title: A low cost light diffuser made of metal coil.
abstract: We proposed a low cost flexible light diffuser made of metal coil to obtain an appropriate light dose against certain laser therapies in narrow bending organs. We investigated experimentally the diffusion light dose of prototype coils made of stainless steel (sus304). We measured the diffusion light intensity of the prototype coils along the irradiation direction and the circumferential direction with the various pitch distances of the prototype coils and numerical aperture (NA) of laser light beam as the characteristic parameters of the light diffusion. We measured the temperature elevation of the prototype coils to study the waste energy of these prototype coils. The FWHM on the light intensity along the prototype coils marked up to 12.8mm with the constant pitch distance of 0.09 mm and the fiber output light NA of 0.038. The FWHM on the light intensity was improved to 13.7 mm with the composite pitch distance coils of which the pitch distances were 0.09 mm in the proximate and 0.18 mm in the distal. Since the efficiency of the diffusion irradiation against the fiber output was typically 7.7% in the prototype coils of which the surface reflectance was 50%, approximately 90% of the laser light energy was transferred to the temperature elevation. We estimated the practical diffusion efficiency around 75% using the high reflection of the prototype coils surface up to 90%.
authors.affiliation: School of fundamental Science and Technology, Graduate School of Science and Technology Keio University (Japan).
authors.forename: Nozomi
authors.initials: N
authors.lastname: Morita
authors.forename: Tsunenori
authors.initials: T
authors.lastname: Arai
mesh_terms: D004058:Diffusion; D004867:Equipment Design; D007834:Lasers; D008027:Light; D055095:Optics and Photonics; D011874:Radiometry / Q000191:economics / Q000379:methods*; D012542:Scattering, Radiation; D013696:Temperature