AN OPTICAL ASSEMBLY FOR USE IN A SKIN TREATMENT DEVICE

Provided is an optical assembly 1 for use in a skin treatment device 2, and the use thereof in a treatment method. The optical assembly 1 comprises a light source 10, a first prism 11 and first and second guiding elements 12 and 13 with enclosed reflective faces disposed facing each other. The first prism 11 includes a first surface 111, a second surface 112 inclined with the first surface 111 and a third surface 113 adjoining the first 111 and the second 112 surfaces. The first guiding element 12 is arranged to guide the light transmitted from the light source 10 through the first surface 111 of the first prism. The second guiding element is further arranged to receive through the second surface 112 of the first prism 11, the light reflected from the third surface 113 of the first prism and output the received light for illuminating the skin. The first surface 111 and the second surface 112 of the first prism 11 are separated from the first guiding element 12 and the second guiding element 13, respectively, by a refractive index interface.