In this paper, we review recent advances in the generation of ultrabroadband and ultrafast infrared laser sources with high brightness, broad spectral bandwidth, and stable carrier-envelope phase (CEP). We discuss cutting-edge technologies for producing these infrared pulses, including optical parametric amplifiers, nonlinear frequency conversion techniques, and efficient pulse-compression schemes for a variety of laser platforms. The review highlights how ongoing improvements in pulse energy, phase stability, and wavelength tunability are enabling experiments in new regimes, particularly in the mid-infrared range, where strong-field interactions become increasingly efficient, opening new opportunities for attosecond science, high-harmonic generation, and ultrafast spectroscopy.

We are pleased to welcome Dr. Martin Kretschmar, who has recently joined our group as a postdoctoral researcher. His work will focus on developing a bright soft X-ray light source using high-harmonic generation, as well as on producing near-single-cycle pulses for time-resolved spectroscopy.

We have developed a compact and efficient method for generating high-energy ultrashort pulses in the short- to mid-wave infrared. Such light sources are essential for many experiments in strong-field physics, attoscience, and advanced spectroscopy, but producing suitable high-energy seed pulses for parametric amplification remains a major challenge.

In collaboration with the Attosecond and Ultrafast Optics group of Prof. Dr. Jens Biegert at ICFO, we investigate how ultrashort and broadband mid-infrared (mid-IR) optical pulses are reshaped as they propagate through ambient air. Although all optical pulses experience dispersion and absorption during propagation, these effects become particularly pronounced in the mid-IR spectral region. This is due to the significantly stronger oscillator strengths of atmospheric molecules compared to those in the visible or near-infrared. As a consequence, even propagation over relatively short distances can substantially modify the temporal structure of broadband mid-IR pulses.