Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Alexander Bekker is active.

Publication


Featured researches published by Alexander Bekker.


Applied Physics Letters | 1993

Broadband second‐harmonic generation in SrxBa1−xNb2O6 by spread spectrum phase matching with controllable domain gratings

Moshe Horowitz; Alexander Bekker; Baruch Fischer

We have demonstrated, for the first time to our knowledge, second‐harmonic generation for a broad input wavelength range of 750–1064 nm in SrxBa1−xNb2O6 crystals, with a controllable spread spectrum of quasiphase matching. Second‐harmonic conversion efficiencies of up to ∼1% were observed. This was done without any temperature or angular tuning of the crystal. The phase matching was obtained by inducing alternating ferroelectric domains in the crystal in real time, using a novel fixing process which is based on screening. The broadband capability of the conversion is allowed by a spread in the range of the domain widths.


Optics Letters | 2000

Dispersion-mode pulsed laser

Baruch Fischer; Boris Vodonos; Shimie Atkins; Alexander Bekker

A new self-consistency condition in pulsed lasers with strong intracavity dispersion imposes dispersion modes with specific cavity-length dependent pulse rates, utilizing pulse-train self-imaging properties of a temporal Talbot effect. We give an experimental demonstration of such a laser operation, using a long fiber cavity. We also demonstrate temporal Talbot imaging of a train of short pulses that propagate along large distances of dispersive fibers.


Optics Communications | 2003

Compression of periodic light pulses using all-optical repetition rate multiplication

Naum K. Berger; Boris Vodonos; Shimie Atkins; Vladimir Smulakovsky; Alexander Bekker; Baruch Fischer

We propose a novel method for compression of periodic optical pulses based on all-optical repetition rate multiplication of pulses without requiring propagation in a dispersive delay line. The compression principle is explained using the temporal Talbot effect. The proposed method is demonstrated experimentally with the generation of ∼20 ps pulses from cw radiation of a laser diode. The repetition rate multiplication is performed with fiber Bragg gratings. The proposed method simultaneously implements two important requirements of many fields, for example, of optical communications: pulse compression and pulse repetition rate multiplication.


Optics Letters | 1993

Image and hologram fixing method with SrXBa 1− XNb 2 O 6 crystals

Moshe Horowitz; Alexander Bekker; Baruch Fischer

We demonstrate a new fixing method with Sr(x)Ba(1-x)Nb(2)O(6) crystals. This is done by inducing ferroelectric domains in the crystal in real time, by a screening mechanism. Images or their holograms can be recorded in small separate locations in the crystal. This crystal pixelization permits the recording of many pictures and their individual readout and erasure.


Optics Letters | 2005

Experimental study of the stochastic nature of the pulsation self-starting process in passive mode locking

Boris Vodonos; Alexander Bekker; Vladimir Smulakovsky; A. Gordon; Omri Gat; Naum K. Berger; Baruch Fischer

We present an experimental study of the probabilistic nature of pulsation self-starting in passively mode-locked lasers. It is a Poissonian process that results from a noise-activated switching barrier. The switching rate from cw operation to pulsation when the laser pump level is turned on has an exponential dependence that is inversely proportional to the square of the laser power.


Applied Physics Letters | 1998

OPTICALLY INDUCED DOMAIN WAVEGUIDES IN SRXBA1-XNB2O6 CRYSTALS

Alexander Bekker; Aviad Peda’el; Naum K. Berger; Moshe Horowitz; Baruch Fischer

Optically induced refractive index patterns, which can be used for waveguides, were formed in SrxBa1−xNb2O6 crystals using an erasable fixing mechanism, based on domains formation by the screening effect. The sign and strength of the refractive index change of the fixed waveguides was controllable by an applied electric field. Fixed patterns are shown to allow the storage of many spatially multiplexed holograms.


Optics Letters | 2002

Experimental demonstration of localization in the frequency domain of mode-locked lasers with dispersion

Baruch Fischer; Boris Vodonos; Shimie Atkins; Alexander Bekker

Mode-locked lasers with intracavity dispersion are experimentally shown to exhibit localization behavior in their frequency domain. The localization, with its typical exponential spectrum structure, is analogous to that which occurs for the quantum kicked rotor. The experimental demonstration of our optical kicked rotor is done with a long mode-locked dispersive fiber laser. The localization effect sets a basic limit on the spectrum bandwidth and the minimum pulse width in such lasers. It also provides a special experimental test bed for the study of optical kicked rotors and localization effects.


Optics & Photonics News | 2013

Many-Body Photonics

Baruch Fischer; Alexander Bekker

Researchers are using statistical mechanics to uncover thermodynamic-like properties in optical systems. This unique research direction could have far-reaching implications for photonics.


conference on lasers and electro optics | 1999

Cavity-resonance-activated wavelength selectable fiber and diode lasers

Baruch Fischer; Ofer Shapira Boris Levit; Alexander Bekker

Summary form only given. Wavelength-controllable components, such as laser sources, which can operate at several selectable wavelengths, can be very attractive for many applications, especially for dynamic wavelength division multiplexing (WDM) networks in fiber optic communication. It is difficult to obtain fiber lasers and even diode laser-based systems with several wavelengths, which can be tuned and selected at high speeds. We report on wavelength selectable fiber and diode lasers, which can operate at each of several chosen wavelengths, with the possibility of switching between them at high speeds. The obtained selection time was /spl sim/5 ns for the diode laser system and /spl sim/150 ns for the fiber laser. The method is based on mode-locking or cavity-resonance-operated wavelength selection (CROWS). It is done by applying the suitable mode-locking frequency of a multiple-length fiber laser cavity, formed by multiple successive fiber grating reflectors, each with a different Bragg wavelength. It allows selection and high speed switching between these wavelengths. Such lasers can be useful for dynamic wavelength division multiplexing (WDM) in fiber optic networks.


Optica | 2014

Classical condensation of light pulses in a loss trap in a laser cavity

Gilad Oren; Alexander Bekker; Baruch Fischer

We present an experimental demonstration of condensation in a many-light-pulse system in a loss trap (loss well) in a one-dimensional laser cavity. The route to condensation is similar to Bose–Einstein condensation in a potential trap (potential well), but classical. The pulses, their loss levels, and the noise-induced power distribution take the role of “particles”, “energy” levels, and quantum-thermal population-statistics, respectively. The multipulse system is formed by high harmonic active mode-locking modulation and the trap by an envelope modulation. The experiment is done with an erbium-doped fiber laser. Condensation is shown to occur when the loss trap has near the lowest-loss pulse a power law dependence with exponent smaller than 1, as the theory predicts.

Collaboration


Dive into the Alexander Bekker's collaboration.

Top Co-Authors

Avatar

Baruch Fischer

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Vladimir Smulakovsky

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Boris Levit

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Rafi Weill

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Boris Vodonos

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Omri Gat

Hebrew University of Jerusalem

View shared research outputs
Top Co-Authors

Avatar

Amir Rosen

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Naum K. Berger

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Shimie Atkins

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

A. Gordon

Technion – Israel Institute of Technology

View shared research outputs
Researchain Logo
Decentralizing Knowledge