Considering the importance of the laser wavelength response and the difficulty in its real-scenario measurement in WMS, a high-accuracy and universal method was developed to characterize the relative wavelength response (RWR) by analyzing the laser current response. A coupling term that depends on both the current scan and the modulation characteristic was introduced to describe the coupling effect between the wavelength scan and modulation. The accuracy of the proposed method was verified with different laser working conditions and scan waveforms. All fitting residuals of the RWR result from the proposed method are smaller than 0.1% of the total scan range and the fitting residual of the ramp scanned WMS is twice smaller than the minimum value from literature. The better calibration-free 2f/1f fitting and more accurate CO2 concentration results also suggest the high accuracy and superiority of the proposed method. Finally, based on the precise prediction of RWR with small scan and modulation indices, the spectral parameters, including line strength and self-collisional broadening coefficient, of CO2 transition at 6976.2026 cm-1 were successfully measured using WMS.

中文翻译：

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一种高精度，通用的方法来表征波长调制光谱（WMS）中的相对波长响应（RWR）。

考虑到激光波长响应的重要性及其在WMS中实际测量的困难，开发了一种高精度且通用的方法，通过分析激光电流响应来表征相对波长响应（RWR）。引入了既取决于电流扫描又取决于调制特性的耦合项，以描述波长扫描与调制之间的耦合效应。通过不同的激光工作条件和扫描波形验证了该方法的准确性。所提出的方法对RWR的所有拟合残差均小于总扫描范围的0.1％，而斜波扫描WMS的拟合残差比文献中的最小值小两倍。更好的免校正2f / 1f拟合和更准确的CO2浓度结果也表明了该方法的高精度和优越性。最后，基于具有较小扫描和调制指数的RWR的精确预测，使用WMS成功测量了6976.2026 cm-1处CO2跃迁的光谱参数，包括线强度和自碰撞加宽系数。