Controlling Photon Echo in a Quantum-Dot Semiconductor Optical Amplifier Using Shaped Excitation

Storage and manipulation of quantum information requires (nearly) perfect timing---or precisely timed pulse sequences, anyhow. In quantum memory based on photon echoes, for example, the appearance time of the echo must be determined with great accuracy. This study shows how to control photon echoes in a quantum-dot optical amplifier operating at room temperature. As the amplifier is a distributed device, propagation effects are dominant in the generation of the echo pulse, and shaping the excitation pulse serves to control the echo's appearance time and strength.