Passively Mode-Locked Radially Polarized Nd-Doped Yttrium Aluminum Garnet Laser Based on Graphene-Based Saturable Absorber

We report the first demonstration of a graphene-mode-locked, radially polarized Nd-doped yttrium aluminum garnet (Nd:YAG) laser, generating ${\sim}15.6$ ps pulses with output power up to 2 W. The peak wavelength is at ${\sim}1064$ nm with a pulse repetition rate of 112 MHz. The maximum output pulse energy and peak power are 18 nJ and 1.08 kW respectively. Our radially polarized all-solid-state laser is a simple and low-cost optical source for a range of applications, such as optical trapping and high-resolution microscopy.