高精度的激光雷达探测对发射波长的精确定标和稳定有极其严格的要求，可调谐激光器进行多次波长调节时存在的激光器空回问题会严重影响系统的探测精度。为此，提出了一种解决可调谐激光器空回问题的算法，得出了通过来回跳转使正负误差相抵消以消除空回误差的方法，并首先将其应用到大气CO2浓度垂直廓线高精度探测中的稳频部分。通过多次实验表明，该算法提高了可调谐激光器的激光波长调节精度，消除了激光器多次反转调节波长时空回误差对测量精度的影响，弥补了机械转动进行波长调节的不足，对高光谱激光技术的发展有十分重要的意义。

Lidar detection requires strict calibration and stabilization on transmitted wavelength. The backlash errors, which occurs in wavelength control of the tunable laser, seriously reduce the detection accuracy. In order to solve the backlash problem of the tunable laser, a algorithm which can offset the positive and negative backlash error by jumping back and forth is proposed and firstly applied to the frequency stabilization of the high detection of vertical profiles of atmospheric CO2 concentration. The experiment result indicates that the algorithm not only can improve the adjusting precision of the tunable laser′s wavelength, but also eliminate the backlash error of the laser′s wavelength adjustment caused by multiple reverse. This method reduces the shortage of the wavelength adjustment caused by mechanical rotating and has great significance for the development of hyperspectral laser technology.