On August 8, 1962, a 34-year-old General Electric engineer named Nick Holonyak Jr. filed a patent application for a semiconductor device that could do something no diode had done before: emit visible light you could see with the naked eye. The patent — US 3,293,513, "Semiconductor Radiant Diode" — was granted December 20, 1966. It was the birth of the LED.

Infrared-emitting diodes already existed (Robert Baird and Gary Pittman at Texas Instruments demonstrated one earlier in 1962). What Holonyak did was harder: he grew a crystal of gallium arsenide phosphide (GaAsP), a ternary alloy, whose bandgap sat high enough that recombining electron-hole pairs released photons in the red end of the visible spectrum. The same crystal, cooled and pumped harder, also produced the first visible-spectrum semiconductor laser diode — in the same paper, in the same lab, in the same year.

The claim in the patent is elegantly narrow: a p-n junction diode of GaAsP composition emitting radiation in the visible range. The drawings show a tiny chip mounted on a header — the ancestor of every indicator LED you have ever seen.

What Holonyak said out loud in 1963: in a Reader's Digest interview, he predicted his diodes would eventually replace the incandescent bulb. His colleagues laughed. Edison's bulb had held the market for 80 years. Holonyak was off by about 50 years on timing, and completely right on outcome.

What his patent led to:

• Lighting. LEDs now provide the majority of new lighting installations worldwide. The 2014 Nobel Prize (Akasaki, Amano, Nakamura) for the blue GaN LED completed the RGB triad Holonyak started — enabling white light and finally displacing Edison.
• Displays. Every LCD monitor, TV, and phone uses LED backlights; every OLED phone screen is a matrix of Holonyak's descendants, each pixel a tiny diode.
• Fiber optics. The transmitters on every long-haul fiber link, every data-center interconnect, and every fiber-to-the-home ONT are laser diodes — the same physics Holonyak demonstrated alongside the LED.
• Automotive. Headlights, taillights, dashboards, and cabin lighting are almost fully LED. Adaptive-matrix headlights use thousands of individually addressable Holonyak-lineage diodes.
• LiDAR and 3D sensing. The dot projectors in Face ID, the flood illuminators in phone cameras, and the emitters in automotive LiDAR are all specialized semiconductor light-emitters.
• Horticulture and medicine. Indoor vertical farms grow food under tuned red/blue LEDs. Phototherapy for jaundice, photodynamic cancer therapy, and pulse oximeters all sit on the same lineage.
• Li-Fi and visible-light communication. Modulated LED bulbs can transmit gigabits per second — the direct realization of Holonyak's original insight that his diodes were fast.

Why the patent is surprising: in 1962, "solid-state lighting" was not a phrase anyone used. Bulbs were glass, vacuum, and hot metal. Displays were phosphor-coated CRTs. Data traveled on copper. Holonyak's little red dot on a GE workbench was the seed of all three industries collapsing into semiconductor industries — the same wafer fabs, the same epitaxial growth, the same doping tricks that make CPUs.

He kept working at the University of Illinois for six more decades, mentoring students who invented the quantum-well laser and the transistor laser. He died in 2022. Every screen you look at is his monument.