Laser diffraction through single slit

[Danyon]

Will a laser diffract through a single slit if the laser beam width is smaller than the slit? Such that the laser beam can pass though without touching the sides.

 

[blue_leaf77]

There is practically no diffraction in such a configuration.

 

[jtbell]

Example: shine a laser beam (e.g. from a laser pointer) through the center of an open doorway.

 

[mfb]

The laser exit itself is like a single slit already, and you see its effect: you don't see its diffraction (for most lasers).