This work is aimed at creating new types of portable sources and detectors of radiation. These will be handheld, about the size of a normal torch, and will run off batteries. They work in the terahertz (THz) range, this can be thought of either as very high frequency radio waves or as light which is invisible to the human eye. For a long time it has been quite difficult to generate and detect THz, but over recent years people have used large powerful lasers to create pulses of THz radiation. This has proved very useful in medical applications to build up pictures of body tissue, rather like an x-ray, which can show up abnormalities. Other interesting areas being studied include using THz in fossil imaging, analysing chemicals and gases, in security and in astronomy.The work in the project aims to make a new generation of THz 'torches' and 'cameras' which can be carried in the pocket. Making the devices, small, low power and portable, will allow people to use THz radiation in applications like airport security to screen for explosive chemicals or drugs, to look for pollution in the local environment, and even to be used in pharmacies or GPs for helping with diagnosis. Moreover the radiation they use will be very 'pure' and that will help to make very sensitive detection.A feature of the work is to build upon the optoelectronic technologies developed for optical communications systems which provides a good foundation of advanced fabrication techniques leading to high reliability components capable of low power and efficient room temperature operation. UCL, Bath and Essex will work together with the Centre for Integrated Photonics (CIP), to design, fabricate and characterise novel components for THz operation. Leeds will focus on users and applications issues undertaking a detailed comparison between the performances of old and new systems.

This work is aimed at creating new types of portable sources and detectors of radiation. These will be handheld, about the size of a normal torch, and will run off batteries. They work in the terahertz (THz) range, this can be thought of either as very high frequency radio waves or as light which is invisible to the human eye. For a long time it has been quite difficult to generate and detect THz, but over recent years people have used large powerful lasers to create pulses of THz radiation. This has proved very useful in medical applications to build up pictures of body tissue, rather like an x-ray, which can show up abnormalities. Other interesting areas being studied include using THz in fossil imaging, analysing chemicals and gases, in security and in astronomy.The work in the project aims to make a new generation of THz 'torches' and 'cameras' which can be carried in the pocket. Making the devices, small, low power and portable, will allow people to use THz radiation in applications like airport security to screen for explosive chemicals or drugs, to look for pollution in the local environment, and even to be used in pharmacies or GPs for helping with diagnosis. Moreover the radiation they use will be very 'pure' and that will help to make very sensitive detection.A feature of the work is to build upon the optoelectronic technologies developed for optical communications systems which provides a good foundation of advanced fabrication techniques leading to high reliability components capable of low power and efficient room temperature operation. UCL, Bath and Essex will work together with the Centre for Integrated Photonics (CIP), to design, fabricate and characterise novel components for THz operation. Leeds will focus on users and applications issues undertaking a detailed comparison between the performances of old and new systems.

We are interested in the incorporation of nitrogen into semiconductors such as GaAs, InAs and GaSb. This is important because the band gap of the parent III/V semiconductor is substantially reduced by the incorporation of very small amounts of nitrogen. These so-called dilute nitrides show promise for use in tailoring the wavelength and efficiency of novel semiconductor lasers and other optoelectronic devices. Although GaAsN and InGaAsN are currently being studied mainly for their applications in photodetectors and lasers in the 1.3 to 1.55 um telecomms wavelength range there is far less research into dilute nitride compounds for the mid-infrared (2-5 um) spectral range which is rich in applications. However, there are problems associated with incorporation of N and degradation of the crystalline quality and especially as nitrogen content in the material is increased beyond 1%. This project seeks to investigate the growth of dilute nitrides for the mid-infrared spectral range using growth from the liquid phase rather than from the gas phase.One key advantage of this approach is that we do not need any N plasma to introduce the nitrogen atoms and so we can avoid all the damage from the energetic N ion species generated as a by-product from the plasma source normally used in vapour phase growth. Liquid phase epitaxy (LPE) is well known to produce material of excellent crystalline perfection. The proposed project seeks to build on our existing expertise in LPE growth and mid-infrared optoelectronics at Lancaster and study the resulting material properties of GaAsN, InAsN, GaSbN with a view towards evaluating their potential for use in mid-infrared optoelectronic devices. We aim to investigate both bulk materials and also corresponding dilute N nanostructures. The preparation of dilute N III-V alloys with high quantum efficiency would be a real breakthrough, particularly for use within mid-infrared light sources and detectors for which there are many practical applications. Moreover, if the approach proves successful it can be readily extended to other technologically important alloys such as InGaAsN and GaAsPN.

This work is aimed at creating new types of portable sources and detectors of radiation. These will be handheld, about the size of a normal torch, and will run off batteries. They work in the terahertz (THz) range, this can be thought of either as very high frequency radio waves or as light which is invisible to the human eye. For a long time it has been quite difficult to generate and detect THz, but over recent years people have used large powerful lasers to create pulses of THz radiation. This has proved very useful in medical applications to build up pictures of body tissue, rather like an x-ray, which can show up abnormalities. Other interesting areas being studied include using THz in fossil imaging, analysing chemicals and gases, in security and in astronomy.The work in the project aims to make a new generation of THz 'torches' and 'cameras' which can be carried in the pocket. Making the devices, small, low power and portable, will allow people to use THz radiation in applications like airport security to screen for explosive chemicals or drugs, to look for pollution in the local environment, and even to be used in pharmacies or GPs for helping with diagnosis. Moreover the radiation they use will be very 'pure' and that will help to make very sensitive detection.A feature of the work is to build upon the optoelectronic technologies developed for optical communications systems which provides a good foundation of advanced fabrication techniques leading to high reliability components capable of low power and efficient room temperature operation. UCL, Bath and Essex will work together with the Centre for Integrated Photonics (CIP), to design, fabricate and characterise novel components for THz operation. Leeds will focus on users and applications issues undertaking a detailed comparison between the performances of old and new systems.

This work is aimed at creating new types of portable sources and detectors of radiation. These will be handheld, about the size of a normal torch, and will run off batteries. They work in the terahertz (THz) range, this can be thought of either as very high frequency radio waves or as light which is invisible to the human eye. For a long time it has been quite difficult to generate and detect THz, but over recent years people have used large powerful lasers to create pulses of THz radiation. This has proved very useful in medical applications to build up pictures of body tissue, rather like an x-ray, which can show up abnormalities. Other interesting areas being studied include using THz in fossil imaging, analysing chemicals and gases, in security and in astronomy.The work in the project aims to make a new generation of THz 'torches' and 'cameras' which can be carried in the pocket. Making the devices, small, low power and portable, will allow people to use THz radiation in applications like airport security to screen for explosive chemicals or drugs, to look for pollution in the local environment, and even to be used in pharmacies or GPs for helping with diagnosis. Moreover the radiation they use will be very 'pure' and that will help to make very sensitive detection.A feature of the work is to build upon the optoelectronic technologies developed for optical communications systems which provides a good foundation of advanced fabrication techniques leading to high reliability components capable of low power and efficient room temperature operation. UCL, Bath and Essex will work together with the Centre for Integrated Photonics (CIP), to design, fabricate and characterise novel components for THz operation. Leeds will focus on users and applications issues undertaking a detailed comparison between the performances of old and new systems.