Highly efficient femtosecond Yb:KYW laser pumped by single narrow-stripe laser diode

A highly efficient and low threshold passively modelocked femtosecond Yb:KYW laser pumped by an InGaAs narrow-stripe laser diode is demonstrated. Near-transform limited pulses of 123 fs at 1047 nm were produced at an average modelocked power of 107 mW for only 308 mW of incident pump power. An optical-to-optical conversion efficiency of 35% was achieved and the corresponding electrical-to-optical efficiency exceeded 14%.