Slight confusion of optical fiber refraction

if there is no cladding, pulses of light will pass into any fibres adjacent in contact, within the fibre optic cable, which you do not want.

I don’t know if you have seen them before but these lamps are an example of when cladding is not needed. I also didn’t mention that the cladding stops scratches which would alter the angle of the normal and it is good for general protection aswell
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im assuming here that you know how to calculate the critical angle. Hope this makes sense as to why it’s ‘better’ with cladding. Lmk if it doesn’t

give me a second on the other question

another thought…

so on the second question, I don’t see why a thinner core would help reduce pulse broadening. I’ve done some calculations here

Since pulse broadening is caused by variation in distance of paths that light takes and then this causes the signals to arrive at different times I calculated the distance that the light would travel in the core at a given angle. Nowhere in my calculations does the diameter x become significant in determining this so it seems like there would be just as large variation in path difference for a thin core as a thick core resulting in just as significant pulse broadening. I am only an AS student so I might be missing something so if anyone else knows I am invested now too because I have come across the idea before that a thinner core reduces pulse broadening.

Also one thing, I looked at your profile, and we are doing the same A levels and are both in year 12, andd your predicted grades are amazing. Do you have any tips

so on the second question, I don’t see why a thinner core would help reduce pulse broadening. I’ve done some calculations here

Since pulse broadening is caused by variation in distance of paths that light takes and then this causes the signals to arrive at different times I calculated the distance that the light would travel in the core at a given angle. Nowhere in my calculations does the diameter x become significant in determining this so it seems like there would be just as large variation in path difference for a thin core as a thick core resulting in just as significant pulse broadening. I am only an AS student so I might be missing something so if anyone else knows I am invested now too because I have come across the idea before that a thinner core reduces pulse broadening.