水体光谱测量应用光纤的优选及其影响因素初步分析

比较了两种石英光纤以及不同芯径的光纤对水体光谱测量的影响。通过对水体光谱的实地测量,发现芯径为0.6mm、数值孔径(NA)为0.37的PCS光纤,在波长为350～550nm之间透光量的GER信号损耗较小,与镜头测量值曲线的相似性较好,光纤接入光谱仪的实测值达到原配4度视场角镜头测量值的20%,而0.4mm的PCS光纤以及大芯径光纤,分别只能达到镜头测量值的15%和5%。10m长的芯径为0.6mm的PCS光纤弯折(半径为30cm)后其GER信号仍能达到镜头信号的15%,符合光谱测量的要求。

Influence of fibers on the hyperspectral measurement of ambient light in water: Preliminary results

The effects of two quartz optic fiber and optic fiber with different diameter on water column spectrum measurement were compared.Field measurements of water column spectrum showed that PCS optic fiber with diameter 0.6 mm and digital diameter 0.37 has the lowest GER signal loss within 350 to 550 nm wavelength.This PCS optic fiber also has good comparability with lens measurement curve.The real measurement achieved when the optic fiber is connected to spectrometer was 20% of the value measured by the original 4 degree optical field lens.Real measurements achieved by PCS optic fiber with diameter 0.4 mm and optic fibers with big diameter as well as big digital diameter,on the other hand,were only 15% and 5% of lens measurements.10-meter-PCS optic fiber with diameter 0.6 mm,after curved to a circular with diameter larger than 30 cm,achieved real measurements 15% of the lens measurement value,which meets the water column spectrum measurement requirement.