Technical usage typically involves some sense of center or concentration such as:
physics — a point of convergence such as the point where light rays meet
geometry — a fixed reference point (as of a parabola)
geology — the point of origin of an earthquake
See a comprehensive dictionary for other less common meanings.
But it has a tight enough beam. Well-focused. You can aim it and make a three-inch circle of light on a wall a hundred meters off.
Maybe tear big chunks out of them by reflecting the planet’s own gravity back on itself, only from another direction, and focused down to a smaller point.
At the focal point of two beams, it sets up a field in which molecules can’t hold together anymore.
You can’t see through the shield to aim and focus the beams, but since the generator of the Ecstatic Shield is always in the exact center, it isn’t hard to figure it out.
One, two, four, seven of his fighters were blown away. It was all a gamble now, whether any of his ships would survive long enough to get in range. It would not take long, once they could focus on the planet’s surface.
There are no more uses of "focus" identified with this meaning, but check unspecified meaning below.
Show samples from other sources
The satellite dish focuses the signal into a relatively narrow beam.
The focus of a parabola is a fixed point on the interior of the parabola used in the formal definition of the curve.
a state where something has come into view or can be seen clearly
(Typically this is said of the appearance of an image or picture, but it can also be said of an issue or something else that get's attention; or of an understanding that become clear.)