Time-to-space conversion of ultrafast waveforms at 1.55 μm in a planar periodically poled lithium niobate waveguide

We report the first demonstration, to our knowledge, of time-to-space conversion of subpicosecond pulses in a slab nonlinear waveguide. By vertically confining the nondegenerate sum-frequency generation interaction between a spatially dispersed 100 fs signal pulse at 1.55 μm and a reference pulse in a titanium indiffused planar periodically poled lithium niobate crystal waveguide, we have attained a conversion efficiency of 0.1% and a conversion efficiency slope of 4% per watt of reference beam power. This was achieved while maintaining high conversion resolution, with a measured time window of operation of 48 ps resulting in a serial-to-parallel demultiplexing factor of 90.