Wavelength Division Multiplexing (WDM) is a technology in fiber-optic communications that multiplexes multiple optical signals onto a single fiber using different wavelengths of laser light. There are two main types of WDM: Coarse Wavelength Division Multiplexing (CWDM) with fewer channels and Dense Wavelength Division Multiplexing (DWDM) with more closely spaced channels. The technology offers advantages such as reduced fiber requirements, increased redundancy, and the ability to manage and expand services efficiently.

1. Made by:
Nalin Dubey
B.Tech (ECE)
130020204016
WDM (Wavelength Division Multiplexing)

2. Definition
In fiber-optic communications, wavelength division
multiplexing (WDM) is a technology which multiplexes a
number of optical carrier signals onto a single optical fiber
by using different wavelengths (i.e., colors) of laser light.

3. A WDM system uses a multiplexer at the transmitter to join the several signals together, and a
demultiplexer at the receiver to split them apart. With the right type of fiber it is possible to
have a device that does both simultaneously, and can function as an optical add-drop
multiplexer.
WDM operating principle

4. Types of WDM
 CWDM(Coarse Wavelength Division Multiplexing)
 DWDM(Dense Wavelength Division Multiplexing)

5. DWDM
 More channels closely spaced together than WDM.
 These help in creation of low cost way to quickly
respond the customer bandwidth demands and
protocol changes.

6. CWDM
 Number of channel is fewer than in DWDM but more
than in standard WDM.
 Done by laser emission.

8. Advantages
 Allows multiple connection over one fiber thus
reducing fiber plant requirement.
 This can provide fiber redundancy.
 This provides a managed fiber service.
 Smooth Expansion
 Long Haul transmission
 Data Transparency

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