Ultrafast Nonlinear Optics and Biophotonics Laboratory

research
 

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Biopolymer photonics - silk optics


We are revisiting biopolymers in a high-tech context. Specifically, silk fibroin extracted from silkworm cocoons is a unique biopolymer that combines biocompatibility, implantability, along with excellent optical properties. We study the use of silk as an optical material in order to integrate optics with living tissue. Silk can be nanopatterned with features smaller than 20 nm. This allows manufacturing of structures  such as (among others) holographic gratings, phase masks, beam diffusers and photonic crystals out of a pure protein film. The properties of silk allow these devices to be "biologically activated" offering new opportunities for sensing and biophotonic components.   (learn more)


Transient electronics


We work on redefining electronics to resorb into the surrounding environment in a benign way, at prescribed times and with well-defined rates.  This behavior is opposite to that of conventional electronics, where the goal has historically been to achieve physical forms that remain invariant over time.   This approach will enable important new classes of devices that cannot be achieved with conventional, ‘invariant’ electronics, ranging from environmental monitors that dissolve when exposed to water (‘eco-resorbable’) to eliminate the need for collection and recovery to medical monitors that fully resorb when implanted into the human body (‘bio-resorbable’) to avoid adverse long-term effects.  Other concepts involve ‘compostable’ circuits, to facilitate disposal.  



 

Structural color and photonic crystals


Photonic crystals are investigated, with particular attention devoted to  manufacturing these structures in naturally occuring materials such as biopolymers.  Naturally occurring photonic structures have local, refined nanostructured features that are arranged hierarchically in mostly aperiodic or multi-scale, complex geometries - such as the scales in a butterfly wing for example. Additionally, periodic and aperiodic geometries are also investigated as paths for sensing and understanding of hierarchy in biological structures.  (learn more)




Biopolymer-based metamaterials


Over the last decade, artificially structured electromagnetic (EM) composites, often dubbed metamaterials (MMs), have attracted interest from researchers, including physicists, material scientists and engineers. We are interested in the fusion of biopolymers with electromagnetic resonator structures to develop a new class of antennas that are truly biologically integrated (learn more)




Nonlinear optics in fibers/photonic crystal fibers


Use of high intensity pulses in optical fibers provides a rich array of physical effects because of the highly nonlinear interaction between the light and the bulk constituent of the optical waveguide.


A new class of fibers which manipulates light in unconventional ways has inspired a renaissance in fiber optics allowing unprecedented control on nonlinear effects, and on wavelength. These fibers are generally called photonic crystal fibers (PCFs). These unique waveguides have equally unique nonlinear behavior which manifests itself in a more dramatic way compared to conventional fiber. Furthermore, these fibers can guide light either in a solid or in a hollow core.


These new fibers have spawned a variety of applications such as supercontinuum generation from pulsed laser sources, wavelength conversion and soliton propagation; hollow core devices such as gas-laser Raman cells, particle and atom guidance; soliton formation with ultra high energy fs pulses; optical fibre sensors; intra-fibre devices; high power fibre lasers; compact solid-state pump lasers for nonlinear PCF devices; laser machining; sources for optical coherence tomography; non-silica glass PCFs for infrared transmission; and frequency metrology.   Particular interest is paid to research in mid-IR PCF, and is short PCF SC generation. (learn more)



Ultrafast laser interaction with biological tissues


We are bringing together optical physics and bioengineering by performing a preliminary yet systematic study  of the interplay between tightly focused, high-energy femtosecond laser pulses and engineered biological surfaces.  From a general point of view, these preliminary experiments will provide an indication on how to use lasers to cleave biological tissues while addressing the more specific goal of selective interaction with biological samples at the cellular level.    In fact, it is possible to focus laser radiation to spot sizes that are as small as a few micrometers in diameter.  These dimensions are commensurate  both with the typical sizes of cells (which range from the tens to the hundreds of microns) and with the cell nuclei.