Ultrafast and nonlinear quantum optics

The scope of applications that require intense and ultrafast terahertz (THz) fields has been increasing during the last years. Applications such as THz time-domain spectroscopy, the study of carrier dynamics in semiconductors, electric field gating of interlayer charge transport in superconductors, or THz-assisted attosecond pulse generation benefit from higher pulse energies than currently available, and so there is keen interest in scaling the peak power of the THz generation schemes. More recently, high peak power THz sources have been proposed for charged particle acceleration, undulation, deflection, and spatiotemporal arbitrary manipulation.

Relevant publications in this area:

The generation and propagation of ultra-intense laser light at a variety of wavelengths with relativistic intensities can unfold new horizons in the nonlinear optical regime, where laser–matter interactions are dominated by the relativistic motion of electrons. Optical waveforms at sub-optical-cycle timescale enable fully controlled manipulation of electron dynamics in chemical and atomic processes. Only coherent sources generating ultrafast pulses can achieve such control.

There are key applications that continue to drive the development of ultrafast laser sources. A major advantage of using ultrashort pulses is that their short time duration allows fast temporal characterization of physical phenomena. Similarly to a flash light freezing the motion of a moving object, a mode locked laser can take “pictures” of processes that occur at extremely fast time scales, such as chemical reactions or electronic transport in semiconductors.

Since the pulse duration produced by ultrafast systems is extremely short, the output peak power of the laser is greatly enhanced. This high peak power can be used

in a number of applications, such as material processing by cold ablation or to generate other wavelengths through nonlinear frequency conversion. Nonlinear conversion

provides access to a range of new wavelengths that are of interest in a wide range of research and industrial applications.