A laser device for dermocosmetic, medical, or aesthetic treatments, comprising:A) a laser system comprising a lamp-pumped source；B) an optical fibre transporting the laser beam produced by said source；C) a handpiece or a scanner connected to said optical fibre, comprising a lens and mirror system projecting the image of the laser beam onto the area to be treated；characterized in that said optical fibre has a rectangular section and said image is rectangular.A method of dermocosmetic laser treatment characterized by rectangular laser spots is also claimed.
