A5086802766- Photonic and Optical Devices
- Mechanical and Optical Resonators
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Laser Technologies
- Advanced MEMS and NEMS Technologies
- Semiconductor Quantum Structures and Devices
- Advanced Fiber Optic Sensors
- Analytical Chemistry and Sensors
- Optical Network Technologies
- Force Microscopy Techniques and Applications
- Spectroscopy and Laser Applications
- Quantum Information and Cryptography
- Quantum Dots Synthesis And Properties
- Photonic Crystals and Applications
- Quantum and electron transport phenomena
- Advanced Chemical Sensor Technologies
- Advanced Photonic Communication Systems
- Near-Field Optical Microscopy
- Spectroscopy Techniques in Biomedical and Chemical Research
- Analytical Chemistry and Chromatography
- Quantum optics and atomic interactions
- Optical Coatings and Gratings
- Nanowire Synthesis and Applications
- Silicon Nanostructures and Photoluminescence
- Integrated Circuits and Semiconductor Failure Analysis
United States Naval Research Laboratory
2016-2025
Optical Sciences (United States)
2010-2025
United States Navy
2022-2024
Naval Research Laboratory Optical Sciences Division
2018-2019
K Lab (United States)
2007-2015
University of Tulsa
2012
Association of Professors of Gynecology and Obstetrics
2008
Roswell Park Comprehensive Cancer Center
2005-2006
University of Michigan
1998-2003
Coherent (United States)
2003
We report coherent optical control of a biexciton (two electron-hole pairs), confined in single quantum dot, that shows oscillations similar to the excited-state Rabi flopping an isolated atom. The pulse dynamics, combined with previously demonstrated single-exciton rotation, serves as physical basis for two-bit conditional logic gate. truth table gate features all-optical interacting yet distinguishable excitons qubits. Evaluation fidelity yields value 0.7 operation. Such experimental...
Transient nonlinear optical spectroscopy, performed on excitons confined to single GaAs quantum dots, shows oscillations that are analogous Rabi in two-level atomic systems. This demonstration corresponds a one-qubit rotation dot which is important for proposals using computing. The dipole moment inferred from the data consistent with directly obtained linear absorption studies. measurement extends artificial atom model of excitonic transitions into strong-field limit, and makes possible...
Nondegenerate (two-wavelength) two-photon absorption using coherent optical fields is used to show that there are two different quantum mechanical pathways leading formation of the biexciton in a single dot. Of specific importance information applications resulting dynamics between ground state and from pathway involving only optically induced exciton/biexciton coherence. The data provide direct measure decoherence rate which equivalent Bell this system, as well other critical parameters.
Compact silicon-on-insulator (SOI) waveguide thermo-optically tunable Fabry-Perot microcavities with silicon/air Bragg mirrors are demonstrated. Quality factors of Q=4,584 measured finesse F=82. Tuning is achieved by flowing current directly through the silicon cavity resulting in efficient thermo-optic tuning over 2 nm for less than 50 mW applied electrical power. The high-Q cavities enable fast switching (1.9 mus rise time) at low drive power (<10 mW). By overdriving device, times 640 ns...
Weak scattering and short optical interaction lengths have, until this work, prevented the observation of trace gas Raman spectra using photonic integrated circuitry. spectroscopy is a powerful analytical tool, its implementation chip-scale waveguide devices represents critical step toward detection identification in small handheld systems. Here, we report first measurements gases nanophotonic waveguides. These were made possible highly evanescent rib waveguides functionalized with thin...
We have measured the optical absorption due to an exciton confined a single interface fluctuation quantum dot by directly measuring transmission through both submicron aperture and near-field microscopy. The measurements reveal large dipole moments approaching 100 D at 6 K. These results are compared theoretical predictions based on physical size estimated from photoluminescence excitation spectroscopy. very moment makes these dots attractive candidates for use in microcavities logic gates.
We combined coherent nonlinear optical spectroscopy with nano-electron volt energy resolution and low-temperature near-field microscopy subwavelength (<lambda/2) to provide direct local access the excitonic dipole in a semiconductor nanostructure quantum system. Our technique allows ability address, excite, probe single eigenstates of solid-state systems spectral spatial selectivity while simultaneously providing measurement all various time scales excitation including state relaxation...
We demonstrate in-plane microfabricated Fabry-Perot cavities with cryogenically etched silicon/air distributed Bragg reflector (DBR) mirrors and integrated silicon-on-insulator rib waveguides. Several DBR configurations cavity lengths were measured. Various devices exhibit Q=26963, FWHM=0.060 nm, finesse F=489, free spectral range FSR=81.7 mirror reflectance R=99.4%. Thermo-optic tuning over 6.7 nm is also demonstrated.
We report the measurement of waveguide-enhanced Raman spectra from trace concentrations four vapor-phase chemical warfare agent simulants: dimethyl methylphosphonate, diethyl trimethyl phosphate, and triethyl phosphate. The are obtained using highly evanescent nanophotonic silicon nitride waveguides coated with a naturally reversible hyperbranched carbosilane sorbent polymer exhibit extrapolated one-σ detection limits as low 5 ppb. use finite-element model to explain polarization wavelength...
Light sources monolithically integrated with optical filters, modulators, and detectors are necessary components for photonic systems on a chip. For broadband applications such as chemical or biological sensing using absorption spectroscopy, white light preferred over lasers amplified spontaneous emission sources. In particular, thermal offer straightforward means emission. However, to date, there have been few reports of waveguide-coupled this work, we demonstrate suspended nanophotonic...
We develop a set of laser rate equations that accurately describes mechanical amplification in optomechanical oscillators driven by photothermal or radiation pressure forces. In the process we introduce parameters describing gain, stored energy, slope efficiency, and saturation power laser. identify three-phonon parametric interactions as microscopic mechanism enabling self-oscillation. Our theory shows remarkable agreement with our experimental data, demonstrating self-oscillation is...
We detect trace gases at parts-per-billion levels using evanescent-field absorption spectroscopy in silicon nitride microring resonators coated with a functionalized sorbent polymer. An analysis of the resonance line shapes enables measurement differential spectra for number vapor-phase analytes. The are obtained near-infrared overtone OH-stretch resonance, which provides information about toxicity analyte vapor.
Photonic integrated circuits have enabled progressively active functionality in compact devices with the potential for large-scale integration. To date lowest loss photonic are achieved silica or silicon nitride-based platforms. However, these materials generally lack reconfigurability. In this work we present a platform achieving any dielectric waveguide via opto-electro-mechanical tuning of effective refractive index (Δneff≈0.01-0.1) and phase (Δϕ>2π). A suspended microbridge weakly...
Waveguide-enhanced Raman spectroscopy (WERS) is an analytical technique frequently employed for chemical and biological sensing. Operation at visible wavelengths to harness the inverse fourth power with excitation wavelength signal scaling of scattering intensity desirable, combat inherent inefficiency spectroscopy. Until now, WERS demonstrations in have required custom materials fabrication, resulting high losses low yields. In this work, we demonstrate a silicon nitride (SIN) platform...
The development of efficient low-loss electro-optic and nonlinear components based on silicon or its related compounds, such as nitrides oxides, is expected to dramatically enhance photonics by eliminating the need for non-CMOS-compatible materials. While bulk Si centrosymmetric thus displays no second-order (\c{hi}(2)) effects, a body experimental evidence accumulated in last decade demonstrates that when strain gradient present, significant \c{hi}(2) Pockels coefficient can be observed. In...
The precise quantification of a dielectric waveguide core thickness, width, refractive index, and cladding index across wafer is critical for greater consistency accuracy in photonic circuit fabrication. However, accurate wafer-scale measurements these parameters have not yet been demonstrated. We previously described method extracting four simultaneously from silicon nitride waveguides using unbalanced Mach–Zehnder interferometers on single die. In this work, we show that technique can be...
A cryogenic etch process using low temperature (T⩽−100°C) and SF6 O2 gases is presented for fabricating high aspect ratio silicon microstructures, including photonic devices micro- nanoelectromechanical systems. The requires only a single electron beam resist mask results in open area rates of 4μm∕min. Various parameters, flow, rf forward power, substrate temperature, chamber pressure were studied, the resulting effect on quality was evaluated terms sidewall verticality surface roughness....
Cavity opto-mechanics exploits optical forces acting on mechanical structures. Many demonstrations either require extensive alignment of components for probing and measurement, which limits the number opto-mechanical devices on-chip; or approaches limit ability to control parameters independently. In this work, we propose an architecture incorporating a waveguide-DBR microcavity coupled in-plane micro-bridge resonator, enabling large-scale integration on-chip with individually tune designs....
We experimentally demonstrate mid-infrared difference-frequency generation in suspended 181 nm thick GaAs waveguides. Generation of the idler at wavelengths between 2800 and 3150 is enabled by form-birefringent phase-matching ultrahigh index-contrast Nonlinear mixing has a measured efficiency 0.4 W⁻¹ 1.2 mm long waveguide using CW signal tunable 1490 1620 pump 1018 1032 powers few mW.
Germanium-on-silicon (GOS) represents the leading platform for foundry-based long-wave infrared photonic integrated circuits (LWIR PICs), due to its CMOS compatibility and absence of oxides. We describe ring resonance (Q-factors between 2×10 3 1×10 4 ) thermo-optic tunability in germanium-on-silicon waveguides throughout long-wave-infrared. The resonances are characterized by Q-factors couplings that agree with measurements propagation loss (as low as 6 dB/cm) simulations enabled broadband...
Low temperature relaxation of excitons between polarization eigenstates in single interface fluctuation quantum dots is studied using copolarized and cross-polarized transient differential transmission spectroscopy. The measured spin times are on the order ∼100 ps. Such a time longer than reported for thin wells, but considerably shorter predicted dots.
We demonstrate a surface-normal coupled-quantum-well InGaAs-InAlAs electroabsorption modulator that provides optical modulation with contrast ratio in excess of 1.5 at only 6 V. The device operates 1.55 μm and is based on novel strain-balanced layer structure. operating voltage about two times lower than conventional square quantum-well achieves comparable ratio.