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Related papers: Focusing of light beyond the diffraction limit

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This paper proposes a non-computational method of counteracting the effect of image degradation introduced by the diffraction phenomenon in lensless microscopy. All the optical images (whether focused by lenses or not) are diffraction…

Optics · Physics 2021-04-08 Sanjeev Kumar , Manjunatha Mahadevappa , Pranab Kumar Dutta

Far-field characterization of small objects is severely constrained by the diffraction limit. Existing tools achieving sub-diffraction resolution often utilize point-by-point image reconstruction via scanning or labelling. Here, we present…

While the deflection of light is achromatic in General Relativity, it is not always so in several new-physics models (e.g. certain quantum-gravity and string-inspired models, models with nonminimal photon-gravity coupling or with massive…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-31 P. Egorov , M. Guzinin , H. Hakopyan , S. Troitsky

A fundamental issue that limits the efficiency of many photoelectrochemical systems is that the photon absorption length is typically much longer than the electron diffusion length. Various photon management schemes have been developed to…

We experimentally demonstrate optical control of filamentation that occurs during propagation of intense, ultrashort laser pulses through crystals like barium fluoride and sapphire. Control is exercised by rotating the plane of polarization…

Plasma Physics · Physics 2007-05-23 A. K. Dharmadhikari , K. Alti , J. A. Dharmadhikari , D. Mathur

{The problem of laser beam concentration in a focal spot via wavefront variations is formulated as a maximization of the $beam$ $propagation$ $functional$ defined as the light power passing through aperture of an arbitrary shape located in…

Pattern Formation and Solitons · Physics 2025-12-02 A. Yu. Okulov

Based on fundamental properties of light scattering by a particle we reveal the existence of the ultimate upper limit for the light absorption by any partial mode. First, we obtain this result for scattering of a plane wave by a symmetric…

Optics · Physics 2018-01-24 Andrey E. Miroshnichenko , Michael I. Tribelsky

The numerical aperture (NA) of a lens determines its ability to focus light and its resolving capability. Having a large NA is a very desirable quality for applications requiring small light-matter interaction volumes or large angular…

A recent paper demonstrated that two lenslet arrays with focal lengths f_1 and f_2, separated by f_1 + f_2, change the direction of transmitted light rays approximately like the interface between isotropic media with refractive indices n_1…

Optics · Physics 2009-05-18 Johannes Courtial

An examination of the propagation of intense 200 fs pulses in water reveals light filaments not sustained by the balance between Kerr-induced self-focusing and plasma-induced defocusing. Their appearance is interpreted as the consequence of…

With a conventional lens sharpness of the image is always limited by the wavelength of light. An unconventional alternative to a lens, a slab of negative refractive index material, has the power to focus all Fourier components of a 2D…

Optics · Physics 2025-07-03 JB Pendry

Occultation and microlensing are different limits of the same phenomena of one body passing in front of another body. We derive a general exact analytic expression which describes both microlensing and occultation in the case of spherical…

Astrophysics · Physics 2009-11-07 Eric Agol

Pixel lensing, gravitational microlensing of unresolved stars, is potentially much more sensitive and much more widely applicable than is generally recognized. I give explicit expressions for the pixel noise induced by a time-variable PSF,…

Astrophysics · Physics 2008-11-26 Andrew Gould

Free electrons moving in an optical standing wave field feel the ponderomotive potential, acting as a refractive-index medium in electron optics. Emerging technologies involving this potential have been proposed and realized in electron…

Optics · Physics 2022-01-25 Yuuki Uesugi , Yuichi Kozawa , Shunichi Sato

Multi-filamentation opens new degrees of freedom for manipulating electromagnetic waves in air. However, without control, multiple filament interactions, including attraction, repulsion or fusion often result in formation of complex…

Light scattering by small particles has a long and interesting history in physics. Nonetheless, it continues to surprise with new insights and applications. This includes new discoveries, such as novel plasmonic effects, as well as exciting…

Optics · Physics 2014-07-10 Xiaofeng Fan , Weitao Zheng , David J. Singh

We worked out a new group of collimated plasmon beams by the means of in-plane diffraction with symmetric phase modulation. As the phase type changes from 1.8 to 1.0, the beam undergoes an interesting evolution from focusing to a straight…

Optics · Physics 2015-06-12 L. Li , T. Li , S. M. Wang , S. N. Zhu

The brightness theorem---brightness is nonincreasing in passive systems---is a foundational conservation law, with applications ranging from photovoltaics to displays, yet it is restricted to the field of ray optics. For general linear wave…

Optics · Physics 2019-10-24 Hanwen Zhang , Chia Wei Hsu , Owen D. Miller

Evanescent light can be localized at the nanoscale by resonant absorption in a plasmonic nanoparticle or taper or by transmission through a nanohole. However, a conventional lens cannot focus free-space light beyond half of the wavelength…

Optics · Physics 2018-05-31 Guang Hui Yuan , Edward T. F. Rogers , Nikolay I. Zheludev

We describe a research project carried out with a group of undergraduate physics students and aimed at exploring the use of a neural network to study a classical problem in wave optics whose analytical solution is well known: the…

Physics Education · Physics 2022-04-20 Christophe Finot , Sonia Boscolo