Editing Diffraction grating (section)

=== Other gratings ===
A new technology for grating insertion into [[Integrated optics|integrated photonic lightwave circuits]] is [[digital planar holography]] (DPH). DPH gratings are generated in computer and fabricated on one or several interfaces of an optical waveguide planar by using standard micro-lithography or nano-imprinting methods, compatible with mass-production. Light propagates inside the DPH gratings, confined by the refractive index gradient, which provides longer interaction path and greater flexibility in light steering.