In the study of Geometric Optics, the concept of light says that it is a physical entity capable of sensitizing our eyes. Thus, we can say that it is through her that we see.
The light ray can be defined as the oriented line associated with the direction and direction of propagation of light.
So that we can have a good understanding of what is light front and light brush, let’s go to the following example. When we turn on a light bulb, it starts to emit light in all directions. Thus, if we take light as a wave, we can call the wavefront itself a light front, as shown in the figure below.
In this way, it is possible to call the region between the illuminated and non-illuminated part as a light front . In the same way, we can define light brush as a set of light rays.
It is possible to classify light rays as follows:
Divergent – light rays diverge from a point.
Convergent – light rays converge at a point.
Parallel – all light rays in the set are parallel to each other.