I found this 4 year old thread in the archives. It speculated about the use of lasers (and other light sources) for focusing in low light.

I often face this challenge in situations where I can't walk out and place a torch to focus on, so I need to be able to shine a focus-capable beam of light up to (say) 10 meters. Has anyone proved the conjecture in that thread or pioneered an alternative approach?

Thanks.