Noa Voloch-bloch - Academia.edu (original) (raw)

Papers by Noa Voloch-bloch

arXiv (Cornell University), Jan 16, 2024

Philosophical Magazine, 2008

Journal of the Optical Society of America B, 2008

Applied Physics Letters, 2009

We present experimentally the control of free space propagation of an Airy beam. This beam is gen... more We present experimentally the control of free space propagation of an Airy beam. This beam is generated by a nonlinear wave mixing process in an asymmetrically poled nonlinear photonic crystal. Changing the quasi-phase matching conditions, e.g., the crystal temperature or pump wavelength, alters the location of the Airy beam peak intensity along the same curved trajectory. We explain that the variation in the beam shape is caused by noncollinear interactions. Owing to the highly asymmetric shape of nonlinear crystal in the Fourier space, these noncollinear interactions are still relatively efficient for positive (nonzero) phase mismatch.

Journal of the Optical Society of America B, 2007

We recently described a general solution to the phase-matching problem that arises when one wishe... more We recently described a general solution to the phase-matching problem that arises when one wishes to perform an arbitrary number of nonlinear optical processes in a single medium [Phys. Rev. Lett. 95, 133901 (2005)]. Here we outline in detail the implementation of the solution for a one-dimensional photonic quasicrystal, which acts as a simultaneous frequency doubler for three independent optical beams. We confirm this solution experimentally using an electric-field poled KTiOPO 4 crystal. In optimizing the device, we findcontrary to common practice-that simple duty cycles of 100% and 0% may yield the highest efficiencies, and we show that our device is more efficient than a comparable device based on periodic quasi-phase matching.

2021 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS)

Computing the fastest rout in traffic is a long researched problem, with several solutions to it.... more Computing the fastest rout in traffic is a long researched problem, with several solutions to it. Most of these solutions consider the current status of the road in a given time, including vehicles that are currently in the planned rout. The problem with this approach is that vehicles that are currently placed in a point that will be reached within a certain amount of time, will no longer be there at the arrival time. This creates a problem, that even exists in the most popular navigation application such as Waze and Google Maps, where the ETA is constantly changing during the travel. In this research we suggest a different approach, that finds the fastest traffic rout according to the future positions of vehicles at the designated points in the rout. This approach will give a much more efficient navigation paradigm, in which the estimated travel times are realistic and accurate.

Conference on Lasers and Electro-Optics, 2020

We introduce an efficient, nonperturbative method for calculating the first and second order quan... more We introduce an efficient, nonperturbative method for calculating the first and second order quantum correlations of down converted photons that recovers experimental results. Our algorithm paves the way towards engineering arbitrarily structured nonclassical light.

Quantum Information and Measurement (QIM) V: Quantum Technologies, 2019

We present a method for simulating the spatial distribution of the SPDC generated state based on ... more We present a method for simulating the spatial distribution of the SPDC generated state based on classical equations. This enables the design of nonlinear crystals and pumping conditions for generating non-classical light with desired properties.

$Research paper thumbnail of Nonlinear Diffraction from a Virtual Beam$

Physical Review Letters, 2010

We observe experimentally a novel type of nonlinear diffraction in the process of two-wave mixing... more We observe experimentally a novel type of nonlinear diffraction in the process of two-wave mixing on a nonlinear quadratic grating. We demonstrate that when the nonlinear grating is illuminated simultaneously by two noncollinear beams, a second-harmonic diffraction pattern is generated by a virtual beam propagating along the bisector of the two pump beams. The observed diffraction phenomena is a purely nonlinear effect that has no analogue in linear diffraction.

Physical Review Letters, 2007

Quasiperiodicity is the concept of order without translation symmetry. The discovery of quasiperi... more Quasiperiodicity is the concept of order without translation symmetry. The discovery of quasiperiodic order in natural materials transformed the way scientists examine and define ordered structure. We show and verify experimentally that quasiperiodicity can be observed by scattering processes from a periodic structure, provided the interaction area is of finite width. This is made through a momentum conservation condition, physically realizing a geometrical method used to model quasiperiodic structures by projecting a periodic structure of a higher dimension.

Philosophical Magazine, Jan 1, 2008

Two well-known methods for the design of quasicrystal models are used to create novel nonlinear o... more Two well-known methods for the design of quasicrystal models are used to create novel nonlinear optical devices. These devices are useful for efficient three-wave mixing of several different processes, and therefore offer greater flexibility with respect to the more common periodic nonlinear photonic crystals. We demonstrate applications for polarization switching as well as multi-wavelength and multi-directional frequency doubling. The generalized dual grid method is proven to be efficient for designing photonic quasicrystals for one-dimensional collinear devices as well as elaborate twodimensional multi-directional devices. The cut and project method is physically realized by sending finite-width optical beams at an irrational angle through a periodic two-dimensional nonlinear photonic crystal. This enables two simultaneous collinear optical processes that can be varied by changing the angle of the beams.

IEEE Journal of Quantum Electronics, 2000

Standard quasi-phase-matching (QPM) schemes assume exact momentum relations between the interacti... more Standard quasi-phase-matching (QPM) schemes assume exact momentum relations between the interacting beams, thus necessitating the direct use of a reciprocal lattice vector to satisfy momentum balance. Usage of finite width beams for colinear interactions permits to use a projection of the reciprocal lattice vector along the propagation direction of the beams. We analytically derive this result and exam the new options given by this projection-based QPM for the analysis and design of nonlinear optical devices.

A nonlinear photonic quasicrystal accommodating any set of arbitrary &# 967;< sup>(2)</s... more A nonlinear photonic quasicrystal accommodating any set of arbitrary &# 967;< sup>(2)</sup> processes can be designed using a known quasi-crystallographic algorithm. We demonstrate the design of multiple second harmonic generation and of cascaded polarization rotation.

Applied Network Science

Smart cities and traffic applications can be modelled by dynamic graphs for which vertices or edg... more Smart cities and traffic applications can be modelled by dynamic graphs for which vertices or edges can be added, removed or change their properties. In the smart city or traffic monitoring problem, we wish to detect if a city dynamic graph maintains a certain local or global property. Monitoring city large dynamic graphs, is even more complicated. To treat the monitoring problem efficiently we divide a large city graph into sub-graphs. In the distributed monitoring problem we would like to define some local conditions for which the global city graph G maintains a certain property. Furthermore, we would like to detect if a local city change in a sub-graph affect a global graph property. Here we show that turning the graph into a non-trivial one by handling directed graphs, weighted graphs, graphs with nodes that contain different attributes or combinations of these aspects, can be integrated in known urban environment applications. These implementations are demonstrated here in two ...

Nature, Feb 1, 2013

We report the first experimental generation and observation of Airy beams of free electrons. The ... more We report the first experimental generation and observation of Airy beams of free electrons. The electron Airy beams are generated by diffraction of electrons through a nanoscale hologram, that imprints a cubic phase modulation on the beams' transverse plane. We observed the spatial evolution dynamics of an arc-shaped, self accelerating and shape preserving electron Airy beams. We directly observed the ability of electrons to self-heal, restoring their original shape after passing an obstacle. This electromagnetic method opens up new avenues for steering electrons, like their photonic counterparts, since their wave packets can be imprinted with arbitrary shapes or trajectories. Furthermore, these beams can be easily manipulated using magnetic or electric potentials. It is also possible to efficiently self mix narrow beams having opposite signs of acceleration, hence obtaining a new type of electron interferometer.

Laser & Photonics Reviews

Conference on Lasers and Electro-Optics, 2016

We study theoretically and experimentally the varying polarization states and intensity patterns ... more We study theoretically and experimentally the varying polarization states and intensity patterns of self-accelerating vector beams. It is shown that as these beams propagate, the main intensity lobe and the polarization singularity gradually drift apart. Furthermore, the propagation dynamics can be manipulated by controlling the beams' acceleration coefficients. We also demonstrate the self-healing dynamics of these accelerating vector beams for which sections of the vector beam are being blocked by an opaque or polarizing obstacle. Our results indicate that the self-healing process is almost insensitive for the obstacles' polarization direction. Moreover, the spatial polarization structure also shows selfhealing properties, and it is reconstructed as the beam propagates further beyond the perturbation plane. These results open various possibilities for generating, shaping and manipulating the intensity patterns and space variant polarization states of accelerating vector beams. Airy beams, as part of the group of wave-functions coined sometimes "non-diffracting beams" or "self-accelerating beams" have drawn significant scientific interest, due to their shape-preserving and accelerating propagation dynamics in space or in time. Ever-since their first introduction 1 , Airy beams have been investigated in a wide range of physical systems 2-5 , in various symmetries 6,7 , in linear and nonlinear mediums 4,8 , and suggested for many applications such as micro-particles manipulations 9 , optical routing 10 and super resolution imaging 11. The research of Airy beams has also triggered the developing of other forms of accelerating beams 12-15. One of the most intriguing properties of self-accelerating beams is their ability to self-heal from blocking obstacles 16 , a property now researched in the context of other beam types and polarizations 17-19. The common way to characterize accelerating beams is by tracing the trajectory of the highest intensity lobe as it curves while propagating through space. To date, in the vast majority of reported experiments, a linearly polarized Gaussian beam has been used as the excitation source. While such beams are probably the most common form of coherent light source, we are recently witnessing a growing interest in light with a spatially varying polarization, generally known as vector beams 20. One of the many types of vector beams is the radially polarized mode, which exhibits a spatially varying polarization, with the transverse electric field directed outward from the optical axis, and which is an axial-symmetric solution to Maxwell's equations 21-23. Now implemented in different systems, radially polarized light was proved to be efficient in nano-focusing 24-29 , microscopy and particle manipulations 30. The combination of Airy patterns and vector beams (shown in Fig. 1), which can be defined as Airy vector beams, has been somewhat overlooked by researchers, with very little reports so far 7,31. In such beams, the interplay between the Airy pattern and polarization states, symmetry differences and different propagation dynamics, rises many interesting outcomes. In this report we present theoretical predictions along with numerical and experimental results showing the propagation dynamics, self-healing mechanisms and polarization distribution of radially-polarized vector Airy beams (RAVB). While RAVBs are the basic form of accelerating vector beams, this research can be further extended to any accelerating wave packet and any type of polarization structure. This paper will show that when a radially polarized Gaussian beam illuminates a cubic phase mask and focused, RAVBs are generated at the focal plane. As illustrated in Fig. 1c, the main lobe of RAVB's is divided into two lobes by a radially shaped polarization singularity (zero-order topological charge 32). The checkerboard

CLEO/Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference, 2009

... LiTaO 3 (ASLT); (c) short-range ordered poled structure patterned in LiNbO 3 (SRO-LNB); (d) n... more ... LiTaO 3 (ASLT); (c) short-range ordered poled structure patterned in LiNbO 3 (SRO-LNB); (d) nonlinear photonic octagonal quasi-crystal sructure patterned in LiNbO 3 (OQC-LNB); and (e ... crawler. Your institute subscribes to: IEEE/IET Electronic Library (IEL); What can I access? ...