Systems and methods for terahertz imaging

A terahertz vehicle imaging device comprising:

• first imaging optics to receive terahertz radiation from a vehicle of interest;
• a receiver assembly comprising a cryostat, the cryostat containing second imaging optics and a terahertz radiation detector array, the second imaging optics being configured to form at least a one-dimensional image on the terahertz radiation detector array;
• and
• imaging electronics to generate an image of the vehicle of interest using signals read from the terahertz radiation detector array,
• wherein the first imaging optics are configured to direct the terahertz radiation into the receiver assembly,
• wherein the first and second imaging optics have an instantaneous vertical field of view that encompasses a height of the vehicle of interest, and
• wherein the image of the vehicle of interest is generated following relative movement of the vehicle of interest with respect to the terahertz vehicle scanning device.

A method of scanning an object using a terrestrial terahertz imaging system, the method comprising:

• during a scanning procedure that scans a first extent of the object in a first direction, iteratively, for different portions of the object along the first direction:
• receiving electromagnetic radiation from a second extent of the object at an imaging assembly of a terrestrial terahertz imaging system, the second extent of the object being in a second direction that is orthogonal to the first direction, wherein the imaging assembly comprises reflective optical components arranged in a confocal configuration that is arranged to image at finite conjugates;
• directing the electromagnetic radiation into a receiver assembly of the terrestrial terahertz imaging system, the receiver assembly comprising a cryostat containing a terahertz radiation detector and reflective cold re-imaging optical components, the reflective cold re-imaging optical components comprising a reflective, confocal optical relay;
• and
• receiving, from the reflective cold re-imaging optical components, the electromagnetic radiation at a detector array of the terrestrial terahertz imaging system, the detector array capturing an image covering the second extent of the object at the terahertz radiation detector;
• and
• generating a two-dimensional image of the object including the first extent and the second extent using data read from the terahertz radiation detector during the scanning procedure;
• wherein the object is a moving object and the method comprises:
• directing a pointing mirror at the object at a first location and performing the scanning procedure;
• and
• directing the pointing mirror at the object at a second location following motion of the object and performing the scanning procedure,
• wherein generating a two-dimensional image of the object comprises generating at least two two-dimensional images of the object, each two-dimensional image featuring the object at a different orientation.

A method of scanning an object using a terrestrial terahertz imaging system, the method comprising:

• during a scanning procedure that scans a first extent of the object in a first direction, iteratively, for different portions of the object along the first direction:
• receiving electromagnetic radiation from a second extent of the object at an imaging assembly of a terrestrial terahertz imaging system, the second extent of the object being in a second direction that is orthogonal to the first direction, wherein the imaging assembly comprises reflective optical components arranged in a confocal configuration that is arranged to image at finite conjugates;
• directing the electromagnetic radiation into a receiver assembly of the terrestrial terahertz imaging system, the receiver assembly comprising a cryostat containing a terahertz radiation detector and reflective cold re-imaging optical components, the reflective cold re-imaging optical components comprising a reflective, confocal optical relay;
• and
• receiving, from the reflective cold re-imaging optical components, the electromagnetic radiation at a detector array of the terrestrial terahertz imaging system, the detector array capturing an image covering the second extent of the object at the terahertz radiation detector;
• and
• generating a two-dimensional image of the object including the first extent and the second extent using data read from the terahertz radiation detector during the scanning procedure;
• wherein the object is a vehicle, the first extent comprises a length of the vehicle in a direction of motion of the vehicle and the second extent comprises a height of the vehicle, wherein the scanning procedure is performed using relative motion between the vehicle and the terrestrial terahertz imaging system.