Which laser to choose?

The choice of the device, as we have seen, is very important to obtain satisfying results. As a future patient, it is useful for you to know about the existing devices in order to decipher the different advertising discourses. It is the laser wavelength that will determine the skin penetration and the targets aimed.

- The Ruby laser at 694 nm : its wavelength is the best absorbed by melanin : one shot can heat up the hair to more than 200°C (R.M. Clement, M.N. Kierman). But its side-effects on dark skins render it less attractive than wavelengths less absorbed by skin melanin. The small dimensioned laser spot is also considered as an inconvenience to professional use.

- The Alexandrite laser at 755nm: its wavelength is well absorbed by melanin. As a matter of fact, it is sufficiently absorbed to treat blond hair on light skins. Its skin cooling systems allow advances in the treatment of tanned or dark skins.

The device is very big (it weights 150 kg, with a 1 m3 volume). The new generation of devices is equipped with a shooting system created to adapt to the different skin types.

From our viewpoint, the Alexandrite remains the “Rolls Royce” of hair removal. Powerful, multifunctional and comfortable, it provides an excellent visibility of the treatment area, spot diameters up to 18 mm, and the most sophisticated improvements and accessories. Its wavelength enables a deep penetration of the light beam without using a high fluence. We believe that all these characteristics guarantee unequalled efficiency, comfort and safety as compared to other laser families. The only disadvantage of this device is its high cost (130 000€ approximately or 200 000 CHF), a very big investment!

- The laser diode at 790-810nm : its wavelength is not absorbed much by melanin but allows a deeper penetration of the light beam. This technology is promising as lasers are manufactured at a low cost, with a tendency to a decrease due to the advances in the miniaturization of semiconductors. One of their advantages consists in being compact and relatively portable. The low absorption by melanin is both an advantage (skin tan and pigmentation are not affected much) and a disadvantage (the treatment is ineffective on lighter and thinner hair).

- The Nd:Yag laser at 1064 nm: its wavelength is even less absorbed by melanin. But it allows a deep penetration of the light beam. The thermal effect on the hair is low and leads to the emission of high fluences.

It provides very interesting results on patients with very dark skins, who could not be treated otherwise. Nowadays, this type of laser can only provide long-lasting hair removal, but after all, patients are glad to undergo only two or three sessions per year and not to bother with their hair the rest of the time.

We have developed new protocols at the CMH, which combine the Yag treatment and the Alexandrite treatment, so as to treat deep hair more easily (men backs or some bikinis). The results are very interesting and many of our colleagues are now testing this new process.

SOME MORE INFORMATION: the laser must be powerful enough to keep its energy high when the spot gets larger: what is lost in power is gained in skin penetration.