Superradiant Smith-Purcell Emission in the Mid-Infrared via Guided-Wave Electron Optics
Abstract
The mid-infrared portion of the electromagnetic spectrum is of fundamental interest to science and technology. With wavelengths from around 3 to 20 micrometers, this part of the electromagnetic spectrum has numerous scientific, industrial, and medical applications ranging from spectroscopy to surgery, as well as military applications ranging from sensing to countermeasures. In recent years, compact laser and photonictechnologies have pushed to longer wavelengths in the infrared. However, despite advances in quantumcascade lasers, difference-frequency-generation systems, and other photonic technologies, compact midinfraredsources offer limited wavelength tunability and comparatively low output powers. At frequenciesbelow the infrared, in the microwave domain, electron-beam-driven sources of electromagnetic radiationhave been incredibly successful. However, efficiently scaling these devices to output wavelengths below~1 mm, without the use of relativistic electron beams (as in free-electron lasers), has proven challenging.In this project, we will use guided-wave techniques, inspired by photonics, to overcome this challenge. Wewill develop microscale electron-beam waveguides (analogous to nano-photonic waveguides) to tightlyconfine kilo-electronvolt (keV) electron beams near engineered electromagnetic-coupling structures in order to generate mid-infrared light with tremendous wavelength tunability and power scalability. Specifically, in this program, we will use electron-beam waveguides to enhance Smith-Purcell interactions. We will extend Smith-Purcell emission from the spontaneous regime to the domain of collective effects, the so-called superradiant regime.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502110270
Entities
People
- William C Putnam
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California, Davis