Mode-selective frequency up-conversion in a X~((2)) waveguide

摘要

We study sum-frequency generation (SFG) in a multimode PPKTP waveguide. We show that under proper quasi-phase-matching, it can support one of the two scenarios. In the first, a single pump mode up-converts several different signal modes to different SFG modes. In the second, several different pairs of signal and pump modes are converted to the same SFG mode. By adjusting the relative phases and magnitudes of the pump modes, any superposition of the corresponding signal modes can be selected for up-conversion without affecting other modes, which can be used for spatial-mode de-multiplexing in both classical and quantum communications.