Công nghệ sợi quang, phụ kiện đấu nối

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.