用两块玻璃夹持一层几个μm厚的磁性液体薄膜。将这一磁性液体薄膜垂直放置于由亥姆霍兹线圈建立的均匀磁场中。在迈克尔孙干涉仪上用对比测量法测量在不同外加磁场强度作用下磁性液体薄膜的折射率。实验发现, 磁性液体薄膜的折射率随外加磁场强度的变化而变化。结合实验研究, 提出了外加磁场改变了磁性液体颗粒链的大小, 改变了磁性颗粒链的大小和入射光波波长的比值, 从而改变了磁性液体的折射率的设想。初步建立起了磁性液体薄膜的折射率和外加磁场强度之间的关联式。为磁场测量、光学阀门等新型磁光器件的开发提供了新的技术。

The ferrofluid film(several micrometers thick), located between two glass plates, was placed vertically in the uniform magnetic field produced by the Helmholtz coil. Measurement of the refractive index of the ferrofluid film under different magnetic field intensities with Michelson interferometer by contrast measuring method, shows that the refractive index changes with the variation of the external magnetic field intensity. This phenomenon is explained by the modification of the size of ferrofluid particles under external magnetic field, which changes the ratio of dimension of the chain of magnetic particles to incident wavelength, thus altering the refractive index of the magnetic fluid. Based on this, the relation between the refractive index and external magnetic field intensity is established, which will provide a new technique for the development of new magneto-optical devices for magnetic field measurement, optical valves and so on.