Light as a carrier of information

The light, as we all know, is a very important mean of exploring the universe. The color of light we see gives us important data. From the very beginning, we can discriminate the things we see by their colours. 
The discussion about the origin and its structure has puzzled philosophers from the very beginning of history. Each of the early philosophers wrote their opinion about the nature of light. Only in the 17th century did the development of modern science put the discussion of this topic in a modern way with a mathematical theory. 
We know that things come in particles (the matter is made of these) and in waves (the sailors and the musicians know it well…), so we have to understand if the light is made of particles or waves.
Isaac Newton, from the existence of the rays and their linear paths, said that light is made of different particles of matter (one for each color), which are emitted from the matter.  The refraction is then explained by the forces that act on the particles of light during their transition through the separation surface of two media
Conversely, Christiaan Huygens wrote in its Traitè de la Lumiére (Treaty about the light) that light is made of waves which run in a very thin and special matter named ether, which is throughout the whole universe. The ether is an elastic medium made of very light particles of matter. This idea let him explain the properties of light (refraction, interference, diffraction, colors) in a very similar way to the well-known properties of sound. Like we can have from 
different wavelengths of the disturbance in the air/water/fluid, different sounds we have from the different wavelengths of the disturbance in the ether the different colors we can see. 
The success of the ondulatory theory of Huygens in explaining led the scientific community to adopt his theory and to put aside the corpuscular theory of light.
The development of the study of the electrical and magnetic phenomena led James Clerk Maxwell to understand that light is an electrical and magnetic phenomenon. The light, in his vision, is a wave that goes through the space carried by that thin substance called ether. 
At the beginning of the XX century, the physicists found that sometimes the light seems to interact with the matter in a continuous way as a wave, but in a discrete way as a particle or as a packet or quantum of energy. The photoelectric effect, the Compton effect, and the black body radiation are some of these phenomena. The explanation of these effects came from the development of quantum mechanics. 
The finding of the LASER (Light Amplification by Stimulated Emission of Radiation) effect is another consequence of Quantum Mechanics, which perhaps is the physical theory with the greatest success. 
This study aims to stimulate interest in a topic that lends itself well to a multidisciplinary approach in the field of STEM through the discovery of the basics of laser technology and to increase curiosity towards a topic whose research is at the forefront of research and has important implications in every field of modern life, including the well-being and health through diagnostics and surgical applications.

Exploring the generation and use of laser technology is enhanced through the Augmented Reality exercise “Laser Technology and Medical Applications”, developed using Delightex Studio – Spaces (Marker). This AR experience guides students through five interactive scenes: three-level atomic systems with population inversion, stimulated emission and photon amplification, optical cavity design with mirrors, and medical laser applications (CO2, Argon, Nd:YAG). Six integrated quizzes provide immediate feedback, allowing students to visualize invisible quantum processes and connect atomic physics to clinical practice.