超连续谱激光-单色仪在偏振遥感器定标中的影响因素分析

Influencing factors analysis of supercontinuum laser monochromator in calibration of polarization remote sensors

偏振遥感器的相对光谱响应度和带内光谱响应非一致性是遥感器实验室定标的基本参数。文中利用新型的超连续谱激光作为单色仪的前置照明光源,搭建了一套基于超连续谱激光-单色仪的细分光谱扫描定标装置,可用于偏振遥感器的相对光谱响应度定标。实验中以490、670、910 nm三个偏振通道作为例,分别在单色仪直接输出光和单色光导入积分球两种状态下,得到通道式偏振遥感器的相对光谱响应度结果,并对两种状态下定标光源的偏振特性进行了测量。实验结果表明,单色仪直接输出光模式下,光源存在明显的偏振度和偏振方位角变化,三个偏振通道的带内光谱响应非一致性分别为0.91%、4.25%和1.06%;而在单色光导入积分球后,光源的偏振度明显降低,此时带内光谱响应非一致性结果分别为0.15%、0.47%和0.57%,说明消偏后的光源能有效适用偏振遥感器的光谱响应度定标,基于超连续谱激光-单色仪的系统级定标装置在偏振遥感器的定标中具有广泛应用前景。

Relative spectral responsivity and the in-band spectral response non-consistency of polarization remote sensors are the basic parameters for laboratory calibration.In this paper,a spectrally-resolved calibration facility was assembled for the calibration of relative spectral responsivity by using novel supercontinuum laser and monochromator.Taking three polarization channels of 490 nm,670 nm and 910 nm as examples,the relative spectral responsivity of the channel polarization remote sensors was obtained under the two states of the monochromator output light directly and the monochromatic light steered into an integrating sphere respectively,and the polarization state of the calibrated light source was measured under the two states.The experimental results show that there are obvious changes in degree of linear polarization(DOLP)and polarization orientation angle in the mode of direct output light of monochromator,and the non-consistency of in-band spectral response of the three polarization channels were 0.91%,4.25%and 1.06%,respectively.When the monochromatic light steered into the integrating sphere,the DOLP of the light source decreases significantly,and the non-consistency of in-band spectral response were 0.15%,0.47%and 0.57%,respectively,which indicates that depolarized light source can be effectively applied to the spectral responsivity calibration of polarization remote sensors.And the system-level calibration facility based on supercontinuum laser and monochromator has wide application prospects in the calibration of polarization remote sensors.