Laser-assisted resonance energy transfer
On input of a laser beam (of adequate intensity) the transfer rate of resonance energy transfer may be altered - this mechanism is known as laser-assisted resonance energy transfer.
Its Feynman diagram is shown on the left:
- Region I (before interaction i) - the right and left molecules are excited (red) and unexcited (blue), respectively
- Region II (between i and j) - a laser photon is absorbed by the right molecule and it moves into an intermediate state (green)
- Region III (between j and k) - a photon is emitted by the right molecule and it moves into the unexcited state (blue)
- Region IV (between k and l) - this photon is absorbed by the left molecule and it moves into an intermediate state (green)
- Region V (after l) - a laser photon is stimulated from the left molecule and it moves into an excited state (red)
All-optical switching is the ability of light to control light, circumventing the bottlenecks resulting from conversion of an optical signal into an electronic signal within applications such as routers.
As a result, all-optical switching has the capacity to greatly increase the speeds of telecommunication and computing systems. Our proposed all-optical switch is based on laser-assisted resonance energy transfer and is illustrated on the right.
In certain configurations RET is excluded, but may be reactivated on the input of the laser - i.e. the basis for an all-optical switch:
- Left-hand side: the initially excited molecule (red dot) will not transfer energy to the unexcited molecule (green dot) below it.
- Right-hand side: the presence of the laser beam (green arrow) activates the energy / photon transfer.