Hello experts! I was taking class of optical fiber and communication. My teacher was teaching the class via projector and slides (transparencies). He taught us light models and he just changed his slide after reading the few lines. I was not able to note down the main points of the slides. The topic was models of light. 1) Ray model of light 2) Wave model of light 3) Quantum model of light My questions are: 1) explain these 3 models with definition 2) obviously we can't use any model everywhere, so where to use the specific model? How to know when to use which one? Thank you all.