Pre-Chirp-Managed Adiabatic Soliton Compression in Pressure-Gradient Hollow-Core Fibers

Post-pulse-compression is demanded to produce energetic few-cycle pulses. We propose pre-chirp-managed adiabatic soliton compression (ASC) in gas-filled pressure-gradient hollow-core fibers to suppress the detrimental pedestals and therefore significantly improve the compressed pulse quality. We show that two-stage ASC can compress 125 μJ, 130 fs pulses at 2 μm to a nearly two-cycle pulse 15 fs in duration. Our analytical analysis suggests that ASC is in favor of compressing pulses centered at a longer wavelength. As an example, a 280 μJ, 220 fs Gaussian pulse at 4 μm is compressed to 60 fs with minimal pedestals. We expect that the resulting high-quality, energetic few-cycle pulses will find important applications in high-field science.

Wakefield acceleration

The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefields of relativistic amplitude with the high phase velocity robustly supported by the plasma. The structures of wakes and sheaths in plasma are contrasted. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ~ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. When the phase velocity gets smaller, wakefields turn into sheaths. When we deploy laser ion acceleration or high density LWFA in which the phase velocity of plasma excitation is low, we encounter the sheath dynamics. A large number of world-wide experiments show a rapid progress of this concept realization toward both the high energy accelerator prospect and broad applications. The strong interest in this has driven novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression (TFC), the Coherent Amplification Network, and the Relativistic Compression (RC). These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. Applications such as ion acceleration, X-ray free electron laser, electron and ion cancer therapy are discussed. A new avenue of LWFA using nanomaterials is also emerging, adopting X-ray laser using the above TFC and RC. Meanwhile, we find evidence that the Mother Nature spontaneously created wakefields that accelerate electrons and ions to very high energies.

Science of High Energy, Single-Cycled Lasers

With the advent of the Thin Film Compression, high energy single-cycled laser pulses have become an eminent path to the future of new high-field science. An existing CPA high power laser pulse such as a commercially available PW laser may be readily converted into a single-cycled laser pulse in the 10PW regime without losing much energy through the compression. We examine some of the scientific applications of this, such as laser ion accelerator called single-cycle laser acceleration (SCLA) and bow wake electron acceleration. Further, such a single-cycled laser pulse may be readily converted through relativistic compression into a single-cycled, X-ray laser pulse. We see that this is the quickest and very innovative way to ascend to the EW (exawatt) and zs (zeptosecond) science and technology. We suggest that such X-ray laser pulses have a broad and new horizon of applications. We have begun exploring the X-ray crystal (or nanostructured) wakefield accelerator and its broad and new applications into gamma rays. Here, we make a brief sketch of our survey of this vista of the new developments.

Extreme light infrastructure nuclear physics (ELI-NP)

ELI - Extreme Light Infrastructure, a project to build an international research infrastructure “dedicated to the investigation and applications of laser matter interaction at the highest intensity level” is one of the 35 projects in the first Roadmap, in 2006, of the European Strategy Forum on Research Infrastructures (ESFRI) [1]. “ELI will comprise three branches: ultra high field science that will explore laser matter interaction up to the nonlinear QED limit including the investigation of pair creation and vacuum structure; attosecond laser science designed to conduct temporal investigation at the attosecond scale of electron dynamics in atoms, molecules, plasmas, and solids; lastly, the highenergy beam facility devoted to the development of dedicated beam lines of ultra short pulses of high energy radiation and particles up to 100GeV for users.”