Iryna Khodasevych | RMIT University (original) (raw)

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Papers by Iryna Khodasevych

Research paper thumbnail of Hybrid waveguide-integrated plasmonic crystals on silicon-on-insulator platform

Research paper thumbnail of Laser-Induced Dewetting for Precise Local Generation of Au Nanostructures for Tunable Solar Absorption

Abstract: A precise and scalable method is introduced for realizing deeply subwavelength nanostru... more Abstract: A precise and scalable method is introduced for realizing deeply subwavelength nanostructures through laser-induced dewetting. This fabrication method is used to realize a three layer planar absorber device that allows for highly tunable selective visible–IR light absorption. This large area laser dewetting method uses a 532 nm laser with a μm ranged focal spot on a translation stage allowing for fine pattern control. A range of laser powers from 60 to 130 mW is explored and it is found that three dramatically different structures, all aperiodic and random in nature are developed. An interconnected metallic nanowire network, partially connected nanowire networks, and spherical or elliptically shaped nanoparticles are observed for low, intermediate, and high laser powers, respectively. Optical absorptance spectra demonstrate a noticeable variation in response to the structures formed. A tunable absorption in the visible range is demonstrated and the partially connected nanowires show the greatest enhancement in broadband absorption compared to the other structures. Finite element simulations uncover plasmonic and magnetic resonances as the underlying mechanisms for the absorbing behavior. This high degree of control over the dewetting area makes this technique a suitable candidate for many photonic and solar applications allowing for precise engineering of the absorbing nanostructure design.

Research paper thumbnail of Micro- and Nanostructured Surfaces for Selective Solar Absorption

Advanced Optical Materials, 2015

Abstract: Efficient absorption of solar radiation is desired for the renewable energy sector, suc... more Abstract: Efficient absorption of solar radiation is desired for the renewable energy sector, such as solar thermophotovoltaics and solar thermal applications. In order to minimize thermal re-radiation, wavelength-selective devices are required. Absorbers with structured surfaces are attractive because they derive their electromagnetic properties to a greater extent from their geometry and to a lesser extent from the intrinsic properties of the constituent materials. Thus, they offer greater flexibility in the design and control of absorber features and can be tailored to suit requirements. This article reviews various classes of patterned structures: photonic crystals, metal–dielectric–metal slab arrays, metamaterials, and nanostructures operating in the visible and infrared wavelength ranges. Operation requirements, design principles and underlying physical phenomena, material and temperature considerations, as well as fabrication methods are discussed. Recent progress in achieving various desirable absorber features, such as broadband and multiband operation, polarization and angle independence, flexibility, and tunability is presented. Suggestions are also given regarding future research directions.

Research paper thumbnail of Dielectrophoretically controlled Fresnel zone plate

Switchability is a highly sought after feature for planar optical systems. Suspensions of nanomat... more Switchability is a highly sought after feature for planar optical systems. Suspensions of nanomaterials can be used for generating controllable changes in such systems. We report a planar diffractive microfluidic lens which integrates controlled dielectrophoresis (DEP) for trapping suspended nanomaterials. Silicon and tungsten oxide nanoparticle suspensions are used. These nanomaterials are trapped in such a way as to form alternating opaque and transparent rings using the DEP forces on demand. These rings form a planar diffractive Fresnel zone plate to focus the incident light. The Fresnel zone plate is tuned for the visible light region and the lens can be turned on (DEP applied) or off (DEP removed) in a controlled manner. This proof of concept demonstration can be further expanded for a variety of switchable optical devices and can be integrated with lab-on-a-chip and optofluidic devices.

Research paper thumbnail of Nonlinear microwave metamaterial resonators using gravitational restoring force realized on a microfabricated perforated substrate

Applied Physics Letters, 2014

Research paper thumbnail of Pneumatically switchable graded index metamaterial lens

Applied Physics Letters, 2013

A low-profile pneumatically switchable graded index metamaterial lens operating at 9 GHz is propo... more A low-profile pneumatically switchable graded index metamaterial lens operating at 9 GHz is proposed and practically demonstrated. An effective graded refractive index is engineered using an array of electric resonators of differing resonant frequency. Normal orientation of the resonators allows ultrathin single metamaterial layer lens design. Switching between focusing and non-focusing states is practically demonstrated by shorting the gaps in split ring resonators and eliminating the resonant response and the phase difference between the elements across the lens with pneumatically actuated metal patches that are pressed against the gaps of the resonators as the pressure in the chamber is reduced. V C 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4788918]

Research paper thumbnail of Elastomeric silicone substrates for terahertz fishnet metamaterials

Dynamics of solvent-free grafted nanoparticles J. Chem. Phys. 136, 044902 (2012) Energy transfer ... more Dynamics of solvent-free grafted nanoparticles J. Chem. Phys. 136, 044902 (2012) Energy transfer and dynamics studies of photoluminescence of polythiophene derivative in blend thin films J. Appl. Phys. 111, 023512 (2012) Note: Percolation in two-dimensional flexible chains systems J. Chem. Phys. 136, 046101 (2012) Ultraviolet and infrared femtosecond laser induced periodic surface structures on thin polymer films

Research paper thumbnail of Reconfigurable Fishnet Metamaterial Using Pneumatic Actuation

Progress In Electromagnetics Research B, 2012

The design, fabrication and measurement of a reconfigurable fishnet metamaterial based on a new m... more The design, fabrication and measurement of a reconfigurable fishnet metamaterial based on a new method of tuning by changing unit cell geometry is reported. Retractable elements are added to the unit cell utilizing pneumatically actuated switching. It is shown that the pneumatic actuation approach can unite a number of metallic elements into a complex conducting structure. Experimental demonstration confirms that the structure operates at two different frequencies in the GHz range in distinct actuation states. The measured results also show good agreement with numerical simulations.

Research paper thumbnail of Tunable fluid infiltrated optical fishnet metamaterial

Abstract: We show that infiltrating fishnet metamaterial with fluids of different permittivity ca... more Abstract: We show that infiltrating fishnet metamaterial with fluids of different permittivity can provide tuning at infrared frequencies. Substantial tunability range of the material is achieved with very minor changes in the permittivity of the fluid.

Research paper thumbnail of Hybrid waveguide-integrated plasmonic crystals on silicon-on-insulator platform

Research paper thumbnail of Laser-Induced Dewetting for Precise Local Generation of Au Nanostructures for Tunable Solar Absorption

Abstract: A precise and scalable method is introduced for realizing deeply subwavelength nanostru... more Abstract: A precise and scalable method is introduced for realizing deeply subwavelength nanostructures through laser-induced dewetting. This fabrication method is used to realize a three layer planar absorber device that allows for highly tunable selective visible–IR light absorption. This large area laser dewetting method uses a 532 nm laser with a μm ranged focal spot on a translation stage allowing for fine pattern control. A range of laser powers from 60 to 130 mW is explored and it is found that three dramatically different structures, all aperiodic and random in nature are developed. An interconnected metallic nanowire network, partially connected nanowire networks, and spherical or elliptically shaped nanoparticles are observed for low, intermediate, and high laser powers, respectively. Optical absorptance spectra demonstrate a noticeable variation in response to the structures formed. A tunable absorption in the visible range is demonstrated and the partially connected nanowires show the greatest enhancement in broadband absorption compared to the other structures. Finite element simulations uncover plasmonic and magnetic resonances as the underlying mechanisms for the absorbing behavior. This high degree of control over the dewetting area makes this technique a suitable candidate for many photonic and solar applications allowing for precise engineering of the absorbing nanostructure design.

Research paper thumbnail of Micro- and Nanostructured Surfaces for Selective Solar Absorption

Advanced Optical Materials, 2015

Abstract: Efficient absorption of solar radiation is desired for the renewable energy sector, suc... more Abstract: Efficient absorption of solar radiation is desired for the renewable energy sector, such as solar thermophotovoltaics and solar thermal applications. In order to minimize thermal re-radiation, wavelength-selective devices are required. Absorbers with structured surfaces are attractive because they derive their electromagnetic properties to a greater extent from their geometry and to a lesser extent from the intrinsic properties of the constituent materials. Thus, they offer greater flexibility in the design and control of absorber features and can be tailored to suit requirements. This article reviews various classes of patterned structures: photonic crystals, metal–dielectric–metal slab arrays, metamaterials, and nanostructures operating in the visible and infrared wavelength ranges. Operation requirements, design principles and underlying physical phenomena, material and temperature considerations, as well as fabrication methods are discussed. Recent progress in achieving various desirable absorber features, such as broadband and multiband operation, polarization and angle independence, flexibility, and tunability is presented. Suggestions are also given regarding future research directions.

Research paper thumbnail of Dielectrophoretically controlled Fresnel zone plate

Switchability is a highly sought after feature for planar optical systems. Suspensions of nanomat... more Switchability is a highly sought after feature for planar optical systems. Suspensions of nanomaterials can be used for generating controllable changes in such systems. We report a planar diffractive microfluidic lens which integrates controlled dielectrophoresis (DEP) for trapping suspended nanomaterials. Silicon and tungsten oxide nanoparticle suspensions are used. These nanomaterials are trapped in such a way as to form alternating opaque and transparent rings using the DEP forces on demand. These rings form a planar diffractive Fresnel zone plate to focus the incident light. The Fresnel zone plate is tuned for the visible light region and the lens can be turned on (DEP applied) or off (DEP removed) in a controlled manner. This proof of concept demonstration can be further expanded for a variety of switchable optical devices and can be integrated with lab-on-a-chip and optofluidic devices.

Research paper thumbnail of Nonlinear microwave metamaterial resonators using gravitational restoring force realized on a microfabricated perforated substrate

Applied Physics Letters, 2014

Research paper thumbnail of Pneumatically switchable graded index metamaterial lens

Applied Physics Letters, 2013

A low-profile pneumatically switchable graded index metamaterial lens operating at 9 GHz is propo... more A low-profile pneumatically switchable graded index metamaterial lens operating at 9 GHz is proposed and practically demonstrated. An effective graded refractive index is engineered using an array of electric resonators of differing resonant frequency. Normal orientation of the resonators allows ultrathin single metamaterial layer lens design. Switching between focusing and non-focusing states is practically demonstrated by shorting the gaps in split ring resonators and eliminating the resonant response and the phase difference between the elements across the lens with pneumatically actuated metal patches that are pressed against the gaps of the resonators as the pressure in the chamber is reduced. V C 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4788918]

Research paper thumbnail of Elastomeric silicone substrates for terahertz fishnet metamaterials

Dynamics of solvent-free grafted nanoparticles J. Chem. Phys. 136, 044902 (2012) Energy transfer ... more Dynamics of solvent-free grafted nanoparticles J. Chem. Phys. 136, 044902 (2012) Energy transfer and dynamics studies of photoluminescence of polythiophene derivative in blend thin films J. Appl. Phys. 111, 023512 (2012) Note: Percolation in two-dimensional flexible chains systems J. Chem. Phys. 136, 046101 (2012) Ultraviolet and infrared femtosecond laser induced periodic surface structures on thin polymer films

Research paper thumbnail of Reconfigurable Fishnet Metamaterial Using Pneumatic Actuation

Progress In Electromagnetics Research B, 2012

The design, fabrication and measurement of a reconfigurable fishnet metamaterial based on a new m... more The design, fabrication and measurement of a reconfigurable fishnet metamaterial based on a new method of tuning by changing unit cell geometry is reported. Retractable elements are added to the unit cell utilizing pneumatically actuated switching. It is shown that the pneumatic actuation approach can unite a number of metallic elements into a complex conducting structure. Experimental demonstration confirms that the structure operates at two different frequencies in the GHz range in distinct actuation states. The measured results also show good agreement with numerical simulations.

Research paper thumbnail of Tunable fluid infiltrated optical fishnet metamaterial

Abstract: We show that infiltrating fishnet metamaterial with fluids of different permittivity ca... more Abstract: We show that infiltrating fishnet metamaterial with fluids of different permittivity can provide tuning at infrared frequencies. Substantial tunability range of the material is achieved with very minor changes in the permittivity of the fluid.