Standing-wave, velocity-matched gate

摘要

An ultrafast gate is produced by locally modulating the coupling along a pair of coupled wavepaths (11, 12) by means of a standing-wave electrical signal. By resolving the electrical signal into two, oppositely travelling waves propagating at the same velocity as the signal in the coupled wavepaths, it can be shown that the effect is to simulate an alternating DELTA beta coupler. It is further shown that side lobes in the output signal can be reduced by tapering the coupling along the coupling interval.