Daytime observation technique for Fe Boltzmann Lidar

In this paper, a Fe Boltzmann temperature-measuring lidar featuring narrow-linewidth solid-state lasers and daytime detection capability is presented. The system adopts seed-injected optical parametric oscillator and amplifier technology, effectively compressing the laser linewidth to below 200 MHz. Moreover, a frequency stabilization scheme based on potassium saturated absorption spectroscopy locks the laser wavelength to the center of the iron resonance lines. In addition, the system is equipped with dual-wavelength etalons at 372 nm and 374 nm, with filter bandwidths of 8.3 GHz and 9.8 GHz, respectively. Together with high-precision coordinated temperature-pressure control and a large-aperture receiving telescope, the system effectively suppresses intense daytime background light and enables daytime observations. The demonstrated daytime-capable Fe lidar provides an effective scheme for precise probing of atmospheric dynamics in the mesosphere and lower thermosphere.