The degree of coherence(DOC)function that characterizes the second-order correlations at any two points in a light field is shown to provide a new degree of freedom for carrying information.As a rule,the DOC varies al...The degree of coherence(DOC)function that characterizes the second-order correlations at any two points in a light field is shown to provide a new degree of freedom for carrying information.As a rule,the DOC varies along the beam propagation path,preventing from the efficient information recovery.In this paper,we report that when a partially coher-ent beam carrying a cross phase propagates in free space,in a paraxial optical system or in a turbulent medium,the modulus of the far-field(focal plane)DOC acquires the same value as it has in the source plane.This unique propaga-tion feature is employed in a novel protocol for far-field imaging via the DOC,applicable to transmission in both free-space and turbulence.The advantages of the proposed approach are the confidentiality and resistance to turbulence,as well as the weaker requirement for the beam alignment accuracy.We demonstrate the feasibility and the robustness of the far-field imaging via the DOC in the turbulent media through both the experiment and the numerical simulations.Our findings have potential applications in optical imaging and remote sensing in natural environments,in the presence of op-tical turbulence.展开更多
The physical properties of light fields at the subwavelength scale have emerged as extensively pursued objectives in nano-optics,photonics,and plasmonics.Here,we report that in the paraxial regime,the spectral density...The physical properties of light fields at the subwavelength scale have emerged as extensively pursued objectives in nano-optics,photonics,and plasmonics.Here,we report that in the paraxial regime,the spectral density and the spectral axial coherence(z-coherence)structures in a submicron range can be generated by employing a light beam with a suitably chosen spatial coherence state in a counter-propagating configuration,in an open-end cavity.It is established that while the spectral density forms an optical standing wave,the z-coherence state depends on the symmetry of the selected point pair and in particular,the phenomenon termed as periodical coherence switch is found.Our findings shed new light on the discussion of the role of spatial coherence in the photonic cavities,possibly inspiring further studies in the field of enhanced light-nanomaterials interactions by optical cavity.This provides a versatile framework for tailoring coherence in subwavelength space with promising applications in metrology and imaging.展开更多
We suggest tailoring of the illumination's complex degree of coherence for imaging specific two-and three-point objects with resolution far exceeding the Rayleigh limit.We first derive a formula for the image inte...We suggest tailoring of the illumination's complex degree of coherence for imaging specific two-and three-point objects with resolution far exceeding the Rayleigh limit.We first derive a formula for the image intensity via the pseudo-mode decomposition and the fast Fourier transform valid for any partially coherent illumination(Schell-like,non-uniformly correlated,twisted)and then show how it can be used for numerical image manipulations.Further,for Schell-model sources,we show the improvement of the two-and three-point resolution to 20%and 40%of the classic Rayleigh distance,respectively.展开更多
文摘The degree of coherence(DOC)function that characterizes the second-order correlations at any two points in a light field is shown to provide a new degree of freedom for carrying information.As a rule,the DOC varies along the beam propagation path,preventing from the efficient information recovery.In this paper,we report that when a partially coher-ent beam carrying a cross phase propagates in free space,in a paraxial optical system or in a turbulent medium,the modulus of the far-field(focal plane)DOC acquires the same value as it has in the source plane.This unique propaga-tion feature is employed in a novel protocol for far-field imaging via the DOC,applicable to transmission in both free-space and turbulence.The advantages of the proposed approach are the confidentiality and resistance to turbulence,as well as the weaker requirement for the beam alignment accuracy.We demonstrate the feasibility and the robustness of the far-field imaging via the DOC in the turbulent media through both the experiment and the numerical simulations.Our findings have potential applications in optical imaging and remote sensing in natural environments,in the presence of op-tical turbulence.
基金supported by the National Natural Science Foundation of China(Grant Nos.11874321,and 12174338)the Major Discipline Academic and Technical Leaders Training Program of Jiangxi Province(Grant No.20204BCJ22012)the UM for Copper Fellowship support。
文摘The physical properties of light fields at the subwavelength scale have emerged as extensively pursued objectives in nano-optics,photonics,and plasmonics.Here,we report that in the paraxial regime,the spectral density and the spectral axial coherence(z-coherence)structures in a submicron range can be generated by employing a light beam with a suitably chosen spatial coherence state in a counter-propagating configuration,in an open-end cavity.It is established that while the spectral density forms an optical standing wave,the z-coherence state depends on the symmetry of the selected point pair and in particular,the phenomenon termed as periodical coherence switch is found.Our findings shed new light on the discussion of the role of spatial coherence in the photonic cavities,possibly inspiring further studies in the field of enhanced light-nanomaterials interactions by optical cavity.This provides a versatile framework for tailoring coherence in subwavelength space with promising applications in metrology and imaging.
基金the National Key Research and Development Program of China(No.2019YFA0705000)the National Natural Science Foundation of China(Nos.11525418,11874046,11947239,11974218,and 91750201)+1 种基金theInnovation Group of Jinan(No.2018GXRC010)the China PostdoctoralScience Foundation(No.2019M662424)。
文摘We suggest tailoring of the illumination's complex degree of coherence for imaging specific two-and three-point objects with resolution far exceeding the Rayleigh limit.We first derive a formula for the image intensity via the pseudo-mode decomposition and the fast Fourier transform valid for any partially coherent illumination(Schell-like,non-uniformly correlated,twisted)and then show how it can be used for numerical image manipulations.Further,for Schell-model sources,we show the improvement of the two-and three-point resolution to 20%and 40%of the classic Rayleigh distance,respectively.
