Dual lattice photonic-crystal beam splitters

Light propagation in photonic crystals (PhC) is both sensitive to incident angle and wavelength. By combining two different PhC lattices, we utilize this effect to demonstrate a wavelength-dependent beam splitter with enhanced angular separation. The first lattice acts as a superprism that separates the incoming light according to wavelength, whereas the second lattice acts as an angular amplifier. We obtain 90 degrees angular separation for two wavelengths separated by 70 nm (1300 nm regime) in a structure that is less than 10 mu m long. (c) 2005 American Institute of Physics.