In the NOISE-Lab, we are building ultra low-power nanoscale optoelectronic devices by engineering the interaction between light and matter. A fundamental tradeoff in integrated photonics exists between the extent at which one can engineer the amplitude, phase and frequency of light and the energy, speed, active area, and cost needed to do so. In our research, we want to address this tradeoff by exploring new materials (with strong electro-optic and nonlinear optical properties), new photonic devices (nanoscale high quality resonators) and new system architectures (different types of coupled resonator architectures coupled via optoelectronic feedback circuits) to sculpt and tune the properties of light at few photon levels. If you are interested, you can see here the recent talk given by Arka in UW-EE research colloquium in Fall, 2014.
Two main research themes in my group are: integrated low power hybrid silicon compatible photonic platform for optical communication and computing; and miniature optical systems (image sensor, microscope, spatial light modulator and spectrometer) based on nano-photonic devices. Some of the ongoing research projects are:
Hybrid silicon photonics(HySiP)To improve the transceivers in current silicon photonics (SiP), we are looking into new materials, cavities and new modulation techniques. The current SiP devices are limited either by the large size of the devices, and hence large power and low speed (in MZI); or by high Q-resonators (thermal stabilization necessitates large power consumption; and photon lifetime reduces speed). We are exploring nanophotonic innovation to solve this three dimensional optimization problem (speed, power and size). Our approach is to explore a hybrid silicon photonic platform, where the underlying photonic devices are made of silicon, on top of which we will integrate new materials (like electro-optic oxides, polymers etc.). We, however, want to go beyond signal communication, and want to explore the avenues of optical computing. For that we are actively working on new nonlinear optical materials. We want to push the energy of these devices to few photon levels, where we can also study quantum optical effects. These devices can be thought of as precursors to future quantum information processing devices.
Self electro-optic devices for optical computingUsing a photo-absorbing material in a silicon ring resonator, we have proposed a platform, where an optoelectronic feedback could be easily implemented. This device provides a way to have optical bistability, without explicitly relying on any optical nonlinearity. Moreover, this device is shown to satisfy all th criteria, an optical swicth should have to build a scalable digital optical computing system. In our current research, we are looking into new materials, that can be integrated on top of silicon photonics, and can absorb light. Then we will build the optoelectronic feedback.
Funding Sources: AFOSR (YIP-Program)
2D-material nanophotonicsWe are actively collaborating with leading researchers in the 2D material community to build photonic devices using 2D materials. 2D materials are a newly discovered materials, which are monolayer and single-atom thick. Due to such low volume, the energy required to change this material can be very low. Moreover, these materials can be easily transferred to other materials. In our reseach, we are looking into building new light source, electro-optic modulator as well as strongly nonlinear optical devices using the 2D materials.
Funding Sources: NSF-EFRI (Emerging Frontiers in Research and Innovation); AFOSR (YIP-Program)