Fast Echo Memory
To be competitive, future photonics technology is required to perform well at high speed. This is why finding ways of controlling and storing ultrashort, namely broadband, light pulses becomes crucial. In our work, see Phys. Rev. Lett. 113, 123602 (2014), we present a solution for this challenge. In nature, a chosen atom will only absorb photons with specific frequencies. However, the atomic absorption frequency can be shifted by another intense control laser. The key of our idea is using a control laser with longitudinally inhomogeneous intensity to alter the quantum behavior of an atomic medium. Under this action, different frequency components of a broadband light pulse can be absorbed and stored over a different slice of a medium. Furthermore, our results show that one can retrieve or even manipulate the stored ultrashort pulse by changing the phase or intensity of the control laser. This may pave the way towards ultrafast processing and high-performance photonic devices.
