Light diffuser for photodynamic therapy

An optical light diffuser (10) which provides a light emission pattern generally cylindrical (18) comprising an optical fiber (12) having a guiding core and a cladding surrounding the core, optical fiber having a proximal end for be coupled to a source of optical radiation and a distal end for emitting optical radiation, and operable to transmit the optical radiation from its proximal to its distal end, characterized in that the optical fiber has an abraded section ( 14) at its distal end which shrinks into a shaped tip bullet (16), which section allows light to escape uniformly over the abraded section forming a generally cylindrical pattern of diffuse light that surrounds the distal end of the optical fiber.