[corkoman]

How does one go about focusing a laser on a year?

You don't focus a laser - its light is already in-phase and wavelength is also in-phase.

When I hear people with letters behind their names use this phrase I stop listening.

[GingisK]

I was being facetious. I read deep on lasers in 1961.

[GingisK]

Oh, by the way. You do focus a laser when needed. Focusing does not affect phase; and, phase is not related to focus. Wavelength is the measure associated with color; and, focusing has no affect on that either.

Laser light does diverge, and focus can help with that.