Publications

Results 351–400 of 419
Skip to search filters

Single-mode lasing from top-down fabricated gallium nitride nanowires

IEEE Photonic Society 24th Annual Meeting, PHO 2011

Wright, J.B.; Li, Q.M.; Luk, Ting S.; Brener, Igal B.; Wang, George T.; Westlake, K.R.; Lester, L.F.

We study lasing in individual top-down fabricated GaN nanowires by optical pumping. We observe single mode emission with a side mode suppression of 15 dB, linewidths of less than 1 nm and thresholds as low as 250 kW/cm 2. © 2011 IEEE.

More Details
TYPE Conference YEAR 2011
ScopusOSTI

Multilayer infrared metamaterial fabrication using membrane projection lithography

Journal of Vacuum Science and Technology. B, Nanotechnology and Microelectronics

Wendt, J.R.; Brener, Igal B.; Sinclair, Michael B.

Membrane projection lithography is extended from a single layer fabrication technique to a multilayer process, adding polymeric backfill and planarization after each layer is completed. Unaligned contact lithography is used as a rapid prototyping tool to aid in process development, patterning resist membranes in seconds without requiring long e-beam write times. The fabricated multilayer structures show good resistance to solvent attack from subsequent process steps and demonstrate in-plane and out of plane multilayer metallic inclusions in a dielectric host, which is a critical step in the path to develop bulklike metamaterials at optical frequencies.

More Details
TYPE Journal Article YEAR 2011
OSTIDOI

Mid-infrared amplitude and phase measurement of metamaterials using tandem interferometry

Optics InfoBase Conference Papers

Passmore, Brandon S.; Anderson, J.; Ten Eyck, Gregory A.; Wendt, J.R.; Brener, Igal B.; Sinclair, M.B.; Shaner, Eric A.

A tandem interferometer system measuring the absolute phase and amplitude of planar split-ring resonators fabricated on a BaF2 substrate with a designed resonance at 10.5 μm is presented. © 2010 Optical Society of America.

More Details
TYPE Conference YEAR 2010
ScopusOSTI

Active infrared materials for beam steering

Shaner, Eric A.; Brener, Igal B.; Gin, Aaron G.; Reno, J.L.; Barrick, Todd A.

The mid-infrared (mid-IR, 3 {micro}m -12 {micro}m) is a highly desirable spectral range for imaging and environmental sensing. We propose to develop a new class of mid-IR devices, based on plasmonic and metamaterial concepts, that are dynamically controlled by tunable semiconductor plasma resonances. It is well known that any material resonance (phonons, excitons, electron plasma) impacts dielectric properties; our primary challenge is to implement the tuning of a semiconductor plasma resonance with a voltage bias. We have demonstrated passive tuning of both plasmonic and metamaterial structures in the mid-IR using semiconductors plasmas. In the mid-IR, semiconductor carrier densities on the order of 5E17cm{sup -3} to 2E18cm{sup -3} are desirable for tuning effects. Gate control of carrier densities at the high end of this range is at or near the limit of what has been demonstrated in literature for transistor style devices. Combined with the fact that we are exploiting the optical properties of the device layers, rather than electrical, we are entering into interesting territory that has not been significantly explored to date.

More Details
TYPE SAND Report YEAR 2010
OSTIDOI

Nanocomposite plasmonic fluorescence emitters with core/shell configurations

Proposed for publication in the Journal of Optical Society of America B.

Miao, Xiaoyu M.; Brener, Igal B.

This paper is focused on the optical properties of nanocomposite plasmonic emitters with core/shell configurations, where a fluorescence emitter is located inside a metal nanoshell. Systematic theoretical investigations are presented for the influence of material type, core radius, shell thickness, and excitation wavelength on the internal optical intensity, radiative quantum yield, and fluorescence enhancement of the nanocomposite emitter. It is our conclusion that: (i) an optimal ratio between the core radius and shell thickness is required to maximize the absorption rate of fluorescence emitters, and (ii) a large core radius is desired to minimize the non-radiative damping and avoid significant quantum yield degradation of light emitters. Several experimental approaches to synthesize these nanocomposite emitters are also discussed. Furthermore, our theoretical results are successfully used to explain several reported experimental observations and should prove useful for designing ultra-bright core/shell nanocomposite emitters.

More Details
TYPE Journal Article YEAR 2010
OSTI

Fabrication techniques for 3D metamaterials in the mid-infrared

Wendt, J.R.; Burckel, David B.; Ten Eyck, Gregory A.; Ellis, A.R.; Brener, Igal B.; Sinclair, Michael B.

The authors have developed two versions of a flexible fabrication technique known as membrane projection lithography that can produce nearly arbitrary patterns in '212 D' and fully three-dimensional (3D) structures. The authors have applied this new technique to the fabrication of split ring resonator-based metamaterials in the midinfrared. The technique utilizes electron beam lithography for resolution, pattern design flexibility, and alignment. The resulting structures are nearly three orders of magnitude smaller than equivalent microwave structures that were first used to demonstrate a negative index material. The fully 3D structures are highly isotropic and exhibit both electrically and magnetically excited resonances for incident transverse electromagnetic waves.

More Details
TYPE Conference YEAR 2010
OSTI

Fabrication of 3-D cubic unit cells with measured IR resonances

Sinclair, Michael B.; Brener, Igal B.; Ten Eyck, Gregory A.; Ellis, A.R.; Ginn, James C.; Wendt, J.R.

3-D cubic unit cell arrays containing split ring resonators were fabricated and characterized. The unit cells are {approx}3 orders-of-magnitude smaller than microwave SRR-based metamaterials and exhibit both electrically and magnetically excited resonances for normally incident TEM waves in addition to showing improved isotropic response.

More Details
TYPE Conference YEAR 2010
OSTI

Amplitude and phase-resolved measurements of optical metamaterials in the mid-infrared by phase matched electro-optic sampling

Brener, Igal B.; Passmore, Brandon S.; Ten Eyck, Gregory A.; Wendt, J.R.; Sinclair, Michael B.

We describe a time-domain spectroscopy system in the thermal infrared used for complete transmission and reflection characterization of metamaterials in amplitude and phase. The system uses a triple-output near-infrared ultrafast fiber laser, phase-locked difference frequency generation and phase-matched electro-optic sampling. We will present measurements of several metamaterials designs.

More Details
TYPE Conference YEAR 2010
OSTI

Resonant coupling to a dipole absorber inside a metamaterial: Anticrossing of the negative index response

Journal of Vacuum Science and Technology B

Smolev, Svyatoslav; Ku, Zahyun; Brueck, S.R.J.; Brener, Igal B.; Sinclair, Michael B.; Ten Eyck, Gregory A.; Langston, William L.; Basilio, Lorena I.

The authors experimentally demonstrate a resonant hybridization between the magnetic dipole structural resonance in the permeability of a fishnet metamaterial and an electric dipole material resonance in the permittivity of the dielectric spacer layer. The hybrid resonances in the permeability and the negative index response exhibit an anticrossing behavior. A simple analytic model and numerical simulations using a rigorous coupled-wave analysis are in excellent qualitative agreement with the experiment. © 2010 American Vacuum Society.

More Details
TYPE Conference YEAR 2010
ScopusOSTI
Results 351–400 of 419
Results 351–400 of 419