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THÔNG TIN TÀI LIỆU
Cấu trúc
PowerPoint Presentation
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Advantages of Fiber Optics
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Electromagnetic Spectrum
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Light Properties
Refractive Index
Snell and Fresnel
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Total Internal Reflection
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Fiber Optic
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Fiber Fabrication
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Fiber Types
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Measurement Units
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Reflectance (-dB)
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Optical Return Loss (ORL) (dB)
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Measurement Units dB/Km
Attenuation (dB/Km)
Intrinsic Absorption in Optical Fiber
Scattering
Macrobendings
Microbendings
Discontinuities the IOR Reflectance
Fusion Splicing
Fusion Splice
Mechanical Splice
Loss
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LED, LASER AND VCSEL
Launching Conditions in MM Fibers: LED vs VCSEL
Optical Fibers and Sources Different Sources for Different Needs
Optical Fibers and Power Meters Power Meters Can Measure MM and SM
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Connectors
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Connector Typical Specifications
Bulkhead Adaptors
Connector Cleaning & Inspection
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Nội dung
Introduction to Optical Fiber Công ngh s i quang, ph ki n u n iệ ợ ụ ệ đấ ố S u t m: Phan van Tueư ầ 1. Principles 2. Fiber Basics 3. Measurement Units 4. Sources and Power meters 5. Connector Types 6. Cleaning and Inspection PRINCIPLES ADVANTAGES OF FIBER OPTICS Noise immunity Electromagnetic interferences (EMI) or radio frequency interferences (RFI) have no influence on transmission. Low-loss attenuation Singlemode loss as low as 0.2 dB/km (≅4.5%) Multimode loss around 1 dB/km (≅30%) High bandwidth Transmission rates going up to 40 Gb/s (OC-768) ADVANTAGES OF FIBER OPTICS Small size A fiber is the size of human hair (125 µm). A cable containing 12 pairs of optical fiber, 1.4 cm in diameter, is equivalent to a cable containing 900 pairs of copper wire that has an 8 cm diameter. Light weight Copper cable 900 pairs ⇒ 8000 kg/km Optic fiber cable 12 pairs ⇒ 88 kg/km ADVANTAGES OF FIBER OPTICS Transmission security No energy radiation ⇒ no detection, hard to find Intrusion on the link creates loss ⇒ intruders will be detected. Short-circuit free/no fire hazard No electrical energy inside the fiber, therefore no risk of short circuit, no sparks, and no heat. Ideal for hazardous environments. Environmental temperature Fiber can operate in a wide temperature range ( -40 o C/100 o C). ELECTROMAGNETIC SPECTRUM Speed of light in a vacuum=299 792 458 m/s Wavelength=Speed of light / Frequency λ (nm)=c (m/s) / f (Hz) 10 9 10 10 10 11 10 12 10 13 10 14 10 15 10 6 10 7 10 8 10 16 10 17 10 18 10 19 10 20 10 21 Frequency (Hz) 10 -1 10 -2 10 -3 10 -4 10 -5 10 -6 10 -7 100 10 1 10 -8 10 -9 10 -10 10 -11 10 -12 10 -13 Wavelength (m) Infrared Ultraviolet Visible Light ELECTROMAGNETIC SPECTRUM Optical fiber domain 850 nm ⇒ 353 000 GHz 1650 nm ⇒ 182 000 GHz Units Micrometers (µm) - 10 -6 m Nanometers (nm) - 10 -9 m Mega - 10 6 Giga - 10 9 Tera - 10 12 Peta - 10 15 Pico - 10 -12 LIGHT PROPERTIES The light consists of Electric Field - E Magnetic Field - H Traveling in time (t) along the axis of propagation (Z) Electric field Magnetic field Y X Z Y X 90 o REFRACTIVE INDEX The speed of light = c = 299793 km/s under vacuum Each material that can transmit light has it’s own index of refraction represented by n Example n = c vac / c mat In a given index of refraction, the speed of light gets slower Speed of light in water ≈ 225 000 km/s Speed of light in fiber optic ≈ 215 300 km/s Index (n) 1.000 1.400 1.333 Material Air Fiber Optic Water . Introduction to Optical Fiber Công ngh s i quang, ph ki n u n iệ ợ ụ ệ đấ ố S u t m: Phan van Tueư ầ 1. Principles 2. Fiber Basics 3.