JP7057444B2 - Fiber optic probe - Google Patents

Description

The present invention relates to an optical fiber probe.
This application claims priority based on Japanese Patent Application No. 2018-232881 filed in Japan on December 12, 2018, the contents of which are incorporated herein by reference.

For example, in prostate laser evaporation, which is a treatment for prostate hypertrophy, photodynamic therapy, which is a treatment for early lung cancer, and lower concha mucosal laser treatment, which is a treatment for allergic rhinitis, etc., is connected to a medical laser oscillator. The affected area is irradiated with a laser beam by using the optical fiber.
In order to reliably irradiate the affected area with laser light, laser light irradiation from the optical fiber to the affected area is more lateral irradiation from the optical fiber tip than forward irradiation along the optical axis direction from the optical fiber tip. Is valid. By irradiating the laser beam from the tip of the optical fiber to the side, the irradiation range can be increased. Therefore, for example, as shown in FIG. 1 of Patent Document 1, a microlens portion and a microlens that evenly magnify and project the light guided by the optical fiber onto the grip portion into which the tip portion of the optical fiber is inserted. A side-reflection type probe incorporating a reflection mirror portion that reflects light that has passed through the portion to the side of the grip portion has been proposed.

Japanese Patent Application Laid-Open No. 2006-288500

However, in the lateral reflection type probe described in Patent Document 1, the light reflected by the reflection mirror portion is transferred between the microlens portion inside the grip portion and the reflection mirror portion arranged so as to be separated from the microlens portion. The structure is such that the light is emitted in a specific direction on the side of the probe, and the light irradiation range is narrow. Therefore, when irradiating the entire irradiation target range with light, a large number of operations such as movement of the probe and rotation around the axis are required, which may result in inefficiency in the light irradiation work.

Further, the lateral reflection type probe described in Patent Document 1 has a configuration in which a reflection mirror portion is attached to a cylindrical grip portion capable of accommodating an optical fiber tip portion and a microlens portion, and it is difficult to reduce the cost. rice field.
The reflection mirror portion needs to be attached to a predetermined position of the grip portion in a predetermined direction with high accuracy. The grip portion needs to accurately support the microlens portion and the reflection mirror portion at predetermined positions in predetermined directions. Therefore, it is difficult to reduce the manufacturing cost of the lateral reflection type probe described in Patent Document 1.

An object to be solved by the aspect of the present invention is to provide an optical fiber probe that can secure a wide lateral irradiation range of light incident on an optical fiber at low cost.

In order to solve the above problems, the optical fiber probe of the first aspect has an optical fiber, a coreless fiber, and a reflective film, and an end portion of the optical fiber and a first end portion of the coreless fiber are formed. It is connected and the reflective film is arranged at the second end of the coreless fiber.

Further having a light-transmitting coreless fiber exterior material covering the side surface of the coreless fiber, the coreless fiber exterior material may have a refractive index equal to or higher than that of the coreless fiber.

The coreless fiber exterior material may be a resin coating layer formed on at least a side surface of the coreless fiber.
The coreless fiber exterior material may be a glass capillary accommodating the coreless fiber.

In the above-mentioned optical fiber probe, a rough surface portion having a plurality of irregularities may be formed on the side surface of the coreless fiber exterior material.
In the above-mentioned optical fiber probe, the end surface of the second end portion of the coreless fiber may be a convex curved surface.

The end surface of the second end portion of the coreless fiber is a non-flat surface having at least one of a convex portion and a concave portion and having no flat surface orthogonal to the optical axis at the end portion of the optical fiber on the coreless fiber side. There may be.

The side surface of the optical fiber may be covered with a fiber coat layer formed of polyimide.
The optical fiber has a core and a clad covering the core, the core has a core diameter expanding portion having an expanded core diameter, and the core diameter expanding portion may be connected to the coreless fiber. ..
The optical fiber has a core and a clad covering the core, and the outer diameter of the coreless fiber may be the same as the outer diameter of the clad.

According to the optical fiber probe according to the aspect of the present invention, it is possible to provide an optical fiber probe that can secure a wide lateral irradiation range of light incident on the optical fiber at low cost.
Further, according to the above aspect of the present invention, a part of the light propagated from the optical fiber to the coreless fiber and diffused in the coreless fiber is emitted from the side surface of the coreless fiber. Further, this optical fiber probe can travel through the coreless fiber from the tip of the optical fiber and emit the reflected light reflected by the reflective film from the side surface of the coreless fiber.
As a result, the light propagated from the optical fiber to the coreless fiber can be emitted from a wide range on the side surface of the coreless fiber (a wide lateral irradiation range can be secured), and the work efficiency of light irradiation to the irradiation target can be improved. ..

The lateral reflective probe of FIG. 1 of Patent Document 1 requires a tubular grip portion that accommodates the optical fiber tip portion and the microlens portion and can arrange the reflection mirror portion at a predetermined position separated from the microlens portion. On the other hand, the optical fiber probe according to the above aspect does not require the tubular grip portion of the lateral reflective probe of FIG. 1 of Patent Document 1, and is compared with the lateral reflective probe of FIG. 1 of Patent Document 1. It has a simple structure and can be manufactured at low cost.
The optical fiber probe according to the above aspect has a probe tip portion (side radiation portion) including a coreless fiber and a reflective film on the emission end side of the optical fiber, so that the light incident on the optical fiber is lateral. A wide irradiation range can be secured.

It is sectional drawing which shows the optical fiber probe which concerns on 1st Embodiment. It is sectional drawing which shows the optical fiber probe which concerns on 2nd Embodiment, and shows the structure which formed the coreless fiber coating layer which is the resin coating layer which covers a coreless fiber only on the side surface of a coreless fiber. It is sectional drawing which shows the optical fiber probe which concerns on 2nd Embodiment, and shows the structure which formed the coreless fiber coating layer of FIG. 2A so as to cover the reflective film at the tip of a coreless fiber. It is sectional drawing which shows the optical fiber probe which concerns on 3rd Embodiment. It is sectional drawing which shows the optical fiber probe which concerns on 4th Embodiment. It is sectional drawing which shows the optical fiber probe which concerns on 5th Embodiment.

Hereinafter, the optical fiber probe according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an optical fiber probe according to the first embodiment.
The optical fiber probe 10A of FIG. 1 comprises an optical fiber 11, a coreless fiber 12 fused and connected to the tip (emission end) of the optical fiber 11, and a reflective film 13 formed on the tip surface 12a of the coreless fiber 12. Have.
The optical fiber probe 10A has a side radiation portion 20A composed of a coreless fiber 12 and a reflective film 13.

The optical fiber 11 has a core 11a and a clad 11b that covers the side circumference of the core 11a. The core 11a is formed in the central portion in a cross section perpendicular to the longitudinal direction of the optical fiber 11. The optical fiber 11 is a quartz glass fiber having a core-clad structure. The refractive index of the clad 11b is lower than that of the core 11a.
As the optical fiber 11, a multimode optical fiber or the like can be preferably used.

The coreless fiber 12 is a quartz glass fiber having a uniform refractive index as a whole.

In FIG. 1, the cross-sectional shapes of the optical fiber 11 and the coreless fiber 12 are circular, and the optical fiber 11 and the coreless fiber 12 are formed extending along the longitudinal direction.
The length (axis direction dimension) of the coreless fiber 12 is preferably, for example, about 10 to 100 mm.
The coreless fiber 12 has a base end (first end portion) 121, which is one end in the axial direction thereof, fused and connected to the tip of the optical fiber 11 and coaxially attached to the optical fiber 11.

In FIG. 1, the optical fiber 11 and the coreless fiber 12 have the same diameter (outer diameter). Therefore, the coreless fiber 12 is integrated with the optical fiber 11 so that the side surface (outer circumference) 12b of the coreless fiber 12 is continuous with the side surface of the optical fiber 11.
The outer diameter of the coreless fiber 12 may be the same as the outer diameter of the core 11a of the optical fiber 11, or the outer diameter of the coreless fiber 12 may be larger than the outer diameter of the core 11a of the optical fiber 11. The outer diameter of the coreless fiber 12 may be larger than the outer diameter of the optical fiber 11 (outer diameter of the clad 11b), but in consideration of workability when connecting the coreless fiber 12 to the optical fiber 11, the outer diameter of the coreless fiber 12 is taken into consideration. The diameter is preferably 1.5 times or less the outer diameter of the optical fiber 11, and more preferably the same outer diameter.
For the fusion splicing of the coreless fiber 12 to the tip of the optical fiber 11, a known method such as using a commercially available fusion splicer or the like can be used.

The reflective film 13 is formed on the tip surface 12a of the coreless fiber 12. The tip surface 12a is the end face of the tip (second end) 122 on the opposite side of the base end (first end) 121 connected to the optical fiber 11 in the axial direction of the coreless fiber 12.
The reflective film 13 is formed in a layer on the entire tip surface 12a of the coreless fiber 12.

In the optical fiber 11, the optical H is incident from the base end of the optical fiber 11 on the side opposite to the tip to which the coreless fiber 12 is connected. The end where the light H of the optical fiber 11 is incident is also referred to as an incident end. The light H incident from the incident end guides the light H toward the tip (emission end) of the optical fiber 11. The light H guided from the incident end of the optical fiber 11 propagates from the tip of the optical fiber 11 to the coreless fiber 12, and further propagates toward the tip 122 side (tip surface 12a side) of the coreless fiber 12.
The light H guided by the optical fiber 11 and propagating from the tip of the optical fiber 11 through the coreless fiber 12 and reaching the reflective film 13 is reflected by the reflective film 13.

The reflective film 13 may have a structure capable of reflecting light H.
When the light H is a laser beam that irradiates the affected part of the human body for prostate laser evaporation, photodynamic treatment, lower concha mucosal laser treatment, etc., the reflective film 13 is in terms of maintaining stable reflection characteristics. It is preferable to use a metal film or a dielectric multilayer film.

As the reflective film 13, for example, an electroless plating layer formed on the tip surface 12a of the coreless fiber 12 can be suitably adopted.
Further, the reflective film 13 may be a metal vapor-deposited film or the like formed on the tip surface 12a of the coreless fiber 12.
Examples of the material of the reflective film 13 include nickel, tin, gold, silver, and alloys containing two or more selected from these.

Here, an example of a method for manufacturing the optical fiber probe 10A will be described.
In the optical fiber probe 10A of FIG. 1, for example, (1) the base end 121 opposite to the tip surface 12a of the coreless fiber is fused and connected to the tip of the optical fiber 11, and (2) the coreless fiber is connected by a fiber cleaver. It can be cut to an arbitrary length and (3) manufactured by adhering, fusing or vapor-depositing a reflective film on the tip surface 12a of the coreless fiber. When the outer diameters of the coreless fiber 12 and the clad 11b of the optical fiber 11 are the same, these fibers can be fused and connected with a general fusion splicer, so that the optical fiber probe 10A can be easily used. Can be manufactured in.

As another manufacturing method of the optical fiber probe 10A, for example, (1) first, a base end 121 of a long coreless fiber 12 having a length of more than 100 mm is fused and connected to the tip of the optical fiber 11 (2). The coreless fiber 12 is cut at a position separated from the tip of the optical fiber 11 by about 10 to 100 mm, and (3) then the cut surface of the coreless fiber 12 is polished to form the tip surface 12a. (4) Next, the tip surface 12a of the coreless fiber 12 is brought into contact with the plating solution to form a reflective film 13 which is an electroless plating layer on the tip surface 12a of the coreless fiber 12, and an optical fiber probe 10A is manufactured. May be good.

The tip surface 12a of the coreless fiber 12 of the optical fiber probe 10A illustrated in FIG. 1 is a flat surface perpendicular to the central axis of the coreless fiber 12.
However, the tip surface 12a of the coreless fiber 12 is not limited to a flat surface perpendicular to the central axis of the coreless fiber 12, and may be formed into various shapes by polishing the cut surface of the coreless fiber 12.
Polishing of the cut surface of the coreless fiber 12 may be omitted. The optical fiber probe 10A may be manufactured by forming the reflective film 13 directly on the cut surface (the tip surface 12a of the coreless fiber 12) where the unevenness is present.
The formation of the reflective film 13 on the tip surface 12a of the coreless fiber 12 is not limited to the formation of the electroless plating layer, and vapor deposition of a metal material or the like can also be adopted.

As shown in FIG. 1, the light H (transmission light) guided from the incident end of the optical fiber 11 is propagated from the tip of the optical fiber 11 to the coreless fiber 12, and further, the tip 122 side (tip surface) of the coreless fiber 12. Propagate toward the 12a side). Hereinafter, the traveling direction of the optical H propagating from the optical fiber 11 to the coreless fiber 12 is referred to as an optical axis direction.
However, the optical H propagating from the tip of the optical fiber 11 to the coreless fiber 12 expands the beam diameter from the tip of the optical fiber 11 toward the tip 122 of the coreless fiber 12. The beam diameter of the light H propagating from the tip of the optical fiber 11 to the coreless fiber 12 is larger than the outer diameter of the coreless fiber 12 between both ends in the axial direction of the coreless fiber 12. Therefore, a part of the optical H (transmission light) propagating from the tip of the optical fiber 11 to the coreless fiber 12 is emitted from the side surface 12b of the coreless fiber 12 to the outside of the coreless fiber 12 without reaching the reflective film 13. Ru.

Of the light H (transmission light) propagating in the coreless fiber 12 from the tip of the optical fiber 11, the light H emitted from the side surface 12b of the coreless fiber 12 to the outside of the coreless fiber 12 without reaching the reflective film 13 is Hereinafter, it is referred to as the first emitted light H1. The first emitted light H1 is light emitted from the side surface 12b of the coreless fiber 12 to the outside of the coreless fiber 12 in the light H propagating from the base end 121 side to the tip 122 side of the coreless fiber 12.
The optical fiber probe 10A has a length of the coreless fiber 12 so that 40 to 60% of the light H propagated from the tip of the optical fiber 11 to the coreless fiber 12 does not reach the reflective film 13 and becomes the first emitted light H1. It is possible to preferably adopt a configuration in which such factors are adjusted and set.

As shown in FIG. 1, from the side surface 12b of the coreless fiber 12, in addition to the first emitted light H1, the light propagates from the tip of the optical fiber 11 through the coreless fiber 12 to reach the reflective film 13 and is formed by the reflective film 13. The reflected light H (reflected light) is also emitted (exited) to the outside of the coreless fiber 12.
Of the light H (reflected light) propagating from the tip of the optical fiber 11 through the coreless fiber 12 and reflected by the reflective film 13, the light H emitted from the side surface 12b of the coreless fiber 12 to the outside of the coreless fiber 12 is described below. , The second emitted light H2. The second emitted light H2 is light emitted from the side surface 12b of the coreless fiber 12 to the outside of the coreless fiber 12 in the light H propagating the coreless fiber 12 from the tip 122 side toward the base end 121 side.
The optical fiber probe 10A emits the first emitted light H1 and the second emitted light H2 from the side surface 12b of the coreless fiber 12 by injecting light from the incident end of the optical fiber 11, and these emitted lights are emitted from the coreless fiber 12. It is possible to irradiate the surrounding object to be irradiated.

In the optical fiber probe 10A shown in FIG. 1, the first emitted light H1 is not emitted from the vicinity of the base end 121 of the coreless fiber 12.
On the other hand, the second emitted light H2 is also emitted (radiated) from the side surface 12b on the base end 121 side of the coreless fiber 12. That is, the second emitted light H2 is emitted (radiated) from the entire side surface 12b including the base end 121 side.
As described above, the optical fiber probe 10A shown in FIG. 1 can emit (radiate) the light incident from the incident end of the optical fiber 11 from the entire side surface 12b of the coreless fiber 12.
The optical fiber probe 10A can irradiate a wide range of the irradiation target around the coreless fiber 12 with the light incident from the incident end of the optical fiber 11.

As the optical fiber probe 10A, it is preferable to use a coreless fiber 12 which is a quartz glass fiber which does not contain a scatterer inside and has a uniform whole and a uniform refractive index. In this case, when the optical fiber probe 10A incidents the laser beam from the incident end of the optical fiber 11, the energy of the laser beam transmitted from the optical fiber 11 to the coreless fiber 12 does not easily generate heat in the coreless fiber 12. As described above, since the optical fiber probe 10A does not easily reach a high temperature even when used for a long time, it can be used for a long time while being inserted into a human body, for example.

Further, the energy loss of the laser beam due to the heat generated by the coreless fiber 12 can be suppressed to a small value, and the power and the amount of the laser beam emitted from the coreless fiber 12 to the outside can be secured. As a result, the power of the laser beam transmitted from the optical fiber 11 to the coreless fiber 12 can be suppressed to a small value. In this way, the adoption of the coreless fiber 12, which is a quartz glass fiber that does not contain a scattering substance inside and has a uniform overall and uniform refractive index, causes the coreless fiber 12 to generate heat due to irradiation with laser light, resulting in deformation of the reflective film 13. It is possible to avoid inconveniences such as causing damage.

The second emitted light H2 emitted from the side surface 12b of the coreless fiber 12 of the optical fiber probe 10A to the outside of the coreless fiber 12 is directed from the reflective film 13 to the base end 121 side of the coreless fiber 12 with respect to the central axis of the coreless fiber 12. Proceed in a sloping direction. The second emitted light H2 can also be irradiated to an irradiation target located at a position shifted from the side radiation portion 20A of the optical fiber probe 10A to the base end 121 side (optical fiber 11 side) of the coreless fiber 12.
For example, as compared with the case where there is no second emitted light H2 and only the first emitted light H1 is emitted from the coreless fiber 12, the configuration in which the second emitted light H2 can be emitted from the coreless fiber 12 is the irradiation around the coreless fiber 12. It is possible to irradiate a wide area of the object with light.

The optical fiber probe 10A of FIG. 1 does not require a grip portion (cylindrical grip portion capable of accommodating a microlens portion) with a reflection mirror portion of the lateral reflection type probe of FIG. 1 of Patent Document 1. Compared with the side reflection type probe of FIG. 1, the structure is simple and can be manufactured at low cost.
The optical fiber probe 10A can realize at low cost that a wide irradiation range of the incident light to the optical fiber 11 from the side radiating portion 20A to the side can be secured.

FIG. 2A shows the optical fiber probe 10B of the second embodiment. In the optical fiber probe 10B, as compared with the optical fiber probe 10A of the first embodiment, the coreless fiber coating layer (coreless fiber exterior material) 14 which is a light-transmitting resin coating layer is formed on the side surface 12b of the coreless fiber 12. The difference is that they are. The coreless fiber covering layer 14 covers the side surface 12b of the coreless fiber 12. The coreless fiber coating layer 14 is an example of a light-transmitting coreless fiber exterior material that covers the side surface 12b of the coreless fiber 12.

The optical fiber probe 10B of FIG. 2A also includes a fiber coat layer 15 formed of polyimide around the optical fiber 11. The fiber coat layer 15 covers the side surface of the optical fiber 11. The fiber coat layer 15 is adhered to the side surface of the optical fiber 11.
Since the fiber coat layer 15 made of polyimide has excellent heat resistance, even if the optical fiber 11 generates heat due to the energy of the laser light incident on the optical fiber 11, the state of covering the side surface of the optical fiber 11 can be kept stable. can.
The polyimide fiber coat layer 15 is also widely applicable to other embodiments of optical fiber probes.

As shown in FIG. 2B, the coreless fiber coating layer 14 formed on the side surface 12b of the coreless fiber 12 of the optical fiber probe 10B has a reflective film 13 not only on the side surface 12b of the coreless fiber 12 but also on the tip 122 side of the coreless fiber 12. It may be formed on top of it. That is, it may be formed so as to cover the reflective film 13 on the tip 122 side of the coreless fiber 12.
The coreless fiber coating layer 14 is formed around the side radiation portion 20A so as to cover at least the side surface 12b of the coreless fiber 12 of the side radiation portion 20A of the optical fiber probe 10A of the first embodiment.
The optical fiber probe 10B of FIGS. 2A and 2B has a side radiation portion 20B having a coreless fiber coating layer 14 formed on the side radiation portion 20A of the optical fiber probe 10A of the first embodiment.

The coreless fiber coating layer 14 has a refractive index equal to or higher than that of the coreless fiber 12. The coreless fiber coating layer 14 can transmit the first emitted light H1 and the second emitted light H2 propagating from the coreless fiber 12 and emit from the side surface of the coreless fiber covering layer 14.

In addition, in order to secure a large amount of emitted light of the first emitted light H1 and the second emitted light H2 from the side surface of the coreless fiber covering layer 14, it is possible to adopt the coreless fiber covering layer 14 having a higher refractive index than the coreless fiber 12. preferable.

The coreless fiber coating layer 14 of the optical fiber probe 10B of FIGS. 2A and 2B is formed on the entire side surface 12b of the coreless fiber 12.
In the optical fiber probe 10B of FIGS. 2A and 2B, the first emitted light H1 and the second emitted light H2 emitted from the side surface 12b of the coreless fiber 12 pass through the coreless fiber coating layer 14 from the coreless fiber 12 and are coreless. It is emitted outward from the side surface of the fiber coating layer 14.

A rough surface portion 14a having a plurality of minute irregularities is formed on the entire side surface of the coreless fiber coating layer 14. That is, minute irregularities are formed on the surface of the rough surface portion 14a.
The rough surface portion 14a scatters the light emitted from the coreless fiber coating layer 14 to the outside through the coreless fiber coating layer 14 from the coreless fiber 12, and equalizes the light emission from the coreless fiber coating layer 14 to the outside. Play a role.

The coreless fiber coating layer 14 is made of a resin material. The coreless fiber coating layer 14 can be formed by applying a liquid resin material to the side surface 12b of the coreless fiber 12 and curing it. As the curable liquid resin material, for example, a thermosetting resin, a reaction curable resin, an ultraviolet curable resin and the like can be used.
The fine unevenness of the rough surface portion 14a can be formed by laser processing, plasma processing, sandblasting, or the like on the coreless fiber coating layer 14 formed on the side surface 12b of the coreless fiber 12.

FIG. 3 shows the optical fiber probe 10C of the third embodiment. The optical fiber probe 10C has a configuration in which the optical fiber probe 10A of the first embodiment is provided with a light-transmitting glass capillary (coreless fiber exterior material) 16 accommodating a side radiation portion 20A thereof.
The optical fiber probe 10C of FIG. 3 has a side radiation portion 20C having a configuration in which a glass capillary 16 is provided on the side radiation portion 20A of the optical fiber probe 10A of the first embodiment.

The glass capillary 16 of the optical fiber probe 10C of FIG. 3 has a cylindrical tubular body portion 16a that houses the coreless fiber 12 and the reflective film 13, and a tip wall portion 16b that closes one end of the tubular body portion 16a in the axial direction. Have. The end of the tubular body 16a on the opposite side of the tip wall 16b is open. The glass capillary 16 is formed in a cylindrical shape with one end closed.

The glass capillary 16 accommodates the coreless fiber 12 and the reflective film 13 inside the tubular body portion 16a in a state where the tip wall portion 16b is arranged on the tip 122 side of the coreless fiber 12. In FIG. 3, on the probe tip side (tip 122 side of the coreless fiber 12), the tip wall portion 16b of the glass capillary 16 is in contact with the reflective film 13.

The inner diameter of the tubular body portion 16a of the glass capillary 16 is equivalent to the outer diameter of the coreless fiber 12.
The tubular body portion 16a is adhered or fused to the side surface 12b of the coreless fiber 12 with an adhesive, and the glass capillary 16 is fixed to the coreless fiber 12.

The tubular body portion 16a of the glass capillary 16 can transmit the first emitted light H1 and the second emitted light H2 propagating from the coreless fiber 12 and emit from the side surface of the tubular body portion 16a.
The tubular body portion 16a of the glass capillary 16 has a refractive index equal to or higher than that of the coreless fiber 12. In order to secure a large amount of emitted light from the first emitted light H1 and the second emitted light H2 from the tubular body portion 16a to the outside, the refractive index of the tubular body portion 16a is higher than that of the coreless fiber 12 in the glass capillary 16. Is also preferable.

The glass capillary 16 of FIG. 3 is uniformly formed of the same material as a whole, and has a uniform refractive index throughout. However, for the glass capillary 16, for example, a configuration in which the material or the refractive index of the tip wall portion 16b is different from that of the cylindrical body portion 16a can be adopted.

The tubular body portion 16a of the glass capillary 16 of the optical fiber probe 10C of FIG. 3 accommodates the entire coreless fiber 12 and the reflective film 13. Further, in FIG. 3, the tubular body portion 16a of the glass capillary 16 also accommodates the emission end portion of the optical fiber 11.
In the optical fiber probe 10C of FIG. 3, the first emitted light H1 and the second emitted light H2 radiated from the side surface 12b of the coreless fiber 12 pass through the tubular body portion 16a of the glass capillary 16 from the coreless fiber 12 and have a cylinder. It is radiated outward from the side surface of the body portion 16a.

A rough surface portion 16c having a plurality of minute irregularities is formed on the entire side surface of the tubular body portion 16a of the glass capillary 16. That is, minute irregularities are formed on the surface of the rough surface portion 16c.
The rough surface portion 16c passes through the tubular body portion 16a of the glass capillary 16 from the coreless fiber 12 and scatters the light emitted from the tubular body portion 16a to the outside, and emits light from the tubular body portion 16a to the outside. Plays a role in equalizing.
The fine irregularities of the rough surface portion 16c can be formed by laser processing, plasma processing, sandblasting, or the like, similarly to the coreless fiber coating layer 14 formed on the side surface 12b of the coreless fiber 12.

FIG. 4 shows the optical fiber probe 10D of the fourth embodiment. The optical fiber probe 10D adopts a configuration in which the optical fiber probe 10A of the first embodiment has a core diameter expanding portion 11c at the exit end portion of the optical fiber 11. For the core diameter expanding portion 11c, for example, a configuration of a core diffusion fiber (so-called TEC fiber; TEC; Thermally-diffused Expanded Core Fiber) may be adopted.
In the optical fiber probe 10D shown in FIG. 4, the coreless fiber 12 is coaxially fused and connected to the tip (emission end) of the optical fiber 11.

As shown in FIG. 4, the optical fiber 11 has a core diameter expanding portion 11c on the coreless fiber 12 side. The core diameter expanding portion 11c is connected to the base end 121 of the coreless fiber 12.
The core diameter of the core diameter enlarged portion 11c is larger than the core diameter of the portion of the optical fiber 11 other than the coreless fiber 12 side. Further, the core diameter of the core diameter expanding portion 11c may increase toward the emission end side of the optical fiber 11. The portion of the core 11a other than the core diameter enlarged portion 11c is formed so as to extend at a constant diameter.
The clad 11b of the optical fiber 11 is formed so as to extend over the entire length of the optical fiber 11 with a constant outer diameter.
The configuration of the core 11a of the optical fiber 11 of FIG. 4 other than the core diameter enlarged portion 11c is the same as that of the optical fiber 11 of the optical fiber probe 10A of the first embodiment.

With this configuration, light H can be emitted to the outside of the coreless fiber 12 on the proximal end 121 side of the coreless fiber 12 as compared with the optical fiber probe 10A.

The adoption of the core diameter expanding portion 11c at the emission end of the optical fiber 11 is widely applicable to the optical fiber probes of other embodiments.

FIG. 5 shows the optical fiber probe 10E of the fifth embodiment. Like the optical fiber probe 10E, the tip surface 12a of the coreless fiber 12 may be a partially spherical convex curved surface.

As shown in FIG. 5, in a cross-sectional view along the longitudinal direction of the optical fiber 11, the tip surface 12a of the coreless fiber 12 has a convex curved surface protruding in the optical axis direction. Since the reflective film 13 is formed along the tip surface 12a of the coreless fiber 12, the reflective film 13 is formed in a partially spherical shape along the tip surface 12a.

The tip surface 12a of the partially spherical coreless fiber 12 can be formed, for example, by melting or polishing the tip of the coreless fiber 12.

An optical fiber probe having a partially spherical tip surface 12a and a reflective film 13 of the coreless fiber 12 can be smoothly inserted into a body cavity such as a human blood vessel, urethra, or nasal cavity, so that the inner wall of the body cavity is not easily damaged. There are advantages.

The optical fiber probe 10E of FIG. 5 is different from the optical fiber probe 10A of the first embodiment in that the tip surface 12a and the reflective film 13 of the coreless fiber 12 are changed to have a partially spherical shape.
However, making the tip surface 12a and the reflective film 13 of the coreless fiber 12 into a partially spherical shape is widely applicable to the optical fiber probe of other embodiments.

However, the tip surface 12a of the coreless fiber 12 is more advantageous in that it has a partially spherical shape than a flat surface perpendicular to the central axis of the coreless fiber 12 in that it can be smoothly inserted into the body cavity and the inner wall of the body cavity is not easily damaged.

Although the present invention has been described above based on the best mode, the present invention is not limited to the above-mentioned best mode, and various modifications can be made without departing from the gist of the present invention.
For example, the tip surface 12a of the coreless fiber 12 has at least one of a convex portion protruding in the optical axis direction and a concave portion recessed in the optical axis direction, and light at the end portion of the optical fiber on the coreless fiber side. It is possible to adopt a non-flat surface that does not have a flat surface orthogonal to the axis. With this configuration, the amount of light that the laser light reflected by the reflective film enters the laser light source via the optical fiber can be suppressed to a very small amount, and the incident of the laser light affects the operation of the laser light source. It can be avoided.

10A-10E ... Optical fiber probe, 11 ... Optical fiber, 11a ... Core, 11b ... Clad, 11c ... Core diameter expansion part, 12 ... Coreless fiber, 12a ... Tip surface (of coreless fiber), 12b ... (of coreless fiber) Side surface, 121 ... base end (of coreless fiber), 122 ... tip (of coreless fiber), 13 ... reflective film, 14 ... coreless fiber exterior material (coreless fiber coating layer), 14a ... rough surface portion, 15 ... fiber coat layer, 16 ... Coreless fiber exterior material (glass capillary), 16a ... Cylindrical body, 16b ... Tip wall, 16c ... Rough surface, 20A, 20B, 20C ... Lateral radiation, H ... Light (transmission light), H1 ... 1st emitted light, H2 ... 2nd emitted light

Claims (11)

It has an optical fiber, a coreless fiber, and a reflective film.
The end of the optical fiber and the first end of the coreless fiber are connected.
The reflective film is arranged at the second end of the coreless fiber, and the reflective film is arranged .
The end surface of the second end portion of the coreless fiber is a flat surface perpendicular to the central axis of the coreless fiber.
When light is propagated from the end of the optical fiber into the coreless fiber, the light emitted from the side surface of the coreless fiber is
The first emitted light emitted to the outside of the coreless fiber without reaching the reflective film,
An optical fiber probe comprising a second emitted light that is reflected by the reflective film and emitted to the outside of the coreless fiber . It has an optical fiber, a coreless fiber, and a reflective film.
The end of the optical fiber and the first end of the coreless fiber are connected.
The reflective film is arranged at the second end of the coreless fiber, and the reflective film is arranged.
An optical fiber probe in which the end surface of the second end portion of the coreless fiber is a convex curved surface. It has an optical fiber, a coreless fiber, and a reflective film.
The end of the optical fiber and the first end of the coreless fiber are connected.
The reflective film is arranged at the second end of the coreless fiber, and the reflective film is arranged.
The end surface of the second end portion of the coreless fiber has at least one of a convex portion and a concave portion, and there is no flat surface orthogonal to the optical axis at the end portion of the optical fiber on the coreless fiber side. An optical fiber probe. Claims 1 to 3 that when light is propagated from the end of the optical fiber to the coreless fiber, 40 to 60% of the light is emitted to the outside of the coreless fiber without reaching the reflective film. The optical fiber probe according to any one of the above items. Further having a light-transmitting coreless fiber exterior material covering the side surface of the coreless fiber,
The optical fiber probe according to any one of claims 1 to 4, wherein the coreless fiber exterior material has a refractive index equal to or higher than that of the coreless fiber. The optical fiber probe according to claim 5 , wherein the coreless fiber exterior material is a resin coating layer formed on at least a side surface of the coreless fiber. The optical fiber probe according to claim 5 , wherein the coreless fiber exterior material is a glass capillary that houses the coreless fiber. The optical fiber probe according to any one of claims 5 to 7 , wherein a rough surface portion having a plurality of irregularities is formed on a side surface of the coreless fiber exterior material. The optical fiber probe according to any one of claims 1 to 8 , wherein the side surface of the optical fiber is covered with a fiber coat layer formed of polyimide. The optical fiber has a core and a cladding covering the core.
The optical fiber probe according to any one of claims 1 to 9 , wherein the core has a core diameter enlarged portion having an expanded core diameter, and the core diameter expanded portion is connected to the coreless fiber. The optical fiber has a core and a cladding covering the core.
The optical fiber probe according to any one of claims 1 to 10 , wherein the outer diameter of the coreless fiber is equivalent to the outer diameter of the clad.

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