home science hobbies for friends stuff

Currently, I am program manager at the Defense Advanced Research Projects Agency (DARPA). Prior to joining DARPA in the Microsystems Technology Office (MTO) I was involved in both industry and academia through simultaneous positions at HRL Laboratories and California Institute of Technology (Caltech). On the industrial side I was responsible for a lab wide effort applying nonlinear sciences through the Physics group. At Caltech I was working on topics in statistical mechanics, MEMS/NEMS, and condensed matter through the departments of Control and Dynamical Systems (CDS) and Physics.

My broader research interests include a variety of topics in nonlinear sciences, computation (classical, dynamical, and quantum), statistical mechanics, and systems far from equilibrium. Information on this page is limited to my own research. Background on my DARPA activities can be found on the agency's website. Please feel free to contact me with any comments or questions. More detailed information about my science background can be found in my curriculum vitae.


Contact information at DARPA

Recent research areas:
  • Power combining of optical and millimeter wave arrays
  • Lasers
  • Coupled nonlinear oscillators
  • Nanoelectromechanical cantilevers
  • Nonequilibrium statistical mechanics
  • Vertically oscillated Rayleigh-Benard convection turns out to be a interesting system for studying parametrically-forced-spatially-extended systems.

    • Selected Papers
    Effect of Gain-Dependent Phase Shift on Fiber Laser Synchronization
    --Kurt Wiesenfeld, Slavan Peles, and Jeffrey L. Rogers; IEEE Journal of Selected Topics in Quantum Electronics, Vol. 15, Issue 2, pp. 312-319 (2009) [invited paper]

    Coherence between two coupled lasers from a dynamics perspective
    --William Ray, Jeffrey L. Rogers, and Kurt Wiesenfeld; Optics Express, Vol. 17, Issue 11, pp. 9357-9368 (2009)
    Abstract: We compare a simple dynamical model of fiber laser arrays with independent experiments on two coupled lasers. The degree of agreement with experimental observations is excellent. Collectively the evidence presented supports this dynamical approach as an alternative to the traditional static eigenmode analysis of the coupled laser cavities.  PDF version (230 kB).

    Exploiting nonlinearity to provide adaptable energy harvesting
    --Barry E. DeMartini , Jeffrey L. Rogers, and Kimberly L. Turner, Proceedings of ASME Dynamic Systems and Control Conference DSCC2009-2152, (2009) [refereed conference proceedings]

    Refined Fiber Laser Model
    --William Ray, Kurt Wiesenfeld, and Jeffrey L. Rogers, Phys. Rev. E, Vol. 78, Issue 4, 046203 (2008)
    Abstract:  We refine dynamical equations derived to explain recently reported coherence effects in fiber laser arrays by extending the range of validity to include both three-level and four-level lasers. Predicted features of the model, including transitions between distinct dynamical states, are evaluated against both published experiments from other investigators and new experiments we performed. The comparisons demonstrate excellent agreement over a wide range of operating conditions.  PDF version (601 kB).

    Robust synchronization in fiber laser arrays
    --Slaven Peles, Jeffrey L. Rogers, and Kurt Wiesenfeld; Physical Review E 73, 026212 (2006)
    Abstract: Synchronization of coupled fiber lasers has been reported in recent experiments [bruesselbach-2005,minden-2004]. While these results may lead to a dramatic advances in laser technology, the mechanism by which these lasers synchronize is not understood. We analyze a recently proposed [rogers-2005] iterated map model of fiber laser arrays to explore this phenomenon. In particular, we look at synchronous solutions to the maps when the gain fields are constant. Determining the stability of these solutions is analytically tractable for a number of different coupling schemes. We find that in the most symmetric physical configurations the most symmetric solution is either unstable or stable over insufficient parameter range to be practical. In contrast, a lower symmetry configuration yields surprisingly robust coherence. This coherence persists beyond the pumping threshold for which the gain fields become time dependent. This paper is available in pdf (355 kB) or gzipped ps (300 kB) format.

    Synchronization by Reactive Coupling and Nonlinear Frequency Pulling
    --M.C. Cross, J.L. Rogers, Ron Lifshitz, and A. Zumdieck;     Physical Review E 73, 036205 (2006); nlin/0510002 on arXiv.org; Virtual Journal of Nanoscale Science & Technology 13, issue 11 (2006)
    Abstract: We present a detailed analysis of a model for the synchronization of nonlinear oscillators due to reactive coupling and nonlinear frequency pulling. We study the model for the mean field case of all-to-all coupling, deriving results for the initial onset of synchronization as the coupling or nonlinearity increase, and conditions for the existence of the completely synchronized state when all the oscillators evolve with the same frequency. Explicit results are derived for Lorentzian, triangular, and top-hat distributions of oscillator frequencies. Numerical simulations are used to construct complete phase diagrams for these distributions. This paper is available in pdf (568 kB) or gzipped ps (1449 kB) format.


    200 W Self-Organized Coherent Fiber Arrays
    --Hans Bruesselbach, Monica Minden, J.L. Rogers, D.C. Jones, and M.S. Mangir; CLEO (2005)
     Abstract: We report producing 200 Watt coherent fiber laser arrays without active control. This outcome is obtained via self-organization using a non-fiber coupler for two- to ten- laser arrays. Paper available in pdf format.

    Complex-ordered patterns in shaken convection
    --J.L. Rogers, Werner Pesch, Oliver Brausch, and Michael F. Schatz; Physical Review E 71, 066214, June (2005)
    A detailed description of the complex-ordered patterns that we found in shaken convection. Experiments and analysis, including simulations, are presented and compared. Four-wave interactions are found to be responsible for the majority of the observed complex patterns. The paper is available as a gzipped postscript file or a PDF file.

    Model for High-Gain Fiber Laser Arrays
    --J.L. Rogers, Slaven Peles, and Kurt Wiesenfeld; IEEE Journal of Quantum Electronics 41, no. 6, pp. 767--773, June (2005).
    This invited paper presents a model describing the high gain typical of fiber lasers with the intention of understanding experimental results. Analysis and simulations of the model for the case of a single laser and an array are presented. The model reproduces the behaviors observed in the laboratory. A PDF version of the paper is available.

    Self-organized coherence in fiber laser arrays
    --H. Bruesselbach, D.C. Jones, M.S. Mangir, M. Minden, and J.L. Rogers, Optics Letters 30, no. 11, pp. 1339--1341 (2005).
    Reporting experimental results synchronizing lasers in arrays of 4 and 5 elements to form inphase states. These were the initial results from this project and the first experiments to show self-organizing laser arrays. A number of subsequent experimental and analysis findings are in the process of being written up. Download the paper as a PDF.

    Synchronization by Nonlinear Frequency Pulling
    --M.C. Cross, A. Zumdieck, Ron Lifshitz, and J.L. Rogers, Physical Review Letters 93, 224101 (2004); cond-mat/0406673 on arXiv.org;     Virtual Journal of Nanoscale Science & Technology 10, issue 23 (2004);
    In the context of nanoelectromechanical cantilevers we derive a coupled oscillator model that includes reactive coupling and nonlinear frequency pulling in addition to the standard disspative coupling.  The paper details a method for analyzing the model and uses those tools to study four different distributions in natural frequencies.  Download the final draft paper as a PDF format or as a gzipped postscript file. This version has the only paper figure in the intended 2 column format and does not have a couple of errors that were added in the publication process.  The published form of the paper is also available in PDF format or as a gzipped postscript file.

    cover imagePattern formation in vertically oscillated convection
    --J.L. Rogers, W. Pesch, and M.F. Schatz, Nonlinearity 16 C1-C10 (2003)
    Review article featured on the cover for the journal Nonlinearity throughout 2003. Download article as gzipped postscript (.ps.gz, 1.16 Mb) or pdf (.55 Mb).

     Cover images in both high-resolution EPS format (52 Mb) and low-resolution JPEG format (.38 Mb).

    Modulated Pattern Formation: Stabilization, Complex-Order, and Symmetry
    --J.L. Rogers (2001).     My PhD dissertation as a gzipped postscript file (6.9 Mb)

    Superlattice patterns in vertically oscillated Rayleigh-Benard convection
    --J.L. Rogers, M.F. Schatz, O. Brausch and W. Pesch, Physical Review Letters 85, 4281 (2000)
    Letter reporting the first observations of superlattice patterns in convection. These complicated states are found in our experiments and numerical solutions of the Boussinesq equations. Download in PDF format or as a gzipped postscript file.

    Rayleigh-Benard Convection in a Vertically Oscillated Fluid Layer
    --J.L. Rogers, M.F. Schatz, J.L. Bougie and J.B. Swift, Physical Review Letters 84, 87 (2000)
    download paper in     PDF, PS format.

    Working drafts
    All publications