The method is based on measuring the deflection of rays from a collimatedlightbeam due to gradients in refractive index.
平行光通过折射率存在梯度的场，光线产生偏转，即产生云纹效应。
2
Another important application of diffraction theory is the study of the far field divergence Angle of a collimatedlightbeam.
衍射理论的另一个重要应用就是研究准直光束的远场发散角。
3
On the basis of theories of physics, geometrical optics and photometry, the optical properties of collimatedlightbeam incident upon single fiber perpendicular to the fiber axis are studied.