Our research interest ranges from basic phenomena in condensed maters physics to applications integrated photonics. On the basic side we focus on surface plasmons and plasmonic cavities. The study of propagating surface plasmon polaritons on patterned surfaces have revealed interesting results including slow plasmons on Moire surfaces. We are now extending our cavity work to interactions of excitons with surface plasmons having observed large Rabi splittings with dyes.
With recent demonstration of plasmonic enhancement of absorption, we employ laser induced nanoparticle formation to study localized plasmons and their interactions. Ag and Au serpentine networks that we observe are promising for enhanced absorption in photonic management of light in various optoelectronic devices.
It is well known that quantum confinement in nanocrystals leads to band gap widening. With applications to solar cells in mind, we extend the quantum confinement effect to investigate nanocrystal networks in silicon rich oxides with laser induced phase separation via spinodal decomposition. Percolation of the phase separated network with good surface passivation should eventually lead to efficient manipulation of solar spectrum for higher efficiency.
Detection of infrared light has many applications in medical, astronomical and security applications.
We are interested in design, fabrication and testing of high efficiency IR superlattice photodetectors using ultrathin layer pairs of GaSb/InAs. Lowering dark current is critical in the operation of such detectors. We have developed novel passivation techniques including atomic layer deposition of Al2O3, HfO2 that dramatically lowers dark current. Alternatively, low cost and easy to apply approaches such as dipping into solutions of thiol based carbon chains with sulphur heads have been developed. We are currently extending these applications to photodetectors operating at longer wavelengths.
Our integrated optics group is studying applications of hybrid integrated optical devices to add/drop filters for telecommunication applications as well as to displacement meaurements at the nanoscale. Concentrating on ring resonator based add/drop multiplexers, where large ring radii leads to narrow FSRs, we exploit the hybrid material system to engineer large FSRs with large resonator diameters.
Finally, we are pursuing the quantum well potential response to very high intensity electromagnetic fields. In the light of recent theoretical predictions, the transition of a single quantum well to double quantum well will be investigated using a pump-probe absorption approach under far IR ps pulse pumps.
With experience in various optoelectronic devices, we are interested in innovative new ideas both in condensed matter physics and photonic devices and applications, including photodectors, lasers, resonators etc. For detailed list of research topics please click here.