RESEARCH

Lab Picture

Theory of light-matter interactions, tailored by nanostructured environment

Mesoscopic models for describing light-matter interactions on nanoscale

The ability to manipulate and tailor electromagnetic signals on a nanoscale, emerging from recent technological advances, facilitates addressing fundamental and technological challenges as well as to pave the way for variety of new applications. However, considerable reduction in physical dimensions introduces novel types of phenomena. For example, continuous tendency and progress in downscaling electronic devices to the deep nano-scale have already brought to consideration the emergent quantum effects. The interplay between classical and quantum phenomena lead to vast of opportunities to address old challenges and bring new solutions to majority of daily tasks. Light-matter interactions, influenced and tailored by surrounding nano-structuring, with no doubt will be the one of the main challenges and the key features of the future technological progress. Variety of quantum optical effects were already proposed, partially demonstrated, and even employed for several industrial applications. Future devices, engineered according to quantum-mechanical concepts, will find use in various applications, such as communications, computations, imaging, and biomedicine to name a few.

Optical Manipulation for controlling ‘Dynamics of Nanostructures’

Typical ‘Optical Tweezers’ setup

Opto-mechanics studies mechanical action of light on material bodies, e.g. micro and nano-scale particles, and, apart from it fundamental significance, takes it towards variety practical applications. Following J.K Maxwell’s theoretical prediction, the first experimental evidence on mechanical action on matter, induced by light, was provided by P. N. Lebedev at the very end of 19th century. The next major step, revolutionizing the field, was done by A. Ashkin in 70s, who proposed and demonstrated the ability to trap and manipulate micron particles with the help of focused laser beams. This investigation started the era of ‘optical tweezers’. Further exploration of this technique made it one of the most frequently used tools in several niches of bio-physics and bio-medicine, as it offers unique abilities of non-invasive control over living objects’ transport.

Recently, advances in opto-electronic and nano-technologies boosted the development of Opto-mechanics, which provides us with cutting edge abilities in manipulation and control over mechanical motion on nano-scale. For example, holographic optical tweezers enable simultaneous manipulation of hundreds of particles; tractor beams offer additional degree of freedom by attracting objects to a source of illumination, and other systems, aiming to provide ultimate on demand control over complex systems.

One of the major goals, to be archived in the field, is the ability to control nano-scale objects – this niche of Opto-mechanics is usually referred by the name Nano-opto-mechanics. The significant reduction of object’s dimensions to the nanometre range requires novel approaches and involves large span of novel physical phenomena. Several proposed and already demonstrated solutions in the field rely on the employment of auxiliary nanostructures, enabling focusing optical field way beyond the diffraction limit. As the result, severe enhancement of optical forces could be obtained.

Emulation of complex optical phenomena at Radio Frequencies – Analog Computing

Concept of emulation experiments:

A fluorescent molecule, conjugated to a nanoparticle (top), is emulated with a dipolar RF antenna, next to a ceramic ball (bottom)

The far going goal is to develop the large scale analog physical simulator, able to model, predict, and engineer dynamics of complex nano-scale photonic processes. The key approach is to employ scalability of Natural laws in respect to a dimensionless parameter.

Radio physics and engineering is the well established area with long successful history back to the beginning of 20th century. Majority of electromagnetic phenomena could be described from the prospective of Maxwell’s equations. Ability to solve them either analytically or numerically is the key for understanding and designing electromagnetic applications. Recent achievements in modern electrodynamics, partially related to the emergent field of metamaterials, enable addressing variety of complex fundamentally important phenomena by performing emulation experiments. Here we propose to take a new qualitative step in employing the scalability of fundamental laws of nature and investigate the platform for emulation of complex dynamical process, challenging for direct modeling and observation. Scaling up of systems’ physical dimensions makes their fabrications and measurements being straightforward and gives enormous advantages for detailed investigations.

From the scientific stand point ‘Analog Simulator’ approach brings the innovative concept of large scale physical solver, coming to analyze complex micro- and nano-scale processes. From the engineering standpoint, it enables performing designs of complex systems, challenging for direct numerical analysis and experimental verifications. In support, it is worth drawing the analogy to quantum computers, proposed by R. Feynman and aimed (in part) to predict and engineer dynamics of quantum systems. ‘Analog Simulator’ is aimed to solve complex physical scenarios, hard or even impossible for detailed numerical analysis.