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.
基金supported by the Fundamental Research Funds for the Central Universities of China (No.2017B14914)Postgraduate Research&Practice Innovation Program of Jiangsu Province (Nos.B200203143 and KYCX200433)+1 种基金Opening Funding of Hunan Provincial Key Laboratory of High Energy Laser Technology (No.GNJGJS07)National Natural Science Foundation of China (No.11874140)。
文摘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.
基金Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)Foundation for Development of Science and Technology of Shanghai(17JC1400400)+2 种基金fellowship of China Postdoctoral Science Foundation(2020M681275,2021T140452)National Natural Science Foundation of China(11734011,11764020,11974245)National Key R&D Program of China(2017YFA0303701,2018YFA0306301)。
文摘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.