What is Wavelength Selective Switching ?
Wavelength selective switching (wss)
WSS stands for Wavelength Selective Switch.
WSS has become the central heart of modern DWDM reconfigurable Agile Optical Network (AOC).
WSS is a tool which is used to dynamically route, block and attenuate all DWDM wavelengths within a network node.
This Following Figure Shows WSS Functionality
This figure shows that a WSS consists of a single common optical port and N opposing multi-wavelength ports where each DWDM wavelength input from the common port can be switched (routed) to any one of the N multi-wavelength ports, independent of how all other wavelength channels are routed.
This wavelength switching (routing) process can be dynamically changed through a electronic communication control interface on the WSS. So in essence, WSS switches DWDM channels or wavelengths.
How Does WSS Work ?
A. 1X2 Configuration
This figure shows that a WSS consists of a single common optical port and N opposing multi-wavelength ports where each DWDM wavelength input from the common port can be switched (routed) to any one of the N multi-wavelength ports, independent of how all other wavelength channels are routed.
This wavelength switching (routing) process can be dynamically changed through a electronic communication control interface on the WSS. So in essence, WSS switches DWDM channels or wavelengths.
B. 1XN Wavelegth Selective Switch
The 1XN switch can be considered as a generalization of the 1×2 switch. Because every wavelength in the 1XN switch can be switched to any one of the N output ports, this switch can be used in a fully flexible OADM (Optical Add Drop Multiplexer) with multiple add/drop fiber ports, each of which carries single or multiple wavelengths.
1XN switches can be cascaded to form larger architectures, and NxN wavelength selective matrix can be built by interconnecting back-to-back 1XN switches.
In the 1xN switch design, it uses an additional lens in Fourier transform configuration to perform a space to angle conversion in the first stage of the switch. Also the 1xN switch will require tilt mirrors with N different tilt angles. These are usually implemented as analog mirrors.
Optical Design of The 1xN WSS
Here is how the design works.
- The common input fiber enters the switch at point A where light is collimated by a microlens.
- The following lens image the collimated beam on the diffraction grating at point C.
- The wavelength dispersed beams fall then onto the MEMS device plane D
- On MEMS device plane D, the beams are reflected with certain tilt angle depending on micromirrors’ setting.
- All reflected beams are focused on point B again, where the angle to space conversion section will image the beam on the output fiber. Each output corresponds to a specific tilt angle of the micromirrors.
GROUP 15
Phaksi Ghagono Awang Murti (1101154124)
I Gede Aditya Pratama (1101154215)
Wildan Maulani (1101154358)
Leave a Reply