Self-calibrating d-scan: measuring ultrashort laser pulses on-target using an arbitrary pulse compressor

TL;DR

The paper introduces a self-calibrating d-scan method that enables complete measurement of ultrashort laser pulses of any duration directly on-target, using existing pulse compressors without additional calibration.

Contribution

It extends the d-scan technique to arbitrary pulse durations and integrates pulse compression and measurement using standard CPA system components.

Findings

Successfully measured 27.5 fs pulses from a CPA laser.

Demonstrated the method's effectiveness through simulations and experiments.

Calibrated the compressor's differential dispersion without extra diagnostics.

Abstract

In most applications of ultrashort pulse lasers, temporal compressors are used to achieve a desired pulse duration in a target or sample, and precise temporal characterization is important. The dispersion-scan (d-scan) pulse characterization technique usually involves using glass wedges to impart variable, well-defined amounts of dispersion to the pulses, while measuring the spectrum of a nonlinear signal produced by those pulses. This works very well for broadband few-cycle pulses, but longer, narrower bandwidth pulses are much more difficult to measure this way. Here we demonstrate the concept of self-calibrating d-scan, which extends the applicability of the d-scan technique to pulses of arbitrary duration, enabling their complete measurement without prior knowledge of the introduced dispersion. In particular, we show that the pulse compressors already employed in chirped pulse amplification (CPA) systems can be used to simultaneously compress and measure the temporal profile of the output pulses on-target in a simple way, without the need of additional diagnostics or calibrations, while at the same time calibrating the often-unknown differential dispersion of the compressor itself. We demonstrate the technique through simulations and experiments under known conditions. Finally, we apply it to the measurement and compression of 27.5 fs pulses from a CPA laser.