Background-free collinear autocorrelation and frequency-resolved optical gating using mode multiplexing and demultiplexing in aperiodically poled lithium niobate waveguides

Abstract

We use mode multiplexing and demultiplexing in apodized aperiodically poled lithium niobate waveguides to enable characterization of picosecond optical pulses in a collinear but background-free way using autocorrelation and second-harmonic frequency-resolved optical gating.

Attosecond‐precision ultrafast photonics

“…The major limitation in resolution comes from the limited conversion efficiency in the cross correlator. Improvement of the cross-correlation efficiency is possible by using periodically poled waveguide devices, such as aperiodically poled LiNbO 3 waveguides [45] or PPKTP waveguides [46]. Although the demonstration experiment is based on the Er-fiber lasers and a PPKTP cross correlator at 1550 nm, the optical crosscorrelation-based timing jitter measurement techniques are more generally applicable to other laser systems and wavelengths by using appropriate nonlinear crystals and timedelay elements.…”

Ultralow-power second-harmonic generation frequency-resolved optical gating using aperiodically poled lithium niobate waveguides [Invited]

“…This improved sensitivity allowed highquality pulse measurements at nanowatt to tens of nanowatt average power of subpicosecond pulses with a 50 MHz repetition rate. Additionally, some of us have designed and demonstrated asymmetric Y-junction A-PPLN waveguides that result in a background-free SHG FROG setup [21] (in contrast to most of the measurements reported here, in which a background must be removed by software).…”