Layer 1 - Fiber Optics
Fiber Optics uses light (visible and non-visble) to transmit communication signels
All Fiber optic cables are made up of sever important compmen
- Core: is ushally made up of very thin crystal clear glass or platic that allows light to pass through. Think of the core as a guide to help ensure the light passes through to the other side.
- Cladding: is ushally made up of ### which has a high index of refraction, meaning when light its the cladding at the right angle is it reflected (refracted) back into the core. Think of the cladding as bumpers on a bowling lane, making sure the light (bowling ball) stays inside the core, with as little loss as possible.
- Shielding, Buffer, Jackets: these are all names for protective shells that encased the cladding, many times there a multiple stands of fiber incased of several protective layers making 1 Fiber Optic cable with at time 100’s of fiber optic strands.
Single Mode and Multi-mode
| Single Mode Fiber (SMF) | Multi-Mode Fiber (MMF) |
|---|---|
| - Has a very narrow core only allowing a “single mode” of light to propagate, and goes longer distances. | - Has a wider core allow “multiple modes” of light to pass through and goes a shorter distances. |
| - Typically has a core of 8-10 microns | - OM1 has a core size of 62.5 mircons and often has a orange cable color. |
| - Often has a Yellow cable color | - OM2 has a core size of 50 mircos and a calbe |
| - OS1 SMF is used for indoor applications with OS2 used in long hual / outdoor ISP fiber applications. | - OM3 also has a core size of 50 mircos and the often has a Aqua colored cable. OM3 is “laser optimized” made to be used for 10 Gbps connectors. |
Light Soruces and Price
The reason there are differnet types of comes down to requirements. Differnt Optical transmitters used differnt lights sorces with different properites.
- LED light sorurces run at a wave length of 850nm (nano meters) LED light soruce diffuse light quickly and need a larger core to accept the light. This is why many MMF runs with LED light sources and at a wave length of 850nm.
- Laser light sources run at a wave length of about 1600nm
Fiber Connectors
- ST
- SC
- LC
Form Factors
-
GBIC
-
SPF
-
SPF+
-
Q40G
-
WDM