Laser light irradiation device

1. A laser light irradiation device comprising:

an optical guide having a columnar portion and configured to transmit laser light through the columnar portion;

a reflecting portion having a reflecting surface configured to reflect the laser light transmitted through the optical guide, the reflecting portion including an optically transmissive portion through which light is transmitted and a reflecting film disposed outside the optically transmissive portion;

a transmitting portion having a window part, the transmitting portion being disposed between the columnar portion of the optical guide and the reflecting portion in such a manner that one end of the transmitting portion is in contact with the columnar portion, the transmitting portion configured to transmit the laser light emitted from the columnar portion to the reflecting portion and to transmit the laser light reflected by the reflecting surface to cause the laser light to be radiated externally through the window part;

a cap configured to surround at least part of the columnar portion, the transmitting portion, and the optically transmissive portion, the reflecting film being disposed outside the cap to cover the optically transmissive portion, and the reflecting surface being formed by a boundary between the reflecting film and the cap; and

wherein a diameter of the reflecting surface gradually becomes smaller as a distance from a boundary between the transmitting portion and the reflecting portion increases, and a diameter of the transmitting portion becomes smaller as a distance from the columnar portion increases.

2. The laser light irradiation device according to claim 1 , wherein in intensity distribution of the laser light radiated from the window part in an axial direction of the laser light irradiation device, a position at which maximum intensity is indicated is closer to the optical guide than a center of the transmitting portion in the axial direction.

3. The laser light irradiation device according to claim 1 , wherein reflectance of the reflecting surface is highest at a central part of the reflecting surface.

4. The laser light irradiation device according to claim 3 , wherein the reflecting surface has a plurality of regions different from each other in the reflectance.

5. The laser light irradiation device according to claim 1 , wherein the reflecting surface has a focal point and the laser light reflected by the reflecting surface passes through the focal point and is radiated to the external.

6. The laser light irradiation device according to claim 5 , wherein the reflecting surface is a spherical surface.

7. The laser light irradiation device according to claim 5 , wherein the reflecting surface is a parabolic surface.

8. The laser light irradiation device according to claim 1 , wherein the columnar portion of the optical guide, the transmitting portion, and an optically transmissive portion of the reflecting portion are formed of a same material and having a continuous monolithic structure.

9. A method of treating varicose veins, the method comprising:

inserting a laser light irradiation device into a vein of a subject, the laser light irradiation device comprising:

an optical guide having a columnar portion and configured to transmit laser light through the columnar portion;

a reflecting portion having a reflecting surface configured to reflect the laser light transmitted through the optical guide, the reflecting portion including an optically transmissive portion through which light is transmitted and a reflecting film disposed outside the optically transmissive portion;

a transmitting portion having a window part, the transmitting portion being and is disposed between the columnar portion of the optical guide and the reflecting portion in such a manner that one end of the transmitting portion is in contact with the columnar portion, the transmitting portion configured to transmit the laser light emitted from the columnar portion to the reflecting portion and to transmit the laser light reflected by the reflecting surface to cause the laser light to be radiated externally through the window part;

a cap configured to surround at least part of the columnar portion, the transmitting portion, and the optically transmissive portion, the reflecting film being disposed outside the cap to cover the optically transmissive portion, and the reflecting surface being formed by a boundary between the reflecting film and the cap; and

wherein a diameter of the reflecting surface becomes smaller as a distance from a boundary between the transmitting portion and the reflecting portion increases, and a diameter of the transmitting portion becomes smaller as a distance from the columnar portion increases; and

irradiating a wall of the vein by transmitting the laser light emitted from the columnar portion through the transmitting portion to the reflecting portion and wherein the laser light is reflected by the reflecting surface and radiates externally through the window part.

10. The method according to claim 9 , comprising:

occluding the vein with the laser light radiating externally through the window part.

11. The method according to claim 9 , wherein in intensity distribution of the laser light radiated from the window part in an axial direction of the laser light irradiation device, a position at which maximum intensity is indicated is closer to the optical guide than a center of the transmitting portion in the axial direction.

12. A laser light irradiation device, the laser light irradiation device comprising:

an optical guide having a columnar portion, the optical guide being configured to transmit laser light through the columnar portion;

a reflecting portion having a reflecting surface configured to reflect the laser light transmitted through the optical guide;

a transmitting portion having a window part, the transmitting portion being disposed between the columnar portion of the optical guide and the reflecting portion in such a manner that one end of the transmitting portion is in contact with the columnar portion, the transmitting portion configured to transmit the laser light emitted from the columnar portion to the reflecting portion and to transmit the laser light reflected by the reflecting surface to cause the laser light to be radiated externally through the window part, and wherein a diameter of the reflecting surface becomes smaller as a distance from a boundary between the transmitting portion and the reflecting portion increases; and

wherein the reflecting portion includes an optically transmissive portion through which light is transmitted and a reflecting film disposed outside the optically transmissive portion, and a cap configured to surrounds at least part of the columnar portion, the transmitting portion, and the optically transmissive portion, the reflecting film being disposed outside the cap to cover the optically transmissive portion, and the reflecting surface being formed by a boundary between the reflecting film and the cap.

13. The laser light irradiation device according to claim 12 , wherein in intensity distribution of the laser light radiated from the window part in an axial direction of the laser light irradiation device, a position at which maximum intensity is indicated is closer to the optical guide than a center of the transmitting portion in the axial direction.

14. The laser light irradiation device according to claim 12 , wherein reflectance of the reflecting surface is highest at a central part of the reflecting surface.

15. The laser light irradiation device according to claim 14 , wherein the reflecting surface has a plurality of regions different from each other in the reflectance.

16. The laser light irradiation device according to claim 12 , wherein the columnar portion of the optical guide, the transmitting portion, and an optically transmissive portion of the reflecting portion are formed of a same material and having a continuous monolithic structure.