The use of femtosecond laser pulses (1 fs=10-15 s) with duration from the single- to the multi-cycle regime (≈3-100 fs), in various applications in research, industry or medicine demands a precise characterization and control of each laser pulse. The idea behind this proof of concept is a novel real-time characterization device for short laser pulses, based on SIngle-shot dispersion SCAN (SISCAN). The dispersion scan technique consists in recording the second harmonic spectrum, while a variable amount of dispersion is introduced to the pulses. From a recorded trace (i.e. second harmonic spectrum vs. dispersion), the intensity and phase of the pulses can be retrieved in an iterative numerical procedure. Our device allows furthermore the measurement of the intensity and the phase of individual laser pulses; hence the name “single-shot”. It provides real-time feedback essential to the adjustment and optimization of any femtosecond laser system.
In an effort to improve the control of light pulses required for our ERC-supported research, we developed two variants of a single-shot d-scan, i.e. one for single- and few-cycle pulses (3-10 fs) and one for longer pulses (15-70 fs). This allows the complete characterization of a femtosecond laser chain from the oscillator (generally few-cycle pulses) to amplifiers (often longer, multi-cycle pulses) as well as pulse post-compression stages (close to single-cycle).
In a collaboration between Lund University and the spinoff company Sphere Ultrafast Photonics, we developed prototypes of the two variants of the single-shot d-scan in order to prepare for commercial exploitation. The product portfolio of Sphere Ultrafast Photonics is now extended by two powerful products, addressing the complete characterization of laser chains from the oscillator to the experiment or application, with large potential for increased sales and market share. Through technical verification (Lund University) and business activities (Sphere Ultrafast Photonics), we demonstrated the functionality of the concept and the risks were assessed and minimized. Sphere Ultrafast Photonics is now preparing for the commercial exploitation of the two new products.
