THz Imaging Objective Lens, 0.1 - 30 THz

Overview

This is an imaging objective for the terahertz band, covering 0.1 to 30 THz, supplied with a camera adapter, an optical component bracket, a post-assembly mount and an adapter ring. Depending on configuration it weighs between 30 and 200 grams, so it mounts on standard optomechanics without special support.

What an objective adds to a THz camera

A bare terahertz camera records whatever field distribution reaches its focal plane array, which is useful for beam profiling but not for imaging an object. An objective forms an image of the sample onto the array, setting the field of view, the working distance and the achievable spatial resolution. Terahertz wavelengths are hundreds of micrometres to millimetres, so the diffraction limit is coarse compared with visible optics and the objective aperture is what determines whether you reach it.

Applications

Real-time terahertz imaging is used for non-destructive testing, security screening, moisture and layer-thickness mapping, and quality control on production lines. Terahertz radiation passes through paper, plastics, textiles and ceramics while being strongly attenuated by water and blocked by metals, so a straightforward transmission geometry reveals concealed structure and moisture distribution without ionising radiation.

Integration notes

Specify the object distance and the field of view you need, not just a focal length: in the terahertz band the two are tightly coupled and the sensible configuration depends on the camera format. The supplied adapter ring and bracket are designed to mate with microbolometer terahertz cameras, so state the camera model when ordering so the correct adapter is supplied.