Browsing by Subject "Metamaterial"

Now showing 1 - 20 of 45

Open Access
Adaptive metasurface designs for thermal camouflage, radiative cooling, and photodetector applications
(2022-01) Buhara, Ebru
Metamaterials, described as artificial sub-wavelength nanostructures, refer to a class of manufactured materials that possess distinctive electromagnetic features which cannot be found with natural materials. Thermal tunability, negative re-fractive index, perfect absorption, and invisible cloaking are examples of these attributes. Here, we design and implement metamaterials in four important ap-plication areas, namely 1) Multi-spectral infrared camouflage through excitation of plasmon-phonon polaritons in a visible-transparent hBN-ITO nanoantenna emitter, 2) Adaptive visible and short-wave infrared camouflage using a dynami-cally tunable metasurface, 3) Mid-infrared adaptive thermal camouflage using a phase-change material coupled dielectric nanoantenna, 4) An All-Dielectric Meta-surface Coupled with Two-Dimensional Semiconductors for Thermally Tunable Ultra-narrowband Light Absorption. In the first work, a metasurface design is developed to provide adaptive camou-flage in both visible and SWIR ranges. The proposed metasurface is made of an indium tin oxide (ITO) grating on a metal-insulator-metal (MIM, Ag-Sb2S3-Ag) nanocavity. In the amorphous state, the design operates as a colored transmis-sive window while, in the crystalline phase, it switches into a reflective mirror. In the meantime, the cavity acts as a thermally tunable host for the ITO nanoan-tenna providing tunable SWIR absorption to cover two transmissive regions at 1150-1350 nm (Region I) and 1400-1700 nm (Region II). It is found that the excitation of extended surface plasmons (ESPs) and guided mode resonances (GMRs) are responsible for light absorption in the SWIR range. Our theoretical calculations show that, besides the design’s ability for color adoption, the SWIR reflectance in Region I/Region II are reduced to 0.37/0.53 and 0.75/0.25 in the amorphous/crystalline phases. In the second work, a hybrid nanoantenna architecture made of ITO-hBN grating is proposed to satisfy all multi-spectral camouflage requirements. In this design, simultaneous excitation of plasmon-phonon polaritons in ITO and hBN leads to broadband absorption in the NTIR range and reflection in MWIR and LWIR ranges. Moreover, the bulk absorption in ITO film provides SWIR mode camouflage. Moreover, to highlight the importance of this hybrid design, the ITO-hBN design is compared with ITO-TiO2 heterostructure(TiO2 is a lossless dielectric in our desired ranges). Finally, the camouflage performance of the meta-surface is evaluated as the outgoing emission suppression when the metasurface design is on top of the blackbody object. In the third work, a PCM-dielectric based metasurface nanoantenna emitter design is proposed to achieve low observability at the MIR region by tailoring the spectral emissivity of the design. The proposed thermal nanoantenna emitter is composed of a high index dielectric (silicon (Si) in our case) nanograting on top of a thick silver (Ag) mirror. An ultrathin VO2 interlayer is embedded within the grating to actively tune its absorption response. The design geometries are adopted to place the resonance wavelengths in the atmospheric absorption win-dows for thermal camouflage applications. Based on the position of the VO2 layer, the optical response of the design in the metal phase can be diversely tuned from a narrowband to a broadband thermal emitter. Therefore, upon increase in the surface temperature, the proposed metasurface based thermal nanoantenna emitter turns into a broadband emitter with a stronger radiative thermal emission while it compatibly releases its heat based on the camouflage technology require-ment. The proposed design has perfect matching with atmospheric absorption windows so that it can efficiently release its heat without being observed by ther-mal camera systems. The detectability of the structure by a possible IR sensor is calculated using power calculations over the selected spectra. In addition, due to the hysteresis behavior of VO2, the calculations are done separately for cooling and heating conditions. In the fourth and final work, a dielectric based metasurface platform is pro-posed to achieve ultra-narrowband light absorption within a monolayer thick TMDC layer. For this purpose, the metasurface design is optimized. Then, this design is coupled with mono and multilayer TMDCs to observe better absorption results. For this purpose, MoS2, and WS2 are chosen as the most commonly used TMDCs. The coupling of light into Mie resonances, supported by dielec-tric nanograting, provides narrowband absorption within the TMDC layer. To reach further enhancement, a cavity design is integrated into this dielectric-based metasurface. For the best optimized design, the absorptance efficiency reaches to 0.85 and FWHM stays as narrow as 3.1 nm. Finally, the thermal tunability char-acteristic of the design is shown, without use of any phase change material. This is achieved due to strong light confinement within the design. Due to this con-finement, any small change in the refractive index is seen by the resonant design. Thus, the resonance frequency shifts and thermal tunability is acquired. The thermal sensitivity of the above-mentioned optimized design reaches to 0.0096 nm/◦C.
Open Access
Beaming and localization of electromagnetic waves in periodic structures
(2010) Çağlayan, Hümeyra
We want to manipulate light for several applications: microscopy, data storage, leds, lasers, modulators, sensor and solarcells to make our life healthier, easier or more comfortable. However, especially in small scales manipulating light have many difficulties. We could not focus or localize light into subwavelength dimensions easily, which is the key solution to beat today’s devices both in performance and cost. Achievements in three key research fields may provide the answer to these problems. These emerging research fields are metamaterials, photonic crystals and surface plasmons. In this thesis, we investigated beaming and localization of electromagnetic waves in periodic structures such as: subwavelength metallic gratings, photonic crystals and metamaterials. We studied off-axis beaming from both a metallic subwavelength aperture and photonic crystal waveguide at microwave regime. The output surfaces are designed asymmetrically to change the beaming angle. Furthermore, we studied frequency dependent beam steering with a photonic crystal with a surface defect layer made of dimmers. The dispersion diagram reveals that the dimer-layer supports a surface mode with negative slope. Thus, a photonic crystal based surface wave structure that acts as a frequency dependent leaky wave antenna was presented. Additionally, we investigated metamaterial based cavity systems. Since the unit cells of metamaterials are much smaller than the operation wavelength, we observed subwavelength localization within these metamaterial cavity structures. Moreover, we introduced coupled-cavity structures and presented the transmission spectrum of metamaterial based coupled-cavity structures. Finally, we demonstrated an ultrafast bioassay preparation method that overcomes the today’s bioassay limitations using a combination of low power microwave heating and split ring resonator structures.
Open Access
Bilayer metamaterial: analysis of left-handed transmission and retrieval of effective medium parameters
(Institute of Physics Publishing Ltd., 2007) Guven, K.; Cakmak, A. O.; Caliskan, M. D.; Gundogdu, T. F.; Kafesaki, M.; Soukoulis, C. M.; Özbay, Ekmel
We report an experimental and numerical analysis of a planar metamaterial designed for normal-to-plane propagation, and operating at microwave frequencies. The metamaterial consists of cutwire and wire patterns, which are arranged periodically on both sides of a dielectric layer, in the form of a bilayer. The left-handed transmission band of the metamaterial is demonstrated experimentally. The effective index of refraction retrieved from the S parameters is found to be negative within this transmission band. An independent negative refraction experiment supports the existence of the negative index of refraction for the metamaterial.
Open Access
Characterization and applications of negative-index metamaterials
(2008) Aydın, Koray
Metamaterials offer novel electromagnetic properties and promising applications including negative refraction, flat-lenses, superlenses, cloaking devices. In this thesis, we characterized the negative-index metamaterials that is composed of periodic arrangements of split-ring resonators (providing negative permeability) and thin wire (providing negative permittivity) arrays. The resonances of split-ring resonators (SRR) are investigated experimentally and theoretically. By combining SRR and wire arrays together, we observed a transmission band where both permittivity and permeability are simultaneously negative, indicating a left-handed behavior. Reflection measurements reveal that the impedance is matched to the free space at a certain frequency range. The lefthanded metamaterial is also shown to exhibit negative refractive index by using three different experimental methods namely, refraction from a wedge-shaped negative-index metamaterial (NIM), beam-shift from a slab-shaped NIM and phase shift from NIMs with different lengths. Flat-lens behavior is observed from a slabshaped negative-index metamaterial based microwave lenses. Furthermore, we demonstrated subwavelength imaging and subwavelength resolution by using thin superlenses constructed from SRR-wire arrays with an effective negative index. We have been able to image a point source with a record-level, λ/8 resolution. SRRand wire arrays exhibit negative index provided that the wave propagates parallel to the plane of SRR structure which makes it hard to fabricate at higher frequencies. An alternative structure called fishnet metamaterial however could yield negative index with wave propagation normal to the structure. We observed left-handed transmission and negative phase velocity in fishnet type metamaterials. Finally, we studied enhanced transmission from a single subwavelength aperture by coupling incident electromagnetic wave to a single SRR placed at the near-field of the aperture.
Open Access
Chiral metamaterial and high-contrast grating based polarization selective devices
(2013) Mutlu, Mehmet
The utilization of purposely designed artificial media with engineered electromagnetic responses enables the obtaining of intriguing features that are either impossible or difficult to realize using readily available natural materials. Here, we focus on two classes of artificial media: metamaterials and high-contrast gratings. Metamaterials and high-contrast gratings are designed within the subwavelength periodicity range and therefore, they are non-diffractive. We exploit the magnetoelectric coupling effect in chiral metamaterials to design several structures. Firstly, we design a linear to circular polarization convertor that operates for x-polarized normally incident plane waves. Then, we combine the chirality feature and the electromagnetic tunneling phenomenon to design a polarization insensitive 90◦ polarization rotator that exhibits unity transmission and crosspolarization conversion efficiencies. Subsequently, we combine this polarization rotator with a symmetric metallic grating with a subwavelength slit for the purpose of enabling the one-way excitation of spoof surface plasmons and achieving a reversible diodelike beaming regime. Then, we exploit the asymmetric transmission property of chiral metamaterials and show that a polarization angle dependent polarization rotation and a strongly asymmetric diodelike transmission is realizable. Afterwards, a brief waveguide theory is provided and eventually, the dispersion relations for a periodic dielectric waveguide geometry are derived. Then, using these relations and considering the finiteness of the waveguide length, we show the theoretical description of high-contrast gratings. Finally, we theoretically and experimentally show that the achievement of a broadband quarter-wave plate regime is possible by using carefully designed high-contrast gratings.
Open Access
Chiral metamaterials: From negative index to asymmetric transmission
(IEEE, 2013) Mutlu, Mehmet; Li, Zhaofeng; Özbay, Ekmel
Chiral metamaterials are attractive for their intriguing properties such as negative refractive index, optical activity and circular dichroism, and asymmetric transmission. In this paper, we review the research we have conducted for the purpose of investigating these exciting properties. © 2013 EurAAP.
Open Access
Chiral metamaterials: from optical activity and negative refractive index to asymmetric transmission
(IOP Publishing, 2013-01-30) Li, Z.; Mutlu, M.; Özbay, Ekmel
We summarize the progress in the development and application of chiral metamaterials. After a brief review of the salient features of chiral metamaterials, such as giant optical activity, circular dichroism, and negative refractive index, the common method for the retrieval of effective parameters for chiral metamaterials is surveyed. Then, we introduce some typical chiral structures, e.g., chiral metamaterial consisting of split ring resonators, complementary chiral metamaterial, and composite chiral metamaterial, on the basis of the studies of the authors’ group. The coupling effect during the construction of bulk chiral metamaterials is mentioned and discussed. We introduce the application of bianisotropic chiral structures in the field of asymmetric transmission. Finally, we mention a few directions for future research on chiral metamaterials.
Open Access
Design and analysis of metamaterial based perfect absorbers
(2019-08) Soydan, Mahmut Can
Subwavelength light absorbers have an enormous potential on applications such as photodetection, optoelectronics, solar cells and sensing. Scaling down the device dimensions provides artificial and advanced properties. That's why achieving higher performance devices with smaller sizes is the main trend in semiconductor technology. Design of an electromagnetic wave absorber has two dominant factors on the performance and spectral operation region: material selection and design configuration. Perfect light absorbers require an absorbing layer, such as a metal, semiconductor or any type of absorbing material, to achieve light confinement. While conventional metals have been mostly the primary choice in designs, there are various material types other than them which can have advantageous thermal properties in fabrication, integration or tunability besides having lossy nature. Although conventional metals are great absorbing materials due to lossy natures, they are not durable against erosion and oxidation. In the first work, we scrutinize unprecedented potential of transition metal carbides (TMCs) and nitrides (TMNs) as optional materials to conventional metals, for realization of light perfect absorption in an ultra-broad frequency range encompassing all of the visible (Vis) and near infrared (NIR) regions. To gain insight on the condition for light perfect absorption, a systematic modeling approach based on transfer matrix method (TMM) is firstly utilized. Our modeling findings prove that the permittivity data of these TMCs and TMNs are closely matched with the ideal data. Thus, they can have stronger and broader absorption behavior compared to metals. Besides, these ceramic materials are preferred to metals due to the fact that they have better thermal properties and higher durability against erosion and oxidation than metals. This could provide the opportunity for design of highly e cient light harvesting systems with long-term stability. Two different configurations which are planar and trapezoidal arrays are employed. Numerical simulations are conducted to optimize the device optical performance for each of the proposed carbides and nitrides. Our findings reveal that these ceramic coatings have the broadest absorption response compared to all lossy and plasmonic metals. In planar configuration, titanium carbide (TiC) has the largest absorption bandwidth (BW) where an absorption above 0.9 is retained over a broad wavelength range of 405 nm-1495 nm. In trapezoid architecture, vanadium nitride (VN) shows the widest BW covering a range from 300 nm to 2500 nm. The results of this study can serve as a beacon for the design of future high performance energy conversion devices including solar vapor generation and thermal photovoltaics where both optical and thermal requirements can be satisfied. Majority of existing designs necessitate a lithography-step during the fabrication, which hinders the repeatability, upscaling and large-scale compatibility of these designs. In the second work, we designed, fabricated and characterized a lithography free, double functional single Bismuth (Bi) metal nanostructure for ultra-broadband absorption in the visible and near-infrared, and narrowband response with ultra-high refractive-index sensitivity in mid-infrared (MIR) range. The superior permittivity data of Bi over conventional metals is comprehensively analyzed and explained using systematic modeling approaches based on TMM and Bruggeman's effective medium theory (EMT). To achieve a large scale fabrication of the design in a lithography-free route, oblique-angle deposition approach is used to obtain densely packed and randomly spaced/oriented Bi nanostructures. It has been shown that this fabrication technique can provide a bottom-up approach to control the length and spacing of the design. Our characterization findings reveal a broadband absorption above 0.8 in Vis and NIR, and a narrowband absorption centered around 6.54 m. Due to densely packed architecture of the Bi nanostructures and its extraordinary permittivity response, they can provide strong field confinement in their ultra-small gaps and this could be utilized for sensing application. An ultrahigh sensitivity of 2.151 m/refractive-index-unit (RIU) is acquired for this Bi nanostructured absorber, which is, to the best of our knowledge, the experimentally attained highest sensitivity so far. The simple and large scale compatible fabrication route of the design together with extraordinary optical response of Bi coating, makes this design promising for many optoelectronic and sensing applications.
Open Access
Design of metamaterial-based nanostructures for 5G applications & thermal radiation management
(2023-06) Boşdurmaz, Ekin Bircan;
The properties of natural materials can be the only limiting factor in today’s technologies. For this, researchers in the last decades found that engineering the features of naturally occurring materials in the subwavelength scales can drasti-cally change their properties. These materials beyond the natural ones are called “metamaterials”, where “meta” means “beyond” in Greek. Although the fabrica-tion of these materials can be quite challenging, clever designs and exploitation of physical phenomena can lead to tunable responses, eliminating the need for multi-ple structures. Here, diﬀerent strategies for designing tunable meta-surfaces for a wide range of applications will be presented by giving two examples. These appli-cations are namely: 1. Graphene-based Metasurface Absorber for the Active and Broadband Manipulation of Terahertz Radiation, 2. Adaptive Thermally Tunable Radiative Cooling with Angle Insensitivity Using Phase-Change Material-Based Metasurface.
Open Access
Development of left-handed composite materials and negative refracting photonic crystals with subwavelength focusing
(SPIE, 2005) Özbay, Ekmel
We review the studies conducted in our group concerning electromagnetic properties of metamaterials and photonic crystals with negative effective index of refraction. In particular, we demonstate the true left handed behavior of a 2D composite metamaterial, by analyzing the electric and magnetic response of the material components systematically. The negative refraction, subwavelength focusing, and flat lens phenomena using 2D dielectric photonic crystals are also presented.
Open Access
EU NoE metamorphose: Metamaterials research activities
(SPIE, 2005) Özbay, Ekmel
We will present the activities of METAMORPHOSE a network of excellence (NoE) formed under EU-FP6 on the area of metamaterials. The main scientific objective of the partners of this consortium is to develop new types of artificial materials, referred to below as metamaterials, with electromagnetic properties that cannot be found among natural materials. The results of this development should lead to a conceptually new range of radio, microwave, and optical technologies, based on revolutionary new materials made by large-scale assembly of some basic elements (nanoscopic and microscopic) in unprecedented combinations. Further information on this NoE can be found in http://www.metamaterials-eu.org.
Open Access
Experimental and numerical study of omega type bianisotropic metamaterials combined with a negative permittivity medium
(Elsevier BV, 2008) Aydin, K.; Li, Z.; Bilge, S.; Özbay, Ekmel
We report on the transmission properties of the omega (Ω) type metamaterials. Transmission through the periodic Ω-only and Ω-wire metamaterials are studied experimentally and numerically. A resonance band gap is observed for the periodic Ω medium around the resonance frequency of the single Ω unit cell. A transmission band is observed below the resonance band gap, when the periodic Ω structure is embedded in a negative permittivity medium composed of thin metallic wire arrays. We also studied the effect of periodicity on the transmission spectra of Ω type metamaterials.
Open Access
Experimental demonstration of sub-wavelength imaging by left handed metamaterials
(SPIE, 2007) Özbay, Ekmel
We review the studies conducted in our group concerning electromagnetic properties of metamaterials and photonic crystals with negative effective index of refraction. In particular, we demonstate the true left handed behavior of a 2D composite metamaterial, by analyzing the electric and magnetic response of the material components systematically. The negative refraction, subwavelength focusing, and flat lens phenomena using left handed metamaterials and photonic crystals are also presented.
Open Access
Experimental demonstration of transmission enhancement through subwavelength apertures at microwave frequencies
(2012) Ateş, Damla
Metamaterials are artificial materials with novel electromagnetic characteristics. They are used in many applications including imaging, super lenses, cloaking, transmission enhancement, beaming and recently in nano applications. One of the major building blocks is the split ring resonators (SRR). We can construct metamaterials by using a single or an array of the SRRs. In this thesis, enhanced transmission through subwavelength apertures, which is one of the applications of metamaterials, is obtained by using various split ring resonators configurations. We demonstrated transmission enhancement with Connected Split Ring Resonators (CSRRs), Omega-like Split Ring Resonators and Stack-like Split Ring Resonators through circular and rectangular subwavelength apertures experimentally and numerically at the microwave frequencies. We report the highest experimental transmission enhancement results in the literature so far. Besides high factors, we also obtained multi-peak resonant characteristics with Stack-like SRR designs. Furthermore, we analyzed these various SRR samples numerically in order to understand the resonance behavior. We also discuss the effects of shorting the loops, omitting the components of the SRRs and aperture geometry to the resonance frequency. Finally, we applied Tight Binding methods to analyze the multi-peak characteristics of the Stack-like SRR design.
Open Access
Ferroelectric based tuneable SRR based metamaterial for microwave applications
(IEEE, 2007) Özbay, Ekmel; Aydın, Koray; Bütün, Serkan; Kolodziejak, K.; Pawlak, D.
We discuss the possibility of achieving tunable split ring resonators at microwave frequencies. One method is to use varying capacitance values to tune the magnetic resonance frequency. As another method ferroelectric thin films can be employed to obtain active response from the split ring resonators. We report the experimental measurements that are performed for single split ring resonators at microwave frequencies.
Open Access
Hybridization of fano and vibrational resonances in surface-enhanced infrared absorption spectroscopy of streptavidin monolayers on metamaterial substrates
(2014) Alici, K. B.
We present spectral hybridization of organic and inorganic resonant materials and related bio-sensing mechanism. We utilized a bound protein (streptavidin) and a Fano-resonant metasurface to illustrate the concept. The technique allows us to investigate the vibrational modes of the streptavidin and how they couple to the underlying metasurface. This optical, label-free, nonperturbative technique is supported by a coupled mode-theory analysis that provides information on the structure and orientation of bound proteins. We can also simultaneously monitor the binding of analytes to the surface through monitoring the shift of the metasurface resonance. All of this data opens up interesting opportunities for applications in biosensing, molecular electronics and proteomics. © 2014 IEEE.
Open Access
Investigation of dual-narrowband plasmonic perfect absorbers at visible frequencies for biosensing
(2019-12) Ali, Farhan
Since the introduction of first plasmonic perfect absorber (PA) in early 2008 by Landy et al., numerous studies have demonstrated their superior optical performance in frequencies ranging from terahertz to visible region of electromagnetic spectrum. In the literature broadband PAs are studied in more detail compared to narrowband PAs as their large absorption bandwidths make them a prime candidate for energy harvesting applications or security and defense. Recently scientists have shown a great interest in designing narrowband PAs by controlling the optical losses of the plasmonic materials as the narrowband resonances with a high quality-factor is particularly important for label-free biosensing. However, given the lossy optical properties of metals, this task has been challenging and requires delicate investigation and parameter control in contrast to broadband perfect absorbers. In this research, we numerically studied and experimentally fabricated a narrow-band plasmonic perfect absorber based on a metal-insulator-metal con- figuration. We analyzed the origin of perfect absorption for our proposed system and investigated the parameters that effect the optical properties. The purposed plasmonic structure comes up with a dual narrow-band absorption peaks at visible and near-infrared region of electromagnetic spectrum with near unity absorption e ciency. The physical origin of these absorption peaks is shown to be the excitation of propagating and localized surface plasmon resonances at certain individual frequencies, that leads to impedance matching and critical coupling when certain conditions are satisfied. Finally, we analyzed the sensing capabilities of PA by embedding nanostructure into different background refractive index, resulting in sensitivity of 500 nm/RIU, making such a platform suitable for biosensing and spectroscopic applications. This work analyzes the perfect absorption phenomena in visible frequencies in detail and will be a go to guide for researchers in the perfect absorber community.
Open Access
Isolation and one-way effects in diffraction on dielectric gratings with plasmonic inserts
(Optical Society of America, 2009-01-02) Serebryannikov, A. E.; Özbay, Ekmel
Diffraction of plane waves on dielectric gratings with planar plasmonic inserts is studied with the emphasis put on the anomalous selectivity of diffraction orders. It is shown that some formally propagating orders can be suppressed within a wide frequency range. The effect of suppression is more general than the isolation effect observed earlier in zero-permittivity and (near-)zero-index slabs and sensitive to the frequency dependent peculiarities of the field distribution within the plasmonic layer. It is required that the real part of the permittivity of this layer is positive less than unity. The wideband features of the suppression effect, i.e., one-way transmission and diffraction-free reflection are demonstrated. Narrowband selectivity effects are also studied. The structures suggested can be used for extending the potential of technologies that are based on multibeam operation and field transformation. (C) 2008 Optical Society of America
Open Access
Labyrinth based left-handed metamaterials and sub-wavelength focusing of electromagnetic waves
(SPIE, 2006) Özbay, Ekmel; Bulu, İrfan; Çağlayan, Hümeyra
We propose and demonstrate a resonant structure that solves two major problems related to the split-ring resonator structure. These major problems may be stated as the bianisotropy and electric coupling to the magnetic resonance. These two problems introduce difficulties in obtaining isotropic left-handed metamaterial mediums. The resonant structure that we propose here solves both of these problems. We further show that in addition to the magnetic resonance, when combined with a suitable wire medium, the structure that we propose exhibits left-handed transmission band. We further demonstrate the sub-wavelength focusing of electromagnetic waves by use of a two dimensional labyrinth based metamaterial. Our experimental results showed that it is possible to focus the source field with half widths as small as λ/4 by using the labyrinth based metamaterial.
Open Access
The left hand of electromagnetism : metamaterials
(2010) Alıcı, Kamil Boratay
Metamaterials are artificial periodic structures whose electromagnetic response is solely dependent on the constituting unit cells. In the present thesis, we studied unit cell characteristics of metamaterials that has negative permeability and permittivity. We investigated negative permeability medium elements, especially in terms of their electrical size and resonance strength. Experimental and numerical study of µ-negative (MNG) materials: multi split ring resonators (MSRRs), spiral resonators (SRs) and multi-spiral resonators are presented. The resonance frequency of the structures is determined by the transmission measurements and minimum electrical size of λ0/17 for the MSRRs and of λ0/82 for the SRs observed. We explain a method for tuning the resonance frequency of the multi-split structures. We investigated scalability of MNG materials and designed a low loss double negative composite metamaterial that operates at the millimeter wave regime. A negative pass-band with a peak transmission value of -2.7 dB was obtained experimentally at 100 GHz. We performed transmission based qualitative effective medium theory analysis numerically and experimentally, in order to prove the double negative nature of the metamaterial. These results were supported by the standard retrieval analysis method. We confirmed that the effective index of the metamaterial was indeed negative by performing far field angular scanning measurements for a metamaterial prism. Moreover, we illuminated the split-ring resonator based metamaterial flat lens with oblique incidence and observed from the scanning experiments, the shifting of the beam to the negative side. The first device was a horn antenna and metamaterial lens composite whose behavior was similar to Yagi-Uda antenna. We numerically and experimentally investigated planar fishnet metamaterials operating at around 20 GHz and 100 GHz and demonstrated that their effective index is negative. The study is extended to include the response of the metamaterial layer when the metamaterial plane normal and the propagation vector are not parallel. We also experimentally studied the transmission response of a one dimensional rectangle prism shaped metamaterial slab for oblique incidence angles and confirmed the insensitivity of split-ring resonator based metamaterials to the angle of incidence. After the demonstration of complete transmission enhancement by using deep subwavelength resonators into periodically arranged subwavelength apertures, we designed and implemented a metamaterial with controllable bandwidth. The metamaterial based devices can be listed under the categories of antennas absorbers and transmission enhancement. We studied electrically small resonant antennas composed of split ring resonators (SRR) and monopoles. The electrical size, gain and efficiency of the antenna were λ0/10, 2.38 and 43.6%, respectively. When we increased the number of SRRs in one dimension, we observed beam steerability property. These achievements provide a way to create rather small steerable resonant antennas. We also demonstrated an electrically small antenna that operates at two modes for two perpendicular polarizations. The antenna was single fed and composed of perpendicularly placed metamaterial elements and a monopole. One of the metamaterial elements was a multi split ring resonator and the other one was a split ring resonator. When the antenna operates for the MSRR mode at 4.72 GHz for one polarization, it simultaneously operates for the SRR mode at 5.76 GHz, but for the perpendicular polarization. The efficiencies of the modes were 15% and 40% with electrical sizes of λ/11.2 and λ/9.5. Finally, we experimentally verified a miniaturization method of circular patch antennas. By loading the space between the patch and ground plane with metamaterial media composed of multi-split ring resonators and spiral resonators, we manufactured two electrically small patch antennas of electrical sizes λ/3.69 and λ/8.26. The antenna efficiency was 40% for the first mode of the multi-split ring resonator antenna with broad far field radiation patterns similar to regular patch antennas. We designed, implemented, and experimentally characterized electrically thin microwave absorbers by using the metamaterial concept. The absorbers consist of i) a metal back plate and an artificial magnetic material layer; ii) metamaterial back plate and a resistive sheet layer. We investigated absorber performance in terms of absorbance, fractional bandwidth and electrical thickness, all of which depend on the dimensions of the metamaterial unit cell and the distance between the back plate and metamaterial layer. As a proof of concept, we demonstrated a λ/4.7 thick absorber of type i), with a 99.8% absorption peak along with a 8% fractional bandwidth. We have also demonstrated experimentally a λ/4.7 and a λ/4.2 thick absorbers of type ii), based on SRR and MSRR magnetic metamaterial back plates, respectively. The absorption peak of the SRR layout is 97.4%, while for the MSRR one the absorption peak is 98.4%. We conveyed these concepts to optical frequencies and demonstrated a metamaterial inspired absorber for solar cell applications. We finalized the study by a detailed study of split ring resonators at the infrared and visible band. We studied i) frequency tuning, ii) effect of resonator density, iii) shifting magnetic resonance frequency by changing the resonator shape, iv) effect of metal loss and plasma frequency and designed a configuration for transmission enhancement at the optical regime. By using subwavelength optical split ring resonator antennas and couplers we achieved a 400-fold enhanced transmission from a subwavelength aperture area of the electrical size λ2 /25. The power was transmitted to the far field with 3.9 dBi directivity at 300 THz.