Acoustoelectric Methods for the Generation Manipulation and Detection of THz Radiation

Lead Research Organisation: Loughborough University
Department Name: Physics

Abstract

The conversion of acoustic signals (sound) to electrical signals, and vice-versa, is a technology that has found widespread practical applications. These include, for example: microphones and loudspeakers for sound recording and reproduction at audio frequencies (approx 20 Hz to 20 kHz); transducers for ultrasonic pulse-echo measurement and ultrasonic imaging systems (approx 20 KHz to 100s of MHz); and surface acoustic wave devices for signal processing in mobile communication devices (100s of MHz to a few GHz). The aim of this project is to develop a new technology for conversion between acoustic and electromagnetic (EM) signals, which works at much higher frequencies (10s of GHz to a few THz) and exploits acoustoelectric and piezojunction effects in semiconductor nanostructures and devices.

Acoustoelectric effects in semiconductors are due to the electrons "riding" the acoustic wave as it travels through the crystal. The electrons are effectively dragged along by the sound wave from one electrical contact to the other, giving rise to an electrical current. We have recently obtained experimental evidence for acoustoelectric effect at acoustic wave frequencies up to 100s of GHz in semiconductor nanostructures which points to the feasibility of the proposed project to reach the THz range. The piezojunction effect is a related phenomenon, where the sound wave modulates the electrical conduction across an interface, or junction, between semiconductors such as found in, for example, diodes and transistors. Again, recent experimental evidence obtained by us shows that the piezojunction effect works to very high (THz) frequencies. In the project we will investigate a number of the most promising devices for acoustoelectric applications, and optimise their sensitivity and speed in response to the THz acoustic waves generated by ultrafast laser techniques or saser (sound laser).

Potential applications, which we will explore in this project, include: new and improved methods of generation, manipulation and detection of THZ EM waves, e.g. heterodyne mixing of THz sound with THz EM waves, which have applications is scientific research, medical imaging and security screening; and the generation and detection of nanometre wavelength hypersound, which may be used to extend the established ultrasonics measurement and imaging techniques to the study of materials and structures at the nanoscale.

Publications

10 25 50
 
Description * theoretically predicted and experimentally confirmed transformation of ultrasound wave into (sub-THz) electromagnetic wave using semiconductor superlattice
* theoretical prediction of THz output from a semiconductor superlattice driven by acoustic wave
* developed a set of semi-classical and quantum models for description of electroacoustic effects in semiconductor superlattices
Exploitation Route THz acousto-electric devices studied in this project could be utilized for the manipulation of THz signals in high-resolution THz spectroscopy systems, for example a "single-chip" spectrometer using an acousto-electric THz generator and mixer both driven by a saser.
Sectors Electronics,Healthcare

 
Description Acoustoelectric Methods for the Generation Manipulation and Detection of THz Radiation 
Organisation University of Leeds
Department School of Electronic and Electrical Engineering Leeds
Country United Kingdom 
Sector Academic/University 
PI Contribution We have provided a theoretical background for the development of acoustoelectric methods for the generation manipulation and detection of THz Radiation
Collaborator Contribution University of Nottingham and the University of Leeds participated in the design and development of new semiconductor devices and performed a series of experiments with semiconductor superlattices, 2DEG devices exited by acoustic pulses. e2v provide consulting on microwave industrial standards and participated in the development of new devices and corresponding microwave systems (guides, antennas, resonators).
Impact the papers https://doi.org/10.1103/PhysRevApplied.7.044024, https://doi.org/10.1103/PhysRevE.95.062203, https://doi.org/10.1134/S0021364016070080, https://doi.org/10.1088/1367-2630/17/8/083064
Start Year 2015
 
Description Acoustoelectric Methods for the Generation Manipulation and Detection of THz Radiation 
Organisation University of Nottingham
Department School of Physics and Astronomy
Country United Kingdom 
Sector Academic/University 
PI Contribution We have provided a theoretical background for the development of acoustoelectric methods for the generation manipulation and detection of THz Radiation
Collaborator Contribution University of Nottingham and the University of Leeds participated in the design and development of new semiconductor devices and performed a series of experiments with semiconductor superlattices, 2DEG devices exited by acoustic pulses. e2v provide consulting on microwave industrial standards and participated in the development of new devices and corresponding microwave systems (guides, antennas, resonators).
Impact the papers https://doi.org/10.1103/PhysRevApplied.7.044024, https://doi.org/10.1103/PhysRevE.95.062203, https://doi.org/10.1134/S0021364016070080, https://doi.org/10.1088/1367-2630/17/8/083064
Start Year 2015
 
Description Acoustoelectric Methods for the Generation Manipulation and Detection of THz Radiation 
Organisation e2v Technologies
Country United Kingdom 
Sector Private 
PI Contribution We have provided a theoretical background for the development of acoustoelectric methods for the generation manipulation and detection of THz Radiation
Collaborator Contribution University of Nottingham and the University of Leeds participated in the design and development of new semiconductor devices and performed a series of experiments with semiconductor superlattices, 2DEG devices exited by acoustic pulses. e2v provide consulting on microwave industrial standards and participated in the development of new devices and corresponding microwave systems (guides, antennas, resonators).
Impact the papers https://doi.org/10.1103/PhysRevApplied.7.044024, https://doi.org/10.1103/PhysRevE.95.062203, https://doi.org/10.1134/S0021364016070080, https://doi.org/10.1088/1367-2630/17/8/083064
Start Year 2015