Telecentric f-theta Lens for high-speed terahertz reflection three-dimensional imaging

High-speed terahertz reflection three-dimensional imaging is demonstrated using electronically controlled optical sampling (ECOPS) and beam steering. The ECOPS is used for a 1 kHz axial scan and a transverse scan is performed using beam steering. Telecentric f-theta lenses essential for beam steering have been fabricated with axial and nonaxial symmetry. Using the imaging system, a volume of 100 × 100 × 7.8 mm
³
can be scanned within 40 seconds, yielding 200 × 200 × 725 voxels.