Lobre produces optical prisms whose top quality is especially appreciated by clients. These are optical instruments created from a glass block or other transparent triangular prism material, used to observe the phenomenon of light refraction.
The two most common models of optical prisms have an angular opening of 60° and 45° respectively. When a beam of white light crosses the prism at a 60 ° angle, the different colours that make it are refracted in different directions, so that a succession of coloured strips, the spectrum, is observed at the outlet.
This phenomenon is known as dispersion and is due to the feature for which different light components (the colours), which are nothing more than electromagnetic waves of different wavelengths, behave differently when passing through the glass.
Experiments conducted on the optical prisms by the English scientist, Isaac Newton, led him to conclude that light coming from the Sun is comprised of all the colours in the spectrum, as seen in a rainbow.
The angle at which a ray of light leaves the optical prisms after undergoing double refraction depends on the angle of incidence; by choosing the latter value you can ensure that the light beam, passing from glass to air, forms an angle with the second face of the prism below a certain value, known as the critical angle.
In this case we can observe the phenomenon of total reflection: the prism works like an extremely efficient mirror.