Direct Detector for Terahertz Radiation

A direct detector that is a depletion mode field-effect transistor built from heterostructures and consisting of electrical contacts and a grating-gate

There has been much interest expressed in terahertz technology due to the diverse range of applications that it applies to. However, the terahertz components have been known to perform poorly due to it lying between traditional electronic and photonic fields. Sandia National Laboratories has created a direct detector for terahertz radiation that seeks to close the “technological gap.”

The present invention is a direct detector that is a depletion mode field-effect transistor built from heterostructures and consisting of electrical contacts and a grating-gate. The grating gate tunes the electron density of the detector and adjusts the Plasmon frequency to match the THz radiation illuminating the device. The detector shows a photo response when the Plasmon frequency under the grating gate was turned to the frequency of the incident illumination, a capability not found in other terahertz devices.

Benefits

• Plasmons are not tied to the bandgap energy and can be excited by small THz photon energies
• Plasmons can be excited at high temperatures than the THz photon energy
• Detector is easier to produce and control
• Easier to integrate with additional electronics
• Requires slower voltage

Applications and Industries

• National Defense and Security
• Molecular Spectroscopy
• Imaging Array
• Medical Imaging
• Remote Sensing
• Electronics