peter.ell said:I was wondering what occurs when a diffraction grating is produced with features smaller than a wavelength of visible light. If the pits in a CD were made to be only a few tens of nanometers wide, what would we see?
Diffraction from sub-wavelength features is a phenomenon where light waves are scattered or bent when they encounter small structures or features that are smaller than the wavelength of the light. This can occur when light passes through or reflects off of objects with dimensions in the nanometer scale or smaller.
Diffraction from sub-wavelength features can cause blurring or distortion in images, making it difficult to resolve small details or features. This is particularly important in fields such as microscopy, where high resolution imaging is crucial.
The amount of diffraction is directly related to the size of the sub-wavelength features. As the size of the features decreases, the amount of diffraction increases, resulting in more pronounced effects on light waves passing through or reflecting off of them.
Diffraction from sub-wavelength features can be controlled or minimized by using techniques such as anti-reflective coatings, which reduce the amount of light reflected off of the surface, or by using specialized optics such as superlenses, which can focus light beyond the diffraction limit.
Diffraction from sub-wavelength features has a wide range of applications, including nanolithography, where it is used to create patterns on a nanoscale, and in optics and photonics, where it is utilized to manipulate and control light waves for various purposes such as sensing, imaging, and communications.