Three-dimensional photonic crystals are advanced materials that have a periodic structure on the scale of the wavelength of light, capable of manipulating the propagation of photons. These structures can create photonic bandgaps, which prevent certain wavelengths of light from propagating in specific directions, thus controlling the flow of light in a highly efficient manner. They can be engineered to interact with light in unique ways, making them essential for various applications in optics and optoelectronics.
congrats on reading the definition of three-dimensional photonic crystals. now let's actually learn it.