To solve the Fresnel reflection which exits generally in optical systems

we designed and analyzed one kind of structures

subwavelength surface-relief periodic structures

which have three-dimension profile

using the coupled wave method. Then comparing the calculated results with the characteristics of multilayer antireflection coatings

it was found that this subwavelength periodic structure is far more efficient than multilayer antireflection coating in a wide wave band

particularly in infrared wave band

and the reflection ratio can be controlled in 0.2% in general. Besides this

the variety of reflection of this subwavelength periodic structure can be maintained in 1% when incident angle of incident wave has a 40? deflection

while for multilayer antireflection coatings

it just can do this in 30?.