Tutorial on Ray Optics & Wave Optics

[Music] let's get started good morning welcome to the third session of introduction to photonics today's session is going to be slightly different in the sense that we we've dealt with a little bit of theory so far so let's try to work out some practical problems ok let's try to design something for example so we

already designed it endoscope earlier this week and so we can we can try to see if there are other things we could design based on the principles that we have learned so far so what did we learn so far we learnt to identify that there are different approaches to you know photonics the the science of light

essentially we said the basic approaches considering that light travels in straight lines which gives us ray optics and then what we have learnt in the last couple of lectures is the law that the ray optics has some limitations in terms of describing properties of light so especially when we have light encountering feature sizes which are

comparable to the wavelength of light we are having to invoke the wave property of light so the last lecture we saw how particular light wave can have a wave length can have face and based on those properties how can we explain certain physical events that are happening right the physical processes that are

happening and we took the example of Young's double slit experiment to show the process of interference constructive and destructive interference which obviously couldn't be described using just ray optics right so what we going to do today is take a couple of examples one related to just ray optics and another related to wave optics in line with the

kind of discussion that we have been having this week and let's see how we can work through that whether we have enough knowledge to work out problems like this okay so let me just take the first example example one is about dispersion in a prism okay so how do we get dispersion in a prism how do we so