High efficiency HOEs for holographic DVD pickup heads

It is well known that holographic hybrid pickup heads have a number of advantages in terms of size, modularity, and perhaps cost, but are less efficient than conventional discrete component type pickup heads. We introduce a new design for the HOE which places the 3-beam grating on the same surface with the holographic beamsplitter and utilizes light that would otherwise be wasted to create the satellite beams for 3-beam tracking. Efficiency is gained by avoiding the /spl sim/35% loss typically associated with the 3-beam grating and by blazing the holographic beamsplitter.