Patent ID: 8620125

Claim:
A light diffusing optical fiber for use in an illumination device, the light diffusing optical fiber comprising: a core portion formed from silica-based glass and comprising helical voids randomly distributed in the core portion and wrapped around a long axis of the light diffusing optical fiber such that an angle between the long axis and the helical voids is non-zero, a pitch of the helical voids varying along an axial length of the light diffusing optical fiber; and a cladding surrounding and in direct contact with the core portion, wherein light guided by the core portion is scattered by the helical voids radially outward and through the cladding such that the light diffusing optical fiber emits light with a predetermined intensity over the axial length of the light diffusing optical fiber, the light diffusing optical fiber having a scattering induced attenuation loss greater than about 0.2 dB/m at a wavelength of 550 nm.