Efficient instantaneous optical switching, frequency conversion and simple logic operations on a femtosecond time scale

摘要

Interference upon temporal overlap of two ultrashort pulse laser beams (80-100 fs) in a wide bandgap material (BaF_2) instantaneously creates an index grating via the optical Kerr effect. This grating causes the diffraction both of the generating beams as well as of further incident beams with an overall efficiency of >23%. Strong third harmonic generation is observed with an efficiency of up to ～ 3% due to an automatic self phase-matching process. The introduction of a third beam leads to a diffraction pattern simulating digital logic gates (e.g. decoder, demultiplexer, AND-and OR-logic), demonstrating the possibility of simple logic operations on a femtosecond time scale.