JP2009168846A - Light condensing device and light condensing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light condensing device and a light condensing method with which light is easily condensed. <P>SOLUTION: The light condensing device 10 includes: a parabolic mirror 1 having a reflection face 11 with a focus A; a plurality of semiconductor lasers 2a-2d placed on the focus A and emitting light beams 20a-20d to the reflection face 11; and a light condensing lens 3 to make the reflection beams 21a-21d reflected on the reflection face 11 converge in the x-axis direction. When cut with the x-z plane, the reflection face 11 has a parabola shape and the focus A assumes a straight line shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light collecting device and a light collecting method, and more particularly to a light collecting device and a light collecting method for collecting light from a plurality of semiconductor lasers.

  For example, a high laser output is required for a medical laser such as a dental laser device or a laser device for laser welding. For this reason, in these laser devices, the light emitted from each of the plurality of semiconductor lasers is condensed and incident on the optical fiber, and the light collected from the optical fiber is taken out, thereby producing a high-power laser. It has gained. Conventionally, in order to collect light emitted from a semiconductor laser and enter it into an optical fiber, the following apparatus has been used.

  FIG. 12 is a diagram schematically illustrating a conventional light collecting device. Referring to FIG. 12, a conventional condensing device 200 (laser optical multiplexing device) is for entering a condensed light beam on an optical fiber 151, and includes a semiconductor laser group 111, a laser block 121, and a light beam. A rearrangement optical system 131 and a convergence optical system 141 are provided. A laser block 121, a light beam rearrangement optical system 131, and a converging optical system 141 are arranged in this order from the semiconductor laser group 111 toward the optical fiber 151.

The semiconductor laser group 111 includes a plurality of semiconductor lasers 111a to 111e arranged in the x-axis direction. Each of the light beams 101 a to 101 e emitted from each of the plurality of semiconductor lasers 111 a to 111 e is propagated in the y-axis direction and passes through each of the collimating lenses 121 a to 121 e constituting the laser block 121. At this time, each of the light beams 101a to 101e is a parallel light beam having optical axes parallel to each other in the x-axis direction and the z-axis direction. Next, each of the light beams 101 a to 101 e passes through each of the prisms 131 a to 131 e constituting the light beam rearrangement optical system 131. At this time, each of the light beams 101a to 101e is arranged such that the direction of the fast axis is aligned on the xy plane. Next, each of the light beams 101 a to 101 e passes through the converging optical system 141. At this time, each of the light beams 101a to 101e is converged in each of the x-axis direction and the y-axis direction. Then, each of the converged light beams 101 a to 101 e is incident on the optical fiber 151. In addition, the condensing apparatus shown in FIG. 12 is disclosed by Unexamined-Japanese-Patent No. 2004-252428 (patent document 1), for example.
JP 2004-252428 A

  However, the conventional light collecting device has a problem that light collection is not easy. That is, in order to make the light emitted from each of the plurality of semiconductor lasers parallel to each other, it is necessary to process the surface of the collimator lens in consideration of the incident angle and width of the incident light. At this time, it is necessary to process the surface of the collimator lens into an aspherical shape, and high accuracy is required for this processing. For this reason, the process of the collimator lens was not easy. In addition, it is necessary to arrange each semiconductor laser with high accuracy so that light emitted from each semiconductor laser passes through a predetermined position of the collimator lens. This arrangement was not easy.

  Therefore, the objective of this invention is providing the condensing apparatus and condensing method which are easy to condense.

  The light collecting device of the present invention includes a reflecting portion having a reflecting surface having a focal point, a plurality of light emitting elements arranged at the focal point and emitting light toward the reflecting surface, and reflected light reflected by the reflecting surface, And a condensing unit for focusing in one axial direction perpendicular to the optical axis of the reflected light.

  The condensing method of the present invention includes a step of disposing each of the plurality of light emitting elements at the focal point of the reflecting surface of the reflecting portion, a step of emitting light from each of the plurality of light emitting elements to the reflecting surface, and a reflection by the reflecting surface. Focusing the reflected light in one axial direction perpendicular to the optical axis of the reflected light.

  When light is emitted from the focal point toward the reflecting surface, the reflected light propagates in one direction regardless of the reflection position on the reflecting surface. Since the condensing device and the condensing method of the present invention obtain light parallel to each other using this property, a collimator lens is unnecessary. In addition, as long as each of the light emitting elements is arranged at the focal point, the light emitted from each of the light emitting elements toward the reflecting surface becomes light parallel to each other, so that the arrangement of each of the light emitting elements becomes easy. As described above, the light can be easily collected.

  In the light collecting device of the present invention, preferably, the reflective surface has a parabolic shape when cut by a plane perpendicular to the reflective surface. Thereby, a reflective surface becomes a simple shape and manufacture of a reflection part becomes easy.

  In the condensing device and the condensing method of the present invention, preferably, the focal point is linear. Thereby, each of the light emitting elements can be easily arranged at the focal point. Moreover, the light projected from each of the light emitting elements can be reflected by using one reflecting portion. As a result, the number of parts can be reduced.

  In the condensing device of the present invention, the reflected light is preferably focused also in another axial direction perpendicular to both the optical axis of the reflected light and the one axial direction.

  Preferably, in the condensing method of the present invention, in the step of focusing the reflected light, the reflected light is also focused in the other axial direction perpendicular to both the optical axis of the reflected light and the one axial direction.

  Thereby, the width | variety of the direction of the other axis | shaft in reflected light can be shrunk | reduced. As a result, when the condensed light is incident on the incident portion, the condensed light is not affected even if the width in the other axial direction in the incident portion is smaller than the width in the other axial direction in the reflected light. All can be incident on the incident part.

  Preferably, in the light collecting method of the present invention, in the step of emitting light, the light is emitted to the position of the reflecting surface so that the reflected light does not include the focal point. Thereby, it can prevent that reflected light is interrupted by the light emitting element, and can increase the light quantity of reflected light.

  According to the condensing device and the condensing method of the present invention, it is possible to easily collect light.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a diagram schematically showing an application example of the light collecting device according to Embodiment 1 of the present invention. With reference to FIG. 1, the condensing apparatus 10 in this Embodiment is applied to the dental laser 70 which is a high output laser apparatus, for example. The dental laser 70 is used for treatment of living tissue and welding of dental metal, and includes a condensing device 10, an optical fiber 30, and a probe 50. The condensing device 10 and the probe 50 are optically connected by an optical fiber 30. The light generated and collected by the light collecting device 10 propagates through the optical fiber 30 and is irradiated from the probe 50 onto the object.

  2-4 is a figure which shows typically the structure of the condensing apparatus in Embodiment 1 of this invention. 2 is a perspective view, FIG. 3 is a side view, and FIG. 4 is a plan view. Note that the upper direction in FIG. 3 is the z axis, the right direction is the y axis, and the upper direction in FIG. 4 is the x axis. Each of the x-axis, the y-axis, and the z-axis intersects each other perpendicularly.

  With reference to FIGS. 2-4, the condensing apparatus 10 in this Embodiment is the parabolic mirror 1 as a reflection part, the several semiconductor lasers 2a-2d as a light emitting element, and as a condensing part. A condenser lens 3 and a base plate 4 are provided. Each of the parabolic mirror 1, the plurality of semiconductor lasers 2a to 2d, and the condenser lens 3 is disposed on the base plate 4 along the y-axis direction. The parabolic mirror 1 is disposed at the end of the base plate 4 far from the optical fiber 30, and the condensing lens 3 is parallel to the x axis at the end of the base plate 4 near the optical fiber 30. Is arranged. A plurality of semiconductor lasers 2 a to 2 d are arranged between the parabolic mirror 1 and the condenser lens 3.

  The parabolic mirror 1 has a reflecting surface 11 parallel to the x-axis. In particular, as shown in FIG. 3, when cut along a plane (yz plane) perpendicular to the reflecting surface 11, the reflecting surface 11 has a parabolic shape. As a result, the reflecting surface 11 has a linear focal point A parallel to the x axis.

  Each of the semiconductor lasers 2a to 2d is a coaxial package, and is mounted with an edge emitting semiconductor chip made of, for example, InP, AlGa, InP, or GaN. Each of the semiconductor lasers 2 a to 2 d is disposed at the focal point A on the inclined surface 12 of the base plate 4. The inclined surface 12 forms a certain angle θ with respect to each optical axis (dotted line in FIGS. 2 to 4) of reflected light 21a to 21d described later. The number of semiconductor lasers can be set arbitrarily.

  The condenser lens 3 has a convex shape when viewed in the xy plane. As shown particularly in FIG. 4, the condensing lens 3 focuses each of the scattered reflected lights 21 a to 21 d in the x-axis direction.

  The base plate 4 is made of, for example, a ceramic material, a metal material, or a metal compound material. Specifically, it is made of aluminum, copper, copper molybdenum, copper tungsten, aluminum nitride, silicon carbide, aluminum carbide silicon, cubic boron nitride, copper diamond, or the like. The base plate 4 preferably has a high thermal conductivity of 200 W / m · K or higher, whereby heat generated in the semiconductor lasers 2 a to 2 d can be efficiently radiated to the outside of the light collecting device 10. In particular, since the parabolic mirror 1 is adjacent to the semiconductor lasers 2a to 2d, the parabolic mirror 1 can be prevented from being deformed by the heat of the semiconductor lasers 2a to 2d. In order to suppress deformation due to heat, the parabolic mirror 1 and the condenser lens 3 are preferably made of a material having a low coefficient of thermal expansion.

  As the optical fiber 30, for example, a multimode fiber having a diameter of 60 μm or 105 μm is used. From the viewpoint of coupling efficiency, the NA (numerical aperture) of the optical fiber 30 is preferably the same as the NA of the condenser lens 3.

Next, the light collection method in the present embodiment will be described.
First, each of the light beams 20a to 20d is emitted from the semiconductor lasers 2a to 2d arranged at the focal point A to the reflecting surface 11. Each of the lights 20a to 20d is reflected by the reflecting surface 11, and becomes reflected light 21a to 21d parallel to each other and propagates in the positive direction of the y-axis. The width W (FIG. 3) in the z-axis direction of each of the reflected lights 21a to 21d is adjusted by the distance from each of the semiconductor lasers 2a to 2d to the reflecting surface 11.

  Here, each of the semiconductor lasers 2a to 2d is disposed on the inclined surface 12 having a certain angle θ. Thereby, the position where each of the lights 20a to 20d is reflected on the reflecting surface 11 is on a straight line parallel to the x axis. Further, the positions of the reflected lights 21a to 21d in the z-axis direction are equal to each other. Moreover, it is preferable to emit the light 20a to 20d (that is, to remove the optical axis) at the position of the reflecting surface 11 where the focal point A is not included in the reflected light 21a to 21d. This can be realized by appropriately adjusting the angle θ of the inclined surface 12 according to the distance between the semiconductor lasers 2 a to 2 d and the reflecting surface 11. The angle θ is 45 ° or 60 °, for example.

  Next, each of the reflected lights 21 a to 21 d is focused in the x-axis direction by the condenser lens 3. As a result, a high-power laser in which the reflected lights 21 a to 21 d are combined enters the end of the optical fiber 30.

  According to the light condensing device 10 and the light condensing method in the present embodiment, light condensing can be easily performed. That is, when light 20a to 20d is emitted from the focal point A toward the reflecting surface 11, the reflected light 21a to 21d propagates in the positive direction of the y axis regardless of the reflection position on the reflecting surface 11. In the present embodiment, since the reflected lights 21a to 21d that are parallel to each other are obtained using this property, a collimator lens becomes unnecessary. In addition, as long as each of the semiconductor lasers 2a to 2d is disposed at the focal point A, the light 20a to 20d emitted from each of the semiconductor lasers 2a to 2d toward the reflecting surface 11 is reflected light 21a to 21d parallel to each other. Therefore, the arrangement of each of the semiconductor lasers 2a to 2d is facilitated.

  Moreover, when cut along a yz plane perpendicular to the reflecting surface 11, the reflecting surface 11 has a parabolic shape. Therefore, the reflecting surface 11 has a simple shape, and the parabolic mirror 1 can be easily manufactured. become.

  Further, since the focal point A is linear, each of the semiconductor lasers 2a to 2d can be easily arranged at the focal point A. Further, the light 20a to 20d projected from each of the semiconductor lasers 2a to 2d can be reflected by using a single reflecting portion. As a result, the number of parts can be reduced.

  Further, the light beams 20a to 20d are emitted to the positions of the reflecting surface 11 where the focal point A is not included in the reflected light beams 21a to 21d, thereby preventing the reflected light beams 21a to 21d from being blocked by the semiconductor lasers 2a to 2d. The amount of reflected light 21a-21d can be increased.

  In addition, the cross-sectional shape of the reflective surface of this invention may be other than a parabola, and should just be a shape which has a focus at least.

  Further, in the present embodiment, the case where each of the lights 20a to 20d is emitted at the same position in the z-axis direction on the reflecting surface 11 has been described, but the light from the light emitting element is emitted at an arbitrary position on the reflecting surface. It only has to be done.

  In the present embodiment, the case where the focal point A is not included in the reflected lights 21a to 21d has been described. However, the focal point A may be included in the reflected lights 21a to 21d.

  In the present embodiment, the case where each of the reflected lights 21a to 21d is focused in the x-axis direction has been described. However, the reflected light is at least in one axial direction perpendicular to the optical axis of the reflected light. It only needs to be focused.

  Further, each of the reflected lights 21a to 21d may be focused in the z-axis direction. FIG. 5 is a side view schematically showing another configuration of the condensing device according to Embodiment 1 of the present invention. Referring to FIG. 5, the condenser lens 3 has a convex shape when viewed in the yz plane. Thereby, the width W in the z-axis direction of the reflected lights 21a to 21d can be contracted. As a result, when the condensed reflected lights 21a to 21d are incident on the end of the optical fiber 30, the width in the z-axis direction of the end of the optical fiber 30 is smaller than the width W of the reflected lights 21a to 21d. Even so, all the collected reflected lights 21 a to 21 d can be incident on the end of the optical fiber 30.

(Embodiment 2)
6 to 9 are partial perspective views schematically showing various configurations of the condensing device according to Embodiment 2 of the present invention. 6 to 9, only the traveling direction of light emitted from one of the plurality of semiconductor lasers is indicated by a dotted line. In FIG. 6, the semiconductor lasers 2a to 2d are made of edge-emitting semiconductor chips. In FIG. 7, a one-dimensional array bar of semiconductor chips is used as the light emitting element. This one-dimensional array bar has a carrier 15 and semiconductor lasers 2 a to 2 g made of semiconductor chips arranged on the carrier 15. The carrier 15 is disposed along the x-axis, whereby each of the semiconductor lasers 2a to 2g is disposed at the focal point A. In FIG. 8, the semiconductor lasers 2a to 2d are composed of surface emitting semiconductor chips. Each of the semiconductor lasers 2 a to 2 d is disposed on the carrier 15. The carrier 15 has an L shape when cut along the yz plane. Thereby, the states of the semiconductor lasers 2a to 2d are rotated 90 degrees around the x axis from the state of the edge emitting semiconductor laser shown in FIG. 2, and the light emitting surface can be directed to the reflecting surface 11 side. Further, the carrier 15 is disposed along the x-axis, whereby each of the semiconductor lasers 2a to 2g is disposed at the focal point A. Further, in FIG. 9, a one-dimensional array bar of semiconductor chips is used as the light emitting element. This one-dimensional array bar is obtained by increasing the number of semiconductor lasers compared to the configuration of FIG. 8 and arranging the semiconductor lasers 2 a to 2 g on the carrier 15.

  In addition, since the structure of those other than the above in FIGS. 6-9 is the same as that of the condensing apparatus of Embodiment 1 shown in FIGS. 2-4, the same code | symbol is attached | subjected to the same member, The description is Do not repeat.

  According to the condensing device in the present embodiment, the same effect as that of the condensing device in the first embodiment can be obtained.

(Embodiment 3)
10 and 11 are diagrams schematically showing the configuration of the light collecting device according to Embodiment 3 of the present invention. 10 is a side view, and FIG. 11 is a plan view. Referring to FIGS. 10 and 11, condensing device 10 in the present embodiment is different from the condensing device of Embodiment 1 in that a plurality of concave mirrors 1 a to 1 d are used as reflecting portions. Each of the plurality of concave mirrors 1 a to 1 d is disposed in parallel to the x axis at the end of the base plate 4 on the side far from the optical fiber 30. Each of the concave mirrors 1a to 1d has a reflecting surface 11a to 11d parallel to the x-axis. In particular, as shown in FIG. 12, each of the reflecting surfaces 11a to 11d has, for example, a partial elliptical shape when cut by a plane (yz plane) and an xy plane perpendicular to the reflecting surfaces 11a to 11d. ing. As a result, each of the reflecting surfaces 11a to 11d has each of the focal points Aa to Ad. Each of the semiconductor lasers 2a to 2d is disposed at each of the focal points Aa to Ad.

  Each of the plurality of semiconductor lasers 2a to 2d emits light 20a to 20d to each of the reflecting surfaces 11a to 11d, and each of the lights 20a to 20d is reflected by each of the reflecting surfaces 11a to 11d and reflected light parallel to each other. Propagate in the positive direction of the y-axis by 21a to 21d.

  10 and 11 are the same as those of the light collecting apparatus according to the first embodiment shown in FIGS. 2 to 4, and therefore, the same members are denoted by the same reference numerals, and the description thereof will be omitted. Do not repeat.

  According to the light collecting device in the present embodiment, it is possible to obtain substantially the same effect as the light collecting device in the first embodiment.

  In addition, each member of the condensing apparatus as described in Embodiments 1-3 can be combined suitably.

  The embodiment disclosed above should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments but by the scope of claims, and is intended to include all modifications and variations within the scope and meaning equivalent to the scope of claims.

  The present invention is suitable for a condensing device and a condensing method of a high-power laser device.

It is a figure which shows typically the example of application of the condensing device in Embodiment 1 of this invention. It is a perspective view which shows typically the structure of the condensing device in Embodiment 1 of this invention. It is a side view which shows typically the structure of the condensing device in Embodiment 1 of this invention. It is a top view which shows typically the structure of the condensing device in Embodiment 1 of this invention. It is a side view which shows typically the other structure of the condensing device in Embodiment 1 of this invention. It is a fragmentary perspective view which shows typically the 1st structure of the condensing apparatus in Embodiment 2 of this invention. It is a fragmentary perspective view which shows typically the 2nd structure of the condensing apparatus in Embodiment 2 of this invention. It is a fragmentary perspective view which shows typically the 3rd structure of the condensing device in Embodiment 2 of this invention. It is a fragmentary perspective view which shows typically the 4th structure of the condensing apparatus in Embodiment 2 of this invention. It is a side view which shows typically the structure of the condensing device in Embodiment 3 of this invention. It is a top view which shows typically the structure of the condensing device in Embodiment 3 of this invention. It is a figure which shows the conventional condensing device typically.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Parabolic mirror, 1a-1d Concave mirror, 2a-2g Semiconductor laser, 3 Condensing lens, 4 Base plate, 10 Condensing apparatus, 11, 11a-11d Reflective surface, 12 Inclined surface, 15 Carrier, 20a-20d Light, 21a-21d reflected light, 30 optical fiber, 50 probe, 70 dental laser, 101a-101e light beam, 111 semiconductor laser group, 111a-111e semiconductor laser, 121 laser block, 121a-121e collimating lens, 131 light beam rearrangement optical system , 131a to 131e prism, 141 converging optical system, 151 optical fiber, 200 condensing device, A, Aa to Ad focal point, W light width, θ angle.

Claims (8)

A reflective part having a reflective surface with a focal point;
A plurality of light emitting elements arranged at the focal point and emitting light toward the reflecting surface;
A condensing device comprising: a condensing unit for converging the reflected light reflected by the reflecting surface in one axial direction perpendicular to the optical axis of the reflected light.   The condensing device according to claim 1, wherein the reflecting surface has a parabolic shape when cut along a plane perpendicular to the reflecting surface.   The light collecting apparatus according to claim 1, wherein the focal point is linear.   The said condensing part converges the said reflected light also to the other axial direction perpendicular | vertical with respect to both the optical axis of the said reflected light, and the said one axial direction. Concentrator. Arranging each of the plurality of light emitting elements at the focal point of the reflecting surface of the reflecting portion;
Emitting light from each of the plurality of light emitting elements to the reflecting surface;
Focusing the reflected light reflected by the reflecting surface in one axial direction perpendicular to the optical axis of the reflected light.   The light collecting method according to claim 5, wherein, in the step of emitting light, the light is emitted to a position of the reflection surface such that the reflected light does not include the focal point.   The condensing method according to claim 5, wherein the focal point is linear.   8. The step of focusing the reflected light, the reflected light is also focused in another axial direction perpendicular to both the optical axis of the reflected light and the one axial direction. The light condensing method according to the item.

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