The cladding means that more people have access to the information as it is easier to send.ĭispersion occurs when information does not all arrive at the same time. Fibre optic cables are used for people to connect to the internet at very high speeds.
This is particularly useful in fibre optic cables. Introducing cladding can help to reduce the critical angle (see above equation). This means that light stays within the confines of the medium.įor total internal reflection to occur the angle that the light makes at the boundary must be at a critical angle:Ĭladding is used as an insulating material around the medium where total internal reflection is taking place to help the light totally internally reflect. Total internal reflection is a phenomena that occurs when a wave is completely reflected between boundaries of the same medium. N2 = refractive index of the second medium N1 = refractive index of the first medium Snell found a relation, something we now call Snell’s Law: The above relation is for when light enters into a medium, but what happens if it goes over a boundary between two different media? Remember this as students often forget this helpful pointer. The refractive index of air has a value of 1. The refractive index of a substance is given as: The refractive index of a substance is a ratio of the speeds of light in the different media. Second order: 33 For the same set up as in question 1, calculate the maximum number of diffracted patterns produced. Your answer should include: 16 / 33 Explanation: First order: 16
Calculate the angle of diffraction for the first two orders. When using a laser ensure you take care of the following: DiffractionĪ laser beam of wavelength 550 nm is directed at a diffraction grating with 500 lines per millimetre. Using lasers can be dangerous as they can damage ones eyes and using them safely is essential. Also notice how the intensity decreases as you move away from the central maximum. Notice that for white light the colours are splits, but there is a central part which remains white. To calculate the fringe spacing we use the following relationship:ĭ = Distance between the slits and the screen (m) The interference pattern recorded looks something like this: At some points there will constructive interference and at some points destructive interference. A screen at a given distance away will show the interference pattern. When light travels through a double slit, the waves diffract and start to interfere with each other.
REFLECTION REFRACTION DIFFRACTION INTERFERENCE PRACTICE HOW TO
This last diagram shows how to get monochromatic coherent light in order to put it through a double slit in order to see the interference patterns.
Refraction Diffraction & Interference Interference Electromagnetic Radiation & Quantum Phenomena.
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