相关论文: Steering, Splitting and Cloning of Optical Beam in…
We present a new scheme to create all-optical tunable and lossless waveguide using a controllable coherent Raman process in an atomic rubidium vapor in N-type configuration. We employ a Gaussian Raman field and a Laguerre-Gaussian control…
A standing-wave control field applied to a three-level atomic medium in a planar hollow-core photonic crystal waveguide creates periodic variations of linear and nonlinear refractive indexes of the medium. This property can be used for…
Interferometers and beam splitters are fundamental building blocks for photonic neuromorphic and quantum computing machinery. In waveguide-based photonic integrated circuits, beam-splitting is achieved with directional couplers that rely on…
We report experimental observation and theoretical explanation of novel propagation regimes for optical beams in an artificial nonlinear material with outstanding photorefractive properties. Nondiffractive beams, which keep their shapes…
We demonstrate in a {\it proof-of-concept} experiment spectral-domain optical coherence tomography where steering of the optical beam that probes the sample in a transverse scan does not make use of any mechanical element. Steering is done…
Beam propagation beyond the paraxial approximation is studied in an optically written waveguide structure. The waveguide structure that leads to diffractionless light propagation, is imprinted on a medium consisting of a five-level atomic…
Rapid and low-power control over the direction of a radiating light field is a major challenge in photonics and a key enabling technology for emerging sensors and free-space communication links. Current approaches based on bulky motorized…
A theoretical model is developed by exploiting the variational technique to investigate the evolution of an optical beam inside an optically pumped graded-index fiber amplifier. The variational analysis is a semi-analytical method that…
In this work, we designed and studied a feasible dual-layer binary metagrating, which can realize controllable asymmetric transmission and beam splitting with nearly perfect performance. Owing to ingenious geometry configuration, only one…
Photoreflectance is used for the characterisation of semiconductor samples, usually by sweeping the monochromatized probe beam within the energy range comprised between the highest value set by the pump beam and the lowest absorption…
Diffractionless propagation of optical beams through atomic vapors is investigated. The atoms in the vapor are operated in a three-level Raman configuration. A suitably chosen control beam couples to one of the transitions, and thereby…
Controlling the polarization state of light with sub-picosecond speed and subwavelength precision remains a key challenge for next-generation nanophotonic devices. Conventional methods such as birefringent crystals, liquid crystals, or…
We propose a multi-field-coupled atomic model that exhibits controllable $symmetric$ and $asymmetric$ evolution of significantly enhanced diffraction peaks in an opto-atomic grating at far-field regime. Such results are obtained by the…
Optical parametric amplification (OPA) comprises essentially a nonlinear four-wave mixing process in which a "pump" and a "signal" field give rise to an "idler" field under certain phase-matching conditions. Here we use a photonic crystal…
We consider dynamically controllable periodic structures, called Raman induced gratings, in three- and four-level atomic media, resulting from Raman interaction in a standing-wave pump. These gratings are due to periodic spatial modulation…
We demonstrate experimentally all-optical beam steering in modulated photonic lattices induced optically by three beam interference in a biased photorefractive crystal. We identify and characterize the key physical parameters governing the…
We show that a very simple structure consisting of a single subwavelength dielectric ridge on the surface of a slab waveguide enables spatial differentiation and integration of the profile of optical beams propagating in the waveguide. The…
The reorientational nonlinearity of nematic liquid crystals enables a self-localized spatial soliton and its waveguide to be deflected or destroyed by a control beam propagating across the cell. We demonstrate a simple all-optical…
Techniques to mold the flow of light on subwavelength scales enable fundamentally new optical systems and device applications. The realization of programmable, active optical systems with fast, tunable components is among the outstanding…
In this paper, ultra-broad band optical signal amplification are analyzed and demonstrated by utilizing supercontinuum generation propagating over the photonic crystal fiber. The coupled nonlinear Schroodinger equation containing parametric…