![Wavelength
Frequency [Hz]
102 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 10 15 10 16 10 17 10 18
3000km 30km 300m 3m 3cm 0.3mm 3 mm 30nm 0.3nm
NF
range
HF
range
Microwaves
range
Optical
range
X / gamma
range](https://image.slidesharecdn.com/7597f48d-2db1-49f6-8570-b66ea7122980-160602104807/85/introduction-to-fibre-12-320.jpg)
![Wavelengths of light used (l)
• Wavelength is defined as the
distance between the one point of the
wave and the next corresponding
point on the wave.
• For multimode the main wavelengths
used are 850 nm (first window) and
1300 nm (second window).
• For singlemode the main
wavelengths used are 1310 nm
(second window) and 1550 nm (third
window).
• 1 nm is equivalent to 0.000001 mm
1 wavelength
Wavelength
Frequency [Hz]
102 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 10 15 10 16 10 17 10 18
3000km 30km 300m 3m 3cm 0.3mm 3 mm 30nm 0.3nm
NF
range
HF
range
Microwaves
range
Optical
range
X / gamma
range](https://image.slidesharecdn.com/7597f48d-2db1-49f6-8570-b66ea7122980-160602104807/85/introduction-to-fibre-13-320.jpg)
introduction to fibre
- 1. Introduction to optical fibres
- 2. Why use optical fibre? Advantages • Higher bandwidth than copper • Smaller, lighter than copper • Does not suffer from electromagnetic interference • Long distance communication • Intrinsically safe Disadvantages • Cannot carry power • Cost of equipment (test, termination and transmission) • Highly skilled to install optical fibre
- 3. History of optical fibres • 1870 John Tyndall showed that light could be guided in a thin stream of water. • 1960 introduction of lasers 1962 introduction of semiconductor lasers. • 1970 introduction of glass that gives loss of 20 dB/km giving low enough loss for communications.
- 4. Light guiding within an optical fibre
- 5. Refractive index materialinlightofspeed airinlightofspeed v c n reflectioninternalfor totalc 5.1 102 103 18 18 msx msx v c Glass n = 1.5 Air n =1 Glass n = 1.5 Air n = 1
- 6. Overview of a simple optical network Transmitter Patch panel Patch panel Receiver Backbone cable Media converter Attenuator Patch cable Pigtail Coupler or WDM
- 7. Types of optical fibre
- 8. 62.5/125 mm Optical fibre • Known as OM1 • Optical Multimode 1 • Core of optical fibre has diameter of 62.5 mm (0.00625 cm) • Cladding of optical fibre has diameter of 125 mm (0.0125 cm)
- 9. 50/125 mm Optical fibre • Either OM2 or OM3 • Optical Multimode 2 or Optical Multimode 3-laser enhanced • Core of optical fibre has diameter of 50 mm (0.005 cm) • Cladding of optical fibre has diameter of 125 mm (0.0125 cm)
- 10. 9/125 mm Optical fibre • Known as OS1 • Optical Single-mode 1 • Core of optical fibre has diameter of 9mm (0.0009 cm) • Cladding of optical fibre has diameter of 125 mm (0.0125 cm)
- 11. Difference between multimode and single mode optical fibre • Multimode fibre; light can take many paths down the core of the optical fibre e.g. m0, m1, m2 etc • This is due to the large size of the optical core either 50 or 62.5 mm. • Singlemode fibre; light can only take one path down the core of the optical fibre. • This is due to the small size of the optical core of 9 mm. Cladding Core Cladding Core Cladding Cladding m0 m1 m2 m0
- 12. Wavelength Frequency [Hz] 102 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 10 15 10 16 10 17 10 18 3000km 30km 300m 3m 3cm 0.3mm 3 mm 30nm 0.3nm NF range HF range Microwaves range Optical range X / gamma range
- 13. Wavelengths of light used (l) • Wavelength is defined as the distance between the one point of the wave and the next corresponding point on the wave. • For multimode the main wavelengths used are 850 nm (first window) and 1300 nm (second window). • For singlemode the main wavelengths used are 1310 nm (second window) and 1550 nm (third window). • 1 nm is equivalent to 0.000001 mm 1 wavelength Wavelength Frequency [Hz] 102 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 10 15 10 16 10 17 10 18 3000km 30km 300m 3m 3cm 0.3mm 3 mm 30nm 0.3nm NF range HF range Microwaves range Optical range X / gamma range