Virtual perfect absorption through modulation of the radiative decay rate
Dimitrios L. Sounas
Abstract
Virtual perfect absorption was recently proposed as a way to trap electromagnetic pulses in lossless cavities by shaping the pulses in the form of exponentially increasing functions. Such an effect may be useful for energy storage and quantum information processing. One problem with this approach is that the exponentially increasing wave form cannot be sustained for a long time, imposing a limit on the maximum energy that can be captured. Here it is shown that this problem can be circumvented by slowly modulating the cavity's radiative decay rate in such a way that the leaking signal from the cavity and the reflected signal at the cavity's port are constantly opposite to each other. This approach allows maintaining zero reflection for the entire duration of the phenomenon for continuous-wave signals and enables trapping electromagnetic energy for significant amounts of time, limited by only the spectrum of the incident signal.