JPH0710731Y2 - Laser probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a laser probe for focusing laser light transmitted from a laser light source through an optical fiber or the like at a desired position on an irradiation target.

[Prior Art] Conventionally, as a laser probe that focuses energy of laser light on an irradiation target object and performs a desired treatment on the irradiation target object,
A so-called non-contact type (for example, see Japanese Patent Laid-Open No. 56-106646) in which a laser beam is focused on the irradiated object without bringing the laser probe into contact with the irradiated object, and the tip of the laser probe is attached to the irradiated object. Contact type in which laser light is focused on the irradiated body while being in contact (for example, refer to JP-A-63-318934).
Is known.

[Problems to be Solved by the Invention] In the conventional non-contact type laser probe, it is difficult to keep the distance between the laser beam emitting point of the laser probe and the irradiation target constant, so that the irradiation target is kept constant. There is a problem that it is difficult to destroy the

On the other hand, the conventional contact type laser probe is a sapphire rod or the like formed in a tapered shape so that the diameter becomes smaller toward the tip, and the laser light is internally reflected and focused on the tip. Is. Therefore, by bringing the tip end into contact with the object to be irradiated, as a result, the distance between the laser light emitting point and the object to be irradiated can always be kept constant, and the problem of the conventional non-contact laser probe does not occur. .

However, this contact type laser probe also has the following problems.

When the irradiated body is irradiated with laser light to evaporate or break the irradiated body, scattered matter generated at the time of the breaking adheres to the periphery of the tip of the laser probe. When the scattered matter adheres, the laser light is absorbed at that portion, or the laser light leaks to the outside. Therefore, the amount of laser light guided to the tip of the laser probe is reduced, and the ability to destroy the irradiated body is reduced.

If this contact type laser probe is used for focusing pulsed laser light, it is highly likely to be broken and is not practical. That is, in general, pulsed laser light has a large peak power of the laser, and thus causes a significant thermal strain inside the laser probe. Therefore, if such thermal strain is repeatedly applied, it will be destroyed by fatigue. Moreover, as described above, when the scattered matter or the like adheres to the tip portion, the scattered matter absorbs the laser beam and locally causes a rapid temperature rise, which accelerates the destruction.

The present invention has been made under the background described above, and it is possible to keep the distance between the laser light emitting point and the irradiation target constant, and to improve the focusing power on the irradiation target as it is used. It is an object of the present invention to provide a laser probe that does not deteriorate and is applicable to pulsed laser light.

[Means for Solving the Problems] The present invention solves the above problems by adopting the following configuration.

By the light focusing means provided in the probe body case, the laser light introduced from the base end of the body case is focused and emitted from the emission hole of the tip end, while the tip end is brought into contact with the irradiated body. It is a laser probe for irradiating the irradiated body with the laser light, wherein the main body case is provided with a gas flow passage for introducing gas into the main body case and discharging the gas from an emission hole of the tip portion. A gas guide groove extending from an injection hole at the tip of the main body case toward the outer peripheral side surface of the tip is formed.

[Operation] According to the above configuration, when laser light transmitted through, for example, an optical fiber is introduced from the base end portion, the laser light is focused by the light focusing means and emitted from the emission hole. . In this case, when the focusing point of the focusing means is set near the exit of the emission hole and the tip of the laser probe is brought into contact with the irradiation target, the irradiation target is irradiated with focused light and The object to be irradiated is transpired, destroyed, or otherwise treated.

On the other hand, when the gas is guided to the injection hole in the probe body through the gas flow passage, the gas is discharged to the outside from the injection hole. The released gas collides with the irradiation target body and diffuses to the outside through the gas guide groove at the tip of the probe body. At this time, when scattered matter is generated from the irradiated body, the gas diffuses the scattered matter to the outside through the guide groove. Therefore, there is no possibility that the scattered matter or the like will enter the probe main body to contaminate the light focusing means or the like. Moreover, the distance between the laser light emitting point and the irradiation target can be kept constant, and, for example, means such as a lens can be used as the light focusing means provided in the probe main body. According to this, It can also be applied to pulsed laser light.

[Embodiment] FIG. 1 is a sectional view of a laser probe according to a first embodiment of the present invention, and FIG. 2 is a front view of the first embodiment. Hereinafter, the first embodiment will be described in detail with reference to these drawings.

In the figure, reference numerals 111 and 112 respectively denote a case base portion and a tip cap constituting the probe body case, and reference numerals 121 and 12
Reference numeral 131 denotes an optical fiber. Reference numeral 131 denotes an optical fiber. In this case, the lenses 121, 122, 123 are housed inside the case base 111, and the case base 111
The tip cap 112 is screwed to the right end of FIG. On the other hand, an optical fiber 131 is coupled to the left end portion of the case base 111 in FIG. 1 via a fiber mounting bracket 132.

The case base 111 has a substantially cylindrical shape, and the left side in FIG. 1 is a small diameter portion 111a and the right side in FIG. 1 is a large diameter portion 111b. The lenses 121, 122, 123 are fitted to the large diameter portion 111b. In that case, ring spacers 121a and 122a are interposed between these lenses. Then, the tip cap 112 is attached to the case base 111.
Screwed to the tip cap 112 and the stepped portion 111c formed by the large diameter portion 111b and the small diameter portion 111a.
Between the lens 121, 122, 123 and the spacer 121a,
The lenses are fixed by sandwiching 122a.

Further, a gas flow groove 111d is formed on the inner peripheral surface of the case base 111 from the left side to the right end in FIG. Therefore, with the lenses 121, 122, 123 and the spacers 121a, 122a attached, the first inside of the case base 111 is passed through the gas flow groove 111d.
Gas can be made to flow from the left side to the right end in the figure.

A male screw 111e is formed on the outer peripheral portion of the right end of FIG. 1 of the case base 111, and the tip cap is attached to the male screw 111e.
A female screw 112a formed on the inner peripheral surface of the left end portion of 112 in FIG. 1 is screwed. That is, the tip cap 112 is
The left side in FIG. 1 is formed in a substantially cylindrical shape, and the female screw 112a is formed on the inner peripheral surface of the cylinder. The diameter of the cylinder is gradually reduced toward the right side in FIG. 1, and an injection hole 112b is formed at the tip. The diameter of the emission hole 112b is formed as small as possible without blocking the laser beam focused on the point P. In this embodiment, the spot diameter of the laser light focused on the point P is 0.5 mm and the hole diameter is 1.0 mm. Further, four gas guide grooves 112 are provided on the tapered outer peripheral surface on the left side.
c, 112d, 112e, 112f are formed. As shown in FIG. 2, the four gas guide grooves 112c to 112f are formed along the inclined direction of the tapered outer peripheral surface from the injection hole 112b, and the width increases as the distance from the injection hole 112b increases. Is formed. The tip cap 11
Gas flow groove 1 at the boundary between the cylindrical part and the tapered part inside 2
12g is formed.

On the other hand, an optical fiber 131 is optically coupled to the left end portion of the case base 111 in FIG. That is, a female screw 111f is formed on the inner peripheral surface of the left end portion of the case base 111 in FIG. 1, and a male screw 132a formed on the outer peripheral portion of the fiber mounting bracket 132 is formed on the female screw 111f.
Are screwed together.

The fiber mounting member 132 has a substantially cylindrical shape, and the tip end of the optical fiber 131 housed in the outer covering tube 133 is fitted inside and fixed by a method such as bonding. That is, the first inside of the fiber mounting bracket 132
The left side in the drawing is a large diameter portion 132b, and the right side is a small diameter portion 132c. The exterior coating tube 133 is fixed to the large diameter portion 132b, and the optical fiber 131 protruding from the tip of the exterior coating tube 133 is fixed to the small diameter portion 132c. And
The end surface 131a of the optical fiber 131 is exposed in the case base 111 so as to face the lens 121.
A gas flow groove 132d is formed in the small diameter portion 132c of the fiber mounting bracket 132.

The inner diameter of the outer sheath tube 133 is larger than the outer diameter of the optical fiber 131, and a gas flow passage 134 is formed between them.

In the above configuration, when the laser light 1 is introduced into the case base 111 from the laser oscillator (not shown) through the optical fiber 131, the laser light 1 is emitted from the lenses 121, 12
The light is focused on point P near the emitted light 112b by 2,123. Accordingly, when the tip end portion of the tip cap 112 is brought into contact with an irradiation target body (not shown), the irradiation target body can be subjected to treatment such as evaporation and destruction.

In this case, a cooling gas (for example, dry air) is supplied into the case base 111 through the gas flow path 134 of the exterior covering tube 133 and the gas flow groove 132d of the fiber mounting bracket 132.
When the gas is introduced, the gas is discharged to the outside through the gas flow groove 111d of the case base 111, the gas flow groove 112g of the tip cap 112 and the injection hole 112b as shown by a solid arrow a, and an object to be irradiated (not shown) is discharged. And is diffused through the gas guide grooves 112c to 112f. In this case, if the cooling gas to be introduced is 5 l / min, it is discharged from the injection hole 112b at a flow rate of 106 m / sec. At that time, if scattered matter, evaporated matter, or the like is generated from the irradiation target, these are carried to the cooling gas and are diffused to the outside. Therefore, there is no possibility that the scattered matter or the like will enter the probe main body to contaminate the light focusing means or the like. Moreover, since the distance between the laser light emitting point and the irradiation target can be kept constant, and the lens is used as the light focusing means provided in the probe body, it can be used for pulsed laser light. Can be applied.

FIG. 3 is a partial view of the second embodiment of the present invention, FIG. 3 (a) is a partial sectional view, and FIG. 3 (b) is a front view. This embodiment corresponds to the tip cap 112b in the first embodiment.
The structure is the same as that of the first embodiment except that the shape of the gas guide grooves 112c to 112g formed in the above is changed to gas guide grooves 212c, 212d, 212e and 212g.

That is, in this embodiment, the gas guide grooves 212c to 212g are made deeper and wider than in the first embodiment. Thus, the cooling gas can be smoothly diffused to the outside even when the tip cap 112 is strongly brought into contact with the object to be irradiated.

FIG. 4 is a partial view of a third embodiment of the present invention, FIG. 4 (a) is a partial sectional view, and FIG. 4 (b) is a front view. This embodiment corresponds to the tip cap 112b in the first embodiment.
It has the same configuration as that of the first embodiment except that the shape of the gas guide grooves 112c to 112g formed in the above is changed to gas guide grooves 312c, 312d, 312e and 312g.

That is, in this embodiment, the gas guide grooves 312c to 312g are used.
The groove depth near the injection hole 112b is deeper than that in the first embodiment. Thus, the cooling gas can be smoothly diffused to the outside even when the tip cap 112 is strongly brought into contact with the object to be irradiated.

FIG. 5 is a sectional view of a fourth embodiment of the present invention.

This embodiment has the same configuration as that of the first embodiment except that the light collecting rod 420 is used as the light collecting means. The condensing rod 420 is made of glass, sapphire, or other translucent material and is formed in a taper shape such that the diameter becomes smaller toward the tip, and the light is incident from the base end, that is, the left end in the figure. The laser light is internally reflected and focused on the tip.

The condensing rod 420 has a base end fixed to the fiber fixing member 132 by a fixing ring 435 having a substantially cylindrical shape. That is, the female screw formed on the inner peripheral surface of the fixing ring 435 is fixed by being screwed into the male screw formed on the outer peripheral surface of the fiber fixing bracket 132.

According to this embodiment, substantially the same advantages as the above-mentioned embodiments can be obtained. However, this embodiment is not applicable to pulsed laser light.

[Advantages of the Invention] As described in detail above, the present invention focuses the laser light introduced from the base end portion of the main body case by the light focusing means provided in the probe main body case, and ejects the light from the emission hole at the front end portion. A laser probe for irradiating the irradiated body with the laser beam while contacting the tip with the irradiated body, wherein a gas is introduced into the main body case into the main body case. And a gas flow passage through which the gas is discharged from the injection hole of the tip portion is formed, and a gas guide groove is formed from the injection hole of the tip portion of the main body case toward the outer peripheral side surface portion of the tip portion. With this, it is possible to obtain a laser probe in which the distance between the laser light emitting point and the irradiation target can be kept constant, and the focusing power on the irradiation target does not decrease with use. What is A.

[Brief description of drawings]

FIG. 1 is a sectional view of a laser probe according to a first embodiment of the present invention, FIG. 2 is a front view of the first embodiment, FIG. 3 is a partial view of a second embodiment of the present invention, and FIG. FIG. 5 is a partial view of a third embodiment of the present invention, and FIG. 5 is a sectional view of a fourth embodiment of the present invention. 111,112 ...... Case base and tip cap constituting the probe body case, 121,122,123 ...... lens constituting condenser means, 112b ...... injection holes, 111d, 112g ...... gas circulation grooves constituting gas flow passages, 112c, 112d , 112e, 112f, 212c, 212
d, 212e, 212f, 312c, 312d, 312e, 312f …… Gas guide groove.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G02B 7/00 H 8102-2K

Claims (1)

[Scope of utility model registration request] 1. A light focusing means provided in a probe main body case focuses laser light introduced from a base end portion of the main body case and emits the laser light from an emission hole of a front end portion, and the front end portion is irradiated. A laser probe adapted to irradiate the irradiated body with the laser beam while contacting with a body, the gas being introduced into the body case to be discharged from an emission hole of the tip portion. A laser probe, characterized in that a flow passage is provided, and a gas guide groove extending from an injection hole at the tip of the main body case toward the outer peripheral side surface of the tip is formed.