Differences

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--- network:fiber-optics [2022/07/18 10:49] – created mh
+++ network:fiber-optics [2024/02/22 10:11] (current) – [To Do on this page] mh
@@ Line 1: / Line 1: @@
 ====== Fiber Optics ======
-=== Advantages over copper connections  ===
+==== General information ====
+<WRAP round info>
+**The speed of light in free space is $c = 3.10⁸ (m/s)$**
+Fiber optics propagate light using the **[[https://en.wikipedia.org/wiki/Refraction|refractive index]]** of different materials.
+It is the ratio of the speed of light in free space to the speed of light in a given material.
+</WRAP>
+In fiber-optics, spectrum notation is generally stated in wavelength ($nm$) over frequency ($Hz$) because it is easier to use.
+<WRAP round tip>
+$\lambda=\frac{c}{f}$ and $f=\frac{c}{\lambda}$ where $\lambda$ is wavelength ($nm$) and $f$ is frequency ($Hz$) and $c$ is the speed of light (approx. 2.10⁸ m/s)
+**As wavelength increases, frequency decreases.**
+</WRAP>
+When discussing Dense Wavelength Division Multiplexing (DWDM), frequency is preferred, in $THz$
+==== Electromagnetic spectrum ====
+{{network:light_spectrum-cropped.png?1500}}
+<WRAP round tip>
+**Infra**-red and **Ultra**-violet are prefixed using **frequency** in mind :
+  *infrared has a lower frequency than the red in the visible spectrum (thus a higher wavelength)
+  * ultraviolets have a higher frequency than the edge of our visible spectrum (thus a lower wavelength)
+</WRAP>
+==== Advantages over copper connections  ====
   ***Extremely wide system bandwith :** With LEDs (5 ns response time) the bandwith is limited to about 100 MHz but with a laser light source data rates of 10 Gbps are possible on a single-mode fiber. By multiplexing, one can reach hundreds of Gbps.
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 Requires efficient optical connectors due to excessive loss that can occur at connection points.
+==== To Do on this page ====
+<WRAP round todo>
+Insert electromagnetic chart.
+Link to wikipedia page on light spectrum.
+</WRAP>