Optical communications
Chapter 2.1Chapter 2.1
Pham Quang Thai
[email protected]
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Content
• Geometrical optics
• Optical propagation in fiber
• Fiber fabrication
• Signal degradation in fiber• Signal degradation in fiber
• Types of fiber
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Think-pair-share
• Broken pencil?
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Think-pair-share
• Broken pencil?
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Think-pair-share
• Bending light
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Think-pair-share
• Guiding light
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Snell’s law
Willebrord van Royen Snell
1580 - 1626
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• Critical angle &
total internal
reflection
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Guiding light using total reflection
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Condition for light to travel inside a
fiber: n1>n2
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Condition for light to enter a fiber:
acceptance angle
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Examples for chapter 2.1
• Problems 2-11:
– Calculate the numerical aperture (NA) of a step
index fiber having n1=1.48 and n2=1.46. What is
the maximum entrance angle θ0max? (nair=1)the maximum entrance angle θ0max? (nair=1)
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