In telecommunications, an optical buffer is a device that is capable of temporarily storing light.
Just as in the case of a regular buffer, it is a storage medium that enables compensation for a difference in time of occurrence of events.
[1] Today, computer networks consist of optical fiber links, interconnected by electrical nodes.
However, at the nodes, this light has to be converted to the electronic domain, in order to switch all data to their separate destinations.
Whenever two or more data packets arrive at a network node at the same time and contend for the same output, external blocking occurs.
Next to the obvious choice of dropping all excess packets, academic literature typically presents three solutions: buffering, deflection routing or wavelength conversion.