Differences

This shows you the differences between two versions of the page.

--- network:fiber-optics [2022/08/29 09:27] – [General information] mh
+++ network:fiber-optics [2022/08/31 11:02] – [Electromagnetic spectrum] mh
@@ Line 4: / Line 4: @@
 <WRAP round info>
-**The speed of light in free space is 3.10⁸m/s**
+**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.
@@ Line 13: / Line 13: @@
 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>