Published: | By: Ira Winkler
The biennial UFO conference brings together leading researchers in the field of ultrashort laser pulses - light flashes lasting only femtoseconds or even attoseconds - used to probe and control matter on its most fundamental timescales.
In his presentation titled “Ångström-scale surface metrology enabled by a compact milliwatt-class HHG source”, Penagos Molina demonstrated how precise surface measurements at the ångström scale can be achieved with a compact extreme ultraviolet (XUV) source based on high-harmonic generation (HHG). To understand the precision achieved, it helps to consider the scales involved: one Ångström (1 Å) equals 10-10 metres, that is, one ten-billionth of a metre -roughly the diameter of a single atom.
Using a tabletop laser system, surface areas of tens of micrometers were mapped with sub-100-nanometer lateral resolution and a height precision better than 4 Å, reaching an unprecedented vertical-to-lateral precision ratio of about 1 in 100,000. The HHG source operated at 46 nm wavelength, powered by 20 fs (10-15 seconds) laser pulses and achieved a measurement throughput of up to 20 Mpix per hour - currently the highest rate reported for ptychographic imaging on a compact experimental platform. Ptychographic imaging (or ptychography) is an advanced lensless imaging technique that reconstructs high-resolution images from diffraction patterns rather than direct optical images. So, it avoids distortions or aberrations caused by imperfect optical components. This makes it ideal for nanometre- and even atomic-scale imaging, particularly in X-ray and extreme-ultraviolet microscopy.
“The UFO conference has always been an inspiring place to share ideas and push the limits of what we can do with ultrafast light,” says Daniel Santiago Penagos Molina. “I was really honored and thankful for the award. I tend to spend quite a bit of time on my slides and figures -sometimes probably too much - but it was great to see that the effort helped make my talk clear and well-received. Hopefully, I can bring that same clarity to my dissertation!”
With this recognition, the Ultrafast and X-ray Sciences community highlights the contribution of young researchers from Jena toward advancing compact coherent XUV light sources and precision optical metrology.