EE Colloquium: Disordered Structures and Their Applications

Zhiwen Liu of Penn State will be the speaker.

Abstract

Applications of passive and active disordered optical structures realized in particle assembly platform will be discussed. A layer of random particles can behave as an imaging encoder, transforming a point source into a scattering pattern. The scattering pattern of an object, being a linear superposition of patterns created by all its constituent point sources, can be inverted to reconstruct its image. Our recent work by using random assembly of nanowires to achieve lensless imaging will be presented, which can achieve a large angular field of view of about ±45°. We also show that a multi-shot approach implemented by using dynamic particle assembly can significantly improve the reconstruction quality. Disordered structures with gain can result in random lasing, which exploits multiple scattering to trap and amplify light without the use of an ordinary laser cavity. Recently we have demonstrated the ability to control disorder in a nanoparticle platform for controlling random lasing and tuning the emission characteristics. Both experimental results and simulations will be discussed.