Terahertz radiation sensor and imaging system

A terahertz imaging system comprising:

• a terahertz source to provide terahertz radiation for imaging an object;
• a terahertz sensor to detect said terahertz radiation;
• a timing adjust device to adjust a relative timing of emission of terahertz radiation from said source and detection of said terahertz radiation by said detector;
• and
• an image processor to receive a plurality of sensed signals from said terahertz sensor for a plurality of different said relative timings, and to output data representing an image of said object determined from said plurality of sensed signals, and wherein said image processor is configured to capture data from said sensor corresponding to an interference pattern generated by said object, and to construct said three-dimensional image of said object by decoding said interference pattern.

A terahertz radiation sensor, the sensor comprising:

• an optical beam input to receive an optical probe beam;
• a detector to modulate said probe beam responsive to terahertz radiation;
• and
• a CMOS photosensitive detector to provide an output responsive to said probe beam modulation;
• wherein said CMOS photosensitive detector is not in a terahertz radiation image plane.

A terahertz radiation sensor, the sensor comprising:

• an optical beam input to receive an optical probe beam;
• an electro-optic detector to modulate said probe beam responsive to terahertz radiation;
• and
• a photosensitive detector to provide an output responsive to said probe beam modulation;
• the sensor being configured simultaneously to provide a first optical path between said optical beam input and said electro-optic detector and to provide a second optical path between said electro-optic detector and said photosensitive detector, and wherein light travels on both said first and said second optical paths whether or not said terahertz radiation is present.