Laser with deepest tissue penetration is:

Nd:YAG laser light is 1.064 m (1064 nm) in wavelength. It is in the near-infrared poion of the spectrum, and, like CO2 laser light, is invisible to the naked eye. A unique feature of the Nd:YAG laser is that 1064-nm light is poorly absorbed by most tissue pigments and therefore travels deep into tissue. Deep tissue penetration provides deep tissue heating. For this reason, the Nd:YAG laser is capable of the greatest amount of tissue destruction with a single application. Ref: Schwaz's principle of surgery 9th edition, chapter 14.