Fiber types and Fiber modes MOAATH ALAAMRI 113

Fiber types and Fiber modes MOAATH AL-AAMRI 113 ICT-TE-7 B Class: 8. 245 16/03/2014

Overview: • • • 2 Introduction. Optical Fiber modes. Optical Fiber types. Step-index Fiber. Graded-index Fiber. Differences Between Step-index and Graded-index. Single mode. Multimode. Differences between Single mode and Multimode. AVP-3 2/2/2022

Introduction • What do you think the Optical Fiber made of? 1. Glass (Glass Optical Fiber). 2. Plastic (Plastic Optical Fiber). 3. Both !!! (The core made of glass, and the cladding made of Plastic) 3 AVP-3 2/2/2022

Optical Fiber modes • There are two modes of Optical fiber cables: 1. Single mode 2. Multimode 4 AVP-3 2/2/2022

hysical differences between Single mode and multimode 5 AVP-3 2/2/2022

Fiber Modes • What mode means ? • The light that propagates through the fiber optic in the form of fixed number of (Beams or Rays). • These different beams or rays called (propagation mode) Single mode Multimode propagates one mode 6 propagates (1 -100) AVP-3 2/2/2022

Optical Fiber types • The Optical Fiber cable divided into two types according to the refractive index: 1. step-index 2. Graded-index 7 AVP-3 2/2/2022

Step-index Fiber • Ease of designed and manufacturing. • The step-index fiber has an uniform refractive index which means the light paths travel at the same speed whatever they are propagated at the fiber’s core or edge. • It travels in the form of straight lines. 8 AVP-3 2/2/2022

Step-index Fiber fiber guides light by the TIR phenomena. What is TIR ? 9 AVP-3 2/2/2022

Graded-index Fiber • The most important characteristic in graded-index fiber is the refractive index of the core is non-uniform which mean it is changing gradually from maximum at the center to a minimum near the edge. 10 AVP-3 2/2/2022

Graded-index Fiber • In particular the light propagates in the core and takes its paths in form of curved lines. 11 AVP-3 2/2/2022

Differences between step index fibres and graded index fibres 12 Step Index Fibre Graded Index Fibre Refractive index Light behave (Propagation) Signal distortion Attenuation AVP-3 2/2/2022

Fiber modes and Fiber types 13 AVP-3 2/2/2022

Single mode • used for long distances and outdoor applications. 14 AVP-3 2/2/2022

Single mode • Performance in terms of bandwidth and attenuation, • Its small core diameter allows almost one mode only to pass through it • Eliminating modal dispersion completely, and when using the right dispersion compensation, it can carry rates up to 100 Gbps! 15 AVP-3 2/2/2022

Multimode (Step-index) • Step-index multimode has higher attenuation and is too slow for many uses. • Dispersion caused by the different path lengths of the various modes travelling in the core. • Core diameter (50 to 200 μm) 16 AVP-3 2/2/2022

Multimode (Graded-index) • Graded-index multimode with no reflection. • It behaves as sinusoidal signal. • Takes shorter paths through the fiber core to the destination, that`s why graded-index fiber can carry light for greater distances than step-index. • Core diameter (50 to 200 μm) 17 AVP-3 2/2/2022

Differences between single mode fibres and multimode fibres 18 Single Mode Fibres Multimode Fibres Ray Propagation (No) Core Diameter Dispersion Signal transmission capacity Distance AVP-3 2/2/2022

Individual Work 19 AVP-3 2/2/2022

Review 20 AVP-3 2/2/2022

Thanks for Attention 21 AVP-3 2/2/2022