Editor D. Meschede released the 23. Volume of the encyclopedia Gerthsen Physik.

Attosecond pulses of light could open electrons’ fast-paced world. Science writer Charles Petit gives insight into attosecond physics.

Researchers in Germany have set up a company to manufacture custom-made optics for ultrafast applications. Nadya Anscombe finds out about the company’s products and its plans for the future.

Breaking the 100 as barrier and making the first movie of electron motion are just two recent milestones achieved by European researchers. Nadya Anscombe talks to key players in the attosecond community to see what the future holds.

By carefully controlling the waveform of an ultrafast laser pulse and sending it through a jet of neon gas, briefly ionizing it, researchers at the Max-Planck-Institut für Quantenoptik (MPQ; Garching, Germany), the Ludwig-Maxmilians-Universitt (also in Garching), and the Lawrence Berkeley National Laboratory (Berkeley, CA) have created the shortest light pulse yet only 80 attoseconds (as) in duration. Such well-controlled photoionization will result in new science, for example by allowing direct observation of quantum-electronic correlations.

During attosecond-scale phenomena may enable electronics 100.000 times faster than todays devices.

Understanding the motions of electrons inside solids is the basis for future technological development in computing speed, ultrahigh-speed communications, and remote surgery, among other possibilities. Such advances depend on detection and measurement of the atomic-scale motion of electrons, which take mere attoseconds to travel from atom to atom in a solid.

Comprehensive knowledge of the dynamic behaviour of electrons in condensed-matter systems is pertinent to the development of many modern technologies, such as semiconductor and molecular electronics, optoelectronics, information processing and photovoltaics. Yet it remains challenging to probe electronic processes, many of which take place in the attosecond (1 as = 10^{-18} s) regime. In contrast, atomic motion occurs on the femtosecond (1 fs = 10^{-15}) timescale and has been mapped in solids in real time using femtosecond X-ray sources. Here we extend the attosecond techniques previously used to study isolated atoms in the gas phase to observe electron motion in condensed-matter systems and on surfaces in real time. We demonstrate our ability to obtain direct time-domain access to charge dynamics with attosecond resolution by probing photoelectron emission from single-crystal tungsten.

Electrons emit light, carry electric current, and bind atoms together to form molecules. Insight into and control of their atomic-scale motion are the key to understanding the functioning of biological systems, developing efficient sources of x-ray light, and speeding up electronics. Capturing and steering this electron motion require attosecond resolution and control, respectively (1 attosecond = 10^{-18} seconds). A recent revolution in technology has afforded these capabilities: Controlled light waves can steer electrons inside and around atoms, arking the birth of lightwave electronics. Isolated attosecond pulses, well reproduced and fully characterized, demonstrate the power of the new technology. Controlled few-cycle light waves and synchronized attosecond pulses constitute its key tools. We review the current state of lightwave electronics and highlight some future directions.

The dial on your kitchen scales spins when a virus lands. The clock on the wall has gone berserk, ticking every billionth of a billionth of a second. Your camera flashes so fast that it captures single molecules in freeze-frame. Prepare to enter attoworld, the ultra-small realm so foreign that no one quite knows whats going on. Hazel Muir zooms in.

The attophysics frontier is about to expand, thanks to the newly won ability to control the phase of amplified laser pulses.

The characteristic time constants of the relaxation dynamics of core-excited atoms have hitherto been inferred from the linewidths of electronic transitions measured by continuous-wave extreme ultraviolet or X-ray spectroscopy. Here we demonstrate that a laser-based sampling system, consisting of a few-femtosecond visible light pulse and a synchronized sub-femtosecond soft X-ray pulse, allows us to trace these dynamics directly in the time domain with attosecond resolution. We have measured a lifetime of 7.9^{+1.0}_{- 0,9} fs of M-shell vacancies of krypton in such a pumpprobe experiment.

In the world of ultrashort optical pulses, the femtosecond (fs) has been superseded by the attosecond (as, or 10^{-18} s). An international collaboration of ten scientists claims to have generated and detected isolated soft x-ray pulses of 650-as duration. Scientists at the Vienna University of Technology, Austria, along with others at the National Research Center (Ottawa, Canada) and the University of Bielefeld, Germany, have developed experimental tools and techniques that could enable attosecond-resolution spectroscopy of bound electron dynamics in atoms and molecules.

The rise time of intense radiation determines the maximum field strength atoms can be exposed to before their polarizability dramatically drops due to the detachment of an outer electron. Recent progress in ultrafast optics has allowed the generation of ultraintense light pulses comprising merely a few field oscillation cycles. The arising intensity gradient allows electrons to survive in their bound atomic state up to external field strengths many times higher than the binding Coulomb field and gives rise to ionization rates comparable to the light frequency, resulting in a significant extension of the frontiers of nonlinear optics and (nonrelativistic) high-field physics. Implications include the generation of coherent harmonic radiation up to kiloelectronvolt photon energies and control of the atomic dipole moment on a subfemtosecond time scale. This review presents the landmarks of the 30-odd-year evolution of ultrashort-pulse laser physics and technology culminating in the generation of intense few-cycle light pulses and discusses the impact of these pulses on high-field physics.

High-quality seed pulses from mirror-dispersion-controlled Ti:sapphire system allow chirped pulse amplification without a pulse stretcher.

Intense light pulses in the single-cycle regime have opened up new avenues in linear optics. These, along with expected impacts on other areas of science and technology, are discussed.

Quantum mechanics have been with us for over sixty years and has been thoroughly put through its paces both experimentally and theoretically. Yet physicists continue to be haunted by its strange implications virtual particles, antimatter, negative energy, Schrödingers cat. Now it appears there is something else to add to the list: light that travels faster than light.