Periodically intensity-modulated pulses by optical parametric amplification for multicycle tunable terahertz pulse generation

The superposition of signal and idler pulses in dual- chirped optical parametric amplification is proposed for the efficient generation of intensity-modulated pulses with periodic modulation. Both the duration and the modulation period are easily and independently adjustable. Numerical simulations for a three-stage optical parametric amplifier system predicted an efficiency as high as ~50% for about 40 mJ of output pulse energy at a wavelength of 2 μm. Sources of such intensity-modulated pulses near 1.6 μm or 2 μm wavelength, pumped by Ti:sapphire or Yb-doped lasers, can be ideally suited for intense multicycle THz pulse generation with tunable frequency and bandwidth by optical rectification for example in organic, semiconductor, or lithium niobate materials

Single-cycle attosecond pulses by Thomson backscattering of terahertz pulses

The generation of single-cycle attosecond pulses based on Thomson scattering of terahertz (THz) pulses is proposed. In the scheme, a high-quality relativistic electron beam, produced by a laser-plasma wakefield accelerator, is sent through suitable magnetic devices to produce ultrathin electron layers for coherent Thomson backscattering of intense THz pulses. According to numerical simulations, single-cycle attosecond pulse generation is possible with up to 1 nJ energy. The waveform of the attosecond pulses closely resembles that of the THz pulses. This allows for flexible waveform control of attosecond pulses

Intense ultrashort terahertz pulses: generation and applications

TOPICAL REVIEW: Ultrashort terahertz pulses derived from femtosecond table-top sources have become a valuable tool for time-resolved spectroscopy during the last two decades. Until recently, the pulse energies and field strengths of these pulses have been generally too low to allow for the use as pump pulses or the study of nonlinear effects in the terahertz range. In this review article we will describe methods of generation of intense single cycle terahertz pulses with emphasis on optical rectification using the tilted-pulse-front pumping technique. We will also discuss some applications of these intense pulses in the emerging field of nonlinear terahertz spectroscopy