[1][2] The essence of the DPH technology is embedding computer designed digital holograms inside a planar waveguide.
Planar waveguides, fabricated by sequential depositing flat layers of transparent materials with a proper refractive index gradient on a standard wafer, confine light in one direction (z axis) and permit free propagation in two others (x and y axes).
The DPH technology, or Yankov hologram, comprises design and fabrication of the holographic nano-structures inside a planar waveguide, providing light processing and control.
It consists of numerous nano-grooves, each about 100 nm wide, positioned in a way, providing maximum efficiency for a specific application.
The small footprint of the DPH makes it possible to combine with other elements of photonic integrated circuits, such as coarse demultiplexers[3] and interferometers.
[4] Nano-Optic Devices, LLC (NOD) Archived 2008-09-30 at the Wayback Machine developed the DPH technology and applied it for commercializing nano-spectrometers.