Abstract

We have demonstrated 175-fs pulses with 1 W and 300-fs pulses with 1.2 W average output power at a pulse repetition rate of 117 MHz from a Nd:phosphate (Schott LG 760) glass laser pumped by a 1-cm-wide, 20 W diode laser bar. Stable soliton modelocking was achieved by using an intracavity semiconductor saturable absorber mirror (SESAM). We obtained more than 2 W average power without modelocking. Using cylindrical cavity mirrors, the laser mode was closely adapted to the highly-elliptical pump beam while maintaining a nearly ideal, circular TEM₀₀ output beam with a M²≈l.2. Over-pumping the laser mode in the tangential plane and efficient uni-directional heat removal in the sagittal plane using a 0.8-mm-thin Nd:glass also contributed to the good output beam quality.

© 1998 Optical Society of America