– Why does the light from a laser pointer look “grainy”? Like it is made up of a bunch of little dots?

Question

When I shine a laser pointer at something, the point looks like it is made of a bunch of tiny dots, how is the laser diode different from a normal LED?

In: Technology

Answer 1

laser lets light out of a small hole. the light has a narrow range of wavelengths. small hole with the same colour of light gives you the speckly interference pattern

[https://en.wikipedia.org/wiki/Diffraction#Single-slit_diffraction](https://en.wikipedia.org/wiki/Diffraction#Single-slit_diffraction)

For a proper ELI5 go and look at water waves passing through a single gap in a sea wall.