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You can see the spot from a PL520 single mode laser diode on clouds bases up to about 7,000 feet high (when in a relatively dark area without a lot of city lights). DTR sells a set of R, G and B single mode laser diodes which all have low divergence beams when collimated to 4 mm or larger diameter. The longer the focal length of the collimating lens, the larger the beam diameter and the lower the collimated divergence.
Any laser diode can produce low divergence if the beam is expanded enough, even our multimode laser diodes. The worst of them for divergence; the NUBM44 450 nm laser diode, can also have low divergence, but you are going to expand the beam to several inches diameter to get it.
https://sites.google.com/site/dtrlpf/home/diodes/rgb-diode-budle
Any laser diode can produce low divergence if the beam is expanded enough, even our multimode laser diodes. The worst of them for divergence; the NUBM44 450 nm laser diode, can also have low divergence, but you are going to expand the beam to several inches diameter to get it.
https://sites.google.com/site/dtrlpf/home/diodes/rgb-diode-budle