High-Repetition-Rate Structured Oval Pulsed Fields with Controllable Mode Order by an Nd:YVO4Cr4+:YAG Laser in a Near-Hemispherical Resonator

Generation of high-transverse-order structured pulsed fields with oval-shaped morphologies is explored by an Nd:YVO
4
/Cr
⁴⁺
:YAG passively Q-switched (PQS) laser in a tightly-focusing pumped near-hemispherical cavity. By increasing the input pump power, the mode order of the generated structured oval beams can be directly controlled with good beam stability. At a pump level of 8 W, the average output power of the oval structured PQS field can reach up to 2.27 W with the pulse repetition rate and the peak power respectively beyond 125 kHz and 400 W while maintaining quite regular PQS performance.