RESUMO
Phototherapy has become a treatment of choice in many areas of medicine. Light can deliver energy to tissue selectively, targeting specific structures in order to induce the desired therapeutic outcome. For the safe and effective removal of unwanted hair, the key optical parameters are wavelength, pulse duration and energy density, and can vary dependent upon skin and hair color. In recent years, the use of broad spectrum white light sources has proved to be safe and efficacious in the removal of hair with minimal short- or long-term side effects. Whilst these highly flexible devices can achieve the desired results, there is scope for improvement. There are two key limitations to these devices: an inability to produce a 'true' long pulse matched to the thermal relaxation time of the hair structure and fluctuations in the output spectrum can lead to ineffective treatment with an increased risk of side effects. This paper describes an alternative approach to producing long pulse, constant spectrum optical pulses and presents clinical data showing improved efficacy in long-term hair removal.