Pulse Duration Measurement using Nonlinear Detection in As2Se3 Chalcogenide Glass Fibre

In this work we build upon a methodology that employs time-averaged nonlinear detection to measure the duty cycle (and thus the pulse duration) of a signal under test (SUT). The technique employed TPA in silicon APDs, while in our technique the TPA in the chalcogenide fibre forms the basis of the nonlinear detection. Our technique has the key advantage of being fibre-based that allows for a long interaction length, and therefore more nonlinear absorption, which allows for greater sensitivity in the nonlinear detection measurements.