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Research

Nonlinear metamaterials

Quantum Coherent Control

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Robust wireless energy transfer - We have applied the adiabatic passage dynamics to the fast growing field of mid-range wireless power transfer. The proposed technique that we suggest is robust and has broadband conversion response over existing methods.  Read More...

Modal dynamics in multimode fibers - We have applied four level dynamical analysis to explore the evolution of polarized light in multimode fibers. We have shown that the propagation of light in multimode fibers can be decomposed into two natural sub-systems of two mode dynamics, which are represented on two separate modified Poincare spheres, instead of one as in the single mode case.  Read More...

Femto-Nano Laboratory


Suchowski Haim Group

Ultrafast phenomena at the nanoscale

Ultrafast photo-induced hot carrier dynamics in plasmonic nanostructures span time scales from femtoseconds to picoseconds. Probing the evolution of the hot electrons toward equilibrium (tens to hundreds of fs), which occur in very small dimensions, requires developing measurement methods that will allow a simultaneous access to the spatio-temporal domains. In our lab, we are interested in exploring ultrafast hot carrier dynamics and related nonlinear effects in plasmonic nanostructures, and in particular to study ultrafast energy harvesting mechanisms. We plan to develop novel ways to observe, retrieve and even manipulate the hot electron spatio-temporal evolution in these nano-structures.

The ability to tailor the electromagnetic response of matter by subwavelength nano-structures introduces new regimes of light-matter interaction, such as negative and zero refractive index materials. In recent years, the nonlinear properties of such new index materials have been explored theoretically and experimentally, showing rich nonlinear dynamics. we have perform experimental study to reveal the mechanism behind the nonlinear generation process and far-field emission from plasmonic nanostructures.

Our recent experimental study of nonlinear propagation in a zero index materials, which have an inherent phase matching between the interacting beams, provides a new degree of freedom in controlling the nonlinear dynamics. The demonstrated control scheme, only possible with such novel materials, leads to simultaneous generation of backward and forward nonlinear generated optical frequencies, and is the first step toward exploring these exciting effects. Read More...

In another experimental research, we have explored the underlying physics that describe the nonlinear generation in nanostructures and the design rules that maximize the nonlinear emission from these nanostructures. By studying the geometrical dependence of the second harmonic and third harmonic emission from gold nanostructures, we have shown that the nonlinear scattering theory allows the prediction of the nonlinear optical response using the linear quantities. 

Adiabatic frequency conversion is a novel method for efficient conversion of broadband sources. The method circumvents the almost inherent trade-off between the efficiency of the conversion and the bandwidth over which the device functions. By exploiting the adiabatic dynamics, we have shown in a series of experimental works, the possibility to achieve efficient scalable broadband frequency conversion. With a collaboration with the Kärtner’s group from MIT, we have recently obtained efficient conversion of octave spanning source to the mid-infrared, generating a 1.5 cycles mid-infrared pulse, which is the shortest pulse ever achieved in the mid-infrared regime. Read More...

Two photon frequency conversion is a scheme, which allows frequency conversion through an opaque media. We also predict a new mechanism for intensity dependent phase matching analogous to the Stark effect from the quantum literature. Read More...

Frequency conversion

Coherent control of a quantum system enables an initial quantum state to be steered to a desired final state. By tailoring the spectrum and phase of the exciting laser fields, one can select a specific target state by inducing constructive interference between the pathways leading to that target state. The powerful approach known as geometrical control theory, which have been harnessed in recent years to study quantum systems, provides a general framework for determining controllability. In this approach, controllability is assessed using a criterion based on the Lie algebra structure of the control Hamiltonians.

In Complete inversion in 4-level system by Pythagorean coupling, we analyzed the light-matter interaction of 4-level quantum systems from a geometrical point of view. We have shown that such system can be decomposed into two different sub-systems of 2-level dynamics (qubits). We also found the constraints for achieving complete inversion in such systems, which has a surprising connection to the family of the Pythagorean triples from Number theory. Read More...

In Classification of Uncontrollable quantum system, we use continuous group theory (Lie algebra) to determine whether a quantum system is fully controllable, uncontrollable or sub-space controllable. This theoretical research gave me much of the physical intuition that I have today in most of my research. Read More...

We have also explored light-matter interaction in the weak- and strong-field coupling regimes by Spatio-temporal Coherent Control method, which utilizes not only temporal phase manipulations, but also controls the pulse shape evolution along the propagation axis. Read More...