The frontiers in ultrafast intense laser science are rapidly expanding thanks to the progress in ultrashort and high-power laser technologies, and the interd- ciplinary nature of this research ?eld is attracting researchers with di?erent expertise and backgrounds. As in the ?rst two volumes of PUILS, each chapter in the present volume, whose page length is in the range of 15 to 25 pages, begins with an int- duction in which clear and concise accounts of the signi?cance of the topics is described, followed by a description of the authors most recent research results. All chapters are peer-reviewed. The articles of this third volume cover a diverse range of the interdisciplinary research ?eld, and the topics may be grouped in ?ve categories: strong ?eld ionization of atoms (Chaps. 13), i- ization and fragmentation of molecules and clusters (Chaps. 48), generation of high-order harmonics and attosecond pulses (Chaps. 911), ?lamentation and laser plasma interaction (Chaps. 1214), and the development of ult- short and ultrahigh-intensity light sources (Chap. 15). The PUILS series has been edited in liaison with the activities of the MEXT Priority Area Program on Control of Molecules in Intense Laser Fields (FY20022005), the JSPS Core-to-Core Program on Ultrafast Intense Laser Science (FY2004), and JILS (Japan Intense Light Field Science Society). Starting with the present volume, JILS has become a sponsor organization for the PUILS series, taking on responsibility for its regular publication.

Foundations of the Strong-Field Approximation.- Trajectory Description of Ionization Processes in Strong Optical Fields.- Many Electron Ionization Processes in Strong and Ultrastrong Fields.- Molecular Rearrangements in Intense Laser Fields.- Optical Control of Chiral Molecular Motors.- Non-Coulomb Explosions of Molecules in Intense Laser Fields.- Excitation, Fragmentation and Control of Large Finite Systems: C60 in Moderately Strong Laser Fields.- Theoretical Description of Rare-Gas Clusters Under Intense Laser Pulses.- Molecular High Order Harmonic Generation.- Nonlinear Multiphoton Process in the XUV Region and its Application to Autocorrelation Measurement.- Controlling Light Polarization for Attosecond Pulse Generation.- Some Fundamental Concepts of Femtosecond Laser Filamentation.- The Transport of Relativistic, Laser-Produced Electrons in Matter Part 1.- The Transport of Relativistic, Laser-Produced Electrons in Matter Part 2.- Ultrafast, Ultrahigh Intensity Lasers: Challenges and Perspectives.