针对最高分辨率可达0.1 pm的布里渊近红外光谱仪波长标定的难题,基于多次标定逐步降低波长误差的思路,提出了一种协同融合标定原理的标定流程:首先,基于布里渊光谱分析理论模型,结合泵浦信号波长、受激布里渊频移、增益谱线型函数等推导出超高分辨率光谱的理论波长;然后,采用FP标准具进行相对波长的标定;最后,基于气室完成绝对波长的标定。气室中充入HCN+ 12CO+ 13CO混合气体,以实现C+L波段的覆盖。针对可能存在的光谱鬼线,提出了一种基于受激布里渊增益谱与衰减谱共生特性的鬼线识别方法。实验结果表明:布里渊光谱仪的理论波长偏差超过了10 pm,相对标定可将波长不确定度降低到±2.5 pm,绝对标定可将波长不确定度进一步降低到±0.035 pm。

To address the problem of wavelength calibration of a Brillouin NIR spectrometer with a maximum resolution of 0.1 pm, a calibration process using the principle of collaborative fusion calibration is proposed. This process is based on the idea of gradually reducing the wavelength error of multiple calibrations. The calibration process is as follows: first, the theoretical wavelength was calculated based on the Brillouin spectral analysis modal and relative parameters, such as the pump signal wavelength, Brillouin frequency shift, and gain in spectrum lineshape; then, the relative wavelength was calibrated using the Fabry-Perot etalon; finally, the absolute wavelength calibration based on the gas chamber was completed. The gas chamber was filled with a mixed gas of HCN, ¹²CO, and ¹³CO to achieve absolute wavelength calibration in the C and L bands. A ghost identification and correction algorithm was also presented based on the commensalism of gain and loss spectrum of stimulated Brillouin scattering. Experimental results show that the theoretical wavelength deviation is more than 10 pm, and wavelength uncertainty of ±2.5 pm can be achieved by relative wavelength calibration. Moreover, the wavelength uncertainty of the absolute wavelength calibration is ±0.035 pm.