Hanieh Fattahi

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/64438

#### **Abstract**

In this chapter, the principle, design, and characteristics of high-efficiency, short-pulsepumped, few-cycle optical parametric chirped-pulse amplification (OPCPA) systems are reviewed. To this end, the feasibility of two techniques to increase the conversion efficiency of few-cycle OPCPA systems is demonstrated and discussed. The techni‐ ques result in 2.5 mJ, 7.5 W pulses and correspond to a pump-to-signal conversion efficiency of 30%. The broadband amplified spectrum supports 5.7 fs. Finally, the feasibility of extending the amplified spectrum to a near-single-cycle regime by using the combination of different crystals and phase matching is shown.

**Keywords:** optical parametric chirped-pulse amplification, Yb:YAG thin-disk laser, attosecond pulse, femtosecond laser
