JP6635365B2 - Single crystal growing device with laser beam splitting device - Google Patents

Description

  The present invention relates to a single crystal growing apparatus having a laser beam splitting device.

2. Description of the Related Art Conventionally, in a single crystal manufacturing apparatus of a floating melting zone method using a heating laser beam, a method of directly irradiating a raw material rod with a plurality of heating laser beams from the surroundings and heating the same is known (for example, Patent Document 1).
[Prior art documents]
[Non-patent literature]
[Non-Patent Document 1] Matsuda, et al. , "Magnetic dispersion and anisotropy in multiferroic BiFeO 3" Phys. Rev .. Lett. , USA, The American Physical Society, August 8, 2012, Vol. 109,067205.
[Patent Document]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2011-140881

  FIG. 26 shows an example of the configuration of a conventional single crystal growing apparatus 500. The single crystal growing apparatus 500 includes a plurality of laser power supplies 510a, 510b, 510c, 510d, 510e, a plurality of semiconductor lasers 520a, 520b, 520c, 520d, 520e, and a plurality of light sources for heating the raw material rod 501. Fibers 540a, 540b, 540c, 540d, 540e and a plurality of laser irradiation heads 550a, 550b, 550c, 550d, 550e are provided. FIG. 26 shows a case where five semiconductor laser sources and five constant current sources for the semiconductor laser light source are used. The semiconductor laser 520 used for the floating melting zone method is an expensive device whose cost is several million yen. The laser power supply is also in the price range of hundreds of thousands of yen, and if the number of laser power supplies is five, it will be expensive at several million yen. Five laser power supplies 510a, 510b, 510c, 510d, 510e are respectively connected to the five semiconductor lasers 520a, 520b, 520c, 520d, 520e, and the five laser power supplies 510a, 510b, 510c, 510d, 510e are simultaneously connected. A computer control system to control is essential. The development of such control software is expensive. In addition, the semiconductor laser 520 requires temperature control accuracy within ± 0.5 ° C., and when cooling water with high temperature accuracy is branched from one cooling device, fine adjustment of the amount of branch water is required. . The environment gas used for the semiconductor laser 520 needs dry air with low humidity. The semiconductor laser device is cooled by cooling water. For this reason, dew condensation easily occurs around the semiconductor laser 520, and it is necessary to introduce a dry gas into each semiconductor laser 520. As described above, the plurality of semiconductor lasers 520 and the laser power supply 510 not only greatly increase the cost of the single crystal growing apparatus 500 but also increase the load on the auxiliary equipment.

  According to a first aspect of the present invention, there is provided a single crystal growing apparatus for growing a single crystal from a raw material rod, comprising a laser power supply, and emitting a semiconductor laser beam based on power supplied by the laser power supply. A single crystal growing apparatus including a laser beam splitting device that splits a semiconductor laser beam into M heating laser beams and a laser irradiation head that irradiates the M heating laser beams toward a raw material rod.

FIG. 1 shows an example of a perspective view of a single crystal growing apparatus 100. An example of a top view near the raw material rod 1 is shown. 1 shows an example of the configuration of a semiconductor laser device 20. FIG. 2 shows a schematic diagram of an optical fiber 40. 1 shows an example of the configuration of a semiconductor laser device 20. 1 shows an example of a top view of a semiconductor laser device 20. FIG. 1 shows an example of a front view of a semiconductor laser device 20. FIG. FIG. 1 shows an example of a side view of a semiconductor laser element 201 and a collimator lens. FIG. 1 shows an example of a top view of a semiconductor laser element 201 and a collimator lens. An example of a method of dividing the semiconductor laser light 5 will be described. An example of a method of attenuating the semiconductor laser light 5 and an example of a fiber condenser lens will be described. The simulation experiment result of the semiconductor laser beam 5 divided into M lines is shown. 7 shows a method of dividing the semiconductor laser beam 5 according to the second embodiment. An example of the configuration of the first condenser lens 36 and the second condenser lens 37 is shown. 10 shows an example of a configuration of a laser beam splitting device 30 according to a third embodiment. 10 shows an example of the configuration of a laser beam splitting device 30 according to a fourth embodiment. 13 shows an example of a configuration of a laser beam splitting device 30 according to a fifth embodiment. 13 shows an example of the configuration of a laser beam splitting device 30 according to a sixth embodiment. An example of a method of entering the laser beam splitting device 30 according to the first splitting method will be described. 1 shows an example of the configuration of a laser beam splitting device 30 according to a second splitting method. An example of a method of entering the laser beam splitting device 30 according to the second splitting method will be described. An example of a splitting fiber 80 according to a third splitting method is shown. An example of a splitting fiber 80 according to a third splitting method is shown. 1 shows an example of the configuration of a laser irradiation head 50. 1 shows a top view of a single crystal growing apparatus 500 according to Comparative Example 1. FIG. FIG. 1 shows an example of a top view of a single crystal growing apparatus 100. 5 shows a configuration of a single crystal growing apparatus 500 in which a laser head is fixed to an upper part of the apparatus. An example of the configuration of a conventional single crystal growing apparatus 500 is shown.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of the features described in the embodiments are necessarily essential to the solution of the invention.

[Example 1]
FIG. 1 shows an example of a perspective view of a single crystal growing apparatus 100. FIG. 2 shows an example of a top view near the raw material rod 1. The single crystal growing apparatus 100 includes a laser power supply 10, a semiconductor laser device 20, a laser beam splitting device 30, M optical fibers, M laser irradiation heads, and M dampers. In this example, a case where the number of divisions M = 5 is shown.

  The single crystal growing apparatus 100 grows a single crystal on the seed crystal rod 2 by a floating melting zone method. In the floating melting zone method, a heating source for heating the raw material rod 1 and the seed crystal rod 2 to a high temperature is required. The single crystal growing apparatus 100 of this example uses a heating laser beam 3 as a heating source for a columnar raw material rod 1 and a seed crystal rod 2. The heating laser beam 3 is radially incident on the raw material rod 1 and the seed crystal rod 2 about the central axis of the raw material rod 1 and the seed crystal rod 2. The heating laser beam 3 is a laser beam having a substantially square irradiation shape and a two-dimensional surface intensity of the substantially square irradiation shape.

  The semiconductor laser device 20 is driven by the power from the laser power source 10 to generate the semiconductor laser light 5. The semiconductor laser device 20 emits the generated semiconductor laser beam 5 to the laser beam splitting device 30. The single crystal growing apparatus 100 of this example has one laser power supply 10 and one semiconductor laser apparatus 20. The number of semiconductor laser beams 5 emitted from the semiconductor laser device 20 is not limited to one, and a plurality of semiconductor laser beams 5 may be divided into M laser beams.

  The laser beam splitting device 30 splits the semiconductor laser beam 5 into M beams. The laser beam splitting device 30 makes the split semiconductor laser beam 5 incident on the optical fibers 41, 42, 43, 44 and 45. The laser beam splitting device 30 of this example splits the semiconductor laser beam 5 into M beams. The laser beam splitting device 30 has first to third three splitting methods for splitting the semiconductor laser beam 5 into M beams.

  The optical fibers 41, 42, 43, 44, and 45 emit M semiconductor laser beams 5 as M heating laser beams 3. The shape of the entrance of the optical fibers 41, 42, 43, 44, 45 is circular. The incident semiconductor laser beam 5 becomes uniform due to the mutual interference effect of a large number of quartz glass tubes constituting the optical fibers 41, 42, 43, 44, 45. On the other hand, near the exit ports of the optical fibers 41, 42, 43, 44, and 45, the core shape of the optical fibers is substantially square. As a result, the semiconductor laser beam 5 emitted from the optical fibers 41, 42, 43, 44, 45 becomes a heating laser beam 3 having a substantially square shape and a completely uniform laser beam intensity in cross section.

  The laser irradiation heads 51, 52, 53, 54, 55 condense the heating laser light 3 incident from the optical fibers 41, 42, 43, 44, 45 on the raw material rod 1 and the seed crystal rod 2. It is arranged so as to irradiate a plurality of heating laser beams at equal intervals and radially for confirmation of laser illumination. That is, the laser irradiation heads 51, 52, 53, 54, and 55 irradiate the heating laser beam 3 from five directions at an angle of approximately 72 degrees around the raw material rod 1 and the seed crystal rod 2. When the number of divisions M is 5, the uniformity of the light irradiation intensity around the raw material rod 1 and the seed crystal rod 2 is 95% or more. This is because the heating laser beam 3 has a substantially square irradiation shape, and a laser beam having a substantially square irradiation shape and uniform two-dimensional surface intensity is used. The light intensity distribution of the heating laser light 3 with a constant light intensity on a two-dimensional surface is called a top flat shape distribution. Thus, the laser irradiation heads 51, 52, 53, 54, 55 may shape the heating laser beam 3 into a desired irradiation shape.

  The dampers 61, 62, 63, 64, and 65 shown in FIG. 2 have a water cooling mechanism and absorb a part of the heating laser beam 3. The dampers 61, 62, 63, 64, 65 are provided opposite to the laser irradiation heads 51, 52, 53, 54, 55 with the raw material rod 1 and the seed crystal rod 2 interposed therebetween. For example, the damper 61 absorbs the heating laser light 3 that has passed through the right and left of the raw material rod 1 and the seed crystal rod 2 among the heating laser light 3 emitted by the laser irradiation head 51. This can prevent the laser irradiation head 51 from damaging the inside of the single crystal growing apparatus 100.

  Here, the raw material rod 1 is a columnar rod formed of a material corresponding to the single crystal to be grown. The raw material rod 1 and the seed crystal rod 2 are heated by the heating laser beam 3 to form a molten zone 4 on the seed crystal rod 2. For example, the melting temperature of the raw material rod 1 and the seed crystal rod 2 is 300 ° C. to 2000 ° C. The melting zone 4 is a layer in which the raw material rod 1 and the seed crystal rod 2 are melted by the heating laser light 3, and forms a single crystal according to the material of the raw material rod 1 and the seed crystal rod 2 by cooling. The raw material rod 1 and the seed crystal rod 2 are installed in a quartz tube 6 and fixed to a raw material rod holding unit 11 and a single crystal holding unit 12, respectively. Since the single crystal growing apparatus 100 of this embodiment does not require the raw material rod 1 and the seed crystal rod 2 to be placed in the crucible, it is possible to grow an extremely high-purity single crystal rod without impurity contamination from the crucible. Also, it is possible to add a trace element to the raw material rod 1.

  The quartz tube 6 is a transparent tube formed of quartz. The raw material rod 1 and the seed crystal rod 2 are arranged on the central axis of the quartz tube 6. A suitable gas is filled in the quartz tube 6 according to the material of the raw material rod 1 and the seed crystal rod 2. For example, oxygen gas is supplied to the quartz tube 6 to adjust the inside of the quartz tube 6 to a predetermined pressure.

  The raw material rod holding unit 11 holds the raw material rod 1 in the quartz tube 10. The raw material rod holding unit 11 rotates the raw material rod 1 counterclockwise with respect to the central axis of the raw material rod 1 in plan view. For example, the raw material rod holding unit 11 has a shaft, and the raw material rod 1 is suspended from the shaft with a high melting point wire such as a platinum wire. The rotation speed of the raw material rod 1 may be determined at an arbitrary speed, and is about 10 to 60 rpm in one example.

  The single crystal holding unit 12 holds the seed crystal rod 2 in the quartz tube 10. The single crystal holding unit 12 rotates the seed crystal rod 2 clockwise with respect to the central axis of the seed crystal rod 2 in plan view. That is, the raw material rod holder 11 and the single crystal holder 12 rotate so that the rotation direction of the raw material rod 1 and the rotation direction of the seed crystal rod 2 are opposite. The rotation speed of the seed crystal rod 2 may be determined at an arbitrary speed, and is about 10 rpm to 60 rpm in one example. The rotation speed of the seed crystal rod 2 is preferably the same as the rotation speed of the raw material rod 1, but is not limited thereto. By rotating the raw material rod 1 and the seed crystal rod 2, the temperature uniformity of the molten zone 4 is improved. Further, the rotation speed is controlled so that the melting zone 4 is located on the center axis of the shaft.

  The raw material rod holding unit 11 and the single crystal holding unit 12 gradually move the holding positions of the raw material rod 1 and the seed crystal rod 2 downward with the melting zone 4 stabilized at a predetermined temperature. Thereby, the melting zone 4 is gradually crystallized in the crystal orientation of the seed crystal from a region above the seed crystal where the heating laser beam 3 is no longer irradiated. The moving speed of the raw material rod holding unit 11 and the single crystal holding unit 12 is arbitrarily set according to the characteristics of the single crystal material, the intensity of the heating laser beam 3, and the like.

  In the first embodiment, a description will be given of a laser beam splitting device 30 of the first splitting method. In the first division method, the semiconductor laser beam 5 from the semiconductor laser device 20 is immediately divided into M semiconductor laser beams 5. The greatest advantage of the first division method is that the semiconductor laser beam 5 from the semiconductor laser device 20 is divided into M laser beams before the semiconductor laser beam 5 is introduced into the optical fibers 41, 42, 43, 44, and 45. By doing so, it is possible to minimize the influence of the optical fibers 41, 42, 43, 44, and 45 on the substantially square irradiation shape having a top flat intensity distribution. It is because of the optical fibers 41, 42, 43, 44, 45 that the top flat intensity distribution and the substantially square shape can be obtained. In the first division method, it is preferable to realize the first division method with a small number of optical systems in order to reduce the loss of laser light intensity in the laser light division device 30.

  FIG. 3 shows an example of the configuration of the semiconductor laser device 20. The semiconductor laser device 20 of the present example includes a semiconductor laser element 201 including a semiconductor chip 21, a submount 22, and a heat sink 23.

  The semiconductor chip 21 emits the semiconductor laser light 5. The semiconductor chip 21 has L light emitting points 24 arranged in a line. The semiconductor chip 21 is fixed on the submount 22. In this example, the direction in which the L light-emitting points 24 are arranged is the X axis, the direction in which the semiconductor laser light 5 is irradiated is the Z axis, and the direction perpendicular to the X axis and the Z axis is the Y axis.

  The submount 22 is formed of a material having a high thermal conductivity such as aluminum nitride, copper tungsten, or artificial diamond. The submount 22 is fixed on the heat sink 23.

  The heat sink 23 absorbs heat generated when the semiconductor chip 21 is driven. The heat sink 23 is a metal heat sink having a high thermal conductivity such as Cu.

  The size of the L light emitting points 24 has a width W1 in the X-axis direction and a height H1 in the Y-axis direction. The L light emitting points 24 are arranged at a pitch P1. The pitch P1 indicates a distance from an end on the X axis direction negative side of a certain light emitting point 24 to an X axis direction negative side end of an adjacent light emitting point 24. That is, one light emitting point 24 is arranged for each pitch P1.

  The semiconductor laser light 5 has a large divergence angle in the X-axis direction and the Y-axis direction. Usually, the laser beam diverges at a divergence angle of 8 to 10 degrees in the X direction and 30 to 70 degrees in the Y direction. Therefore, in order to make the semiconductor laser light 5 incident on the optical fibers 41, 42, 43, 44, and 45, it is necessary to convert the semiconductor laser light 5 into parallel light.

  FIG. 4 shows a schematic diagram of the optical fiber 40. The optical fiber 40 is an example of the optical fibers 41, 42, 43, 44, 45. The optical fiber 40 has an optical fiber core 46 and an optical fiber clad 47.

  The structure of the optical fiber 40 is a two-layer structure including an optical fiber core 46 and an optical fiber clad 47 covering the periphery thereof. The refractive index of the optical fiber core 46 is higher than the refractive index of the optical fiber clad 47. Thus, the semiconductor laser light 5 propagates in the optical fiber core 46.

Here, a beam parameter product (BPP) is used as an index for designing the semiconductor laser device 20 and the laser beam splitting device 30. BPP is obtained from the following equation.
[Formula 1]
BPP = λ1 × θf
Here, λ1 indicates the diameter of the optical fiber core 46. θf indicates a divergence angle of the optical fiber 40. That is, BPP is the product of the diameter of the optical fiber core 46 and the divergence angle θf of the optical fiber 40. The BPP provides important guidelines for selecting the number of stacked semiconductor chips 21 of the laser beam splitting device 30, the number of split mirrors, and the width of the split mirror reflection surface.

When the L light emitting points 24 arranged in the X-axis direction are divided into M semiconductor laser beams 5 and are incident on the M optical fibers 40, the number L of light emitting points is selected so as to satisfy the following equation. .
[Formula 2]
{(L-1) × P1 + W1} × θl ≦ M × BPP

  W1 in the expression (2) is the horizontal length of the light emitting point of the semiconductor laser device. The pitch interval P1 between the semiconductor laser elements indicates the distance between the light emitting point 24 of the semiconductor laser element and the light emitting point 24 of the adjacent semiconductor laser element. θ1 indicates the divergence angle of the semiconductor laser beam 5 emitted from the light emitting point 24 in the lateral direction. When the number L of light emitting points in the semiconductor laser device 20 is in the range of the expression (2), the light is incident on the entrance of the optical fiber 40 with high light energy utilization efficiency. If the BPP is exceeded, the semiconductor laser light 5 damages the optical fiber 40.

  FIG. 5 shows an example of the configuration of the semiconductor laser device 20. The semiconductor laser device 20 includes semiconductor laser elements 201, 202, 203, 204, and 205 stacked in the Y-axis direction.

  The semiconductor laser device 20 can obtain a laser beam intensity sufficient to heat the raw material rod 1 and the seed crystal rod 2 by stacking the semiconductor laser elements 201, 202, 203, 204, and 205. The laser beam intensity of the semiconductor laser device 20 must be large enough to heat the raw material rod 1 and the seed crystal rod 2 to about 1000 ° C. to 2000 ° C. However, the raw material rod 1 and the seed crystal rod 2 cannot be heated to about 1000 ° C. to 2000 ° C. with the laser beam intensity of one semiconductor laser element 201. In order to heat the raw material rod 1 and the seed crystal rod 2 to about 1000 ° C. to 2000 ° C., a semiconductor laser device 20 of 1 kW class is required. The 1 K watt class semiconductor laser device 20 can heat the raw material rod 1 and the seed crystal rod 2 to desired temperatures even if the laser beam is divided into M laser beams.

The semiconductor laser device 20 of this example has N semiconductor laser elements stacked so as to satisfy the following equation.
[Equation 3]
{(N-1) × Pc + H1} × θv ≦ BPP
Pc indicates the stacking interval of the semiconductor laser device. The stacking interval Pc of the semiconductor laser devices indicates the interval between the light emitting point 24 of a certain semiconductor laser device and the light emitting point 24 of the semiconductor laser device to be stacked. θv indicates a vertical divergence angle of the semiconductor laser light 5 emitted from the light emitting point 24. When the number N of stacked semiconductor laser elements in the semiconductor laser device 20 is in the range of the expression (3), the semiconductor laser element is guided to the entrance of the optical fiber 40 with high light energy utilization efficiency. If the BPP is exceeded, the semiconductor laser light 5 damages the optical fiber 40.

  FIG. 6A shows an example of a top view of the semiconductor laser device 20. FIG. 6B shows an example of a front view of the semiconductor laser device 20. The semiconductor laser device 20 includes semiconductor laser elements 201, 202, 203, 204, and 205 stacked in a stepwise manner. Further, the semiconductor laser device 20 of the present example has reflection mirrors 25, 26, 27, and 28.

  The semiconductor laser elements 201, 202, 203, 204, and 205 are stacked in a stepwise manner. Laminating in a stepwise manner refers to disposing in the X-axis direction and / or the Z-axis direction and displacing in the Y-axis direction. For example, the semiconductor laser elements 201, 202, 203, 204 and 205 are stacked at the same pitch in the order of the semiconductor laser elements 201, 202, 203, 204 and 205 from the positive side in the Y-axis direction. Further, the semiconductor laser elements 201, 202, 203, 204, 205 may be completely displaced on the XZ plane, or may be partially overlapped.

  More specifically, the semiconductor laser element 201 irradiates the semiconductor laser light 5 toward the reflection mirrors 25, 26, 27, and 28. The semiconductor laser device 202 faces the semiconductor laser device 203 with the reflection mirror 25 and the reflection mirror 26 interposed therebetween. The semiconductor laser device 204 faces the semiconductor laser device 205 with the reflection mirror 27 and the reflection mirror 28 interposed therebetween.

  The reflection mirrors 25, 26, 27, 28 convert the optical path of the semiconductor laser light 5 emitted from the semiconductor laser elements 202, 203, 204, 205. In this example, the reflection mirrors 25, 26, 27, and 28 travel straight without changing the optical path of the semiconductor laser light 5 emitted from the semiconductor laser element 201. The reflection mirror 25 and the reflection mirror 26 convert the semiconductor laser light 5 emitted from the semiconductor laser elements 202 and 203 in the same direction as the semiconductor laser light 5 of the semiconductor laser element 201, respectively. Further, the reflection mirror 27 and the reflection mirror 28 convert the semiconductor laser light 5 emitted from the semiconductor laser elements 204 and 205 in the same direction as the semiconductor laser light 5 emitted from the semiconductor laser element 201, respectively. In this example, the direction in which the semiconductor laser light 5 is converted is defined as the Z-axis direction for convenience. However, the direction in which the L light emitting points 24 are arranged may be appropriately changed depending on the direction in which the semiconductor laser elements 201, 202, 203, 204, and 205 face. That is, the light emitting points 24 of the semiconductor laser elements 201 are arranged in the X axis direction, and the light emitting points 24 of the semiconductor laser elements 202, 203, 204, 205 are arranged in the Z axis direction.

  FIG. 7A shows an example of a side view of the semiconductor laser element 201. FIG. 7B shows an example of a top view of the semiconductor laser element 201. The semiconductor laser light 5 emitted from the semiconductor laser element 201 is converted into parallel light by a Y-direction collimator 31 and an X-direction collimator 32. The Y-direction collimator 31 and the X-direction collimator 32 are examples of the configuration of the laser beam splitting device 30.

  The Y-direction collimator 31 converts the semiconductor laser light 5 so that the light becomes parallel to the Z-axis when viewed from the X-axis direction. That is, the semiconductor laser light 5 spreading in the Y-axis direction becomes light parallel to the Z-axis when viewed from the X-axis direction. The Y-direction collimator 31 has a cylindrical (cylindrical) lens.

  The X-direction collimator 32 converts the semiconductor laser light 5 so that the light becomes parallel to the Z-axis when viewed from the Y-axis direction. That is, the semiconductor laser light 5 spreading in the X-axis direction becomes light parallel to the Z-axis when viewed from the Y-axis direction. The X-direction collimator 32 has a large number of convex lens arrays arranged in the X-axis direction.

  The semiconductor laser light 5 of this example was incident on the X-direction collimator 32 after being incident on the Y-direction collimator 31. However, the semiconductor laser light 5 may enter the Y-direction collimator 31 after entering the X-direction collimator 32. The semiconductor laser light 5 passes through the Y-direction collimator 31 and the X-direction collimator 32 to become laser light parallel to the Z-axis direction.

  FIG. 8 shows an example of a method of dividing the semiconductor laser light 5. The laser beam splitting device 30 of the present example further includes a split mirror 33. The split mirror 33 splits the parallel light of the semiconductor laser light 5 emitted from the X-direction collimator 32 into M semiconductor laser lights 5.

  The split mirror 33 has a mirror reflection surface 332 formed on a flat substrate 331. The division mirror 33 divides the semiconductor laser beam 5 into M semiconductor laser beams 5 by providing a number corresponding to the division number M. For example, the split mirror 33 that reflects the semiconductor laser light 5 located on the positive side in the X-axis direction with respect to the semiconductor laser light 5 located at the center is 45 degrees with respect to the traveling direction of the semiconductor laser light 5, in the X-axis direction. With a vertical axis inclined to the negative side of Further, the split mirror 33 that reflects the semiconductor laser light 5 located on the negative side in the X-axis direction with respect to the semiconductor laser light 5 located at the center is 45 degrees with respect to the traveling direction of the semiconductor laser light 5, With a vertical axis inclined to the positive side of The split mirror 33 of the present example splits the semiconductor laser beam 5 in five directions with five split mirrors 33a, 33b, 33c, 33d, and 33e. In the present specification, when an angle such as 45 degrees is indicated, the angle does not necessarily need to be exactly 45 degrees, but may be substantially 45 degrees.

  The mirror reflection surface 332 is inclined so that the semiconductor laser light 5 is incident at an angle of 45 degrees with respect to the surface of the mirror reflection surface 332. That is, the mirror reflection surface 332 tilts the vertical axis at a positive angle or a negative angle in the X-axis direction by 45 degrees with respect to the traveling direction of the semiconductor laser light 5. As a result, the semiconductor laser light 5 incident on the mirror reflection surface 332 bends at right angles to the traveling direction.

  More specifically, the split mirror 33 is arranged in the order of the split mirrors 33a, 33b, 33c, 33d, and 33e from the positive side of the X axis. The split mirror 33 is arranged in the order of the split mirrors 33c, 33b, 33d, 33a, and 33e from the positive side of the Z axis. The split mirrors 33a, 33b, and 33c of the present example bend the semiconductor laser light 5 by 90 degrees to the right with respect to the traveling direction. On the other hand, the split mirrors 33d and 33e bend the semiconductor laser light 5 90 degrees to the left with respect to the traveling direction. In this case, the semiconductor laser light 5 travels in two directions. As described above, the division mirror 33 divides the semiconductor laser light 5 by allocating it to the left and right, so that an installation space for an optical system that controls the semiconductor laser light 5 for each divided semiconductor laser light 5 can be obtained.

  Since the split mirror 33c is located at the center in the X axis, the semiconductor laser beam 5 may be bent 90 degrees to the left with respect to the traveling direction. Further, the semiconductor laser light 5 may be made to travel straight without disposing the split mirror 33c. In this case, the semiconductor laser light 5 travels in three directions.

Here, the laser beam splitting device 30 that splits a plurality of semiconductor laser beams 5 emitted from the L light emitting points 24 of one semiconductor laser device 20 into M beams splits the split mirror 33 so as to satisfy the following equation. Deploy. D indicates the distance between the split mirrors 33 in the X-axis direction.
[Equation 4]
D = n × d1
Here, n is an arbitrary integer. Also, d1 indicates the width of each of the semiconductor laser beams 5 divided into M lines in the X-axis direction. D in FIG. 8 indicates the distance between the center lines of the split mirror 33a and the split mirror 33c. d1 satisfies the following equation.
[Equation 5]
d1 = {(L−1) × P1 + W1} / M

  The split mirror 33 may include a mechanism such as an actuator in order to move without changing the angle with respect to the incident semiconductor laser light 5. When the split mirror 33 includes an actuator, the optical path length of each of the M semiconductor laser beams 5 can be freely adjusted. Since the longer the optical path length of the semiconductor laser light 5 is, the larger the loss of the semiconductor laser light 5 is, the optical path length of the semiconductor laser light 5 is preferably equal among the M divided semiconductor laser lights 5.

  FIG. 9 shows an example of a method of attenuating the semiconductor laser light 5. In this example, the laser beam splitting device 30 further includes an attenuation mirror 34, a damper unit 35, a first condenser lens 36, and a second condenser lens 37.

  The attenuating mirror 34 equalizes the laser light intensities of the M semiconductor laser lights 5 by attenuating the incident semiconductor laser light 5. For example, the attenuating mirror 34 reflects at least a part of the M semiconductor laser beams 5 divided by the dividing mirror 33, and passes the others. Thus, the attenuation mirror 34 freely adjusts the laser light intensity of the semiconductor laser light 5. A plurality of attenuating mirrors 34 may be provided according to the number of split mirrors 33.

  The damper unit 35 has a water cooling mechanism and is installed at a position where the light reflected from the attenuation mirror 34 enters. Thus, the damper unit 35 absorbs the reflected light from the attenuation mirror 34. When a plurality of damping mirrors 34 are provided, the damper unit 35 may be provided commonly to the plurality of damping mirrors 34.

  The first condenser lens 36 and the second condenser lens 37 condense the semiconductor laser light 5 attenuated by the attenuation mirror 34 and enter the optical fiber 40. The first condenser lens 36 and the second condenser lens 37 are arranged so as to satisfy the BPP condition of the optical fiber 40. The lens for condensing the semiconductor laser light 5 on the optical fiber 40 is composed of the first condenser lens 36 and the second condenser lens 37 which are the minimum number of two condenser lenses. It may be a combination of optical lenses.

  The attenuating mirror 34 may include a mechanism such as an actuator in order to move the M semiconductor laser light 5 incident thereon without changing the angle between the M axis and the vertical axis of the attenuating mirror 34. When the attenuation mirror 34 includes an actuator, the attenuation rate of each of the M semiconductor laser beams 5 can be freely adjusted. Therefore, it is possible to control the laser beam intensity of the semiconductor laser beam 5 divided into M lines to be uniform.

  FIG. 10 shows a simulation experiment result in Example 1 of the semiconductor laser beam 5 divided into M lines. The laser division number M in this example is 5.

  The experimental result of this example shows the semiconductor laser light 5 that the laser beam splitting device 30 according to the first embodiment enters the optical fiber 40. The laser beam splitting device 30 according to the first embodiment is different from the laser beam splitting device 30 in that the laser beam splitting device 30 is a Y-direction collimator 31, an X-direction collimator 32, a split mirror 33, an attenuation mirror 34, a damper unit 35, a first condenser lens 36, and a second This is a case in which a condenser lens 37 is provided. The diameter λ1 of the optical fiber core 46 of this example is 0.8 mmφ. From the simulation experiment results, it was demonstrated that the split semiconductor laser beam 5 was stored in the optical fiber core 40 in each of the optical fibers 41, 42, 43, 44, and 45.

  As described above, the single crystal growing apparatus 100 according to the first embodiment can irradiate the M laser beams 5 into the entrances of the M optical fibers 40 with uniform intensity. Since the single crystal growing apparatus 100 has an optical system in which the semiconductor laser light 5 is controlled within the BPP of the optical fiber 40, the loss of the semiconductor laser light 5 is small and uniform laser light intensity can be achieved.

[Example 2]
FIG. 11 illustrates a method of dividing the semiconductor laser beam 5 according to the second embodiment. The laser beam splitting device 30 of this example splits the semiconductor laser beam 5 in one direction and extracts it. The attenuating mirror 34, the damper unit 35, the first condenser lens 36, and the second condenser lens 37 at the subsequent stage may have the same configuration as in the first embodiment.

  The split mirror 33 has a mirror reflection surface 332 formed on a flat substrate 331. The division mirror 33 divides the semiconductor laser beam 5 into M semiconductor laser beams 5 by providing a number corresponding to the division number M. For example, when splitting into M semiconductor laser beams 5 in the X-axis direction, all of the split mirrors 33 are inclined 45 degrees with respect to the traveling direction of the semiconductor laser beam 5 toward the positive side or the negative side in the X-axis direction. With a vertical axis. The split mirror 33 of this example is such that five split mirrors 33a, 33b, 33c, 33d, and 33e are vertically inclined at 45 degrees to the forward direction of the X-axis direction with respect to the traveling direction of the semiconductor laser beam 5. Has an axis.

  More specifically, the split mirror 33 is arranged in the order of the split mirrors 33a, 33b, 33c, 33d, and 33e from the positive side of the X axis. The split mirror 33 is arranged in the order of the split mirrors 33a, 33b, 33c, 33d, and 33e from the positive side of the Z axis. Each of the split mirrors 33a, 33b, 33c, 33d, and 33e of the present example bends the semiconductor laser light 5 by 90 degrees to the left with respect to the traveling direction. The split mirrors 33a, 33b, 33c, 33d, and 33e may bend the semiconductor laser light 5 by 90 degrees to the right with respect to the traveling direction. That is, the M semiconductor laser beams 5 travel in one direction. With the arrangement of the split mirror 33 in this example, it is easy to uniformly control the optical path lengths of the M semiconductor laser beams 5 from the time when they are emitted from the X-direction collimator 32 to the time when they are incident on the attenuation mirror 34. In this case, the split mirror 33 of this example is arranged so as to satisfy the equations (4) and (5).

  FIG. 12 shows an example of the configuration of the first condenser lens 36 and the second condenser lens 37. The first condenser lens 36 and the second condenser lens 37 each have an integral structure type lens array.

  Since the first condenser lens 36 and the second condenser lens 37 have an integrated lens array, the distance between the lenses can be made smaller than when the lens arrays are individually formed. That is, even when the interval between the M semiconductor laser beams 5 is narrow, the light is easily focused on the optical fiber 40. Therefore, the use of the first condenser lens 36 and the second condenser lens 37 of the present example makes it easy to emit M semiconductor laser beams 5 in one direction as in the case of the split mirror 33 of the second embodiment. The M semiconductor laser beams 5 can be focused on the optical fibers 41, 42, 43, 44, and 45. For example, the first condenser lens 36 and the second condenser lens 37 have a plurality of spherical lenses and a plurality of cylindrical lenses.

[Example 3]
FIG. 13 illustrates an example of a configuration of the laser beam splitting device 30 according to the third embodiment. The laser beam splitting device 30 of the present example includes a triangular prism mirror 38 instead of the split mirror 33.

  The triangular prism mirror 38 divides the semiconductor laser light 5 into M semiconductor laser lights 5. The triangular prism mirror 38 includes a triangular substrate 381 and a mirror reflecting surface 382.

The triangular substrate 381 has a triangular prism shape whose oblique side has a length T. The mirror reflection surface 382 is formed on a slope having a length T of the triangular substrate 381. The mirror reflecting surface 382 of this example has a vertical axis inclined at 45 degrees with respect to the traveling direction of the semiconductor laser beam 5 toward the positive side or the negative side in the X-axis direction. Here, the length T of the hypotenuse satisfies the following equation.
[Equation 6]
T = d1 × √2

  More specifically, the triangular prism mirror 38 of this example is composed of two triangular prism mirrors 38a and 38b. The triangular prism mirror 38 is disposed in the order of the triangular prism mirrors 38a and 38b from the positive side of the X axis. The triangular prism mirror 38 is arranged in the order of the triangular prism mirrors 38a and 38b from the positive side of the Z axis. That is, the triangular prism mirror 38a and the triangular prism mirror 38b are displaced from each other in the X-axis direction and the Z-axis direction. The triangular prism mirror 38a divides the semiconductor laser beam 5 in the positive direction and the negative direction of the X axis. The triangular prism mirror 38b divides the semiconductor laser beam 5 in the positive direction and the negative direction of the X axis. Thus, the triangular prism mirror 38 extracts four of the five semiconductor laser beams 5 from the semiconductor laser beam 5. The remaining one semiconductor laser beam 5 passes without passing through the triangular prism mirror 38. Further, the remaining one semiconductor laser beam 5 may be bent by the split mirror 33 to either the positive side or the negative side in the X-axis direction.

  Note that the attenuation mirror 34, the damper unit 35, the first condenser lens 36, and the second condenser lens 37 may have the same configuration as in the first embodiment. As described above, the first to third embodiments have been described as examples of the first splitting method that satisfies the BPP of the optical fiber 40. May be included.

[Example 4]
FIG. 14 illustrates an example of a configuration of the laser beam splitting device 30 according to the fourth embodiment. The laser beam splitting device 30 of the present example includes a laser beam splitting device including a total reflection mirror 33 and a half mirror 39.

  The laser beam splitting device splits the semiconductor laser beam 5 into M beams. The laser beam splitting device of this example splits one semiconductor laser beam 5 into three beams by using total reflection mirrors 33f and 33g and half mirrors 39f and 39g. However, the laser beam splitting device may split the semiconductor laser beam 5 into an arbitrary number by changing the number of the total reflection mirror 33 and the half mirror 39.

  The half mirror 39 bends a part of the incident semiconductor laser light 5 in a predetermined direction and transmits another part. That is, the division number M of the semiconductor laser light 5 is determined according to the number of the half mirrors 39. The half mirror 39 has a mirror semi-transmissive surface 392 formed on a flat substrate 391. The half mirror 39 is arranged such that the vertical axis of the mirror semi-transmissive surface 392 forms an angle of 45 degrees with the traveling direction of the incident semiconductor laser light 5. Further, the half mirror 39 bends the semiconductor laser light 5 by 90 degrees to the right with respect to the traveling direction. The reflectances of the half mirrors 39f and 39g are arbitrarily set according to the number of the half mirrors 39.

  The total reflection mirror 33 reflects the semiconductor laser light 5 reflected by the half mirror 39 in an arbitrary direction. A multilayer film having a reflectivity close to 100%, or an aluminum or gold thin film is used. The total reflection mirror 33 has a mirror reflection surface 332 formed on a flat substrate 331. For example, the mirror reflection surface 332 has a vertical axis inclined by 45 degrees with respect to the traveling direction of the semiconductor laser light 5 reflected by the half mirror 39. The total reflection mirror 33 of this example is configured such that, when the half mirror 39 bends the semiconductor laser light 5 to the right by 90 degrees with respect to the traveling direction, the semiconductor laser light 5 is bent to the left by 90 degrees with respect to the traveling direction. The semiconductor laser light 5 is reflected in the same direction as the semiconductor laser light 5 transmitted through the half mirror 39. The total reflection mirrors 33f and 33g are arranged corresponding to the half mirrors 39f and 39g, respectively, so as to reflect the semiconductor laser light 5 reflected by the half mirrors 39f and 39g, respectively. The total reflection mirror 33 may reflect the semiconductor laser light 5 transmitted by the half mirror 39.

[Example 5]
FIG. 15 illustrates an example of a configuration of the laser beam splitting device 30 according to the fifth embodiment. The laser beam splitting device 30 of this example includes a splitting prism 90.

  The splitting prism 90 splits the semiconductor laser light 5 incident from the semiconductor laser device 20 into M light beams. The split prism 90 includes a multilayer film 902 having a high reflectance, an aluminum metal film, or a gold thin film on the slope of the prism base 901. The shape of the split prism 90 in this example is a quadrangular pyramid. The splitting prism 90 is disposed at a position where the semiconductor laser light 5 enters from the vertex of the quadrangular pyramid. Thereby, the semiconductor laser light 5 is emitted from the four surfaces adjacent to the apex where the semiconductor laser light 5 is incident. The shape of the splitting prism 90 may be appropriately changed according to the number of splitting semiconductor laser beams 5. The laser beam splitting device 30 can simplify the optical system by using the splitting prism 90.

[Example 6]
FIG. 16 illustrates an example of a configuration of the laser beam splitting device 30 according to the sixth embodiment. The laser beam splitting device 30 of this example includes a splitting prism 91.

  The splitting prism 91 splits the semiconductor laser light 5 incident from the semiconductor laser device 20 into M light beams. The split prism 91 includes a multilayer film 912 having high reflectance, an aluminum metal film, or a gold thin film on the slope of the prism base 911. The split prism 91 of this example has a polyhedral split prism 91a formed inside a cubic split prism 91b. The splitting prism 91 splits the semiconductor laser beam 5 in an arbitrary direction by adjusting the shapes of the splitting prisms 91a and 91b. The shape of the split prism 91a in this example is a quadrangular pyramid. For example, the split prism 91 is arranged so that the semiconductor laser beam 5 incident on the split prism 91b is incident on the apex of the M pyramid of the split prism 91a. Thus, the splitting prism 91a splits the incident semiconductor laser light 5 into M light beams.

[Example 7]
FIG. 17 shows an example of a method of entering the laser beam splitting device 30 according to the first splitting method. The laser beam splitting device 30 of the present example includes a Y-direction collimator 31, an X-direction collimator 32, an optical fiber 48, and a condenser lens 49.

  The laser beam splitting device 30 causes the semiconductor laser light 5 emitted from the semiconductor laser device 20 to enter one optical fiber 48 via a condenser lens 49. Thereafter, the semiconductor laser light 5 emitted from the optical fiber 48 is converted into a parallel semiconductor laser light 5 by passing through the Y-direction collimator 31 and the X-direction collimator 32. The order of the Y-direction collimator 31 and the X-direction collimator 32 may be interchanged. The Y-direction collimator 31 and the X-direction collimator 32 divide the emitted parallel light into M laser beams by the lens system disclosed in the first to sixth embodiments. The laser beam splitting device 30 of the present embodiment can bend the semiconductor laser beam 5 from the semiconductor laser device 20 in an arbitrary direction inside the laser beam splitting device 30, so that the laser power source 10, the semiconductor laser device 20, and the laser beam The degree of freedom of arrangement of the dividing device 30 is improved.

Example 8
FIG. 18 shows an example of a method of entering the laser beam splitting device 30 according to the second splitting method. In the second division method, the semiconductor laser light 5 emitted from the semiconductor laser device 20 is divided by a plurality of half mirrors. The single crystal growing apparatus 100 of this example has one semiconductor laser device 20. The number of divisions M is 5. The laser beam splitting device 30 of this example includes a Y-direction collimator 31, an X-direction collimator 32, an attenuation mirror 34, a first condenser lens 36, a second condenser lens 37, and a half mirror 39.

  The laser beam splitting device 30 makes the semiconductor laser light 5 emitted from the semiconductor laser device 20 enter the Y-direction collimator 31 and the X-direction collimator 32. The Y-direction collimator 31 and the X-direction collimator 32 convert the semiconductor laser light 5 into parallel laser light.

  The half mirror 39 divides the parallel semiconductor laser light 5 converted by the Y-direction collimator 31 and the X-direction collimator 32 into M beams. The half mirror 39 has a reflective film having a multilayer structure. Accordingly, the half mirror 39 bends a part of the incident semiconductor laser light 5 in a predetermined direction and transmits another part. The half mirror 39 is disposed such that the vertical axis of the half mirror 39 forms an angle of 45 degrees with the traveling direction of the incident semiconductor laser light 5. The half mirror 39 bends the semiconductor laser light 5 by 90 degrees to the left with respect to the traveling direction. The half mirror 39 of this example has half mirrors 39a, 39b, 39c, 39d, and 39e. The reflectivities of the half mirrors 39a, 39b, 39c, 39d, and 39e are 15%, 18.4%, 23.5%, 32.8%, and 54%, respectively, from the half mirror 39 near the optical fiber 48.

  Note that the loss of each half mirror 39 in this example is 3%. In this case, the semiconductor laser light 5 having approximately the same reflection intensity within 15 ± 0.1% is obtained as the reflection intensity of the semiconductor laser light 5 divided into five. Further, the intensity of the semiconductor laser beam 5 transmitted through the five half mirrors 39 is suppressed to 2% or less.

  The attenuation mirror 34 adjusts the reflection intensity of the five semiconductor laser beams 5 reflected by the half mirror 39. The attenuation mirror 34 is arranged such that the vertical axis of the attenuation mirror 34 is at 45 degrees with respect to the traveling direction of the semiconductor laser light 5 from the half mirror 39. The attenuating mirror 34 may include a mechanism such as an actuator in order to move the M semiconductor laser light 5 incident thereon without changing the angle between the M axis and the vertical axis of the attenuating mirror 34. The attenuating mirror 34 of the present example is constituted by attenuating mirrors 34a, 34b, 34c, 34d, 34e corresponding to the half mirrors 39a, 39b, 39c, 39d, 39e. The attenuation mirror 34 does not need to include all of the half mirrors 39a, 39b, 39c, 39d, and 39e.

  The first condenser lens 36 and the second condenser lens 37 condense the M semiconductor laser beams 5 on the M optical fibers 40. The laser beam splitting device 30 is designed to satisfy the BPP of the substantially square optical fiber 40.

  The laser beam splitting device 30 according to the second splitting method is an effective method when the semiconductor laser device 20 does not have a stacked structure of the semiconductor chips 21. In the second division method, the configuration of the laser beam division device 30 can be simplified.

[Example 9]
FIG. 19 shows an example of the configuration of the laser beam splitting device 30 according to the second splitting method. The single crystal growing apparatus 100 of this example has one semiconductor laser device 20. The number of divisions M is 5. The laser beam splitting device 30 of the present example further includes half mirrors 39a, 39b, 39c, 39d, 39e and an optical fiber 48.

  The laser beam splitting device 30 causes the semiconductor laser light 5 emitted from the semiconductor laser device 20 to enter one optical fiber 48 via a condenser lens 49. Thereafter, the semiconductor laser light 5 emitted from the optical fiber 48 is converted into a parallel semiconductor laser light 5 by passing through the Y-direction collimator 31 and the X-direction collimator 32. The order of the Y-direction collimator 31 and the X-direction collimator 32 may be interchanged. The method of splitting the semiconductor laser light 5 emitted from the Y-direction collimator 31 and the X-direction collimator 32 may be the same as in the eighth embodiment.

  20 and 21 show an example of the split fiber 80 according to the third splitting method. In the third division method, the semiconductor laser beam 5 is divided using a division fiber 80 instead of using a division mirror.

  The laser beam splitting device 30 of this example has a split fiber 80. The split fiber 80 has M emission ports 82 that split and emit the semiconductor laser light 5 incident on the incidence port 81. The split fiber 80 of the present example has one entrance 81 and two exits 82. Further, if the split fiber 80 is used, the semiconductor laser light 5 incident from one entrance 81 can be emitted from five exits 82. By using the split fiber 80, the lens system of the laser beam splitting device 30 is simplified. Note that the split fiber 80 in FIG. 20 shows a case where the exit port 82 is circular. On the other hand, the split fiber 80 in FIG. 21 shows a case where the exit port 82 is substantially rectangular.

[Example 10]
FIG. 22 shows an example of the configuration of the laser irradiation head 50. The laser irradiation head 50 is an example of the laser irradiation heads 51, 52, 53, 54, 55. The laser irradiation head 50 of this example includes a condenser lens 57 and a folding mirror 58.

  The condenser lens 57 condenses the heating laser light 3 incident from the optical fiber 40 on the return mirror 58. The turning mirror 58 turns the heating laser beam 3 condensed by the condensing lens 57 toward the raw material rod 1 and the seed crystal rod 2. An example of a 3 mm × 8 mm substantially square irradiation having a top flat irradiation intensity distribution is shown. Since the optical fiber 40 has the fiber allowable radius R1, the installation area of the single crystal growing apparatus 100 may be large. However, in the single crystal growing apparatus 100 of this example, by providing the laser irradiation head 50, the direction of the optical fiber 40 is perpendicular to the irradiation direction of the heating laser beam 3 to the raw material rod 1 and the seed crystal rod 2. Be able to place. Therefore, it is possible to prevent the installation area of the optical bench 56 from increasing due to the limitation of the allowable radius R1 of the optical fiber 40.

[Comparative Example 1]
FIG. 23 shows a top view of the single crystal growing apparatus 500 according to Comparative Example 1. The single crystal growing apparatus 500 of the present example does not have the folding mirror 58. In the single crystal growing apparatus 500, five laser irradiation heads 551, 552, 553, 554, and 555 must be arranged in a horizontal plane in order to keep the limit on the allowable radius R1 of the fiber. Therefore, the single crystal growing apparatus 500 needs to increase the ground area of the optical bench 56 in consideration of the fiber allowable radius R1. For example, if the fiber allowable radius R1 is 30 cm, the optical bench 56 needs to have a size of about 150 cm × 150 cm.

  FIG. 24 shows an example of a top view of the single crystal growing apparatus 100. The single crystal growing apparatus 100 of this example includes a laser irradiation head 50 having a folding mirror 58. Therefore, the laser irradiation head 50 is arranged in parallel with the raw material rod 1 and the seed crystal rod 2. By providing the laser irradiation head 50 in a direction parallel to the single raw material rod 1 and the seed crystal rod 2, the restriction on the allowable fiber radius R1 of the optical fiber 40 introduced into the laser irradiation head 50 is relaxed. Therefore, if the size of the optical bench 56 is about 70 cm × 70 cm regardless of the fiber allowable radius R1, five laser irradiation heads 50 can be installed. As a result, the installation area of the optical bench 56 of the single crystal growing apparatus 100 can be reduced by about 75% as compared with the installation area of the optical bench 56 of the single crystal growing apparatus 500. In the single crystal growing apparatus 100 of this example, the cost is greatly reduced due to the reduction of the installation space.

[Example 11]
FIG. 25 shows an example of the configuration of the single crystal growing apparatus 100. The single crystal growing apparatus 100 of this example has a ceiling 59 of an optical bench.

  The ceiling part 59 is located closer to the raw material rod holding part 11 for hanging the raw material rod 1 than the optical bench 56 is. For example, the ceiling 59 is located above the laser irradiation heads 51, 52, 53, 54, 55. The ceiling 59 fixes the laser irradiation heads 51, 52, 53, 54, 55. Further, the ceiling 59 may fix other components of the single crystal growing apparatus 100 such as the dampers 61, 62, 63, 64, 65 at predetermined positions. Thus, the single crystal growing apparatus 100 according to the sixth embodiment has an advantage that the number of components to be fixed to the optical bench 56 is smaller than that of the single crystal growing apparatus 100 according to the first embodiment. Since the single crystal growing apparatus 100 of this example has the ceiling 59, a space for installing a camera for observation of the molten zone 4, a preliminary raw material rod, a preliminary quartz tube, and the like on the optical bench 56 can be easily secured.

  As described above, since the single crystal growing apparatus 100 according to the present specification only needs to provide at least one laser power supply 10, the cost of the laser power supply 10 is reduced. In addition, since the single crystal growing apparatus 100 only needs to provide at least one semiconductor laser device 20, the cost of the semiconductor laser device 20 and the incidental facilities are greatly reduced. Further, since a plurality of semiconductor laser devices 20 need not be used, a system for controlling the driving of the semiconductor laser devices 20 can be simplified. And, by having the folding mirror 58, the installation space of the single crystal growing apparatus 100 can be reduced.

  As described above, the present invention has been described using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is apparent to those skilled in the art that various changes or improvements can be made to the above embodiment. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

  The execution order of each processing such as operation, procedure, step, and stage in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before”, “before”. It should be noted that they can be realized in any order as long as the output of the previous process is not used in the subsequent process. Even if the operation flow in the claims, the specification, and the drawings is described using “first,” “second,” or the like for convenience, it means that it is essential to perform the operation in this order. Not something.

DESCRIPTION OF SYMBOLS 1 ... Raw material rod, 2 ... seed crystal rod, 3 ... heating laser beam, 4 ... melting zone, 5 ... semiconductor laser beam, 6 ... quartz tube, 11 ... raw material Rod holder, 12: single crystal holder, 10: laser power supply, 20: semiconductor laser device, 201, 202, 203, 204, 205 ... semiconductor laser element, 21: semiconductor chip , 22 ... submount, 23 ... heat sink, 24 ... light emitting point, 25, 26, 27, 28 ... reflection mirror, 30 ... laser beam splitter, 31 ... Y-direction collimator , 32: X-direction collimator, 33: Total reflection mirror, 331: Flat substrate, 332: Mirror reflection surface, 34: Attenuation mirror, 35: Damper section, 36 ... First condenser lens, 37 ... second condenser lens, 38 ... triangle Mirror: 381: Triangular substrate, 382: Mirror reflection surface, 39: Half mirror, 391: Flat substrate, 392: Mirror semi-transmission surface, 40, 41, 42, 43, 44, 45: optical fiber, 46: optical fiber core, 47: optical fiber clad, 48: optical fiber, 49: condenser lens, 50, 51, 52, 53, 54, 55 ..Laser irradiation head, 56 optical bench, 57 condensing lens, 58 folding mirror, 59 ceiling, 61, 62, 63, 64, 65 damper, 80 ··· Split fiber, 81 ··· entrance port, 82 ··· output port, 90 ··· split prism, 91 ··· split prism, 100 ··· single crystal growing apparatus, 500 ··· single crystal growing Apparatus, 501 ... raw material rod, 510 ... le The power source, 520: semiconductor laser, 540: optical fiber, 550, 551, 552, 553, 554, 555: laser irradiation head, 901: prism substrate, 902: multilayer film, 911 ... Prism substrate, 912 ... Multilayer film

Claims (17)

In a single crystal growing device for growing single crystals from raw material rods,
A semiconductor laser device having a laser power source and emitting a single semiconductor laser beam based on the power supplied by the laser power source;
A laser beam splitting device for splitting the single semiconductor laser beam into M beams,
A laser irradiation head for irradiating the M semiconductor laser beams toward the raw material rod ;
It has M entrances and M exits, and the M entrances receive the M semiconductor laser beams from the laser beam splitting device and convert the M semiconductor laser beams into the M entrances. A laser irradiation head comprising: M optical fibers emitted from the M emission ports ;
The laser beam splitting device,
A collimator lens that converts the semiconductor laser light from the semiconductor laser device into parallel light,
A plurality of split mirrors for splitting the semiconductor laser light into M semiconductor laser lights;
A plurality of attenuating mirrors for equalizing the laser beam intensity of the M semiconductor laser beams;
A condenser lens for focusing the M semiconductor laser lights on the M optical fibers;
Has,
The semiconductor laser device has N semiconductor laser elements,
The N semiconductor laser elements each have a width W1 in a first direction, and have a semiconductor chip including L light emitting points arranged in a row at a pitch interval P1 in the first direction.
The N semiconductor laser elements are arranged offset in a second direction perpendicular to the first direction;
The N semiconductor laser elements are arranged in a stepwise manner shifted in the first direction;
A reflecting mirror that reflects the semiconductor laser light emitted by each of the N semiconductor laser elements in a predetermined direction;
The N is
{(N-1) × Pc + H1} × θv ≦ λc × θf
The filling,
Pc indicates a pitch interval between the N semiconductor laser devices in the second direction,
H1 indicates the height of the light emitting point in the second direction,
θv indicates a divergence angle of the semiconductor laser light in the second direction,
λc indicates a core diameter of the optical fiber,
θf indicates the divergence angle of the optical fiber . In a single crystal growing device for growing single crystals from raw material rods,
A semiconductor laser device having a laser power source and emitting a single semiconductor laser beam based on the power supplied by the laser power source;
A laser beam splitting device for splitting the single semiconductor laser beam into M beams,
A laser irradiation head for irradiating the M semiconductor laser beams toward the raw material rod;
It has M entrances and M exits, and the M entrances receive the M semiconductor laser beams from the laser beam splitting device and convert the M semiconductor laser beams into the M entrances. M optical fibers emitted from the M emission ports to the laser irradiation head;
With
The laser beam splitting device,
A collimator lens that converts the semiconductor laser light from the semiconductor laser device into parallel light,
A plurality of split mirrors for splitting the semiconductor laser light into M semiconductor laser lights;
A plurality of attenuating mirrors for equalizing the laser beam intensity of the M semiconductor laser beams;
A condenser lens for focusing the M semiconductor laser lights on the M optical fibers;
Has,
The semiconductor laser device has N semiconductor laser elements,
The N semiconductor laser elements each have a width W1 in a first direction, and have a semiconductor chip including L light emitting points arranged in a row at a pitch interval P1 in the first direction.
The N semiconductor laser elements are arranged offset in a second direction perpendicular to the first direction;
The N semiconductor laser elements are arranged in a stepwise manner shifted in the first direction;
A reflecting mirror that reflects the semiconductor laser light emitted by each of the N semiconductor laser elements in a predetermined direction;
The L is
{(L-1) × P1 + W1} × θ1 ≦ M × λc × θf
The filling,
θl indicates a spread angle of the light emitting point in the first direction.
Single crystal growing equipment. The collimator lens,
A cylindrical lens that converts the semiconductor laser light into light perpendicular to the second direction when viewed from the first direction;
The semiconductor laser light, as viewed from the second direction, a single crystal growth apparatus according to claim 1 or 2 and a lens array for converting the light perpendicular to the first direction. The plurality of split mirrors,
The single crystal growing apparatus according to any one of claims 1 to 3 , wherein an optical path length from the light emitting point to the condenser lens is arranged at a constant distance in each of the M semiconductor laser lights. . In a single crystal growing device for growing single crystals from raw material rods,
A semiconductor laser device having a laser power source and emitting a single semiconductor laser beam based on the power supplied by the laser power source;
A laser beam splitting device for splitting the single semiconductor laser beam into M beams,
A laser irradiation head for irradiating the M semiconductor laser beams toward the raw material rod;
It has M entrances and M exits, and the M entrances receive the M semiconductor laser beams from the laser beam splitting device and convert the M semiconductor laser beams into the M entrances. M optical fibers emitted from the M emission ports to the laser irradiation head;
With
The laser beam splitting device,
A collimator lens that converts the semiconductor laser light from the semiconductor laser device into parallel light,
A plurality of split mirrors for splitting the semiconductor laser light into M semiconductor laser lights;
A plurality of attenuating mirrors for equalizing the laser beam intensity of the M semiconductor laser beams;
A condenser lens for focusing the M semiconductor laser lights on the M optical fibers;
Has,
The semiconductor laser device has N semiconductor laser elements,
The N semiconductor laser elements each have a width W1 in a first direction, and have a semiconductor chip including L light emitting points arranged in a row at a pitch interval P1 in the first direction.
The N semiconductor laser elements are arranged offset in a second direction perpendicular to the first direction;
The plurality of split mirrors,
Assuming that each interval of the plurality of split mirrors in the first direction is D,
D = n × {(L−1) × P1 + W1} / M
The filling,
n is an integer
Single crystal growing equipment. The plurality of split mirrors,
Dividing the semiconductor laser light emitted from the semiconductor laser device into M semiconductor laser lights in the first direction;
In the first direction, the plurality of split mirrors that reflect the semiconductor laser light located on the positive side in the first direction, rather than the semiconductor laser light located at the center, are arranged in the traveling direction of the semiconductor laser light. About 45 degrees, having a mirror reflecting surface having a vertical axis inclined to the negative side in the first direction,
In the first direction, the plurality of split mirrors that reflect the semiconductor laser light located on the negative side in the first direction, rather than the semiconductor laser light located at the center, are arranged in the traveling direction of the semiconductor laser light. The single crystal growing apparatus according to any one of claims 1 to 5 , further comprising a mirror reflecting surface having a vertical axis inclined to the positive side in the first direction by about 45 degrees. The plurality of split mirrors,
About 45 degrees with respect to the traveling direction of the semiconductor laser light, having a mirror reflection surface having a vertical axis inclined to the positive side or the negative side in the first direction,
Said semiconductor of said semiconductor laser light emission of the laser device, the first direction of the positive side or the claims 1 to be divided into M number of the semiconductor laser beam emitted in the negative side direction 6 according to any one single Crystal growing equipment. The plurality of divided mirrors, single crystal growth apparatus according to claim 6 or 7 having an actuator for moving without changing the angle of the axis perpendicular to the traveling direction of the semiconductor laser beam. The single crystal growing apparatus according to any one of claims 1 to 5 , wherein the plurality of split mirrors have a triangular prism shape having a hypotenuse length of T, and a mirror reflection surface on the triangular prism shape slope. In a single crystal growing device for growing single crystals from raw material rods,
A semiconductor laser device having a laser power source and emitting a single semiconductor laser beam based on the power supplied by the laser power source;
A laser beam splitting device for splitting the single semiconductor laser beam into M beams,
A laser irradiation head for irradiating the M semiconductor laser beams toward the raw material rod;
It has M entrances and M exits, and the M entrances receive the M semiconductor laser beams from the laser beam splitting device and convert the M semiconductor laser beams into the M entrances. M optical fibers emitted from the M emission ports to the laser irradiation head;
With
The laser beam splitting device,
A collimator lens that converts the semiconductor laser light from the semiconductor laser device into parallel light,
A plurality of split mirrors for splitting the semiconductor laser light into M semiconductor laser lights;
A plurality of attenuating mirrors for equalizing the laser beam intensity of the M semiconductor laser beams;
A condenser lens for focusing the M semiconductor laser lights on the M optical fibers;
Has,
The plurality of split mirrors have a triangular prism shape with a hypotenuse length of T, and have a mirror reflecting surface on the triangular prism shape slope.
The length T of the hypotenuse is
T = {(L-1) × P1 + W1} × √2 / M
Satisfy
Single crystal growing equipment. The plurality of attenuating mirrors are located between the plurality of split mirrors and the condenser lens,
The single crystal growing apparatus according to any one of claims 1 to 10 , which reflects at least a part of the semiconductor laser light from the plurality of split mirrors. The single crystal growing apparatus according to claim 11 , wherein the plurality of attenuating mirrors include a mirror reflecting surface having a vertical axis inclined by approximately 45 degrees with respect to a traveling direction of the semiconductor laser light from the plurality of split mirrors. The single crystal growing apparatus according to claim 12 , wherein the plurality of attenuating mirrors include an actuator that moves without changing an angle of the vertical axis with respect to a traveling direction of the semiconductor laser light. The condensing lens is a single crystal growth according to claim 1 having a lens array formed by integrally forming said spherical lens and a plurality of cylindrical lens for focusing the M semiconductor laser light to the optical fiber the M respectively apparatus. The laser irradiation head,
The traveling direction of the incident the semiconductor laser beam, a single crystal growth apparatus according to any one of claims 1 to 14 having a folding mirror to bend substantially vertically. M laser irradiation heads for irradiating the M semiconductor laser beams toward the raw material rod,
M dampers that absorb at least a part of the M semiconductor laser lights;
The unit according to any one of claims 1 to 15 , further comprising a ceiling positioned above the M laser irradiation heads and fixing the M laser irradiation heads and the M dampers. Crystal growing equipment. The single crystal growing apparatus according to any one of claims 1 to 15 , comprising one semiconductor laser device and one laser beam splitting device.