Generating extreme laser fields
The basic distinguishing feature of the IAP RAS approach to creating petawatt and multipetawatt femtosecond laser complexes is the use of optical parametric chirped pulse amplification (OPCPA) instead of conventional laser amplification. Parametric amplification is accomplished in nonlinear optical crystals, where pump wave energy is converted to signal wave energy that is amplified as a high-frequency quantum is decaying into two quanta of lower frequency. By selecting a nonlinear crystal, a propagation direction, as well as pump and signal wave frequencies it is possible to obtain broadband synchronism conditions that allow amplifying pulses with a duration up to 10 fs.
The femtosecond laser complex PEARL created at IAP RAS is based on these principles. This complex is one of the most powerful laser systems in the world – the peak power of the generated pulses reaches 0.56 PW.
The experience gained in creating PEARL and its principles are currently used for constructing at IAP RAS of the laser complex PEARL-10 with a power over 5 PW. The concept of an exawatt laser system – the XCELS project that is one of the six Russian megascience projects to be implemented in the territory of the country in the coming decade – has been developed. Appearance of such sources opens up absolutely new horizons for basic research and unique applications.