electromagnetic waves

Using a system that can compare the travel times of two photons with sub-femtosecond precision, scientists have found a remarkably large difference in the time it takes photons to pass through nearly identical stacks of materials with different arrangements of refractive layers.

The technique could provide an empirical answer to a long-standing puzzle over how fast light crosses narrow gaps that do not permit the passage of conventional electromagnetic waves.

Using a system that can compare the travel times of two photons with sub-femtosecond precision, scientists at the Joint Quantum Institute and Georgetown University have found a remarkably large difference in the time it takes photons to pass through nearly identical stacks of materials with different arrangements of refractive layers.

The technique could provide an empirical answer to a long-standing puzzle over how fast light crosses narrow gaps that do not permit the passage of conventional electromagnetic waves.