JPH0350888Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a laser probe that performs medical treatment by emitting laser light from the tip of an optical fiber.

Prior Art Laser probes that emit laser beams from the tip of an optical fiber to perform various treatments are well known, but in conventional laser probes, the light-emitting end surface of the optical fiber is processed into a flat surface, or the light-emitting end surface of the optical fiber is processed into a flat surface. A lens or the like is provided on the end face to widen or narrow the light emission angle for irradiation.

FIG. 3 is a cross-sectional configuration diagram for explaining an example of a conventional laser probe. In the figure, 1 is an optical fiber, 2 is a pipe through which the optical fiber is inserted, and 3 is the tip of the optical fiber 1. As is well known, the protective tube is used to protect the optical fiber 1 from the end face 1a of the optical fiber 1, which emits laser light to perform various treatments. Therefore, the light emitting end face 1 of the optical fiber 1
Generally, a is processed into a flat surface, so that the laser light emitted from the light emitting end face has no spread, and the laser light can only be irradiated onto a very narrow area. In most cases, this is sufficient; in fact, most of the laser fibers currently in use have optical fibers whose light emitting end faces are machined to be flat. However, when the affected area is large, it is more efficient to irradiate as wide an area as possible in one irradiation. Therefore, for example, as shown in FIG. 3, it has been proposed that the light emitting end surface 1a of the optical fiber 1 is made into a lens shape, thereby making the laser light emitted from the end surface 1a broader. has been done.

FIG. 4 is a diagram showing the distribution state of the laser light emitted from the optical fiber 1 as described above, and the aperture angle of the optical fiber 1 is set to θ as shown in FIG. 4a.
When this happens, the light intensity distribution of the laser beam on the irradiation surface A becomes as shown in FIG. 4b, showing a substantially Gaussian distribution. Even if the light emitting end 1a of the optical fiber is made into a lens shape or a lens is provided to disperse the emitted light, the distribution characteristics of the light intensity will be approximately the same as the distribution characteristics shown in FIG. 4b. Therefore, the light intensity distribution on the irradiation surface is not uniform, and the peripheral portions where the light intensity is weak cannot be sufficiently treated, resulting in incomplete treatment in these portions. In addition, if we try to use only the part with strong light intensity in the central part, the light energy in the peripheral part will be wasted, and if the light intensity in the central part required for treatment is constant, There were drawbacks such as the need to narrow the irradiation area.

Purpose This invention was developed in view of the above-mentioned circumstances, and in particular, it was developed with the aim of keeping the laser beam irradiation intensity approximately constant at the treatment site and widening the irradiation area as much as possible. be.

Structure FIG. 5 is a diagram for explaining the operating principle of the present invention. In the figure, 1 is an optical fiber, and 4 is an optical fiber extending from the light emitting end surface 1a to the light emitting end surface 1a side of the optical fiber 1. The inner surface of the cylinder 4 is formed into a reflective surface. Of the laser light emitted from the end face 1a of the optical fiber 1, the light indicated by arrows 5a and 5b is light emitted at an angle corresponding to the aperture angle of the optical fiber 1, and the light indicated by arrow 6
The light shown in is 1/ in the center of the Gaussian distribution.
It is light emitted at an angle corresponding to 3σ, and the fourth
It shows the light at the 1/3σ point in Figure b. Therefore, the light between arrows 6 and 5a (indicated by diagonal lines in FIG. 4a) is reflected by the inner surface of the cylinder 4 and reaches the irradiation surface A, but is not reflected by this reflection surface. The light intensity on the irradiation surface A of the light is the fifth
It will look like curves 5 and 5 in Figure c. That is, the intensity distribution of the light reflected at the reflective surface 4a of the prologue 4 is as shown by curve 5, and the distribution intensity of the light reflected at the reflective surface 4b is as shown by curve 5.
It becomes like this. Therefore, the light intensity distribution on the irradiation surface A becomes as shown in FIG. Laser light can be irradiated.

FIG. 1 is a cross-sectional configuration diagram for explaining an embodiment of a laser probe constructed based on the above-mentioned principle. In the figure, 1 is an optical fiber, 4 is the cylinder, and the cylinder 4 is Light emission end 1 of optical fiber 1
It is attached to extend from the light emitting end 1a on the a side, and its inner surface is coated with a plating film, a light reflective coating film, etc. to form a light reflective surface.
Note that the light emitting end surface 1a of the optical fiber 1 may be cut into a plane or may be formed into a lens, as described above. Length L of cylinder 4
is basically the light emitting end 1a of the optical fiber 1.
For example, as mentioned above, when the light distribution intensity on the irradiation surface A shows a Gaussian distribution, the emission angle of the optical fiber 1 is determined by the light intensity distribution of the laser light emitted from the optical fiber 1. The emitted light is reflected once on the inner surface of the cylindrical body 4, and the length is preferably set to correspond to the length of the reflected light reaching the light emitting end 4'. In this embodiment, the light emitting end 4' of the probe 4 is used close to the treatment area, so a protective glass plate 7 is integrally attached to the light emitting end 4' side. However, this is not necessary.

In the above embodiment, the light irradiation area is approximately determined by the aperture angle of the optical fiber 1, and it is not possible to obtain a very large irradiation area.

FIG. 2 shows an example in which the above-mentioned drawbacks of the embodiment shown in FIG. The light emitted from the cylindrical body 4 as described above is diffused by the convex lens 11, and the light diffused by the convex lens 11 is converged by the concave lens 12 to become parallel light beams. In this way, compared to the laser probe shown in FIG. 1, it is possible to irradiate the laser beam substantially uniformly over a wider area.

Effects As is clear from the above explanation, according to the present invention, the laser light emitted from the optical fiber can be used effectively, that is, without waste, and the laser light can be emitted almost uniformly over a relatively wide area. It can be irradiated.

[Brief explanation of the drawing]

1 and 2 are main part configuration diagrams for explaining an embodiment of the laser probe according to the present invention, FIG. 3 is a configuration diagram for explaining an example of a conventional laser probe, and FIG. 4 Figure 5 shows the light intensity distribution on the irradiation surface by a conventional laser probe.
The figure is a diagram showing a light intensity distribution for explaining the operating principle of the laser probe according to the present invention. 1... Optical fiber, 1a... Light emitting end surface, 2
...Optical fiber insertion pipe, 3...Protection tube, 4
... Cylindrical body, 5a, 5b, 5c, 5, 5... Light intensity distribution characteristic curve, 10... Optical system, 11... Convex lens, 12... Concave lens.

Claims (1)

[Scope of utility model registration request] A laser probe that performs a treatment by emitting laser light from an end face of an optical fiber has a hollow cylinder extending from the light emitting end face of the optical fiber, and the hollow cylinder has an inner surface. A laser probe formed on a reflective surface, wherein the length of the hollow cylinder is approximately equal to the wavelength of laser light propagating within the optical fiber at an aperture angle of the optical fiber.