Undergraduate Scholarship Recipients

The research goal is to observe the formation and interaction of millimeter-wave Laguerre-Gaussian (LG) beams, operating at frequencies centered around 61.25 GHz, with solid state devices fabricated from monolayer graphene. Laguerre-Gaussian beams are unique for experiments when compared to fundamental Gaussian beams because they carry orbital angular momentum (OAM). The interaction of the LG beam with the graphene device while immersed in a static magnetic field will be experimentally analyzed using a four-point van der Pauw test structure as an OAM detector. A systematic approach will be used to observe the influence of LG beam illumination on the graphene device to determine if OAM can be used as another degree of freedom to control the properties of graphene.

Terahertz (THz) imaging has emerged as a powerful tool for a wide range of applications in security, imaging, sensing, quality control, and biomedical sensing. Current THz detector technology consists of custom devices, which are often bulky and expensive, as well as not sensitive enough to operate at room temperature. Technology for THz detection has been demonstrated in silicon, but these devices typically operate below 1 THz, can be power-intensive (>300 mW/pixel), require high-resistivity substrates, or use modifications such as silicon lenses and substrate thinning. In recent years, silicon-based THz imagers have been demonstrated in the 100-1000 GHz range, with NEP in the near 1 THz range of ~1 nW/ Hz. Beyond 1 THz there has been little work on enabling integrated imaging systems. Additionally, integrated chip-scale sources beyond 1.4 THz in silicon have never been demonstrated. In this project, we focus on the frequency range of 2.8 THz with a hybrid QCL-silicon IC solution, using a fully integrated silicon-based THz imager and a QCL laser operating at 2.8 THz.

The project targets detection and intervention of bruxism covertly for autistic children with help of integrated sensors and wireless electronics. The proposed solution is a non-invasive, aesthetically benign electronic wrist detector. The device would detect teeth grinding and provide instantaneous wireless feedback to the phone and/or computer through Bluetooth or Wi-Fi connection. The detection mechanism involves the bone conduction of acoustic or ultrasonic signals. The simplified theory applied in our device is that the signal created by bruxism can both be heard (through the air) and transmitted through the bones, demonstrably powerful acoustic conductor. By placing a sensing device at the wrist, the specific signature of grinding teeth could be detected as it propagates through the skull down through the arm. The processed information is delivered to external health professionals who will perform an intervention program to discontinue teeth grinding.

Zebrafish (Danio Rerio) have extraordinary regenerative abilities and therefore are very useful in numerous biological studies of organ injury. Recently many studies have focused on tracking the zebrafish healing process by monitoring and analyzing Electrocardiogram (ECG) signals. However in most of these studies the zebrafish were sedated in order to obtain the ECG. This would result in affected non-intrinsic ECG readings. A proposed solution to this problem is to measure ECG signals wirelessly through the use of medical implants on non-sedated fish. The implant will be powered, and communicate wirelessly, through inductive-coupling transmitter and receiver antennas. Communication with the implant will be implemented through load modulation. This setup would ensure adequate power and information transfer for the majority of misalignment angles between the transmitter and receiver.

This research focuses on a novel and efficient technique for the computation of high-order derivatives of electromagnetic field over a broad frequency range. Based on the multi-complex step derivative (MCSD) approximation method, which is free of round-off errors associated with finite difference methods, high-order electromagnetic field derivatives can be computed along with full-wave simulations. The MCSD approximation method is embedded and tested in Finite-Difference Time-Domain (FDTD) simulation, running in parallel with the time-stepping loop, to calculate high-order field derivatives with respect to multi design parameters accurately. The accuracy, stability and computation overhead of the proposed technique is analyzed. In addition to FDTD, the MCSD approximation solver can be further integrated with different simulation methods, introducing a powerful and versatile simulation environment for the applications of sensitivity analysis, uncertainty quantification and multi-parametric modelling of microwave structures.

For recent decades the interest to terahertz radiation and its applications in Biophotonics and Biomedicine has increased very high. Despite this, there is a lack of high-quality components, especially polarizing ones. Hence, the aim of my project is to make a tunable polarizer based on chiral metasurface, which could be used in investigations of polarization-changing properties of biological objects, such as cancer, teeth diseases.