With laser hair removal technology continuing to improve rapidly, new techniques and laser types are coming into play.

While laser hair removal is currently FDA-approved for semi-permanent hair removal, the number of treatments, the color of your hair and your skin and the laser used during treatment can help you obtain a significant and persistent reduction in hair growth.

Not all physicians use the same laser types, and it’s always good to educate oneself on what is out there when you are shopping for effective laser hair removal treatments.

In this article we shall explore the Fiber-coupled Diode Laser and Alexandrite lasers via the results of a clinical trial to determine if one performs better than the other.

What are the differences between the Fiber-coupled Diode Laser and the Alexandrite lasers?

Both laser types are frequently used for permanent hair removal treatment, the Fiber Coupled Diode being slightly newer on the market than the Alexandrite.

Fiber Coupled Diode Laser​


The Fiber Coupled Diode(FCD) laser operates at an 808 or 810nm wavelength. This longer wavelength allows for a deeper penetration into the skin, theoretically avoiding the melanin in the skin’s epidermis and therefore targeting the hair follicle directly.

In theory the longer wavelength helps avoid skin damage and pigmentation changes that can happen with shorter wavelength laser types. The diode laser performs well on coarse, dark hair and is a good choice for back or bikini hair.​

Alexandrite Laser​

​The Alexandrite operates at a 755nm wavelength, a shorter wavelength than the Diode laser, and has been used effectively for laser hair removal treatment on skin types I-IV.

The shorter wavelength makes the treatment theoretically more effective on lighter skins than darker skins. With its larger spot size the Alexandrite can cover larger areas quite rapidly, so it is the best choice for larger areas such as the back or the chest.

Clinical Study Findings

While both types of lasers are commonly used on skin types ranging from I-IV we wanted to find out if there is any proof that one provides more effective results than another.

We reviewed a clinical trial entitled Long-term efficacy of linear-scanning 808 nm diode laser for hair removal compared to a scanned Alexandrite laser to see what the long term results of treatment with each laser would yield.

This would help us determine whether one method is better than another.​

Test Details

  • In order to review the long-term efficacy of both Alexandrite and Fiber Coupled Diode lasers 31 patients (male and female) with skin types ranging from I to IV on the Fitzpatrick scale underwent regular treatments with both laser types.
  • Patients received 6 treatments with 4 week intervals to the armpits.
  • The right armpit was treated with the 755 nm Alexandrite laser and the left armpit was treated with a continuously linear-scanning 810 nm fiber coupled diode laser.
  • Hair density was recorded before treatment, right after the 6th treatment and 18 months after the final treatment.

Study Results

Significant reduction in hair density was evaluated for both laser types immediately after the last treatment (77.16% for the Fiber Coupled Diode and 71.30% for the Alexandrite). 18 months after treatment the reduction in hair growth was still highly significant for both laser types (75.71% for the Fiber Coupled Diode and 71.90% for the Alexandrite).


While more patients reported redness of the skin and raised red bumps where they had been treated with the Alexandrite laser, all side effects were minimal and dissipated rapidly.

45.50% of the patients found the Fiber Coupled Diode laser to be more painful than the Alexandrite, but all patients agreed that the pain of both lasers was bearable.

The conclusion of the clinical trial deemed that both Alexandrite and Fiber Coupled Diode lasers provide significant and long-term results when used for hair removal treatment on skin types ranging from I to IV. Both laser types rendered the same type of comparable results, directly after treatment and 18 months later.



While treatment with the Alexandrite laser may result in more temporary and harmless side effects (redness of skin and red bumps), and the Fiber Coupled Diode laser may be slightly more painful, both lasers provided significant results after clinical trial, results that lasted even 18 months later.

It can therefore be said that both laser types perform equally well on darker hairs and skin types ranging from I to IV on the Fitzpatrick scale.

If you fall within these ranges you will most likely not see a difference in results with either laser type.