THz Generation

Introduction

The band within the electromagnetic spectrum between about 300 GHz and 3 THz is often referred to as terahertz radiation. It is in between the frequency regions in which optical and microwave technologies work well and hence there are not a lot of good sources around. Terahertz radiation is considered to be an upcoming technology in material inspection, quality control, gas sensing, surveillance and security applications, and  wireless, short-haul communication.

In a scientific realm, high-resolution THz sources are important for Terahertz spectroscopy, e.g. for astrochemically important molecules and local oscillators for THz  telescopes.

Advancing power, tunability, compactness and affordability of Terahertz sources is a very active research area in academia as well at the industrial interface because progress in applications is currently hindered by a lack of suitable sources.

Experiment

One method to produce THz radiation is to mix two cw infrared lasers in a special kind of semiconductor (low-temperature grown GaAs), which generates their difference frequency that can be tuned into the THz range. Thermal failure was identified to be the limiting factor for THz power and the current investigations are directed on improving heat sinking and understanding temperature characteristics of antennas. We are working to overcome this using diamond heat sinking (see J. Appl. Phys. 2012).

Another area of research is the use of quantum dots for THz generation.

Coverage and Esteem

Publications

People involved

Prof. Thorsten Ackemann Dr. Helen Fraser Mr. Scott Campbell Prof. Erling Riis Dr. Aidan Arnold

Funding

T. Ackemann Lifetime measurements 07/2011 – 12/2011 Strathclyde Links (KE funding)
T. Ackemann, H. Fraser High power Terahertz generation enabled by improved heat sinking 05/2010 -07/2011 The Royal Society London
T. Ackemann Characterization of cw THz emitters 07/2010 – 06/2011 SUPA Start (KE funding)
T. Ackemann, H. Fraser, E. Riis High-power cw Terahertz radiation by photomixing 06/2008 – 04/2009 Research and Development Fund, University of Strathclyde

Collaborations

Prof. Mohamed Missous Microelectronics and Nanostructure Group,
School of Electrical and Electronic Engineering, University of Manchester
Dr. Guillaume Huyet Cork Institute of Technology, Tyndall National Institute Dr. Maria Anna Cataluna University of Dundee

Previous group members

Mrs. Stefanie Keatings Mr. Pradeep Luke Sam