We present spectroscopic data for acute-angle reflection and transmission of two planar metamater... more We present spectroscopic data for acute-angle reflection and transmission of two planar metamaterial samples, one at microwave frequencies and one at far-infrared frequencies. We show that the observed evolution of the magnetic resonance with the increasing angle of incidence is in ...
International Topical Meeting on Microwave Photonics MWP-02, 2002
Binary and ternary 5-bit programmable dispersion matrix is built to control a two-channel receive... more Binary and ternary 5-bit programmable dispersion matrix is built to control a two-channel receives beamformer at 1550 nm. Phase measurements for the delay configurations along with beam-patterns at RF frequencies 0.2-1 GHz are presented.
LEOS 2007 - IEEE Lasers and Electro-Optics Society Annual Meeting Conference Proceedings, 2007
Thin film InGaAs/GaAsP lasers with strained single quantum well active regions have been bonded t... more Thin film InGaAs/GaAsP lasers with strained single quantum well active regions have been bonded to Si and tested. The thin film laser structure was designed and grown with no net strain using strain compensation.
LEOS 2008 - 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2008
Thin film edge emitting lasers with top/bottom stripes are broad area metal/metal bonded to a Si ... more Thin film edge emitting lasers with top/bottom stripes are broad area metal/metal bonded to a Si substrate. The bonding and top/bottom stripes are steps forward toward better heat dissipation, current confinement, and mechanical bonding strength.
Integration ofphotonic active and passive components - and ultimately, full systems - directly on... more Integration ofphotonic active and passive components - and ultimately, full systems - directly onto Si and Si CMOS are a critical step toward chip scale photonic system integration. Thin film compound semiconductor lasers heterogeneously integrated onto silicon open up a wide ...
Metamaterials are emerging as engineered material structures that can be fabricated toward specif... more Metamaterials are emerging as engineered material structures that can be fabricated toward specific magnetic and/or electrical characteristics. Research in the field of negative refractive index and metamaterials has produced demonstrations of artificial magnetic resonances ...
A III-V thin-film single-quantum-well edge-emitting laser is patterned on both sides of the epita... more A III-V thin-film single-quantum-well edge-emitting laser is patterned on both sides of the epitaxial layer and bonded to silicon. Injected threshold current densities of 420 A / cm 2 for gain-guided lasers with bottom p-stripes and top n-stripes and 244 A / cm 2 for index-guided bottom p-ridge and top n-stripe lasers are measured with a lasing wavelength of ϳ995 nm. These threshold current densities, among the lowest for thinfilm edge-emitting lasers on silicon reported to date (to our knowledge), enable the implementation of integrated applications such as power-efficient portable chip-scale photonic sensing systems.
A process is demonstrated for tuning the magnetic resonance frequency of a fixed split-ring reson... more A process is demonstrated for tuning the magnetic resonance frequency of a fixed split-ring resonator array, by way of adding material near the split-ring elements. Applying drops of a silicon-nanospheres/ethanol solution to the surface of the sample decreases the magnetic resonance frequency of the split-ring array in incremental steps of 0.03 THz. This fine tuning is done post fabrication and is demonstrated to be reversible. The exhibited sensitivity of the split-ring resonance frequency to the presence of silicon nanospheres also suggests further application possibilities as a sensor device.
The authors present a spectroscopic analysis of a planar split-ring-resonator ͑SRR͒ medium at ter... more The authors present a spectroscopic analysis of a planar split-ring-resonator ͑SRR͒ medium at terahertz frequencies, quantitatively characterizing the associated magnetic resonance. Experimental quantification at terahertz and infrared frequencies of metamaterial optical constants has been primarily absent, largely due to the difficulty of collecting phase information at these frequencies.
We demonstrate a metamaterial device whose far-infrared resonance frequency can be dynamically tu... more We demonstrate a metamaterial device whose far-infrared resonance frequency can be dynamically tuned. Dynamic tuning should alleviate many bandwidth-related roadblocks to metamaterial application by granting a wide matrix of selectable electromagnetic properties. This tuning effect is achieved via a hybrid-metamaterial architecture; intertwining split ring resonator metamaterial elements with vanadium dioxide ͑VO 2 ͒-a material whose optical properties can be strongly and quickly changed via external stimulus. This hybrid structure concept opens a fresh dimension in both exploring and exploiting the intriguing electromagnetic behavior of metamaterials.
We present spectroscopic data for acute-angle reflection and transmission of two planar metamater... more We present spectroscopic data for acute-angle reflection and transmission of two planar metamaterial samples, one at microwave frequencies and one at far-infrared frequencies. We show that the observed evolution of the magnetic resonance with the increasing angle of incidence is in ...
Memristors are a special case of non-linear resistors which store information about the history o... more Memristors are a special case of non-linear resistors which store information about the history of applied voltage in their instantaneous resistance value. These memory-resistors have attracted considerable attention for their possible uses in information storage and neuromorphic circuits. The same circuit principles behind memory-resistance have been extended to postulate that memory-capacitance and memory-inductance phenomena are also likely to exist^1. In this talk, we discuss experimental results from a Vanadium-Dioxide device which exhibits memory-capacitance^2. The nanoscale phase-separation phenomena which underlie this memory-capacitance suggest similar effects may exist in a variety of materials.[4pt] [1]. M. Di Ventra et.al. Proc. IEEE 97, 1717 (2009) [2]. T.Driscoll et.al. Science. 325, 1518 (2009)
Methods for real-time tuning (dynamic-tuning) of metamaterial electromagnetic response have recei... more Methods for real-time tuning (dynamic-tuning) of metamaterial electromagnetic response have received significant attention as a possible approach to alleviate limitations associated with bandwidth in metamaterials. In a dynamic-tuning configuration, an applied stimulus induces some temporary change in the metamaterial properties -- altering the metamaterial response as long as the stimulus remains. In this talk, we discuss results from a SRR-VO2 hybrid metamaterial which exhibits electrically-controlled persistent tuning.footnotetextT.Driscoll et.al. Science. 325, 1518 (2009) Persistent tuning allows lasting modification to the metamaterial response using a transient stimulus. Such ability is highly desirable in consideration of potential metamaterial applications, such as reconfigurable optics.
Proceedings of Spie the International Society For Optical Engineering, Feb 1, 2010
We present the heterogeneous integration of a 3.8 μm thick InGaAs/GaAs edge emitting laser that w... more We present the heterogeneous integration of a 3.8 μm thick InGaAs/GaAs edge emitting laser that was metal-metal bonded to SiO2/Si and end-fire coupled into a 2.8 μm thick tapered SU8 polymer waveguide integrated on the same substrate. The system was driven in pulsed mode and the waveguide output was captured on an IR imaging array to characterize the mode. The waveguide output was also coupled into a multimode fiber, and into an optical head and spectrum analyzer, indicating lasing at ~997 nm and a threshold current density of 250 A/cm2.
This paper describes implemented methods for characterizing a 5-bit programmable dispersion matri... more This paper describes implemented methods for characterizing a 5-bit programmable dispersion matrix (PDM) that is built to control a two-channel Receive beamformer in the 1550 nm region. The architecture of the PDM, is based on an array of 5 delay lines each having two spliced fiber Bragg gratings. Phase measurements for 32 possible delay configurations of the PMD are presented.
Advances in the field of metamaterials have created many new and exciting devices, but the perfor... more Advances in the field of metamaterials have created many new and exciting devices, but the performance and applicability of these devices to date have been hindered by the reliance on a dispersive resonance. In this talk we present a metamaterial device with the ability to ...
We present spectroscopic data for acute-angle reflection and transmission of two planar metamater... more We present spectroscopic data for acute-angle reflection and transmission of two planar metamaterial samples, one at microwave frequencies and one at far-infrared frequencies. We show that the observed evolution of the magnetic resonance with the increasing angle of incidence is in ...
International Topical Meeting on Microwave Photonics MWP-02, 2002
Binary and ternary 5-bit programmable dispersion matrix is built to control a two-channel receive... more Binary and ternary 5-bit programmable dispersion matrix is built to control a two-channel receives beamformer at 1550 nm. Phase measurements for the delay configurations along with beam-patterns at RF frequencies 0.2-1 GHz are presented.
LEOS 2007 - IEEE Lasers and Electro-Optics Society Annual Meeting Conference Proceedings, 2007
Thin film InGaAs/GaAsP lasers with strained single quantum well active regions have been bonded t... more Thin film InGaAs/GaAsP lasers with strained single quantum well active regions have been bonded to Si and tested. The thin film laser structure was designed and grown with no net strain using strain compensation.
LEOS 2008 - 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2008
Thin film edge emitting lasers with top/bottom stripes are broad area metal/metal bonded to a Si ... more Thin film edge emitting lasers with top/bottom stripes are broad area metal/metal bonded to a Si substrate. The bonding and top/bottom stripes are steps forward toward better heat dissipation, current confinement, and mechanical bonding strength.
Integration ofphotonic active and passive components - and ultimately, full systems - directly on... more Integration ofphotonic active and passive components - and ultimately, full systems - directly onto Si and Si CMOS are a critical step toward chip scale photonic system integration. Thin film compound semiconductor lasers heterogeneously integrated onto silicon open up a wide ...
Metamaterials are emerging as engineered material structures that can be fabricated toward specif... more Metamaterials are emerging as engineered material structures that can be fabricated toward specific magnetic and/or electrical characteristics. Research in the field of negative refractive index and metamaterials has produced demonstrations of artificial magnetic resonances ...
A III-V thin-film single-quantum-well edge-emitting laser is patterned on both sides of the epita... more A III-V thin-film single-quantum-well edge-emitting laser is patterned on both sides of the epitaxial layer and bonded to silicon. Injected threshold current densities of 420 A / cm 2 for gain-guided lasers with bottom p-stripes and top n-stripes and 244 A / cm 2 for index-guided bottom p-ridge and top n-stripe lasers are measured with a lasing wavelength of ϳ995 nm. These threshold current densities, among the lowest for thinfilm edge-emitting lasers on silicon reported to date (to our knowledge), enable the implementation of integrated applications such as power-efficient portable chip-scale photonic sensing systems.
A process is demonstrated for tuning the magnetic resonance frequency of a fixed split-ring reson... more A process is demonstrated for tuning the magnetic resonance frequency of a fixed split-ring resonator array, by way of adding material near the split-ring elements. Applying drops of a silicon-nanospheres/ethanol solution to the surface of the sample decreases the magnetic resonance frequency of the split-ring array in incremental steps of 0.03 THz. This fine tuning is done post fabrication and is demonstrated to be reversible. The exhibited sensitivity of the split-ring resonance frequency to the presence of silicon nanospheres also suggests further application possibilities as a sensor device.
The authors present a spectroscopic analysis of a planar split-ring-resonator ͑SRR͒ medium at ter... more The authors present a spectroscopic analysis of a planar split-ring-resonator ͑SRR͒ medium at terahertz frequencies, quantitatively characterizing the associated magnetic resonance. Experimental quantification at terahertz and infrared frequencies of metamaterial optical constants has been primarily absent, largely due to the difficulty of collecting phase information at these frequencies.
We demonstrate a metamaterial device whose far-infrared resonance frequency can be dynamically tu... more We demonstrate a metamaterial device whose far-infrared resonance frequency can be dynamically tuned. Dynamic tuning should alleviate many bandwidth-related roadblocks to metamaterial application by granting a wide matrix of selectable electromagnetic properties. This tuning effect is achieved via a hybrid-metamaterial architecture; intertwining split ring resonator metamaterial elements with vanadium dioxide ͑VO 2 ͒-a material whose optical properties can be strongly and quickly changed via external stimulus. This hybrid structure concept opens a fresh dimension in both exploring and exploiting the intriguing electromagnetic behavior of metamaterials.
We present spectroscopic data for acute-angle reflection and transmission of two planar metamater... more We present spectroscopic data for acute-angle reflection and transmission of two planar metamaterial samples, one at microwave frequencies and one at far-infrared frequencies. We show that the observed evolution of the magnetic resonance with the increasing angle of incidence is in ...
Memristors are a special case of non-linear resistors which store information about the history o... more Memristors are a special case of non-linear resistors which store information about the history of applied voltage in their instantaneous resistance value. These memory-resistors have attracted considerable attention for their possible uses in information storage and neuromorphic circuits. The same circuit principles behind memory-resistance have been extended to postulate that memory-capacitance and memory-inductance phenomena are also likely to exist^1. In this talk, we discuss experimental results from a Vanadium-Dioxide device which exhibits memory-capacitance^2. The nanoscale phase-separation phenomena which underlie this memory-capacitance suggest similar effects may exist in a variety of materials.[4pt] [1]. M. Di Ventra et.al. Proc. IEEE 97, 1717 (2009) [2]. T.Driscoll et.al. Science. 325, 1518 (2009)
Methods for real-time tuning (dynamic-tuning) of metamaterial electromagnetic response have recei... more Methods for real-time tuning (dynamic-tuning) of metamaterial electromagnetic response have received significant attention as a possible approach to alleviate limitations associated with bandwidth in metamaterials. In a dynamic-tuning configuration, an applied stimulus induces some temporary change in the metamaterial properties -- altering the metamaterial response as long as the stimulus remains. In this talk, we discuss results from a SRR-VO2 hybrid metamaterial which exhibits electrically-controlled persistent tuning.footnotetextT.Driscoll et.al. Science. 325, 1518 (2009) Persistent tuning allows lasting modification to the metamaterial response using a transient stimulus. Such ability is highly desirable in consideration of potential metamaterial applications, such as reconfigurable optics.
Proceedings of Spie the International Society For Optical Engineering, Feb 1, 2010
We present the heterogeneous integration of a 3.8 μm thick InGaAs/GaAs edge emitting laser that w... more We present the heterogeneous integration of a 3.8 μm thick InGaAs/GaAs edge emitting laser that was metal-metal bonded to SiO2/Si and end-fire coupled into a 2.8 μm thick tapered SU8 polymer waveguide integrated on the same substrate. The system was driven in pulsed mode and the waveguide output was captured on an IR imaging array to characterize the mode. The waveguide output was also coupled into a multimode fiber, and into an optical head and spectrum analyzer, indicating lasing at ~997 nm and a threshold current density of 250 A/cm2.
This paper describes implemented methods for characterizing a 5-bit programmable dispersion matri... more This paper describes implemented methods for characterizing a 5-bit programmable dispersion matrix (PDM) that is built to control a two-channel Receive beamformer in the 1550 nm region. The architecture of the PDM, is based on an array of 5 delay lines each having two spliced fiber Bragg gratings. Phase measurements for 32 possible delay configurations of the PMD are presented.
Advances in the field of metamaterials have created many new and exciting devices, but the perfor... more Advances in the field of metamaterials have created many new and exciting devices, but the performance and applicability of these devices to date have been hindered by the reliance on a dispersive resonance. In this talk we present a metamaterial device with the ability to ...
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