The first one is incandescent lightbulb. Thomas Edison is widely considered to be the
inventor of the incandescent bulb. They consists of a glass enclosure containing a tungsten filament.
An electric current passes through the filament, heating it to a temperature that produces light.
They usually contain a stem or glass mount attached to the bulb's base which allows the electrical
contacts to run through the envelope without gas. The next one is fluorescent lightbulb. The
modern CFL was invented by Edward Hammer but was not produced at the time. Philips became
the first manufacturer to mass-produce a compact fluorescent bulb with a screw-in base.
An electric current is applied to mercury vapor inside the tube, causing it to emit ultraviolet (UV)
light. A phosphor on the walls of the tube absorbs the ultraviolet light. And the last one is the first
visible-spectrum LED lightbuld that was invented in 1962 by Nick Holonyak, Jr. He develops the
red LED, by using GaAsP (Gallium Arsenide Phosphide) on a GaAs substrate. There are two methods
is used to create white light.The first is an RGB system, which works by mixing light output from
red, blue, and green diodes in close proximity in order to create white light. The second is using
phosphor-based LEDs, which involves coating an LED with phosphor in order to shift the color into
the white spectrum.