THz imaging technique acts as a perfect tool for the detection of concealed (hidden) metallic objects like arms and ammunition which may be potential threats, thus making it a suitable tool for defence and homeland security applications. THz radiation also known as T-ray lies between the microwave (electronics) and optical region of the electromagnetic spectrum which is extended between 100 GHz to 10 THz frequency or 3 mm to 30 micrometre wavelength range.
