General Competition (November 1993)

Holographic Graded-Index Non-Lambertian Scattering Screens and Components with Light-Shaping Capability

Sponsor: Physical Optics Corporation

• Project Performance Period: 2/1/1994 - 1/31/1996
• Total project (est.): $1,723,643.00
• Requested ATP funds: $850,029.00

Holograms are generally connected with credit-card seals and embossed images on fancy magazine covers, but a number of more exotic applications, such as novel computer memories, have been studied recently. Physical Optics Corp. proposes to develop a new class of hologram applications -- light-diffusion screens with the ability to shape the light beam, scattering it in preferred directions with very little loss. Conventional diffusion screens such as ground glass or plastic produce even, distributed illumination, but because they scatter light randomly in all directions, including backwards, much of it is wasted. The POC technology combines holographic techniques and scattering phenomena to make diffusers with controlled scattering in which almost all the light is directed within a well-defined circular or elliptical cone, and almost none is back-scattered. The results can be dramatic. Displays seen through POC's graded-index (GRIN) scatterers are up to 15 times brighter. Projected displays in bright daylight, which would be almost entirely washed out on a conventional projection screen are bright and clearly defined on a holographic GRIN screen. Because screen illumination consumes most of the power in a portable or laptop computer, GRIN diffusers could lower the energy consumption for a computer display up to 15 times -- an important consideration for battery operation. In general, GRIN diffusers could significantly reduce lighting costs in a wide variety of applications simply by making better use of the light. Although POC has demonstrated the feasibility of such holographic diffusers on a laboratory scale, the application is entirely new, and significant obstacles remain to scaling up to larger screens and volume production. In principle, however, the manufacturing technique will be similar to that used to make embossed surface holograms on credit cards, and can be applied to flat or curved plastic, glass or metal surfaces.

For project information:

Patty Shaw, (310) 320-3088

ATP Project Manager

Thomas Lettieri, (301) 975-3496
thomas.lettieri@nist.gov