23 — HLED

Holographic LED

What It Is

HLED is Hardin Labs' precision holographic light-emitting diode technology — a display and illumination element that combines a standard III-Nitride LED die with a Silixon-PDC holographic diffraction grating integrated directly into the LED package lens, enabling each individual LED to project a pre-programmed holographic light pattern into space rather than emitting omnidirectional light. Unlike conventional holographic LED screens that use an array of transparent LED strips combined with projection tricks to simulate 3D imagery, HLED elements produce true wavefront-controlled illumination from a solid-state chip — each LED acting as a miniature holographic projector capable of generating a unique 3D light field pattern assigned by the system controller.

Construction

The HLED package encapsulates a standard InGaN/GaN LED die beneath a Silixon-PDC transmission hologram — a volume holographic grating recorded in the SiOC matrix by a two-beam interference exposure during the PDC green-body stage, before final pyrolysis seals the grating permanently in the ceramic lens. Each grating pattern is unique to the LED's position in the display array and encodes the phase delay function required to reconstruct the target 3D scene wavefront from that spatial position. When illuminated by the broadband LED emission, the grating diffracts the output into the prescribed 3D wavefront, combining with wavefronts from adjacent LEDs to synthesize the full holographic image in the viewer's space.

Performance and Applications

Individual HLED elements achieve diffraction efficiency above 80%, meaning that 80% of the LED's output power is directed into the intended holographic wavefront rather than wasted in zero-order (straight-through) transmission. Arrays of 65,536 HLED elements on a Silixon-HCB substrate, driven by the SIP processor's holographic rendering pipeline, constitute the HIG system's physical emitter layer. HLED elements also serve as the laser line sources for the SIFR reactor's pellet illumination array — their narrow coherence length at low driving current transitions to high temporal coherence under pulsed Q-switched operation, providing the femtosecond pulses required for ICF target compression.