Efficient and Continuous Carrier-Envelope Phase Control for Terahertz Lightwave-Driven Scanning Probe Microscopy.

The fundamental understanding of quantum dynamics in advanced materials requires precise characterization at the limit of spatiotemporal resolution. Ultrafast scanning tunneling microscopy is a powerful tool combining the benefits of picosecond time resolution provided by single-cycle terahertz (THz) pulses and atomic spatial resolution of a scanning tunneling microscope (STM). For the selective excitation of localized electronic states, the transient field profile must be tailored to the energetic structure of the system.

Measurement of Temporal Coherence of Free Electrons by Time-Domain Electron Interferometry.

The temporal properties of an electron beam are decisive for modern ultrafast electron microscopy and for the quantum optics of the free electron in laser fields. Here, we report a time-domain interferometer that measures and distinguishes the pure and ensemble coherences of a free-electron beam in a transmission electron microscope via symmetry-breaking shifts of photon-order sideband peaks. This result is a free-electron analog to the reconstruction of attosecond busts and photoemission delays in optical attosecond spectroscopy.

Jitter-free terahertz pulses from LiNbO.

Intense terahertz pulses are indispensable for modern science and technology, but time-critical applications require ultimate stability of the field cycles with respect to a reference clock. Here we report the nonlinear optical generation of terahertz single-cycle fields by femtosecond laser pulses under passive compensation of timing jitter. The converter is based on optical rectification in a slab with two silicon prisms for extracting and combining the emitted Cherenkov radiation from both sides into a single beam.

Attosecond metrology in a continuous-beam transmission electron microscope.

Electron microscopy can visualize the structure of complex materials with atomic and subatomic resolution, but investigations of reaction dynamics and light-matter interaction call for time resolution as well, ideally on a level below the oscillation period of light. Here, we report the use of the optical cycles of a continuous-wave laser to bunch the electron beam inside a transmission electron microscope into electron pulses that are shorter than half a cycle of light. The pulses arrive at the target at almost the full average brightness of the electron source and in synchrony to the optical cycles, providing attosecond time resolution of spectroscopic features.

Tilted-pulse-front excitation of strong quasistatic precursors.

It was recently predicted [M. I. Bakunov, A.