301 research outputs found
Ultrafast slow-light: Raman-induced delay of THz-bandwidth pulses
We propose and experimentally demonstrate a scheme to generate
optically-controlled delays based on off-resonant Raman absorption. Dispersion
in a transparency window between two neighboring, optically-activated Raman
absorption lines is used to reduce the group velocity of broadband 765 nm
pulses. We implement this approach in a potassium titanyl phosphate (KTP)
waveguide at room temperature, and demonstrate Raman-induced delays of up to
140 fs for a 650-fs duration, 1.8-THz bandwidth, signal pulse; the available
delay-bandwidth product is . Our approach is applicable to single
photon signals, offers wavelength tunability, and is a step toward processing
ultrafast photons.Comment: 5+4 pages, 4+2 figure
Time-bin to Polarization Conversion of Ultrafast Photonic Qubits
The encoding of quantum information in photonic time-bin qubits is apt for
long distance quantum communication schemes. In practice, due to technical
constraints such as detector response time, or the speed with which
co-polarized time-bins can be switched, other encodings, e.g. polarization, are
often preferred for operations like state detection. Here, we present the
conversion of qubits between polarization and time-bin encodings using a method
that is based on an ultrafast optical Kerr shutter and attain efficiencies of
97% and an average fidelity of 0.827+/-0.003 with shutter speeds near 1 ps. Our
demonstration delineates an essential requirement for the development of hybrid
and high-rate optical quantum networks
Observation of high-order quantum resonances in the kicked rotor
Quantum resonances in the kicked rotor are characterized by a dramatically
increased energy absorption rate, in stark contrast to the momentum
localization generally observed. These resonances occur when the scaled
Planck's constant hbar=(r/s)*4pi, for any integers r and s. However only the
hbar=r*2pi resonances are easily observable. We have observed high-order
quantum resonances (s>2) utilizing a sample of low temperature, non-condensed
atoms and a pulsed optical standing wave. Resonances are observed for
hbar=(r/16)*4pi r=2-6. Quantum numerical simulations suggest that our
observation of high-order resonances indicates a larger coherence length than
expected from an initially thermal atomic sample
IMPACT EVALUATION OF AN ENERGY SAVINGS PLAN PROJECT AT THE LINDE DIVISION OF UNION CARBIDE CORPORATION
This impact evaluation of an energy conservation measure (ECM) that was recently installed at the Linde Division of Union Carbide Corporation (Linde) was conducted far the Bonneville Power Administration (Bonneville) as part of an evaluation of its Energy Savings Plan (ESP) Program. The Program makes acquisition payments to firms that install energy conservation measures in their industrial processes. The objective of this impact evaluation was to assess how much electrical energy is being saved at Linde as a result of the ESP and to determine how much the savings cost Bonneville and the region. The impact of the ECM was evaluated with a combination of engineering analysis, financial analysis, site visit and interviews, and submittal reviews (Linde's Completion Report and Abstract). The ECM itself consists of replacing the plant's nitrogen feed compressor with a larger unit, which allows the plant to meet its argon demand using less compressed air and which results in net energy savings. Energy savings resulting from this ECM were 4,376,500 kWh/yr for the first two years after installation, but, because of a change in Linde's market position, long-term savings are expected to be lower at 2,549,200 kWh/yr. Linde considers energy consumption and savings on a per ton basis to be proprietary, so they are not reported here. The ECM cost 161,426 from Bonneville for the acquisition of energy savings. This ECM would not have been implemented without the acquisition payment from Bonneville. The levelized cost of these energy savings to Bonneville will be 4.5 mills/kWh over the ECM's expected 15-year life, and the levelized cost to th.e region will be 5.9 mills/kWh
Potential for ultrafast dynamic chemical imaging with few-cycle infrared lasers
We studied the photoelectron spectra generated by an intense few-cycle
infrared laser pulse. By focusing on the angular distributions of the back
rescattered high energy photoelectrons, we show that accurate differential
elastic scattering cross sections of the target ion by free electrons can be
extracted. Since the incident direction and the energy of the free electrons
can be easily changed by manipulating the laser's polarization, intensity, and
wavelength, these extracted elastic scattering cross sections, in combination
with more advanced inversion algorithms, may be used to reconstruct the
effective single-scattering potential of the molecule, thus opening up the
possibility of using few-cycle infrared lasers as powerful table-top tools for
imaging chemical and biological transformations, with the desired unprecedented
temporal and spatial resolutions.Comment: 16 pages, 6 figure
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Impact evaluation of a mill tailings thickener installed at J.R. Simplot Company`s Smoky Canyon Mine under the Energy $avings Plan
This report describes Pacific Northwest Laboratory`s (PNL`s) evaluation of the impact of an energy conservation project completed in the fall of 1992. The project (a mill tailings thickener) was installed at J.R. Simplot Company`s (Simplot`s) Smoky Canyon Mine in Caribou County, Idaho near Afton, Wyoming. The project at Simplot is one in a continuing series of industrial energy conservation projects to have its impact evaluated by PNL. All of the projects have received or will receive acquisition payments from the Bonneville Power Administration (Bonneville) under the Energy P) Program. The E250,000. The general objective of the impact evaluation was to determine how much electricity is saved by the project and at what cost to Bonneville and to the region
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