Nonlinear Optics Lab

Théo Lavier (U. of Edingburgh)

Thesis: A First Look at Rate Induced Tipping

The goal of this thesis is to develop an understanding of what rate induced tipping is and explore some of the recent developments in the analytic tools used. This exploration is guided by the development of a set of examples demonstrating rate induced tipping in a simple 1D system and a mechanical system.

Quinn Morgan 

Thesis: Exploring Bistability in a Driven Time-delay System with an Electronic Circuit

This thesis investigates bistabilities within a driven time-delay system using an electronic circuit. This thesis describes the construction of the electronic circuit and demonstrates that the circuit generates dynamics in good agreement with previously developed theory.

Zehui Zhao (Emory)

Thesis: Converse Symmetry Breaking in Two Models

A previous study by Nishikawa and Motter found a coupled-oscillator model that demonstrates converse symmetry breaking, a phenomenon in which the stable states are symmetric only when the system itself is not. This thesis will show analytically that a strong version of this claim is true but the proof is limited to small networks. A modified model is then introduced that shows (weak) converse symmetry breaking for any number of oscillators.

Jesse Cao 

Reed College Science Research Fellowship: Amplitude death of coupled optoelectronic oscillators.

Josh Dey (Software Developer at AI company)

Thesis: Reservoir Computing: Neural Networks and Observing Nonlinear Dynamical Systems

This project deals with reservoir computing and an observation task: inferring the state of a chaotic system. We seek to learn more about the internal dynamics of the reservoir computer by analyzing our observation task using three different activation functions; purely linear, purely nonlinear, and a mix of the two.

Zhongtian (Cosmos) Dong (U. of Kansas)

Thesis: Predicting spatio-temporal chaos with reservoir computing

In this thesis, a basic implementation of reservoir computing is studied. First, the capability to predict the dynamics of relatively simple chaotic systems is tested and a new performance metric is defined. Next, the performance and limitations of reservoir computing is studied when applied to spatio-temporal chaotic systems.

Maham Zia (researcher at U. of Minnesota)

Thesis: Investigating the role of Split discs in craniofacial development using Traction Force Microscopy

For this thesis, I used RNA interference (RNAi) and Traction force microscopy (TFM) to study and quantify cell migration in Drosophila cells with normal and reduced levels of Split discs (Spds)-homolog of SPECC1L in humans which is known to be implicated in craniofacial deformities.

Thomas Malthouse (U. of Freiburg)

Borders Fellowship: Amplitude death of coupled optoelectronic oscillators.

Alex Striff (Cornell)

Integrated circuit design for an all electronic programmable time delay.

Sean C. Allen

Thesis: Reservoir Computing: Observing the Baker’s Map

A link of reservoir computing to generalized synchronization is considered, leading to the idea that the map between the input state space and the reservoir state space should be smooth. The validity of the explanation is then explored numerically via observation tasks on the canonical dissipative Baker’s map.

Nikki Johnston

Thesis: Cells on Gels

This thesis is about traction force microscopy, a method in which a cell translocating on the surface of a gel causes the movement of beads within the gel and one calculates the forces the cell exerts on the surface by imaging the bead movements. This thesis offers background on elastic mechanics and traction force microscopy and a guide to this laboratory method at Reed.

Oona Sullivan-Marcus (OMSI)

Thesis: Methods for Producing Computer Generated Holograms Using a Spatial Light Modulator

Holography is a technique for creating a 3-dimensional image that involves recording an interference pattern between a reference beam and the field of light scattered off an object, then illuminating the recorded interference pattern with the reference beam. In this thesis, the experimental generation of a digital hologram using a spatial light modulator is described.

Kees Benkendorfer (Harvard)

Reed College Science Research Fellowship: Stabilizing fast periodic solutions through bandpass filtering.

Yunjia Bao (Brown)

Delord-Mockett Fund: (1) Periodic and quasiperiodic dynamics of optoelectronic oscillators with narrowband time-delayed feedback. (2) Amplitude Death in directly coupled optoelectronic oscillators.

Noah Shofer (Cambridge, Sperling)

Reservoir computer as observer for 2D spatio-temporal chaos.

Matthew Chau (CompSci at Northeastern)

Thesis: Analyzing 3-Point Symmetric Contacts of Photoelastic Disks

A method is developed for determining the magnitude of three point-contact forces that symmetrically compress a photoelastic disk.

Giovanni Corti (Earth Science at Simon Fraser)

Thesis: Avalanches in Granular Material

In this thesis the physics of granular avalanches are investigated. A rough inclined plane is constructed and the angles of inclination at which a layer of known uniform thickness is either stable, meta-stable or unstable are measured. The location of stability region boundaries are compared to theoretical predictions and we find a good match to the data.

Noah Shofer (Cambridge, Sperling)

Thesis: Reservoir Computing: Memory, Nonlinearity, and Spatial Observers

This thesis covers the background and implementation of reservoir computers. We show that these reservoir computers can act as observers for the Lorenz and Rössler chaotic systems, i.e. they are able to predict unobserved dynamical variables of these systems, and are able to learn the Lorenz or Rössler attractors. Furthermore, coupled map lattice dynamics were generated experimentally and in silico. We found an optimized parameter set that enabled the reservoir computer to predict the dynamics of the unobserved nodes of a 1D lattice when given the dynamics of a few nodes within the lattice.

Yunjia Bao

Reed College Science Research Fellowship: Dynamics of dual delay oscillators with narrowband feedback.

Edgar Perez (NIST, U Maryland)

A high speed all electronic programmable time delay.

Yuka Esashi (UC Boulder/JILA)

Thesis: Generation and Characterization of Nondiffracting Beams

The theory and application of nondiffracting beams beams are reviewed, and the generation of these beams using a setup involving a spatial light modulator is described. Several interesting properties of these beams, including propagation-invariance, self-healing, and angular momentum were measured and found to be in good agreement with theory.

Robby Gottesman (Data Scientist at Nielsen)

Thesis: Lighting the Way: Computations of Stable Forms of Optical Lift

An optical ray tracing module was developed in Mathematica to characterize the efficiency of optical wing designs. This procedure calculates the optical forces and resulting torque on a homogenous, transparent body with constant index of refraction and finds whether the body experiences stable angles of attack and lift forces.

Lara Kincheloe (SFSU)

Thesis: Maxwell's Dæmon in an Information Engine

This thesis is an exploration of the implications of associating thermodynamic entropy with information, and the ways in which chaos dynamics inform the association. The Szilárd engine is identified as a system of particular interest and its thermodynamic, informational, and chaotic properties are assessed and compared with two physical systems exhibiting similar dynamical behavior.

Ella Banyas (UC Berkeley)

James Borders Physics Student Fellowship: Amplitude and phase dynamics of delay coupled oscillators.

Kyu Yeon Cho (Operations Research at UC Berkeley)

Summer Experience Award: Fun with bucket brigade devices.

Edgar Perez

Reed College Science Research Fellowship: A flexible electronic programmable time delay.

Noah Shofer

Reed College Science Research Fellowship: An electro-optic device to investigate cluster synchronization.

Ace Furman (UT Austin)

Thesis: Electromagnetically Induced Transparency: The Zeeman Method

Electromagnetically induced transparency (EIT) — a quantum phenomenon wherein a material undergoes optical and dispersive modifications under the influence of resonant electromagnetic fields — was observed in warm rubidium vapor using the Zeeman method.

Mateo Ochoa Coloma (Software Developer)

Thesis: Origins of Chaos in Nonlinear Oscillatory Hamiltonian Systems

An exposition of chaos in perturbed, oscillatory Hamiltonian systems is provided, including the fundamentals of the Hamiltonian formalism, the construction of Hamiltonian maps, and the use of the KAM theorem and the Poincare-Birkhoff theorem to identify the origin of chaos in the vicinity of the separatrix for arbitrarily small perturbation strengths.

Colleen Werkheiser (Harvard)

Thesis: The Dynamics of a Nonlinear Time-Delayed Electronic System

We study the dynamics of a nonlinear time-delayed electronic oscillator consisting of a comparator, time delay, lowpass filter, and amplifier. Positive feedback resulted in a signal that decayed in finite time, while negative feedback resulted in slowly oscillating periodic solutions.

Anya Demko

Thesis: Dynamic Stabilization of an Invert Pendulum

Counter to intuition, the inverted position of a pendulum with a vertically oscillating pivot point can be stable. A pendulum is constructed using a mechanical wave driver to oscillate the pendulum's pivot point. Experimentally determined regions of stability agree well with theoretically predicted boundary lines.

Rachel Pincus

Thesis: Photoacoustic spectroscopy: a method for investigating weak molecular absorption

Photoacoustic spectroscopy is ideal for the study of samples exhibiting low absorption of light. This thesis aims to explain the basic theory and construction of a photoacoustic spectrometer. To validate its construction, studies were conducted on laboratory air and nitrous oxide.

Tobias Koppel (SAP)

Thesis: Demonstrating a Negative index of Refraction

A metamaterial intended to have a negative index of refraction is fabricated using aluminum plates and split ring resonators printed onto circuit boards. The angle of refraction is used to characterize the index of refraction of the material.

Yudan (Dan) Guo (Stanford)

Chaos in hybrid dynamical systems.

Lindsay Sonderhouse (UC Boulder)

Phase dynamics of two mutually coupled optoelectronic systems with unequal delays.

Andrew Warren (Math, Philosophy at Carnegie Mellon)

Reed College Science Research Fellowship: Phase and amplitude dynamics of delay-coupled oscillators.

Xueping Long (UCLA)

Thesis: Implementation of a Chaotic Electromechanical Oscillator Described by a Hybrid Differential Equation

This thesis describes an electromechanical oscillator whose governing equation of motion is an exactly solvable chaotic differential equation that takes the form of a force driven harmonic oscillator with negative damping coeffcient and a discrete switch condition to control and set two different equilibrium positions. Strong agreement is found between experiment and analytic solutions.

Jon Kindem (Applied Physics at Caltech)

Thesis: Optical Precursors

Starting from Maxwell's equation, the weakly dispersive, narrow resonance approximation is used to derive expressions for the time evolution of the precursor field. Optical precursors are experimentally observed in cold rubidium gas in a magneto-optical trap and a stacking effect between multiple off-resonance precursors is achieved.

Lukas Kuczynski (Portland: Lightcraft Technology)

Thesis: Extending Piecewise-Linear Chaos to Ultra-High-Frequencies Using Time-Delayed Feedback

Extension of exactly solvable piecewise-linear chaos to the regime of ultra-high-frequencies. In doing so, the issues surrounding the decreased timescale of dynamics are mitigated through the use of time-delayed feedback and control loops in a fully electronic circuit.

Lindsay Sonderhouse (NIST; UC Boulder)

Thesis: Phase and Amplitude Instability in an Optoelectronic Oscillator with Delayed Self-Feedback

The dynamics of a single optoelectronic oscillator perturbed by time-delayed self-feedback are explored experimentally and investigated theoretically through the Kuramoto (phase only) model and the Stuart-Landau (phase and amplitude) equation. The experimentally observed behavior can be explained by the stability conditions derived using the Stuart-Landau model but is inconsistent with the predictions of the Kuramoto model.

Xueping Long

Exactly Solvable Chaos

Cris Panda

Dynamics of coupled optoelectronic systems with unequal delays

Gray Davidson (Data Scientist)

Thesis: The Damped Driven Pendulum: Bifurcation Analysis of Experimental Data

When a pendulum is acted on both by a velocity dependent damping force, and a periodic driving force, it can display both ordered and chaotic behaviors, for certain ranges of parameters. Chaotic dynamics and the damped driven pendulum are examined via a professionally manufactured instrument from Daedalon.

Wes Erickson (UOregon)

Thesis: Electromagnetically Induced Transparency

Electromagnetically induced transparency (EIT) is a phenomenon that dramatically modifies the optical properties of a medium by creating a transparency window at a normally highly absorbing atomic resonance, and by greatly enhancing the medium's dispersion. The electric susceptibility describing these properties is derived and an experimental setup to observe the effect is detailed, including results demonstrating EIT in Rubidium 87.

Cris Panda (Harvard)

Thesis: Phase Dynamics and Synchronization of Delay-Coupled Optoelectronic Oscillators

We study experimentally, numerically, and analytically the phase dynamics and synchronization of two nonlinear optoelectronic oscillators with weak time-delayed mutual coupling and strong time-delayed self-feedback. Three distinct phase dynamic behaviors are observed as a function of the ratio of coupling to feedback delay: in-phase locking, anti-phase locking, and multi-timescale oscillations.

Jeremy Lawrence (Portland: Celly)

Thesis: Analyzing photoelastic disks

We develop methods for determining the forces acting on a single diametrically compressed photoelastic disk by analyzing the fringe pattern the disk exhibits when viewed in a crossed circular polariscope illuminated with monochromatic light.

Cris Panda

Chaos and Synchrony of optoelectronic delay system.

Lauren Shareshian, M.A. in Mathematics: Research Assistant

Nonlinear dynamics of coupled delay systems.

Cris Panda

Chaos and Synchrony in a system of three optoelectronic delay system.

Conference Presentation: Isochronous chaos synchronization of delay-coupled optoelectronic oscillators, 12th Annual Meeting of the Northwest Section of APS, Walla Walla, WA, Oct 1-2, 2010 (poster). Bulletin of the APS, Vol. 55, Num. 6
Paper: L. Illing, C. D. Panda, and L. Shareshian, Isochronal chaos synchronization of delay-coupled optoelectronic oscillators, Phys. Rev. E, vol. 84, 016213 (2011).

Alison Saunders (SLAC National Accelerator Laboratory; UC Berkeley)

Reed College Science Research Fellowship: The dynamics of the Malkus water wheel.

Conference Presentation: The dynamics of the Malkus water wheel, 12th Annual Meeting of the Northwest Section of APS, Walla Walla, WA, Oct 1-2, 2010 (poster). Bulletin of the APS, Vol. 55, Num. 6
Papers: L. Illing, A. M. Saunders, and D. Hahs, Multi-parameter identification from scalar time series generated by a Malkus-Lorenz water wheel, Chaos, vol. 22, 013127 (2012).
L. Illing, R. F. Fordyce, A. M. Saunders, and R. Ormond, Experiments with a Malkus-Lorenz water wheel: Chaos and Synchronization, Am. J. Phys., vol. 80 (3), 192 (2012).

Greg Hoth (Materials Science Inst. at UOregon; NIST; UC Boulder)

Thesis: The Dynamics of Delay Coupled Optoelectronic Devices

The oscillation onset for a pair of cross-coupled optoelectronic oscillators is investigated experimentally, analytically, and numerically. It is shown that these systems undergo a sharp onset of oscillations at a critical value of the coupling strength and that there is a scaling law that governs the relationship between the coupling strength and the amplitude of oscillations.

Conference Presentation: The scaling behavior of oscillations arising in delay-coupled optoelectronic devices, APS March Meeting 2010, Portland, OR, May 15-19, 2010 (talk). Bulletin of the American Physical Society, Vol. 55, Num. 2
Paper: L. Illing, G. Hoth, L. Shareshian, and C. May, Scaling behavior of oscillations arising in delay-coupled optoelectronic oscillators,
Phys. Rev. E, vol. 83, 026107 (2011).

Sam Spencer (Optics Institute at URochester)

Thesis: Active Modelocking an Open-Cavity Helium-Neon Laser

We discuss the physical mechanisms that lead to modelocking as well as the nonlinear phenomenon of injection locking and the role it plays in making modelocking an experimental reality. We experimentally demonstrate modelocking using a Helium-Neon laser tube with external cavity mirrors and an acoustooptic modulator.

Matthew Jemielita (UOregon)

Bifurcations and modeling of a pulsed opto-electronic delay system.

Greg Hoth

Reed College Science Research Fellowship: Dynamics of cross-coupled opto-electronic delay systems.

Adarsh Pyarelal (UArizona)

Chaotic dynamics and bifurcations of the Malkus Water Wheel.

Kevin J. Lynagh

Reed College Melon Foundation Opportunity Grant: Nanopore Sequencing

Rachel Fordyce (Plant Biology at UC Davis)

Thesis: Chaotic Waterwheel

Experimental implementation of the chaotic Malkus waterwheel, a mechanical device whose dynamics are modeled by the famous Lorenz equations. The observed dynamical behavior in both the chaotic and periodic operating regime is analyzed qualitatively using phase space plots and spectra.

Paper: L. Illing, R. F. Fordyce, A. M. Saunders, and R. Ormond, Experiments with a Malkus-Lorenz water wheel: Chaos and Synchronization, Am. J. Phys., vol. 80 (3), 192 (2012).

Cody Myers

Thesis: Monochromatic Plane Waves in a Corrugated Tube System

Experimental and theoretical study of acoustic transmission properties of a corrugated tube. As with many periodic systems, there are band gaps for the acoustic wave propagation through the corrugated tube, i.e. large ranges of incident sound frequency over which there is virtually no sound transmission.

Matthew Jemielita

Reed College Science Research Fellowship: Bifurcations of a pulsed opto-electronic delay system

Christopher May

Chaos synchronization of mutually coupled opto-electronic devices.

Seth Terashima

Chaos and bifurcations in the electronic "Rulkov" circuit.

Drew Atwater (Environmental Sciences at UC Riverside)

Thesis: A Brief Study of Thermoacoustic Cooling

Experimental and theoretical study of a thermoacoustic engine, a device where sound from a speaker is used to establish and maintain a temperature difference across a stack inside a pipe.

Christopher May (Portland: Lucky Sort, Puppet Labs)

Thesis: Feedback, Synchronization, and Communication in Chaotic Time-Delay Opto-Electronic Feedback Circuits

Feeding back an amplified output signal of a nonlinear device to itself can result in self-sustained oscillations. Here, the nonlinearity is an integrated opto-electronic mach-zehnder modulator and the oscillations can be periodic or chaotic, depending on the feedback strength. Synchronized chaotic oscillations are achieved by coupling two such devices, which then are utilized for communication.

Conference Presentation: Chaos Synchronization and Communication using Optoelecronic Time-Delay Feedback Circuits, 10th Annual Meeting of the Northwest Section of APS, Portland, OR, May 16-17, 2008 (poster).
Bulletin of the American Physical Society, Vol. 53, Num. 6, C1.00006
Paper: L. Illing, G. Hoth, L. Shareshian, and C. May, Scaling behavior of oscillations arising in delay-coupled optoelectronic oscillators,
Phys. Rev. E, vol. 83, 026107 (2011).

Erin McCowen (Forestry at Colorado State University)

Thesis: Bioconvection: The Effect of Density on Wavelength

Bioconvection of Bacillus subtilis, a phenomenon where the interplay of active upward swimming of the bacteria, gravity, and fluid dynamics result in spontaneous pattern formation.