[cycomanic]

That question does not really make sense. Fibre links use lasers. Maybe what you are asking about is free-space vs fibre links. Yes some HFT players use free-space optical or microwave links, because of the improvement in latency, they typically also eliminate all (or most) FEC which introduces significant latency as well. However, they don't really care about data rate so much.

For almost all other applications the factor 1.5 you gain from free-space vs fibre is not worth it. A trip around the equator in an optical fibre takes 200ms. That is acceptable for almost everything. Moreover, the latency of using any something free-space would likely not be much better, because one would need to regenerate at least 3 times (which might add ~10ms or so for each regeneration)