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We show that proper engineering of a nonlinear interaction induces quantum entanglement between the spatial and spectral degrees of freedom of incident photons via the all-optical analogue of the Stern-Gerlach effect.

We experimentally demonstrate dynamic, electrically controlled shaping of plasmonic beams, propagating at the boundary between a metal and a dielectric, by using the thermo-optic effect. The concept is based on selectively heating a specific region in which the plasmonic beam passes by injecting electrical current to an isolated metal layer. This leads to transverse modulation of the wavefront through the thermal dispersion of the dielectric layer above this metal region. We demonstrate two active plasmonic devices: a plasmonic mode converter between the fundamental and first-order Hermite-Gauss modes and a tunable plasmonic lens with a dynamically varying focal length.

The Smith-Purcell effect is observed when an electron beam passes in the vicinity of a periodic structure. We propose a method to shape the spatial and spectral far-field radiation using complex periodic and aperiodic gratings.

We propose and analyze the generation of a controllable and robust adiabatic geometric phase via a quadratic nonlinear optical process. This approach enables wavefront shaping tasks such as focusing and mode conversion in sum-frequency process.

We demonstrate theoretically the existence of a Stern-Gerlach effect for single photons in a quadratic nonlinear medium. The new effect enables the spatial separation of orthogonal frequency superposition states and might open new possibilities for the manipulation of bichromatic qubits.

The emission of light from electrons passing near a grating includes resonant plasmonic features and Smith-Purcell collective excitations. We observe both and distinguish between them, finding surprising robustness to disorder in the Smith-Purcell radiation.

We demonstrate theoretically and experimentally the generation of second harmonic beams with arbitrary convex caustic trajectories. Different trajectories can be selected using the same nonlinear crystal by varying the crystal temperature or the pump wavelength.

We demonstrate experimentally phase modulation of light beams by fabricating arbitrary microstructures using a 3D-Direct Laser writing method. This approach produces complex structured light beams, in a compact, stable and cost effective manner.

We report a numerical and experimental study of an on-chip optical spectrometer, utilizing propagating surface plasmon polaritons in the telecom spectral range. The device is based on two holographic gratings, one for coupling, and the other for decoupling free-space radiation with the surface plasmons. This 800 μm×100 μm on-chip spectrometer resolves 17 channels spectrally separated by 3.1 nm, spanning a freely tunable spectral window, and is based on standard lithography fabrication technology. We propose two potential applications for this new device; the first employs the holographic control over the amplitude and phase of the input spectrum, for intrinsically filtering unwanted frequencies, like pump radiation in Raman spectroscopy. The second prospect utilizes the unique plasmonic field enhancement at the metal-dielectric boundary for the spectral analysis of very small samples (e.g., Mie scatterers) placed between the two gratings.

The Astigmatic Airy beam is introduced, and accurate, closed-form expressions are derived using ray-tracing methods. These expressions are confirmed in experiment in an extraordinary optical system: the transmission electron microscope.

We study the propagation dynamics of surface gravity water wave Airy pulses in the linear and nonlinear regimes. The low carrier frequency enables observing the position-dependent phase of the Airy pulse for the first time.

Surface plasmon polaritons having an arbitrary broadband spectrum are launched using holographic gratings, allowing unprecedented control over the temporal shape. Among the potential applications are broadband sensors and ultrashort pulse shaping.

The spectral acceptance bandwidth of a standard nonlinear crystal is inversely proportional to the crystal length. We experimentally show that much narrower width is reached by modulating the nonlinear coefficient with a super-oscillation function.

Computer-generated holograms can shape the spatial domain, but also the spectral domain. We shape light spectra using quadratic nonlinear optics, in theory and experiment. These are readily extended to other wave-related fields, such as plasmonics.

Coding schemes for designing computer generated holograms can be implemented in nonlinear optics. Spatial modulation of the quadratic nonlinearity enables to arbitrarily shape the amplitude, phase and spectrum of the frequency converted beam.

By utilizing long-range interactions between solitons and accelerating beams in thermal nonlocal nonlinear media we demonstrate optical analogues of gravitational effects, such as tidal forces, gravitational lensing and gravitational redshift.

The properties of optical, electron and plasmon beams that preserve their shape, while propagating along curved trajectories in free-space or on a surface are discussed. Methods to generate these beams and potential applications are presented.

We experimentally demonstrate quasi-phase-matched second-harmonic generation of surface plasmon waves in a system composed of a metallic structure on top of a periodically-poled nonlinear crystal, and offers highly versatile tailoring of nonlinear processes.

We present experimental observations of self-accelerating beams in quadratic media. Joint acceleration in the nonlinear medium, asynchronous intensity peaks of the harmonic waves and self-healing effects on the jointly-accelerating beams are shown.

A novel all-fiber Q-switched laser is presented and discussed. The Q-switch is based on induced acoustic long period grating on a fiber device which becomes an effective tunable output coupler both in terms of reflectivity and spectral selectivity

We fabricated quadratic nonlinear photonic crystals with singular structures. These structures convert Gaussian beams into vortex beams in the second harmonic. The topological charge of the generated beam is controlled by the structure.

We demonstrate methods for controlling the properties of optical vortex beams, generated within a twisted nonlinear photonic crystal. The latter enables us to all-optically shape polarization, radius, and angular momentum of optical vortex beams.

We experimentally demonstrate efficient tunable up-conversion by cascading optical oscillation and wide-band adiabatic sum frequency generation in a single nonlinear crystal, yielding red light tunable over a 6.2nm wavelength band.

We present a new method for three-dimensional imaging of the inversed ferroelectric domains hidden inside nonlinear photonic structures. The method is based on Cerenkov-type second harmonic generation laser scanning microscopy and offers sub-micrometer resolution.

We report conical second harmonic generation in two-dimensional nonlinear photonic structures with fundamental beam of linear, circular, and elliptical polarizations, respectively. We develop a theoretical model for describing this phenomenon and explore its physical origin.

Nonlinear generation of an accelerating Airy beam in an asymmetrically poled nonlinear photonic crystal enables to all-optically control the sign and magnitude of the acceleration direction and to change the location of its peak intensity.

We study three wave mixing processes of accelerating Airy beams in quadratic periodically poled nonlinear crystal. Experiments of second harmonic generation of 1-D and 2-D Airy beams were performed and analyzed.

Frequency doubling of a surface plasmon-polariton in the metal-nonlinear dielectric boundary is analyzed. Phase matching can be achieved either by varying the metal thickness or periodically modulating the nonlinear coefficient of the crystal.

We demonstrate all-optical intensity-dependent polarization switching, based on double phase-matched cascaded processes in a quadratic nonlinear photonic quasi-crystal. The efficiency is significantly better than that of devices based on cascaded cubic nonlinearities.

We present a novel technique to achieve both high efficiency and broad bandwidth in SFG process using adiabatic conversion scheme, adapted from NMR and light-matter interaction. The robustness and tunability of the scheme are discussed.

We experimentally demonstrate an optical parametric oscillator, whose signal pumps another difference frequency generation process. Engineered idler frequency coincidence of both processes in a single quasiperiodic crystal improves pump-to-idler conversion (slope) efficiency by 16.6% (52.8%).

Sensitive detection of DNA sequences is experimentally demonstrated by attaching magnetic beads to fluorescent-labeled DNA probes and applying alternating magnetic field gradient. This enables elimination of the scattering noise from the solution by synchronous detection.

OPG emission in long periodically-poledMgO:LiNbO3 crystals pumped by a Q-switched Nd:YVO4 laser was characterized. The experimental results obtained for small gain-length product (g0L

All optical processes, e.g. deflection and polarization rotation, can be realized using cascaded χ(2): χ(2)interactions in one-dimensional and two-dimensional nonlinear photonic crystals. Collinear and non-collinear interactions in periodically- and quasi-periodically-modulated crystals are studied.

We have verified experimentally that the d22=dYYY nonlinear coefficient of LiNbO3 changes its sign as a result of periodic poling along the Z direction. This reversal enables the realization of all-optical polarization rotation in PPLN.

A nonlinear photonic quasicrystal accommodating any set of arbitrary χ(2) processes can be designed using a known quasi-crystallographic algorithm. We demonstrate the design of multiple second harmonic generation and of cascaded polarization rotation.

We report experimental realization of a new type of optical parametric oscillator, in which oscillation is achieved by polarization rotation in a linear retarder, followed by nonlinear mixing of the two polarized beams. The mixing is performed by a type II degenerate parametric down conversion in a PPKTP crystal, pumped at 1064nm by a pulsed Nd:YAG laser. A single, linearly polarized beam is generated at the degenerate wavelength. The output spectrum has a narrow linewidth (below the instrumentation bandwidth of 1nm), and is highly stable at degeneracy with respect to variations in the crystal temperature. The frequency locking is explained in terms of balanced roundtrip phase-matching condition.

We experimentally demonstrate that finite width interaction of a co-linear χ(2) process inside a periodic nonlinear photonic crystal leads to new possibilities of phase matching and thus to radiation un-accounted for by regular plane-wave analysis. Article not available.

We present experimental results for a new laser source in the green, combining three different technologies in a rugged, all solid-state device, as will be described in detail below.

69% doubling efficiency of a 50 kHz, 120 µJ/pulse Nd:YAG source was obtained with a periodically poled KTP placed outside the laser resonator.

Measurement of the fringe visibility in a two-beam interferometer is a basic method to characterize the structure function and linewidth of light sources1,2 as well as to determine the sensitivity of interferometric sensors.3

By inserting a linear polarizer after a fiber optic recirculating delay line, the system becomes highly polarization dependent. The transfer function and the phase induced intensity noise for different polarization inputs are studied.