The Alexandrite laser has a shorter wavelength system. However, it frequently produces side effects such as pigmentary changes (lightening or darkening of the skin), or worse, for patients of all but white skin.

While claims have been made regarding safety in treating darker skin types such as type 3, or even 4 and 5 (brown skin), I would not recommend using this lasers for treating unwanted hair in any skin type other than very white skin.

Laser hair removal machine - Nd:Yag Laser (1064 nm)
Laser hair removal machine - Ruby (694 nm)