JPS62248277A - Laser unit selectively producing laser light from optical fiber - Google Patents

Abstract

PURPOSE:To selectively obtain either of two kinds of laser lights from a single optical fiber, by switching operations of a laser unit to produce two kinds of laser lights having different wavelengths along the same axis and switching the distances between a convergent lens and the incident end face of the optical fiber. CONSTITUTION:An XeCl excimer laser having a wavelength of 308 nm is reflected by a mirror M1 to optically pump a dye cell c1 so that 630 nm laser light for a medical treatment is obtained. The laser light thus obtained is reflected by a mirror M6 and collected by a lens L to be guided to an optical fiber OF. The left side of the mirror M1 is lowered and 308 nm excimer laser is reflected by a mirror M3 to optically pump a dye cell c2 so that 405 nm laser light for diagnosis purposes is obtained. The laser light thus obtained is rcflected by a mirror M5 with the left side of the mirror M6 lowered and is collected by the lens L. The lens L is operated in association with the mirrors M1 and M6 to switchover distances with resepct to the optical fiber OF.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is used in medical treatment to selectively transmit high-output therapeutic laser light and diagnostic laser light of other wavelengths through the same optical fiber. The present invention relates to a laser device that selectively generates laser light from an optical fiber, which can be suitably used for laser diagnosis and treatment.

(Prior art) In medical care, if high-output therapeutic laser light and diagnostic laser light of other wavelengths can be selectively transmitted through the same optical fiber, cancer diagnosis and treatment can be realized using the same optical system. can.

In order to introduce a 1/- light guide into an optical fiber with a core diameter smaller than the beam diameter of the laser beam and transmit it to a distant position, the laser beam must be focused once with a lens in order to increase the incidence efficiency. It is necessary to introduce it into the fiber.

(Problems to be Solved by the Invention) The inventor of the present invention has developed various devices for selectively transmitting high-output therapeutic laser light and diagnostic laser light of other wavelengths through the same optical fiber in the medical field. We conducted an experiment.

There is no problem when the laser output is small, but when the laser output is high, the problem of fiber damage occurs.

This is particularly a problem when performing laser medical treatment using MW (10' W) class pulsed laser light.

This is related to the position of the focal point of the laser beam and the input end of the fiber.If the focal point is on the input end face, even if the laser output is as low as 100KW, the focal point will be At this point, the laser output per unit area becomes very large, and the fiber is easily destroyed by energy energy.

If multiple laser beams with different wavelengths are used, the beam diameter on the fiber entrance surface will differ depending on the dispersion of the lens.
An inconvenience will occur.

In particular, cancer diagnosis (detection) using laser light with a wavelength of 405 nm.
In a photochemical reaction type cancer diagnosis and treatment device that performs cancer treatment using Rede light with a wavelength of 630 nm, 405 nm,
Even if the lens position is adjusted so that the beam diameter of the G30nrn light is the same as the fiber core diameter, this condition is not satisfied for other wavelengths, so the fiber Corruption issues arise.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a laser device that selectively generates laser light from an optical fiber, which can selectively output two types of high-output laser light from a single optical fiber. It is in.

(Means for Solving the Problems) In order to achieve the above object, a laser device according to the present invention that selectively generates laser beams from an optical fiber generates two types of laser beams with different wavelengths on the same axis by a switching operation. a laser light source device, a focusing lens disposed on the axis, an optical fiber disposed on the axis, and an optical system support capable of adjusting the distance between the focusing lens and the incident end surface of the optical fiber. and an optical system driving means that drives the optical system support means in conjunction with the switching operation to match the cross-sectional diameter of each beam focused by the focusing lens with the effective entrance cross-sectional diameter of the optical fiber. It is configured.

(Example) The present invention will be described in more detail below with reference to the drawings and the like.

FIG. 1 is a block diagram showing an embodiment of a laser device for selectively generating laser light from an optical fiber according to the present invention.

This embodiment shows a dye laser optical system for generating 405 nm laser light used for cancer diagnosis and 630 nm laser light used for cancer treatment.

A 630 nm laser beam for treatment is obtained by optically exciting a dye cell C1 containing a dye solution in which Rhodamine B dye is dissolved in alcohol at a concentration of 2 mM/j2 with a XeCl excimer laser having a wavelength of 308 nm. The obtained 630 nm laser beam is reflected by mirror M6 and passes through lens L.
is guided, focused and introduced into an optical fiber OF.

This OF is installed in an endoscope by passing through the forceps hole of the endoscope, thereby making it possible to guide laser light into the body.

The cylindrical lens CL is used to increase the efficiency of optical excitation of the dye cell C1 by light having a beam shape of approximately 1×2 cm 2 from an XeCl excimer laser having a wavelength of 308 nm.

Further, in order to increase the pulse repetition rate of the dye Rede, the dye solution is circulated at high speed through the dye reservoir DR by a circulation pump CP.

405 nm laser light for diagnosis is 308 nm Xe
The Cl laser beam is transmitted through mirror M3. Cylindrical lens C
D P S (4-4'-Dipbeny
15tilben) It is obtained by photoexcitation by irradiating the dye cell C2 containing a dioxane saturated solution of the dye.

Note that at this time, the mirror M1 is pulled up to the upper right in the figure, and is in a state of transmitting a wavelength of 308 nm.

The obtained 405 nm laser beam is reflected by mirror M5,
Similarly to the 630nm light, it passes through the lens L and connects to the optical fiber O.
Introduced in F.

The mirror M6 is moved in conjunction with the mirror M, and is in a position where the light from the mirror M5 is transmitted.

As described above, 405 nm light is used for diagnosis, and 6 nm light is used for treatment.
30 nm light is selectively supplied on the same axis (on the optical axis of the focusing lens L).

In the present invention, each laser beam is focused using a lens, and the distance between the lens L and the input end of the fiber OF is determined so that the laser beam diameter matches the core diameter of the fiber OF.

This is to avoid concentration of energy by making the beam diameter as wide as possible without causing connection loss.

Next, the behavior of each laser beam with respect to the focusing lens will be explained with reference to FIG.

Lens L is a quartz lens, and the radius of curvature of the entrance and exit surfaces is 2.
It is 0 mrn.

In FIG. 2, the optical path of a 4 Q 5 n rn laser beam incident parallel to the center of the optical axis of this lens L with a diameter of 2 mtn is shown by a solid line, and the optical path of a 630 nm laser beam is shown by a broken line.

Focal pressure i of lens L for 405 nm laser light? u
F405 is 21.29mm, focal length of lens L for 630nm laser light F630 H21.87
rnm, and the difference is 0.58 mm.

The tip of the optical fiber OF is placed behind the focal point of lens L, and the optical beam diameter of 4.05 nm is adjusted to the fiber core diameter (40 nm).
If the distance between the lens L and the tip of the optical fiber OF is adjusted to 25.55 mrn so that it matches 0μrn), then 6
The beam diameter of 30 n rn light is 340 at the input end of the fiber.
It becomes μm.

In addition, the optical fiber OF end is arranged so that the 405 nm light beam diameter matches the core diameter inside the focal point.
The m-light beam diameter is larger than the fiber core diameter.

Next, referring to FIG. 3, an embodiment of an optical system supporting means for supporting the focusing lens L and the incident end face of the optical fiber OF so as to be adjustable will be described.

The optical system support means includes a lens position adjustment means 1 that supports the focusing lens L on the base 5 so as to be movable in the optical axis direction, and a fiber stand 4 that fixedly supports the input end face of the optical fiber OF on the base 5. It consists of

The lens position adjustment means 1 has a wavelength (405, 630 nm).
Accordingly, the lens L is moved on the optical axis of the laser beam 3 so that the laser beam diameter matches the diameter of the core 6 of the quartz optical fiber 5 attached to the fiber stand 4. .

The optical fiber OF has a core portion 6 with a diameter of 400 μm, a cladding portion 7 (500 μm in diameter), and a nylon protective coating 8 covering the outer periphery, and the outer diameter is 1.2 m.
It is m.

Next, an embodiment of the lens position adjusting means 1 will be described with reference to FIGS. 4 and 5.

As shown in FIG. 3, the lens position adjusting means 1 is fixed to a support rod 116, and is supported by a stand 2 so that the optical axis of the lens L coincides with the center of the optical fiber OF.

A cylindrical magnet 101 with a sufficiently large hole in the center includes a member 102 made of magnetic material (for example, iron) and an outer cylinder 1 also made of magnetic material.
04 to the support rod 116.

The magnetic member 102 and the cylindrical magnet 101 are fixed with an adhesive by the magnetic member 102 and the outer cylinder 104 spring lO5.

1. In the gap between the cylindrical magnet 101 and the outer tube 104, there is a lens barrel 106 with a lens L attached using a lens holder 115.
The left end of is inserted.

Kagami v1106 No right flt surface c, Ji Hane 108. 1
It is fixed to the outer cylinder 104 via 09.

The shapes of the two leaf springs 10B and 109 are shown in FIG.

The outer edges of the leaf springs 108 and 109 are connected to the outer cylinder 10 by inserting four equally spaced screws 113 through spacers 110 and 111.
4 and is fixed by screwing into the lens barrel 10 through a spacer 112 with four screws 114 equally spaced on the inner edge.
It is fixed at 6.

Lens L is tMlllfi 106 and lens holder 11
It is fixed by 5.

A coil 107 is wound around the outer periphery of the left end of this lens barrel 106 so that a current flows therethrough.

The lead wires at both ends of the coil 107 are connected to the midpoint of the switch SW2 of the interlock switch 13, which will be described later, through a hole 103 made in the +AlO2 part.

When a current is applied to the coil 107, the magnet lot and the outer cylinder 104
As a result, an electric current is passed perpendicularly to the lines of magnetic force in the magnetic field created in the gap between the coils 107 and 107, which generates an electromagnetic force in a direction perpendicular to the direction of the magnetic field and coil current, and the coil 107 and the lens integrated therewith are generated in the optical axis direction. You will have to move L.

The amount of movement of this lens L is determined by the coil current (that is, the value of the power supply voltage V, V2), the number of turns of the coil, and the leaf spring 108.1.
It is controlled by constants etc. of 09.

The reason why the two leaf springs 108 and 109 are used to support the lens barrel 16 on the outer barrel 104 is to prevent eccentricity from occurring during movement of the lens L.

The handling springs 108 and 109 are made of phosphor bronze, and the four holes 11 on the outer periphery are
3a is for the screw 113, hole 1 of 4117iI on the inner circumference
14a is for the screw 114.

The window 120 of the center hole 121, 4fRj was formed by etching.

The characteristics of the spring (flexibility, ease of movement, etc.) can be adjusted depending on the shape of the window 120. It is not necessary to use the same slope springs 10B and 109, and it is also possible to use springs with different dimensions and plate thicknesses for the window 120.

Control of the current to the coil 107 of the lens position adjustment means 1 is performed in conjunction with the selection of the light source (405 nm and 630 nm).

As shown in FIG. 3, the interlocking switch 13 includes:
A switch SW1 and a switch SW2 that operate in conjunction with each other are provided.

A motor 9 (MO,) 11 and a motor (MO2) 12 are motors that drive the movable reflecting mirrors M1 and M6 shown in FIG. 1, respectively.

Switch sw1 of the interlocking switch section 13. sw2 to 40
When connected to the 5 nm side, motor (Mol) 11 and motor (
MO2) 12 is driven by a power source (VO) connected via a motor rotation direction control circuit 9, and mirrors M1. M6 is brought to the position shown in FIG.

Power (1) is supplied to the coil of the lens position adjustment means 1 via a switch SW2. When the switches sw and sw2 of the interlocking switch unit 13 are connected to the 630 nm side,
A power supply (V) is connected to the motor (Mol) 11 and the motor (MO2) 12 via the motor rotation direction control circuit 10.
o) to bring the mirrors M, , M6 to other positions, and power (V2) is supplied to the coil of the lens position adjusting means 1 via the switch SW2.

Thereby, the laser light is connected to the optical fiber OF under optimal conditions for each wavelength.

In this example, for 630 nm light, the power supply (V
2) Set the voltage of 16 to OV (state where the position of the lens barrel is not moved).

When a laser beam 3 with a diameter of 2 mm is focused through a lens and incident on a fiber with a core diameter of 400 μm, the distance between the lens and the input end of the fiber is 26.25 mm for 630 nm light, whereas it is 25.55 mm for 405 nm light. becomes.

That is, at the time of wavelength conversion of 630-=405 nm, the lens L is moved 0.70 mrn toward the fiber.

Phosphor bronze leaf spring 108, 109 (7) J & thickness = 0.40
mm, and the number of coil turns is 1400 times, the coil can be moved by 0.70 mm with an applied voltage of 46.2 mm.

(Effects of the Invention) As explained above in detail, the laser device according to the present invention selectively generates laser light from an optical fiber includes a laser light source device that generates two types of laser beams with different wavelengths on the same axis by a switching operation; a focusing lens disposed on the axis; an optical fiber disposed on the axis; an optical system support means for supporting the focusing lens so as to be able to adjust the distance between the incident end face of the optical fiber; and the optical system. The optical system driving means drives the supporting means in conjunction with the switching operation to make the cross-sectional diameter of each beam focused by the focusing lens coincide with the effective incident cross-sectional diameter of the optical fiber.

That is, according to the present invention, for laser beams of two wavelengths (405 nm light necessary for cancer diagnosis and 630 nm light necessary for cancer treatment), the core diameter of the optical fiber and the laser beam diameter incident thereon are made to match. be able to.

Therefore, damage to the optical fiber can be prevented for each wavelength of light, and the laser light transmission characteristics of the fiber can be maintained in a good state.

Note that the same effect can be obtained by moving the input end face of the optical fiber OF.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a radar device for selectively generating laser light from an optical fiber according to the present invention. FIG. 2 is a diagram showing the optical relationship among a laser beam, a focusing lens, and an optical fiber. FIG. 3 is a diagram showing an embodiment of the optical system supporting means, etc. FIG. 4 is a sectional view showing an embodiment of the lens position adjusting means according to the present invention. FIG. 5 is a diagram showing the shape of a temporary spring that is a component of the lens position adjusting means. M, , M6... Moving reflection mirror CL,, cL2... Cylindrical lens C,, C2
...Dye cell DR...Dye reservoir CP...Circulation pump OF...Optical fiber M3. M5... Total reflection mirror L... Lens position adjustment means 2... Stand 3 of lens position adjustment device... Laser beam 4... Optical fiber end support stand 6... Optical fiber OF Core 7... Clad 8 of optical fiber OF... Protective coating of optical fiber OF 9.10... Motor rotation direction control circuit 11.12.
...Motor (for driving the moving reflective mirror) 13...Interlocking switch 14.15.16...Power source 101...Cylindrical magnet 104...Outer tube 106...List barrel 107...Coil 108.109...Plate spring patent applicant Todoroki Director of the Agency of Industrial Science and Technology

Claims (3)

[Claims] (1) A laser light source device that generates two types of laser beams with different wavelengths on the same axis by a switching operation, a focusing lens placed on the axis, an optical fiber placed on the axis, and the focusing lens. and an optical system supporting means for supporting the distance between the incident end surfaces of the optical fiber so as to be adjustable; and the optical system supporting means is driven in conjunction with the switching operation to adjust the cross-sectional diameter of each beam focused by the focusing lens. A laser device that selectively generates a laser beam from an optical fiber, the laser device comprising an optical system driving means that makes the effective incident cross-sectional diameter of the optical fiber coincide with the effective incident cross-sectional diameter of the optical fiber. (2) The optical system driving means moves a lens barrel supporting a focusing lens in the optical axis direction so that the cross-sectional diameter of each beam focused by the focusing lens matches the effective incident cross-sectional diameter of the optical fiber. A laser device that selectively generates laser light from an optical fiber according to claim 1, which is a lens position adjusting means. (3) The lens position adjustment means is integrated with the focusing lens in a gap of an outer cylinder that extends in the optical axis direction and is made of a cylindrical magnet and a magnetic material that allows the laser light to pass through the inside. A laser beam from an optical fiber according to claim 2, wherein a cylindrical coil is disposed via a plate spring, and the lens is moved in the optical axis direction by electromagnetic force generated by passing a current through the coil. Select the generating laser device.