Fiber-coupled on-chip THz spectroscopy of van der Waals materials
Abstract
THz frequencies lie at the heart of the electromagnetic spectrum, and are ideally matched to probing the dynamics of charge carriers in electronic and magnetic materials. However, THz spectroscopy remains underdeveloped as compared to audio and radio frequency electronics, infrared and visible light spectroscopy, and the manipulation of static electric and magnetic fields in its utility for probing modern electronic devices. Nonetheless, THz sources, detectors, and spectroscopy tools have proven invaluable for a range of applications. In particular, THz time-domain spectroscopy (THz-TDS) has become a standard laboratory and industrial tool to characterize materials, finding use in investigating the carrier dynamics of semiconductors, strongly correlated electronic systems, and superconductors. However, for nano-scale devices, the free-space THz wavelength makes standard approaches impractical, putting severe constraints on sample geometries that can be probes. The ever-increasing miniaturization of technologies and devices into the nanoscale calls for novel techniques to capitalize advantages of THz spectrum deep below its diffraction limit. One approach confines THz radiation to a coplanar transmission line to form an on-chip THz spectrometer. These devices function by exciting photoconductive switches with femtosecond optical pulses. The resulting THz pulses are then partially confined to transmission lines patterned on the chip at the micron scale which guide the THz transient to the sample of interest.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502410113
Entities
People
- Andrea Young
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California, Santa Barbara