Photoelectron momentum spectroscopy with near-single-cycle Yb lasers

Intense few-cycle or near-single-cycle light pulses generated by Ti:Sa lasers have revolutionized ultrafast science, enabling temporal resolution on the attosecond timescale. Recently, industrial-grade Yb lasers have gained increasing popularity due to their exceptional stability and high average power. In this work, we present an experimental investigation of the photoelectron momentum distributions from various atomic and molecular targets ionized by intense, carrier-envelope phase (CEP) stabilized sub-4 femtosecond pulses from a Yb laser. Our results demonstrate that the spatial asymmetry of photoelectron emission can approach nearly 100%, and the total ionization probability exhibits strong CEP sensitivity with a periodicity of π. Furthermore, our study benchmarks the pulse duration and contrast of Yb lasers using the field-resolved TIPTOE technique.