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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

ITOS to EDGE "Bridge" Software for Morpheus Lunar/Martian Vehicle

My project Involved Improving upon existing software and writing new software for the Project Morpheus Team. Specifically, I created and updated Integrated Test and Operations Systems (ITOS) user Interfaces for on-board Interaction with the vehicle during archive playback as well as live streaming data. These Interfaces are an integral part of the testing and operations for the Morpheus vehicle providing any and all information from the vehicle to evaluate instruments and insure coherence and control of the vehicle during Morpheus missions. I also created a "bridge" program for Interfacing "live" telemetry data with the Engineering DOUG Graphics Engine (EDGE) software for a graphical (standalone or VR dome) view of live Morpheus nights or archive replays, providing graphical representation of vehicle night and movement during subsequent tests and in real missions.

Hirsh, Robert↗
NASA NTRS1980

Coherent multiple tone technique for ground based SPS phase control

The ground based phase control concept was studied as an alternative approach to the reference SPS phase control system. The details of the ground based phase control system study are documented. The coherent multiple tone technique used for the ground based phase measurement waveform design and phase control system is summarized.

Chie, C. M.↗
NASA NTRS2012

Cognitive Systems Modeling and Analysis of Command and Control Systems

Military operations, counter-terrorism operations and emergency response often oblige operators and commanders to operate within distributed organizations and systems for safe and effective mission accomplishment. Tactical commanders and operators frequently encounter violent threats and critical demands on cognitive capacity and reaction time. In the future they will make decisions in situations where operational and system characteristics are highly dynamic and non-linear, i.e. minor events, decisions or actions may have serious and irreversible consequences for the entire mission. Commanders and other decision makers must manage true real time properties at all levels; individual operators, stand-alone technical systems, higher-order integrated human-machine systems and joint operations forces alike. Coping with these conditions in performance assessment, system development and operational testing is a challenge for both practitioners and researchers. This paper reports on research from which the results led to a breakthrough: An integrated approach to information-centered systems analysis to support future command and control systems research development. This approach integrates several areas of research into a coherent framework, Action Control Theory (ACT). It comprises measurement techniques and methodological advances that facilitate a more accurate and deeper understanding of the operational environment, its agents, actors and effectors, generating new and updated models. This in turn generates theoretical advances. Some good examples of successful approaches are found in the research areas of cognitive systems engineering, systems theory, and psychophysiology, and in the fields of dynamic, distributed decision making and naturalistic decision making.

Norlander, Arne↗
NASA NTRS1980

Vortex pairing in a circular jet under controlled excitation. I - General jet response. II - Coherent structure dynamics

Hot-wire and flow visualization studies were performed in three air jets subjected to pure-tone excitation. The instability, vortex roll-up, and transition to the controlled excitation were investigated. The conditions most favorable to vortex parting were determined as a function of the excitation Strouhal number, the Reynolds number, and the initial shear-layer state; it was shown that the rolled-up vortex rings undergo pairing under 'the shear layer mode', and the 'jet-column mode' when the Strouhal numbers based on the initial shear-layer momentum thickness are 0.012 and 0.85, respectively. Coherent ring-like vortical structures could be educed to the end of the potential core; however, the paired vortex becomes weaker with increasing downstream distances. The transverse transport of 'u' momentum by the coherent structures was much larger during the pairing process than in regions where a single vortex is studied.

Zaman, K. B. M. Q.↗
DOE OSTI2025

Spectrotemporal Shaping of Attosecond X-Ray Pulses with a Fresh-Slice Free-Electron Laser

We propose a scheme allowing coherent shaping, i.e., controlling both the amplitude and phase, of attosecond x-ray pulses at free-electron lasers. Here, we show that by seeding an FEL with a short coherent seed that overfills the amplification bandwidth, one can shape the Wigner function of the pulse by controlling the undulator taper profile. The examples of controllable pulse pairs and trains, as well as isolated spectrotemporally shaped pulses with very broad bandwidths are examined in detail. Existing attosecond XFELs can achieve these experimental conditions in a two-stage cascade, in which the seed is generated by a short current spike in an electron bunch and shaped in an unspoiled region within the same bunch. We experimentally demonstrate the production and control of phase-stable pulse trains using this method at the Linac Coherent Light Source II.

47 OTHER INSTRUMENTATION↗
NASA NTRS2010

Design of Control Software for a High-Speed Coherent Doppler Lidar System for CO2 Measurement

The design of the software for a 2-micron coherent high-speed Doppler lidar system for CO2 measurement at NASA Langley Research Center is discussed in this paper. The specific strategy and design topology to meet the requirements of the system are reviewed. In order to attain the high-speed digitization of the different types of signals to be sampled on multiple channels, a carefully planned design of the control software is imperative. Samples of digitized data from each channel and their roles in data analysis post processing are also presented. Several challenges of extremely-fast, high volume data acquisition are discussed. The software must check the validity of each lidar return as well as other monitoring channel data in real-time. For such high-speed data acquisition systems, the software is a key component that enables the entire scope of CO2 measurement studies using commercially available system components.

Vanvalkenburg, Randal L.↗
DOE OSTI2025

Single-shot magnon interference in a magnon-superconducting-resonator hybrid circuit

Magnon interference is a hallmark of coherent magnon interactions. In this work, we demonstrate single-shot magnon interference using up to four magnon pulses in two remotely coupled yttrium iron garnet spheres mediated by a coplanar superconducting resonator. By exciting one YIG sphere with injected microwave pulses, we achieve coherent energy exchange between the two spheres, facilitating their interference processes, including Rabi-like oscillation with a single pulse, constructive and destructive interference with two pulses, and interference peak sharpening with up to four pulses—analogous to diffraction grating in optical interference. The resulting interference patterns can be precisely controlled by changing the frequency detuning and time delay of the magnon pulses. The demonstration of time-domain coherent control of remote magnon interference opens new pathways for advancing coherent information processing through multi-operation, circuit-integrated hybrid magnonic networks.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2026

UNLOQ: UNderstanding coherence in Light-matter interfaces for Quantum Science (Final Technical Report)

The general goal of this project is to prepare next-generation quantum systems for novel quantum information science applications. Decades of research on quantum optics have provided revolutionary systems for manipulating atomic and photonic quantum coherence in transformative ways. Our hypothesis is that the next-generation quantum systems will come from nano-molecular quantum optics. Specifically, we are interested in coupling the electronic states of molecules or nanoparticles to the quantized radiation field inside an optical cavity to create a set of new photon-matter hybrid excitations, called polaritons. As opposed to atoms, the vibrational modes of molecules and nanoparticles provide new degrees of freedom to mediate the quantum transduction between electronic and photonic states, offering new ways to tune and ultimately control the quantum coherence of the integrated system. In this project we are interested in designing, fabricating, and characterizing the polaritons that arise from coupling CdSe nanoplatelets (NPLs) to a Fabry-Pérot optical cavity. Specific attention was paid to parameters of the system (cavity mode volume, quality factor, etc.) that would maximize the collective coupling strength. Through a combined theoretical and experimental approach, we were able to make important contributions to understanding NPL exciton-polariton photophysics including how to use cavity loss as a tunable parameter in order to manipulate the populations of the upper and lower polariton states. Finally, using state-of-the-art theoretical methods, we were able to show how the collective coupling of many molecular excitons in a cavity can protect polariton coherence from vibrationally-induced decoherence. In particular, for NPL-cavity polaritonic systems, the quantum coherence can be extended by over an order of magnitude at room temperature.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1982

Coherently pulsed laser source

An electronically controllable apparatus is described which modulates a continuous wave laser beam so as to produce an output beam consisting of coherent pulses that are electronically controllable as to both pulse repetition rate and pulse width. The apparatus includes two acoustic devices positioned so that the laser beam passes through them in sequence, and apparatus for passing sound waves through the devices to frequency shift the laser radiation as well as to diffract it. Each acoustic device generates sound waves containing a group of frequencies which result in spaced pulses. The first acoustic device is countered by the second acoustic device to produce a collimated, coherently pulsed, laser beam.

Margolis, J. S.↗
DOE OSTI2026

Manipulating Na/TM Ratio‐Driven Structural Heterogeneity of O3‐NaNi 1/3 Fe 1/3 Mn 1/3 O 2 Cathode for High‐Voltage Sodium‐Ion Batteries

The stability of O3-type NaNi 1/3 Fe 1/3 Mn 1/3 O 2 under high-voltage cycling is dictated by how synthesis encodes lattice strain and redox heterogeneity. Here, in this study, the role of Na:TM stoichiometry is systematically resolved by tuning the NaOH:precursor ratio during solid-state synthesis. The stoichiometric condition (Na:TM = 1.00) yields minimized microstrain, enabling uniform O3–P3 phase evolution and homogeneous multi-metal redox with preserved octahedral symmetry. In contrast, Na-excess compositions inherit disordered intermediates and heterogeneous distortion fields that trigger abrupt multiphase transitions and promote localized charge redistribution. In situ XRD captures the divergence in phase-transition pathways, TXM resolves particle-level redox heterogeneity, and XANES corroborates a stronger and more reversible Fe redox contribution at stoichiometry, shifting to diminished Fe participation and spatially inhomogeneous redox at higher Na content. These results establish Na:TM stoichiometry as a critical synthesis parameter controlling both structural coherence and redox stability. Electrochemically, the stoichiometric composition exhibits smooth voltage profiles with minimal polarization growth and retains nearly 80% of its initial capacity after 100 cycles even at an extended 4.2 V cutoff, whereas Na-excess compositions show significantly reduced initial coulombic efficiency and rapid voltage fade. Precise stoichiometric tuning provides a scalable route to defect-suppressed O3 frameworks, enabling structurally resilient, high-voltage sodium-layered cathodes.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Topology and spectral entanglement in cavity-mediated photon scattering

Here, we develop a microscopic diagrammatic theory for cavity-mediated photon scattering in a topological one-dimensional insulator described by the Su–Schrieffer–Heeger model. Within the velocity-gauge formulation, we derive the photon self-energy and vertex corrections arising from virtual electron–hole excitations coupled to a quantized cavity mode, and we evaluate the resulting polariton dispersion and two-photon correlation spectra. Our analysis shows that vacuum fluctuations of the cavity field induce a momentum-resolved self-energy that mixes conduction and valence bands through virtual photon exchange, producing interband hybridization and avoided crossings in the electronic dispersion. This “cavity dressing” is symmetry-dependent, vanishing at the Brillouin-zone edge where the dipole matrix element is zero, and its strength is controlled by the spatial coherence range ζ ≈ (l c /a) 2 of virtual excitations. We further examine how the cavity modifies nonlinear optical observables, including the Kerr nonlinearity and biphoton spectral entanglement, and identify the regimes where these effects become sensitive to the underlying topological phase. The theoretical framework established here provides a unified description of light–matter coupling in topological and polaritonic systems, bridging solid-state cavity QED with the emerging field of cavity-modified quantum materials. Our results suggest that engineered photonic environments can coherently reshape the electronic landscape of topological insulators, offering new routes to control collective electronic and optical phenomena through vacuum-field fluctuations.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2026

On-Chip Cavity Electroacoustics Using Lithium Niobate Phononic Crystal Resonators

Mechanical systems are pivotal in quantum technologies because of their long coherent time and versatile coupling to qubit systems. So far, the coherent and dynamic control of gigahertz-frequency mechanical modes mostly relies on optomechanical coupling and piezoelectric coupling to superconducting qubits. Here, we demonstrate on-chip cavity electroacoustic dynamics using our microwave-frequency electrically modulated phononic crystal resonators on lithium niobate. Leveraging the high dispersion of phononic crystal, our acoustic modes space unevenly in the frequency spectrum, emulating atomic energy levels. Atomiclike transitions between different acoustic modes are selectively achieved by applying electrical fields to modulate acoustic modes via the nonlinear piezoelectricity of lithium niobate. Among two modes, we demonstrate Autler-Townes splitting, ac Stark shift, and Rabi oscillation with a maximum cooperativity of 4.18. Extending to three modes, we achieve nonreciprocal frequency conversions with an isolation up to 20 dB. Nonreciprocity can be tuned by the time delay between the two modulating pulses. Finally, our cavity electroacoustic platform could find broad applications in sensing, microwave signal processing, acoustic computing, and quantum acoustics.

Rabi model↗
DOE OSTI2025

Conditions of coherent-phonon excitation in SrMnSb2 films and crystals

Excitation of coherent phonons has the potential to dramatically alter the electronic structure of Dirac and Weyl semimetals, enabling sub-picosecond control of their optical and electronic properties. The Dirac semimetal SrMnSb2 is a candidate for such control, with a coherent-phonon mode that is predicted to close and reopen a gap at the Dirac node. Here, through a series of ultrafast pump-probe experiments, we establish suitable samples and conditions for driving the coherent phonon to high amplitude and attempting to observe the gap’s closure. Films of SrMnSb2 grown by molecular-beam epitaxy are shown to have phononic properties matching those of bulk crystals. We find that the phonon can be strongly excited by pump pulses with wavelength near 1500 nm, which will excite a 30-nm film almost uniformly and will penetrate the arsenic capping layers that protect the films. We find that samples withstand pump pulses of fluence up to 20 mJ/cm2, and we demonstrate the potential for sequences of pulses to amplify the oscillation while suppressing other phonon modes. Armed with our new knowledge of the conditions for exciting the desired coherent phonon, future experiments will be well prepared to measure its motion and to observe phononic control of the Dirac-point gap.

Rai, Manita↗
NASA NTRS1992

Studies of turbulent shear flows and their control

The intent of the original proposal and the work carried out under the grant was to explore the instabilities of turbulent free shear flows of an incompressible fluid. The purpose for doing so was that coherent instabilities are susceptible to control via upstream forcing and because at sufficient finite amplitudes, the coherent modes enter into nonlinear interactions with the mean motion and thus, through such nonlinear interactions, the control of mixing and of mean flow spreading can be effected through the control of the coherent structures.

Liu, Joseph T. C.↗
NASA NTRS1981

Coherent multiple tone technique for ground based SPS control

The control system achieves beam forming by adjusting the phases of the individual transmitters onboard the solar power satellite. To specify the correct amount of adjustments, the phases of the power beams from each individual transmitter arriving at the rectanna center are measured, the appropriate corrections determined, and then relayed to the satellite. The functional operation of the ground based phase control concept is summarized. The key issues examined were: measurement waveform design and selection; phase measurement pilot reference design and selection; uplink phase corrections command link format and design; and system synchronization techniques.

Chie, C. M.↗
NASA NTRS1990

Coherent lightwave communications; Proceedings of the Meeting, Boston, MA, Sept. 7, 8, 1989

Various papers on coherent lightwave communications are presented. Individual topics addressed include: overview of coherent light wave communications, frequency stabilization techniques for coherent lightwave systems, characterization of laser diode intensity noise at microwave frequencies with high sensitivity, FP and DFB semiconductor lasers with arbitrary external optical feedback, birefringence-controlled phase-shifter, polarization diversity and scrambling techniques for coherent systems, polarization control scheme for coherent optical systems, simulation of IF filtering effects on the performance of coherent optical receivers. Also discussed are: performance of optical DPSK receivers in the presence of optical channel noise, optical heterodyne communications with polarization modulation, coherent fiber optical subcarrier multiplexed system, engineered rack-mounted coherent transmission system, technology aspects of a coherent optical MAN, broadband exchange by coherent multicarrier switching, generalized temporal CDMA for optical communications. Overviews are given of recent progress at individual companies.

Sunak, Harish R. D.↗