Community Research and Development Information Service - CORDIS

FP7

POLATER Result In Brief

Project ID: 295187
Funded under: FP7-PEOPLE
Country: United Kingdom

Terahertz radiation sources and detectors

The realization of efficient terahertz (THz) radiation sources and detectors is one of the important objectives of modern applied physics. This has wide ranging applications in biology, medicine, security and non-destructive in-depth imaging.
Terahertz radiation sources and detectors
THz radiation can be generated in semiconductor microcavities through exciton polariton lasing, where a radiative THz transition between microcavity polariton branches is allowed. A special design of quantum well microcavity is required, which provides mixing of bright and dark quantum well excitons.

The POLATER (Polaritonic teraHertz devices) project produced a wide range of results underpinning theoretical advances in the above areas. This has included the development of detailed theory and design for radiative THz transitions in quantum microcavities and THz intersub-band polaritons as well as the fabrication of a set of microcavities with effective polaritonic THz radiative transitions.

Researchers modelled, built and theoretically investigated microcavities of various designs. POLATER investigated GaAs, InAs as well as GaN structures. An analysis of the polaritonic THz active area, based on quantum wells, quantum wires and quantum dots with broken symmetry has been completed. The team developed and fabricated a novel type of cavity based on cylindrical Tamm plasmons.

Researchers fabricated and characterised a multi-quantum well structure for polaritonic emitters based on InAs monolayers. The structure demonstrates a pronounced superradiant mode that can be used for the development of THz emitters.

POLATER designed polaritonic cascade structures. An important outcome here is the development of the Bosonic Cascade Laser theory, where each polariton injected to the device emits several THz photons.

The public view of THz has been largely influenced by a number of articles in the press citing its ability to image through clothing and detect explosives or weapons. However, the potential applications of THz light are far more wide-ranging. THz radiation can provide a direct probe to reveal the fundamental properties and operation of life through, for example, the study of conformational changes in protein structures, protein hydration shells and DNA. The creation of inexpensive, reliable, scalable and portable sources and detectors of THz radiation would ensure their widespread exploitation in the future.

Related information

Keywords

Terahertz, radiation sources, detectors, polariton, quantum microcavities
Record Number: 183091 / Last updated on: 2016-07-26
Domain: Industrial Technologies