Research Fellow (Natural Sciences and Science Education Department) [NIE]

The National Institute of Education invites suitable applications for the position of Research Fellow at the Natural Sciences and Science Education Department.

Project Title: Intelligent Single Pixel Opto-Spintronic Terahertz Imaging (iSPOT)

Project Introduction: Terahertz (THz) frequencies represent a frontier with vast potential in non-destructive imaging. However, its application for high-resolution imaging at the micron scale remains hindered by limitations imposed by its sub-millimeter wavelengths [1 THz ~ 300 µm]. This necessitates the need to transcend the diffraction limit of THz waves to unlock imaging capabilities at both surface and sub-surface levels. Recently, computationally intensive THz imaging methods have emerged, leveraging single-pixel detection and spatially patterned THz waves. Generating spatially patterned THz waves typically involves a two-step process: (i) photoexcitation of silicon with patterned laser pulses, leading to conducting (illuminated) and non-conducting (non-illuminated) regions, and (ii) selective reflection/transmission of THz waves from the patterned photoexcited silicon surface, resulting in patterned THz radiation. However, due to the drift current from photoexcited to non-excited regions, the laser-irradiated pattern on silicon manifests blurred transition boundaries and eventually forming distorted THz patterns that introduce errors during the computation and, hence limiting the spatial resolution. Proposed Solution: Spintronic THz emitters, comprising ultrathin ferromagnet/heavy metal (FM/HM) heterostructure, have recently emerged as an efficient solution for generating broadband THz waves through femtosecond laser-induced spin excitation and inverse spin Hall effect. This ultrathin spintronic THz emitter design is hypothesized to prevent drift current between the photoexcited and non-photo-excited regions (activated by spatially patterned incident laser pulse), ensuring sharper transitions between "On" and "Off" states minimizing the THz image distortion. Overall aim: of our project is to achieve intelligent single-pixel-based THz imaging with image resolutions <20 µm (~λ/15) using spatially configurable patterned THz radiation obtained using an emerging concept of spintronic THz source activated selectively in an arbitrary spatial pattern using spatial light modulators. Methodology: involves working on three integrated verticals: (i) Optimization of FM/HM heterostructure, through detailed characterization of spin transport properties, for the realization of high-efficiency broadband spintronic THz emitter for compact THz imaging platform. (ii) Inventing a state-of-the-art single-pixel detector-based THz imaging platform aided by computational image construction methods and active polarization state manipulation of THz waves for THz imaging of metamaterial surfaces. (iii) Optimize and enhance the computational algorithm by introducing a patterned spintronic THz emitter array to resolve the two-dimensional object image from the data set in real-time.

Requirements:

Essential

• PhD in Physics, Engineering or a related field.
• Proven experience in THz Spectroscopy, spintronics and material science.
• Proficiency in optical setup alignment and material characterization.
• Proven experience in development, operation and optimization of THz sources and detection.
• Experience in THz Imaging.
• Proficiency in Python programming to develop codes for post-data processing.
• Strong written and verbal communication skills.
• Demonstrated writing proficiency, with experience producing research papers and research reports.

Preferred

• Strong knowledge of laboratory safety practices and procedures.
• Excellent organizational skills.
• Ability to work within given deadlines with strong attention to detail.
• Ability to work independently with minimum supervision.
• Ability to assist in the supervision of FYP / Masters / Ph.D. candidates.

Responsibilities:

• Contribute and support the fabrication of a spintronic THz spectrometer.
• Design of the pump-probe optical pathway based on the oscillator laser, emission via the spintronic THz emitter, and detection using a photoconductive antenna.
• Development of computational algorithms to achieve high-resolution THz imaging.
• Prepare, write, and contribute to research reports and papers.
• Any other duties as assigned by the Principal Investigator.

Application

Applicants (external and internal) will apply via Workday. We regret that only shortlisted candidates will be notified.

Closing Date

Closing date for advertisements will be set to 14 calendar days from date of posting.

Hiring Institution: NIE