Collaborative Research: Endowing nonlinear optical devices with unprecedented robustness: overcoming fabrication disorder by 'topological protection' against parasitic scattering
Non-technical section of abstract:
Technology based on controlling and manipulating light affects our lives in countless ways: from the optical fibers that enable ultrafast internet speeds, laser manufacturing of automobiles, to solar cells that provide clean energy - optical devices are ubiquitous. Very often, the performance of a given device is limited by fabrication imperfections: random defects that cause unwanted scattering of light, which impedes its flow and adds unwanted noise. Investigators Rechtsman and Chen will demonstrate a method to completely suppress such scattering: so-called 'photonic topological protection' of light beams. This concept, borrowed from solid-state physics (in which the goal was to protect electronic current from scattering) has already been demonstrated to work, and offers the possibility of endowing a wide class of devices with unprecedented robustness. In order to test these concepts in the lab, the investigators will fabricate waveguide arrays (a series of 'wires' for light that together form a desired device) embedded in a type of glass that is particularly useful for so-called 'nonlinear' optical devices. With proper design of the waveguide array, suppression of scattering will be demonstrated in multiple different devices. The implications to optical devices are clear: increased device efficiencies or cheaper fabrication costs (or both). Moreover, the authors expect their work to 'shed light' on the general wave phenomenon of topological protection against scattering in many contexts, including acoustic waves, microwaves, optical waves, and even electron waves.
Technical section of abstract:
The field of 'topological insulators' has captivated condensed matter physics for ten years, due to these materials' universal properties, and striking applications in spintronics and quantum computing. It was recently demonstrated that their key property -'topological protection' against scattering by disorder- could be achieved with photons in waveguide arrays with engineered linear dispersion properties to preserve edge modes.
This proposal will explore the nonlinear optical properties of Photonic Topological Insulators (PTIs). Through the fabrication of high quality PTI waveguide arrays in nonlinear optical substrates such as chalcogenide glass, this research project will explore a nonlinear properties of edge modes and their potential applications. Since PTIs have a fundamentally different dispersion, a novel understanding of nonlinear optics in these structures is bound to yield new scientific knowledge and device applications, which will be of great interest to a highly cross-disciplinary set of intellectual communities.
The activities of this project are: (1) theoretical work to analytically and numerically model nonlinear effects (i.e., modulation instability and solitons) in photonic topological systems; (2) fabrication (laser-written photonic crystal-type structures) in chalcogenide glass, which has a high nonlinear response; (3) characterizing the structures by injecting high-peak-power near-infrared light and observing spatial diffraction patterns.
The collaboration between PI and co-PI with complementary expertise will enable the success of the proposed project from theoretical studies to device fabrication to characterization. If successful, photonic topological protection can potentially be used to dramatically improve the performance of optical devices such as multiplexing systems, all-optical switches and beam-shaping systems - and indeed any optical application limited by fabrication disorder.
|Effective start/end date||9/1/15 → 8/31/19|
- National Science Foundation: $285,000.00