My research focuses on nonlinear optics within the broader context of general wave physics. The emphasis is on propagation problems that are universal to wave systems, taking advantage of the fact that optical systems allow easy control of the input and direct imaging of the output. Using a healthy mix of theory and experiment, my group studies both basic nonlinear physics and advanced design issues for photonic applications. As a prime example, my group is developing optical hydrodynamics, in which the nonlinear propagation of light is described in terms of the equations for ideal fluid flow. For coherent (laser) light, the intensity acts as a fluid density while the direction of the wavefront gives an effective velocity. For incoherent light, the propagation can be treated as a statistical fluid, i.e. a plasma. Using these mappings, we have experimentally demonstrated optical shock waves, instabilities, turbulence, and thermodynamics. There are two primary results of these mappings: (1) optical modeling and observation of fluid behavior that is difficult, if not impossible, to see by other means and (2) a framework for the discovery of new optical physics. If the optical waves carry information, then propagation can be leveraged for dynamical signal processing. For example, nonlinear wave mixing can result in (intensity-dependent) energy transfer between modes, enabling higher resolution, increase field of view, and improved signal-noise properties. Recently, we have generalized computational imaging to include spatial nonlinearity and are applying it to microscopy, phase retrieval, and imaging through scattering media. Particular areas of interest include digital holography, noisy imaging, and biomedical optics.
“Observation of the kinetic condensation of classical waves” Can Sun, Shu Jia, Christopher Barsi, Sergio Rica, Antonio Picozzi, and Jason W. Fleischer, Nature Physics 8, 471 (2012).
“Wrinkles and deep folds as photonic structures in photovoltaics” Jong Bok Kim, Pilnam Kim, Nicolas C. Pegards, Soong Ju Oh, Cherie R. Kagan, Jason W. Fleischer, Howard A. Stone, and Yueh-Lin Loo, Nature Photonics 6, 327 (2012).
“Nonlinear restoration of diffused images via seeded instability” (Invited) Laura Waller, Dmitry V. Dylov, and Jason W. Fleischer, IEEE Journal of Quantum Electronics 18, 916 (2012).
“Optimizing holographic data storage using fractional Fourier transforms” Nicolas C. Pégard and Jason W. Fleischer, Optics Letters 36, 2551 (2011).
"Nonlinear self-filtering of noisy images via dynamical stochastic resonance” Dmitry V. Dylov and Jason W. Fleischer, Nature Photonics 4, 323 (2010).
"Wave tunneling and hysteresis in nonlinear junctions” Wenjie Wan, Stefan Muenzel, and Jason W. Fleischer, Physical Review Letters 104, 073903 (2010).
"Nonlinear light propagation in fractal waveguide arrays” Shu Jia and Jason W. Fleischer, Optics Express 18, 14490 (2010).
"Diffraction from an edge in a self-focusing medium” Wenjie Wan, Dmitry V. Dylov, Christopher Barsi, and Jason W. Fleischer, Optics Letters 35, 2819 (2010).
“Imaging through nonlinear media using digital holography” Christopher Barsi, Wenjie Wan, and Jason W. Fleischer, Nature Photonics 3, 211 (2009).
“Nonlinear light propagation in rotating waveguide arrays” Shu Jia and Jason W. Fleischer, Physical Review A 79, 041804 (2009).
“Observation of all-optical bump-on-tail instability” Dmitry V. Dylov and Jason W. Fleischer, Physical Review Letters 100, 103903 (2008).
“Multiple-stream instabilities and soliton turbulence in photonic plasma” Dmitry V. Dylov and Jason W. Fleischer, Physical Review A 78, 061804R (2008).
“Forward four-wave mixing with defocusing nonlinearity", Shu Jia, Wenjie Wan, and Jason W. Fleischer, Optics Letters 32, 1668 (2007).
“Dispersive shock waves in nonlinear arrays” Shu Jia, Wenjie Wan, and Jason W. Fleischer, Physical Review Letters 99, 223901 (2007).
“Dispersive, superfluid-like shock waves in nonlinear optics" Wenjie Wan, Shu Jia, and Jason W. Fleischer, Nature Physics 3, 46 (2007).