0 to break up light or sound waves by making them go through a narrow space or across an edge -- 衍射（光線、聲波等因受阻礙而發生的擴散性傳播）
The effect of the trailing edge is to diffract sound waves generated by the leading edge.
This avoided any hard edges in the beam, which could diffract and cause damage.
The beam illuminates the first grating and is then diffracted.
In the case of supersonic aerofoils, the trailing edge diffracts both groups as it catches up with them.
It is observed numerically that an initially diffracting beam is accompanied by oscillatory self-focusing of the beam with distance of propagation.
As the first approximation, the spectrum was assumed to be diffracted in the first-order only.
For some materials, especially diffracting ones, the reflectance measured in some directions varies greatly from the reflectance measured in others.
This paper compares the theory with data obtained during experiments with diffracting shocks.
