Holographic Laser Projection

A Holographic Laser Projection (or HLP) system uses a laser to illuminate a hologram that diffracts the laser to create the original image. A diffraction pattern of the desired 2D image is calculated and displayed on an LCoS microdisplay. When illuminated by a coherent laser light, the desired 2D image is projected, remaining in focus at all distances.

The 'holographic' part refers to the way the image is created. The final projected image is not 'holographic' in any way - it's not a 3D display.

An HLP system have several advantage when compared to regular laser-beam-steering or LCoS projection systems:

• Low speckle
• Always in focus (because it's laser based)
• Efficiency
• Image brightness
• Wide throw angle - creating large images at close proximity to the projector aperture

Light Blue Optics is one company that are using such a system for their pico projector. They are also combining an infra-red sensor that makes their projected image a 'touch display'. Here's a short video explaining how HLP works and how LBO are using it: