A 2mm-diameter Silicon hyper-hemispherical lens is attached to the facet of the device to collimate the terahertz output.
From the sciencedaily.com
The gluons interact with each other, not just with the quarks, and at long distances the lines of force collimate into strings.
From the en.wikipedia.org
To collimate is to bring into line.
From the newscientist.com
Normally this spread is overcome using lenses or curved mirrors to focus or collimate the light, but this typically involves meticulous optical alignment.
From the nature.com
More examples
Parallel: make or place parallel to something; "They paralleled the ditch to the highway"
Adjust the line of sight of (an optical instrument)
Collimated light is light whose rays are nearly parallel, and therefore will spread slowly as it propagates. The word is related to "colinear" and implies light that does not disperse with distance (ideally), or that will disperse minimally (in reality). ...
To focus into a narrow beam or column
(collimated) of light beams whose rays are parallel and thus has a plane wavefront
(collimation) the act of collimating or something collimated; aligning lenses along line of sight to minimize aberrations
(Collimated) The degree to which a laser beam is tightly focused and photons do not diverge from the intended beam path.
(Collimation) the process of adjusting the optical components of a telescope so they are aligned with each other.The process of aligning the optics within a telescope. ...
(Collimation) The alignment of the telescope's optics, either the alignment of the elens to the eyepiece in a refracting telesocpe, or the alignment of the mirror on a reflecting telescope, correct collimation is crucial to maximised performance, as incorrect collimation damages the sharpness ...