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Wavelength stabilization for a pulsed laser presents more challenges than that of continuous wave laser. We have developed a simple and efficient long-term wavelength drifts compensation technique for tunable pulsed dye lasers (PDL) applied in sodium detection lidar system. Wavelength calibration and locking are implemented by using optogalvanic (OG) spectroscopy in a Na hollow cathode lamp (HCL) in conjunction with a digital control software. Optimization of OG signals for better laser wavelength discrimination and feedback control is performed. Test results indicate that locking the multimode broadband PDL to the Na atomic transition corresponding to 589.158 nm is well achieved although the temperature in the laboratory is unstable. Through active compensation, the maximum wavelength drift is reduced from over 5 pm to 0.42 pm in 10 h and the maximum wavelength drift rate of the PDL is improved from 3.3 pm/h to 0.3 pm/h. It has been used to efficient sodium resonance fluorescence lidar detection. This technique is economical and easy to implement, and it provides flexible wavelength control and allows generalization for some other applications which require the wavelength of tunable pulsed lasers to be fixed at an atomic resonance transition references. [ABSTRACT FROM AUTHOR]

A precise matching is required between the emitted laser beam and Field-of-View (FOV) of the received telescope to ensure useful observation of middle and upper atmospheric lidar. Nowadays, manual matching is commonly used, but it is time-consuming and has poor stability. Automatic matching is still hard to meet the actual application requirement because it is challenging to balance accuracy and efficiency. Thus, in this paper, a self-adaptive matching algorithm is proposed. In this process, the correlation coefficient between the echo signal and the standard pattern is considered as the matching criterion. It adaptively updates the adjustment step according to the current position's matching state and uses the correlation coefficient's increasing gradient as the adjustment direction. The above matching process is iteratively conducted until meeting the convergence condition. The matching process is within 3 ∼ 5min. These results suggest that the proposed automated matching algorithm can play an important role in unattended atmospheric lidars. • A new method to evaluate the matching state of lidar transmitter and receiver was proposed. • The step size and path optimization can be automatically operated according to the current matching state. • The self-adaptive algorithm can greatly improve the efficiency. [ABSTRACT FROM AUTHOR]