It's worth pointing out that there are aircraft mounted LiDAR systems that already operate at 1550nm, such as [0]. Another company has an interesting paper about which wavelength is best for their activities[1].

http://www.teledyneoptech.com/index.php/product/titan/

[1] (PDF!) http://www.riegl.com/uploads/tx_pxpriegldownloads/Paper_ILMF...