Dual single-emitter diode-pumped passively Q-switched Nd:YAG MOPA laser for wind lidar.

High-resolution wind field sensing in the near-surface layer (up to several hundred meters) is increasingly critical to emerging paradigms such as the low-altitude economy, wind energy optimization, and aviation safety. While traditional Doppler wind lidars are highly accurate, their reliance on complex frequency-shift demodulation and strict optical aberration control limits their cost-effectiveness and environmental adaptability in widespread, near-surface deployments. To address these bottlenecks, this study develops a compact, passively Q-switched Nd:YAG master oscillator power amplifier (MOPA) laser for non-Doppler direct-detection wind lidar. Utilizing a single-diode pump, a two-stage temperature control design, and polarization-coupled double-pass amplification, the laser achieves a highly stable output at a 3.96 kHz repetition rate, with a single-pulse energy of 442.9 µJ, a pulse width of 5.012 ns, and near-diffraction-limited beam quality (MX2=1.62,MY2=1.60). Notably, the system exhibits exceptional thermal robustness; operating across a harsh 30-50 °C temperature range, it maintains power stability better than ±3% and beam angular drift below 50 µrad-performance that exceeds commercial counterparts. Integrated into a multi-beam, scanner-free lidar architecture, the system successfully demonstrated continuous 24-hour wind profile measurements that closely align with those from in-situ meteorological sensors. This robust, lightweight, and cost-effective laser source represents a highly viable solution for scalable near-surface wind remote sensing in complex environments.