Nanopatterning for Physics and Application

Nano-patterning and nano-assembly have been exciting topics of frontier research for quite some time now. The top-down and bottom-up approaches have been used to build novel nanostructured materials that exhibit properties that are enhanced or different compared to bulk. Examples of these are the quantum dot (QD) based low threshold lasers and single photon emitters. Nano-patterning allows us to probe carrier dynamics in single QDs as demonstrated by us recently [1]. In Photonics, nano-patterning is used to fabricate photonic crystals that modulate and localize light. For example, intentionally introduced defects in PCs lead to micro-cavities in which the QD emission can be modified. In the field of Plasmonics, nanopatterned metal-dielectric layers are being used to realize nano-photonic components. In addition, plasmonic nanostructures are employed in enhancing the optical nonlinearities.

In this talk, after a brief introduction to the above fields, some of our results in related areas will be presented. In particular, I will discuss our recent results [2] on enhancing the transverse magneto-optical Kerr effect (TMOKE). We fabricated magneto-plasmonic crystals by combining Gold nano-patterns and ferromagnetic Bi:YIG films. In these structures, a three orders of magnitude enhancement in TMOKE has been observed in transmission geometry compared to unpatterned films. These results show the potential of nanopatterned magneto-plasmonic structures to achieve MO effects strong enough for device applications. An interesting outcome of the TMOKE measurements is that TMOKE can be used as a very high sensitive tool to identify the surface plasmon polariton resonances.
[1] A. Ramsay et al., Phys. Rev. Letts. 104, 017402 (2010).
[2] V. I. Belotelov et al. Nature NanoTech. 6, 370 (2011).