An optical transmissive, light-diffusing, fiber tip assembly having a radiation-scattering particles incorporated therein and a reflective end surface is disclosed for use in phototherapy. As radiation propagates through the fiber tip, a portion of the radiation is scattered in a cylindrical (or partially cylindrical) pattern along the length of the fiber tip. Radiation which is not scattered during this initial pass through the tip is reflected by at least one surface of the assembly and returned through the tip. During this second pass, the remaining radiation (or at least a major portion of this returning radiation) again encounters the scatterers which provide further radial diffusion of the radiation. Preferably, the scattering medium and the reflective end cap interact to provide a substantially uniform axial distribution of laser radiation over the length of the tip apparatus. Methods and devices are also disclosed in which a dielectric structure is operatively coupled to phototherapeutic instrument to reflect light without substantial heating. The invention is particularly useful in light diffusive tip assemblies for phototherapy that have components which increase in temperature after prolonged exposure to light, such as mirrors and metallic structures incorporated into such diffusers to facilitate radiographic or fluoroscopic imaging during a therapeutic procedure.
REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 08/991,130, incorporated herein by reference and filed Dec. 16, 1997 now U.S. Pat. No. 5,947 959, was a continuation-in-part of U.S. patent application Ser. No. 08/827,631, incorporated herein by reference and filed Apr. 10, 1997 (now U.S. Pat. No. 5,908,415), which was a continuation of U.S. patent application Ser. No. 08/303,605, incorporated herein by reference and filed Sep. 9, 1994 (now abandoned).
A light fiber of directional side light extraction type capable of keeping the sectional shape as desired, reducing the undesirable light leakage to the outside through the light diffusive and reflective portion and extracting a highly directional and a highly bright light, and a process for manufacturing the same. Said object can be attained by co-extruding a resinous material only, and a material obtained by light scattering fine particles with a resinous material to disperse them therein so as to form a light diffusive and reflective film in a desired portion at least on the inner periphery of the clad.
A method of controllably heating the annulus of an intervertebral disc is disclosed. The method comprises the steps of forming an access channel through the annulus of an intervertebral disc while avoiding the nucleus of the intervertebral disc, inserting a light-emitting diffuser into the annulus, and activating the light-emitting diffuser to emit diffuse light while maintaining the light-emitting diffuser within the access channel to raise the temperature of the annulus to a value sufficient to cause a change in the characteristics of the annulus.
In crystallizing a semiconductor thin film of large area by overlapping regions of irradiation with a laser beam, uniform crystallinity of the film is achieved. A semiconductor thin film is crystallized by performing shaping laser light emitted to define a laser beam which has a predetermined intensity distribution in a predetermined irradiation region, and repeatedly irradiating the semiconductor thin film with the laser beam while scanning the film so that irradiation regions may be overlapped. The laser beam is shaped so that the sectional intensity distribution of the laser beam in the irradiation region as taken in the direction of the scanning may be convex, and that the peak of the intensity distribution lies at a position which is between the front end and rear end of the irradiation region in relation to the scanning direction and which is nearer to the front end with respect to the middle of the irradiation region. The laser beam is so shaped that an intensity at the front end of the irradiation region becomes lower in a range within 30% as compared with the intensity of the peak, and the intensity at the rear end of the irradiation region becomes lower in a range exceeding 5% as compared with the intensity of the peak.
In the region of a distal end at its circumference the waveguide is formed transparent to the radiation which impinges onto the surface of the waveguide at suitable angles, and in the region of the distal end in the inside of the waveguide there are arranged scatter elements which scatter radiation transmitted by the waveguide in the direction of the distal end in a direction with a proximally directed component which exits the circumference of the waveguide. Alternatively, radiation entering into the waveguide at the circumference of the waveguide in a direction with a distally directed component is transmitted by the waveguide in the direction of the proximal end, as well as to its use and to a method for its manufacture.
