Generation of mode-switchable nanosecond pulsed cylindrical vector beams and vortex beams from a Q-switched solid-state laser

Abstract

We reported and demonstrated a Q-switched solid-state laser for the generation of mode-switchable nanosecond pulsed cylindrical vector beams and vortex beams between different orders. In the cavity, an order-switchable Q-plate, consisted of two Q-plates and two quarter wave plates, was applied to achieve the mode-switch between two different orders by adjusting the angles of quarter wave plates. Besides, two extra quarter wave plates and a Faraday rotator were utilized to realize the intracavitary self-reproducibility of cylindrical vector beams and vortex beams, respectively. The experimental results show that by using two Q-plates of 1st and 3rd orders, the cylindrical vector beams and vortex beams of 2nd and 4th orders can be directly generated from the solid-state laser. For the 2nd order cylindrical vector beam and vortex beam, the slope efficiency, pulse width, and repetition rate are 7.2%, 415 ns, and 227 kHz, respectively. To the best of our knowledge, it is the first time to realize the controlled generation of mode-switchable cylindrical vector beams and vortex beams between two different orders from a solid-state laser.