High signal-noise ratio passively mode-locked femtosecond Yb: CaF2 laser at 1034 nm

Abstract

Stable and self-starting diode-pumped passively mode-locked Yb: CaF2 laser with a high signal-noise ratio is experimentally demonstrated by using a semiconductor saturable absorber mirror (SESAM). By using GTI mirrors to manage the intracavity dispersions, the generated pulses are as short as 573 fs at the central wavelength of 1034 nm with a spectral bandwidth of 2.08 nm. When the fundamental repetition frequency is 51.5 MHz, the single pulse energy is 7.4 nJ, the peak power is 12.9 kW, and the maximum average output power can reach 382 mW, corresponding to an optical-to-optical conversion efficiency of 10.3 %. The recorded RF spectrum shows a signal-noise ratio as high as 70 dB, exhibiting the excellent ability of Yb: CaF2 crystal in generating high-stability femtosecond lasers.