What type of light do semiconductor LEDs emit?

Semiconductor LEDs, or Light Emitting Diodes, primarily emit monochromatic light. This means the light they produce is of a single wavelength or color. The process by which LEDs emit light is known as electroluminescence, where electrons recombine with holes in a semiconductor and release energy in the form of light.

Although incoherent light is a broader category that can include light from a variety of sources, it is not specific to the unique properties of LEDs. Instead, monochromatic light describes the specific characteristic of the light generated by LEDs, which is crucial in applications where a precise color and wavelength are needed, such as in displays, lighting, and optical communication.

In contrast, coherent light, such as that produced by lasers, is made up of waves that are in phase and have a fixed phase relationship, which does not apply to LEDs. Similarly, polarized light has a specific orientation of the light waves, which is not a defining property of the light emitted by LEDs. Thus, considering the fundamental nature of the light produced, monochromatic light is indeed the correct description for what semiconductor LEDs emit.