For instance, opaque substances become transparent (copper); inert materials become catalysts ... that they exhibit compared with larger particles of the same materials. For example, titanium dioxide ...

Opaque materials can transmit light when excited by a high-intensity laser beam. This process, known as optical bleaching, ...

Here are a few specific examples of how terahertz technology is currently being used or researched for use: Imaging: Terahertz imaging, also known as T-ray imaging, can be used to create images of the ...