WO2015045481A1 - Optical unit - Google Patents

Optical unit Download PDF

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Publication number
WO2015045481A1
WO2015045481A1 PCT/JP2014/064283 JP2014064283W WO2015045481A1 WO 2015045481 A1 WO2015045481 A1 WO 2015045481A1 JP 2014064283 W JP2014064283 W JP 2014064283W WO 2015045481 A1 WO2015045481 A1 WO 2015045481A1
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WO
WIPO (PCT)
Prior art keywords
light
optical
incident
optical fiber
incident surface
Prior art date
Application number
PCT/JP2014/064283
Other languages
French (fr)
Japanese (ja)
Inventor
春樹 上山
Original Assignee
シャープ株式会社
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Publication date
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Publication of WO2015045481A1 publication Critical patent/WO2015045481A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
    • G02B6/4207—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms with optical elements reducing the sensitivity to optical feedback
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/022—Mountings; Housings
    • H01S5/0225—Out-coupling of light
    • H01S5/02251—Out-coupling of light using optical fibres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
    • H01S5/4025—Array arrangements, e.g. constituted by discrete laser diodes or laser bar

Definitions

  • the present invention relates to an optical unit that allows light from a plurality of light sources to enter a light collecting member such as an optical fiber.
  • a method using a half mirror disclosed in Patent Document 1 is the most common.
  • a first light emitting element 102 and a second light emitting element 103 are provided orthogonally to a housing 101, and the first light emitting element 102
  • Each light emitted from the second light emitting element 103 is incident on one optical fiber 106 via the half mirrors 104 and 105.
  • a plurality of laser light sources 201... Oriented in the vertical direction are arranged side by side in a lateral direction.
  • a method of guiding the traveling direction to the direction of the optical fiber 202 by refraction is adopted, light is incident on the optical fiber 202 obliquely with a large incident angle to the optical fiber 202.
  • the present invention has been made in view of the above-described conventional problems, and is to provide an optical unit capable of improving the light incident efficiency from a plurality of light sources to a light collecting member.
  • an optical unit is positioned between a light collecting member, a plurality of light sources, and the light collecting member and the plurality of light sources, and is emitted from each light source.
  • An optical unit including an optical member that enters the light incident surface from the light incident surface, changes the traveling direction by refraction, and emits the light from the light emitting surface to guide the light collecting member incident surface of the light collecting member.
  • Each light source is provided such that the optical axis of the emitted light from each light source is inclined with respect to the normal of the incident surface of the light collecting member in the light collecting member, and the optical member includes the optical member
  • the incident angle of the light collecting member which is an angle formed by the optical axis of the light emitted from the light emitting surface of the member and the normal line of the light incident surface of the light collecting member, is the light incident surface of the optical member.
  • the optical axis of the light emitted from each of the light sources and the light collecting member It is characterized in that it is formed to be smaller than the incident light angle of inclination formed by the normal line of the light collector incident surface that.
  • an optical unit that can improve the light incident efficiency from a plurality of light sources to a light collecting member.
  • FIG. 1 is a front view showing the configuration of the optical unit.
  • FIG. 2 is a perspective view showing a beam shape of light emitted from the semiconductor laser.
  • the optical unit 1A of the present embodiment includes an optical fiber 10 as a light collecting member, semiconductor lasers 20 as a plurality of light sources, and an optical fiber 10 and a plurality of semiconductor lasers 20.
  • a prism 30 ⁇ / b> A as an optical member that guides the optical fiber incident surface 11.
  • the optical fiber 10 is a transmission path for transmitting light to a distant place, and has a double structure of a core called a core 12 and a portion called a clad 13 outside the core. A coating (not shown) for covering the clad 13 may be provided.
  • the refractive index of the core 12 is higher than the refractive index of the clad 13, so that light is propagated only to the core 12 at the central portion as much as possible by total reflection and refraction.
  • Both the core 12 and the clad 13 are made of quartz glass or plastic having a very high transmittance with respect to light.
  • the application example to the optical fiber 10 as a light collecting member is described.
  • the light collecting member of the present invention is not necessarily limited to this, for example, a lens or other light receiving body. There may be.
  • two semiconductor lasers 20 are provided as a plurality.
  • the present invention is not necessarily limited to this, and a plurality of, for example, three or more may be provided. As described above, as the number of the semiconductor lasers 20 is increased, a larger output can be condensed on the optical fiber 10.
  • each semiconductor laser 20 is provided such that the optical axes L1 and L1 of the emitted light from each semiconductor laser 20 are inclined with respect to the normal Z of the optical fiber incident surface 11 of the optical fiber 10, respectively. .
  • each of the semiconductor lasers 20 is arranged so that the optical axes L1 and L1 of the emitted light from each of the semiconductor lasers 20 are parallel to the normal line Z of the optical fiber incident surface 11. Compared with the case where it provides in, it can suppress that the distance to a horizontal direction becomes long. Further, it is possible to prevent the incidence efficiency on the optical fiber 10 from being lowered.
  • each semiconductor laser 20 so that the optical axes L1 and L1 of the emitted light from each semiconductor laser 20 are parallel to the normal Z of the optical fiber incident surface 11 means that each semiconductor laser 20 is parallel. It will be shifted in the direction. As a result, the incident angle of the light emitted from the semiconductor laser 20 existing at a position far from the normal line of the optical fiber incident surface 11 to the optical fiber incident surface 11 through the prism 30A becomes larger than the numerical aperture NA of the optical fiber 10. Also grows. For this reason, the incident efficiency to the optical fiber 10 is reduced. Further, in order to solve this problem, it is necessary to arrange a plurality of semiconductor lasers 20 so as to overlap each other. As a result, some of the optical paths are blocked by other semiconductor lasers 20, so that the light utilization efficiency is increased. Will drop.
  • the numerical aperture NA of the optical fiber 10 is defined as the sine of the maximum angle that an incident light beam can have for total internal reflection within the core 12.
  • the apparatus length of the optical unit 1A can be shortened, and the optical unit 1A can be made compact.
  • the size of the optical unit 1A can be suppressed within, for example, a diameter of 15 mm and a height of 13 mm.
  • the height 13 mm is a dimension from the rear end of the semiconductor laser 20 to the optical fiber incident surface 11.
  • the beam shape of the semiconductor laser 20 is an asymmetric ellipse having a major axis and a minor axis different from each other.
  • the beam shape can be approximated from an asymmetric ellipse to a symmetric perfect circle. As a result, the efficiency of incidence on the optical fiber 10 can be increased.
  • the semiconductor lasers 20 output linearly polarized light, but the divergence angles are different from each other in the orthogonal direction.
  • the semiconductor laser 20 is a Fabry-Perot type semiconductor laser having a general Fabry-Perot resonator in which two reflecting surfaces formed by crystal cleavage or the like are opposed to each other at both ends of a path through which light passes
  • the divergence angle is usually about 30 ° and about 10 °.
  • the beam shape of the semiconductor laser 20 becomes an elliptical shape as shown in FIG.
  • the polarization direction is linearly polarized light indicated by an arrow in FIG.
  • the semiconductor laser 20 by arranging the semiconductor laser 20 so that the major axis of the elliptical shape is inclined with respect to the irradiation plane, it becomes possible to correct the beam shape closer to a new circle.
  • the prism 30 ⁇ / b> A of the present embodiment includes optical axes L ⁇ b> 2 and L ⁇ b> 2 of light emitted from the light emission surface 32 of the prism 30 ⁇ / b> A and a normal line Z of the optical fiber incident surface 11 in the optical fiber 10.
  • the incident angle ⁇ 2 of the optical fiber as the incident angle of the light collecting member which is an angle between the optical axes L1 and L1 of the light emitted from each semiconductor laser 20 on the light incident surface 31A of the prism 30A and the optical fiber incident surface 11 It is formed to be smaller than the incident light inclination angle ⁇ 1 formed with the normal line Z.
  • the prism 30A of the present embodiment is integrally formed. However, in the present invention, the prism 30A is not necessarily limited thereto, and may be formed separately for each semiconductor laser 20.
  • the optical axes L1 and L1 of the light from the semiconductor lasers 20 and 20 directed obliquely with respect to the normal line Z of the optical fiber incident surface 11 are bent in a direction close to the normal line Z by the prism 30A, thereby improving efficiency.
  • Light can be incident on the optical fiber 10 well.
  • the light incident surface 31A of the prism 30A is planar. Therefore, when parallel light is emitted from the semiconductor laser 20, the parallel light can be maintained and incident on the prism 30A from the light incident surface 31A.
  • the light emission surface 32 of the prism 30A is planar. Therefore, as will be described later, it is possible to reduce light loss at the light exit surface 32 of the prism 30A.
  • FIG. 3 is a cross-sectional view showing the relationship between p-wave polarized light and s-wave polarized light when laser light passes from a material with a high refractive index to a material with a low refractive index.
  • FIG. 4 is a graph showing the relationship between the incident angle and the reflectance in p-wave polarized light and s-wave polarized light when laser light is transmitted from a material with a high refractive index to a material with a low refractive index. Specifically, the relationship between the incident angle of acrylic resin (PMMA) and the reflectance is shown.
  • PMMA acrylic resin
  • the semiconductor laser 20 is used as the light source.
  • the semiconductor laser 20 is generally linearly polarized light, and p-wave polarized light and s-wave polarized light are changed depending on whether the linearly polarized light is parallel or perpendicular to the light exit surface 32 of the prism 30A. Selectable. Therefore, in the present embodiment, as shown in FIG. 3, when the laser light is incident on the light emitting surface 32 that is the interface of the prism 30A having a high refractive index and is emitted to the air layer having a low refractive index, the air layer is entered. The emitted light is made p-wave polarized light, and the light reflected by the light emitting surface 32 which is an interface and returning to the prism 30A side is made s-wave polarized light.
  • the light transmittance and the reflectance of the s-wave polarized light and the p-wave polarized light change depending on the incident angle ⁇ ′ to the light exit surface 32 of the prism 30A.
  • Wave polarization has a higher transmittance over a wider angle range.
  • the light emitted from each of the semiconductor lasers 20 and 20 is selected so as to be p-wave polarized with respect to the light exit surface 32 of the prism 30A.
  • the light loss due to reflection on the light exit surface 32 of the prism 30A can be reduced, and the light utilization rate can be improved.
  • the direction of the optical axis of the light emitted from each of the semiconductor lasers 20 and 20 after entering the light incident surface 31A of the prism 30A is the light emitting surface 32 of the prism 30A.
  • the Brewster angle is made. That is, as shown in FIG. 4, when the light emitted from each of the semiconductor lasers 20 and 20 is p-wave polarized with respect to the light exit surface 32 of the prism 30A, the incident angle to the light exit surface 32 of the prism 30A. Is the Brewster angle, the light loss due to reflection at the light exit surface 32 of the prism 30A is minimized. Specifically, as can be seen from FIG.
  • the Brewster angle is when the incident angle ⁇ ′ to the light emitting surface 32 is about 35 °, and at this time, the p-wave on the light emitting surface 32 of the prism 30A.
  • the reflectance of the polarized light becomes substantially zero.
  • the optical unit 1A has a configuration that does not use a half mirror, so that the number of parts is small. Further, since the semiconductor lasers 20 and 20 are arranged so that the optical axes L1 and L1 of the light beams from the semiconductor lasers 20 and 20 are inclined with respect to the normal line Z of the optical fiber incident surface 11 of the optical fiber 10, the optical unit 1A. The dimensions can be made compact.
  • the optical unit 1A of the present embodiment when laser light is emitted from one semiconductor laser 20, laser light having an elliptical beam shape is incident on the light incident surface 31A. The light enters the prism 30A.
  • the light exit surface 32 of the prism 30A is a flat surface, and this flat surface is inclined with respect to the optical fiber incident surface 11 of the optical fiber 10.
  • the inclination angle of the planar light emitting surface 32 is such that the elliptical beam shape of the laser light is a perfect circle. That is, the light emitting surface 32 is inclined in a direction to rotate around the major axis about the minor axis of the elliptical beam shape of the laser light.
  • the beam shape of the laser light emitted from the light emitting surface 32 of the prism 30 ⁇ / b> A becomes a perfect circle and is incident on the optical fiber incident surface 11 of the optical fiber 10.
  • the laser light incident on the optical fiber 10 is contained within the core 12 having a perfect cross section of the optical fiber 10, so that all the light is incident on the core 12 of the optical fiber 10 and the incident efficiency is high.
  • the p-wave polarization of the laser beam is transmitted. Furthermore, since the incident angle of the optical axis of the incident light on the light emitting surface 32 formed of a plane in the laser light is a Brewster angle, the reflectance of the p-wave polarized laser light emitted from the light emitting surface 32 Is 0. Therefore, the light is emitted from the prism 30A with the least light loss in the prism 30A.
  • the plurality of semiconductor lasers 20 and 20 can be used to focus on the optical fiber 10 in a small size, high efficiency, and low cost.
  • the optical loss and the like when the wavelengths of the laser beams of the plurality of semiconductor lasers 20 and 20 are different from each other, usually, a dichroic filter is used. However, one or more condensing lenses are required separately, and the number of parts is reduced. Increase.
  • the optical loss in addition to the optical loss at the dichroic filter, the optical loss at both surfaces of the condenser lens is integrated. Specifically, as can be seen from FIG. 4, when the light is incident perpendicularly to the surface not provided with the antireflection film, the light loss is about 4% on one surface.
  • laser light emitted as an ellipse beam like the semiconductor laser 20 has an elliptical shape on the optical fiber incident surface 11 when a normal symmetric lens is used, and therefore enters the core 12 of the optical fiber 10. There may be a loss.
  • the size of the numerical aperture NA must be increased in order to be within the numerical aperture NA of the optical fiber 10.
  • the numerical aperture NA is short, the light incident on the optical fiber incident surface 11 does not fit within the numerical aperture NA, and the light is clad. 13 will result in light loss.
  • the light emission surface 32 of the prism 30A is disposed obliquely with respect to the optical axes L1 and L1.
  • the transmittance can be improved by using the Brewster angle of p-wave polarized light with less reflection.
  • the asymmetric beam shape can be made closer to symmetry, the coupling efficiency can be improved.
  • the optical fiber incident angle ⁇ 2 with respect to the optical fiber 10 is reduced, it is possible to reduce light loss due to light incident outside the numerical aperture NA of the optical fiber 10.
  • the optical unit 1A is located between the optical fiber 10, the plurality of semiconductor lasers 20 and 20, and the optical fiber 10 and the plurality of semiconductor lasers 20 and 20.
  • the prism 30A is provided with the light 30 emitted from the light incident surface 31A, changed in the traveling direction by refraction, emitted from the light emitting surface 32, and guided to the optical fiber incident surface 11 of the optical fiber 10.
  • the semiconductor lasers 20 and 20 are provided such that the optical axes L1 and L1 of the emitted light from the semiconductor lasers 20 and 20 are inclined with respect to the normal line Z of the optical fiber incident surface 11 of the optical fiber 10, respectively.
  • the prism 30A has an optical fiber incident angle ⁇ 2, which is an angle formed between the optical axes L2 and L2 of the light emitted from the light emitting surface 32 of the prism 30A and the normal Z of the optical fiber incident surface 11 of the optical fiber 10.
  • the incident light inclination angle ⁇ 1 formed by the optical axes L1 and L1 of the light emitted from the semiconductor lasers 20 and 20 on the light incident surface 31A of 30A and the normal Z of the optical fiber incident surface 11 of the optical fiber 10 is smaller. It is formed as follows.
  • the prism 30A refraction is used as the prism 30A, and a half mirror as an optical unit is not used, so either one of reflected light and transmitted light when using the half mirror is used. Can prevent light loss. Further, since the half mirror is not used, the optical unit 1A can be provided which can reduce the number of components and can be miniaturized.
  • the semiconductor lasers 20 and 20 are arranged so that the optical axes L1 and L1 of the emitted light from the semiconductor lasers 20 and 20 are parallel to the normal line Z of the optical fiber incident surface 11.
  • the optical fiber that has passed through the prism 30A in the light emitted from the semiconductor laser 20 located far from the normal line of the optical fiber incident surface 11 is arranged. Since the incident angle ⁇ 2 increases and becomes larger than the numerical aperture NA of the optical fiber 10, the incident efficiency to the optical fiber 10 is lowered. Further, in order to solve this problem, it is necessary to arrange a plurality of semiconductor lasers 20 and 20 so as to overlap each other. As a result, a part of the optical path is blocked by another light source. Will drop.
  • the semiconductor lasers 20 and 20 are such that the optical axes L1 and L1 of the emitted light from the semiconductor lasers 20 and 20 are inclined with respect to the normal Z of the optical fiber incident surface 11 of the optical fiber 10, respectively. It is provided as follows.
  • the optical axes L1 and L1 of the emitted light from the semiconductor lasers 20 and 20 are set to the normal line Z of the optical fiber incident surface 11, respectively.
  • the prism 30A has an optical fiber incident angle that is an angle formed by the optical axes L2 and L2 of the light emitted from the light emitting surface 32 of the prism 30A and the normal Z of the optical fiber incident surface 11 of the optical fiber 10.
  • the angle ⁇ 2 is the incident light inclination formed by the optical axes L1 and L1 of the light emitted from the semiconductor lasers 20 and 20 with respect to the light incident surface 31A of the prism 30A and the normal line Z of the optical fiber incident surface 11 of the optical fiber 10. It is formed to be smaller than the angle ⁇ 1.
  • the optical axes L1 and L1 of the light beams from the semiconductor lasers 20 and 20 directed obliquely with respect to the normal line Z of the optical fiber incident surface 11 are directions close to the normal line Z by an optical member having a prism function. That is, the light can be efficiently incident on the optical fiber 10 by being bent so as to approach the vertical direction of the optical fiber incident surface 11.
  • the optical unit 1A is made compact by preventing overlap when the plurality of semiconductor lasers 20 and 20 are arranged, and the optical fiber 10 is transmitted from a direction close to the normal line Z of the optical fiber incident surface 11 without using a half mirror. It is possible to provide the optical unit 1A that can improve the light incident efficiency by being incident on the optical unit.
  • the light emitted from each of the semiconductor lasers 20 and 20 is p-wave polarized with respect to the light exit surface 32 of the prism 30A. That is, the semiconductor laser 20 is generally linearly polarized light, and p-wave polarized light and s-wave polarized light are selected depending on whether the linearly polarized light is parallel or perpendicular to the light exit surface 32 of the prism 30A. Is possible. In this case, the light transmittance and the reflectance of the s-wave polarized light and the p-wave polarized light change depending on the incident angle to the light exit surface 32 of the prism 30A. Basically, the p-wave polarized light has a wider angle range. Increases transmittance.
  • the light emitting surface 32 of the prism 30A is selected by selecting the light emitted from each of the semiconductor lasers 20 and 20 to be p-wave polarized with respect to the light emitting surface 32 of the prism 30A. It is possible to reduce light loss due to reflection at the light source and improve the light utilization rate.
  • the direction of the optical axis of the light emitted from each of the semiconductor lasers 20 and 20 after entering the light exit surface 32 of the prism 30A is the light exit surface 32 of the prism 30A.
  • the Brewster angle is made.
  • the incident angle to the light exit surface 32 of the prism 30A is a Brewster angle.
  • light loss due to reflection at the light exit surface 32 of the prism 30A is minimized.
  • the semiconductor laser 20 is employed as the light source, but the present invention is not limited to this, and other light sources may be used.
  • the light incident surface 31A of the prism 30A is a flat surface.
  • the optical unit 1B of the present embodiment is different in that the light incident surface 31B of the prism 30B has a convex shape.
  • FIG. 5 is a front view showing the configuration of the optical unit 1B of the present embodiment.
  • the light incident surface 31B of the prism 30B has a convex shape as shown in FIG. Since the other configuration is the same as that of the optical unit 1A described in the first embodiment, the description thereof is omitted.
  • one of the light incident surface 31B and the light emitting surface 32 has a convex shape, and one convex shape corresponds to one semiconductor laser 20. It is possible to be.
  • the optical member functions not only as a prism but also as a convex lens.
  • the light can be incident on the optical fiber incident surface 11 of the optical fiber 10 with a sufficiently small spot size, so that the light incident efficiency on the optical fiber 10 can be further increased.
  • the light incident surface 31B of the prism 30B has a convex shape.
  • the light incident surface 31B is a curved surface protruding in a convex shape.
  • the laser light having an elliptical beam shape is emitted from the light incident surface 31B.
  • the light enters the prism 30B.
  • the elliptical beam shape of the laser light is converged by the function of the convex lens. For this reason, the elliptical beam shape of the laser light becomes smaller as the laser light transitions from the light incident surface 31B to the light emitting surface 32 in the prism 30B.
  • the prism 30 ⁇ / b> B has one of the light incident surface 31 ⁇ / b> B and the light emitting surface 32 having a convex shape, and is 1 for one semiconductor laser 20.
  • the two convex shapes correspond to each other.
  • the optical member functions not only as a prism but also as a convex lens.
  • the light can be incident on the optical fiber incident surface 11 of the optical fiber 10 with a sufficiently small spot size, so that the light incident efficiency on the optical fiber 10 can be further increased.
  • the light incident surface 31B of the prism 30B has a convex shape, so that the optical path of the light incident on the prism 30B can be concentrated.
  • the light exit surface 32 of the prism 30B is planar, light loss at the light exit surface 32 can be reduced.
  • the present invention is not limited to this, and the light emitting surface 32 of the prism 30B is convex.
  • the configuration may be a shape.
  • Embodiment 3 The following will describe still another embodiment of the present invention with reference to FIG.
  • the configurations other than those described in the present embodiment are the same as those in the first embodiment and the second embodiment.
  • members having the same functions as those shown in the drawings of Embodiment 1 and Embodiment 2 are given the same reference numerals, and explanation thereof is omitted.
  • the light source is composed of two semiconductor lasers 20 and 20 as a plurality.
  • the optical unit 1C of the present embodiment is different in that the light source is composed of a plurality of four semiconductor lasers 20 and 20.
  • FIG. 6 is a perspective view showing a configuration of the optical unit 1C of the present embodiment.
  • the optical unit 1C of the present embodiment includes a plurality of four semiconductor lasers 20, 20, 20, and 20.
  • the prism 30C is provided with four light incident surfaces 31B and four light emitting surfaces 32 corresponding to the four semiconductor lasers 20, 20, 20, 20.
  • the shape of the prism 30C of the present embodiment is a quadrangular pyramid when viewed from above.
  • the laser light from the four semiconductor lasers 20, 20, 20, and 20 is incident on the optical fiber incident surface 11 of the optical fiber 10, so that high output light is transmitted to the optical fiber 10. It can be made to enter.
  • the optical units 1A, 1B, and 1C include a light collecting member (optical fiber 10), a plurality of light sources (semiconductor laser 20), the light collecting member (optical fiber 10), and a plurality of light sources (semiconductors).
  • the light emitted from each light source (semiconductor laser 20) is incident from the light incident surfaces 31A and 31B, is changed in the traveling direction by refraction, and is emitted from the light emitting surface 32.
  • each of the light sources is The optical axis L1 of the emitted light from each light source (semiconductor laser 20) is the light collecting member incident surface (optical fiber) of the light collecting member (optical fiber 10).
  • the optical members (prisms 30A, 30B, and 30C) are provided so as to be inclined with respect to the normal line Z of the incident surface 11), and the light emitting surfaces of the optical members (prisms 30A, 30B, and 30C) are provided.
  • the incident angle of the focused member which is an angle formed by the optical axis L2 of the emitted light from the beam 32 and the normal Z of the focused member incident surface (optical fiber incident surface 11) of the focused member (optical fiber 10).
  • Incident angle ⁇ 2 is an optical axis L1 of light emitted from each of the light sources (semiconductor laser 20) to the light incident surfaces 31A and 31B of the optical members (prisms 30A, 30B, and 30C) and the focused member ( The optical fiber 10) is formed so as to be smaller than the incident light inclination angle (incident light inclination angle ⁇ 1) formed with the normal line Z of the light collecting member incident surface (optical fiber incident surface 11). It is characterized by a door.
  • each light source is provided such that the optical axis of the emitted light from each light source is inclined with respect to the normal line of the light collecting member incident surface of the light collecting member.
  • each light source when each light source is disposed, each light source is provided so that the optical axis of the emitted light from each light source is parallel to the normal line of the light collecting member incident surface, It can suppress that the distance to a horizontal direction becomes long, can prevent the fall of the light incidence efficiency to a condensing member, and can prevent the fall of light utilization efficiency.
  • the optical member is an angled member formed by an optical axis of light emitted from the light emitting surface of the optical member and a normal line of the light collecting member incident surface of the light collecting member.
  • the incident angle is smaller than the incident light inclination angle formed by the optical axis of the light emitted from each light source on the light incident surface of the optical member and the normal line of the light collecting member incident surface of the light collecting member. It is formed to become.
  • the optical axis of the light from the light source directed obliquely with respect to the normal line of the light collecting member incident surface is a direction close to the normal line by the optical member having a prism function, that is, the light collecting member incident surface.
  • the light can be efficiently incident on the light collecting member by being bent so as to approach the vertical direction.
  • the optical units 1B and 1C according to the second aspect of the present invention are the optical units according to the first aspect, and the optical member (the prisms 30B and 30C) has either one of the light incident surface 31B and the light emitting surface 32 having a convex shape. It is preferable that one convex shape corresponds to one light source (semiconductor laser 20).
  • the optical member also has a function as a convex lens.
  • the optical member also has a function as a convex lens.
  • the optical units 1B and 1C according to the third aspect of the present invention are the optical units according to the first and second aspects, wherein the optical member (prisms 30B and 30C) has a convex light incident surface 31B and the light emission surface.
  • the surface 32 is preferably flat.
  • the light incident surface of the optical member has a convex shape
  • the optical path of the light incident on the optical member can be concentrated.
  • the light emission surface of the optical member has a flat shape, the light loss on the light emission surface can be reduced particularly when the optical member has a configuration described later.
  • the optical units 1A, 1B, and 1C according to the fourth aspect of the present invention are the optical units according to the first, second, and third aspects, in which the light emitted from each light source (semiconductor laser 20) is the optical member (the prisms 30A, 30B, and 30C). ) Is preferably p-wave polarized light.
  • s-wave polarized light and p-wave polarized light change in light transmittance and reflectance depending on the incident angle to the light exit surface of the optical member.
  • p-wave polarized light has transmittance in a wider angle range. Becomes higher.
  • light loss from reflection on the light exit surface of the optical member is reduced by selecting the light emitted from each light source to be p-wave polarized with respect to the light exit surface of the optical member.
  • the light utilization rate can be improved.
  • the optical units 1A, 1B, and 1C according to Aspect 5 of the present invention are the light of the optical members (prisms 30A, 30B, and 30C) in the light emitted from each light source (semiconductor laser 20) in the optical unit according to Aspect 4.
  • the direction of the optical axis L1 after entering the entrance surfaces 31A and 31B preferably forms a Brewster angle with respect to the light exit surface 32 of the optical member (prisms 30A, 30B, and 30C).
  • the present invention can be used for an optical unit that condenses light from a plurality of light sources such as semiconductor lasers on a light collecting member such as an optical fiber or a lens.
  • Optical unit 1A Optical unit 1B
  • Optical unit 1C Optical unit 10
  • Optical fiber (condensed member) 11
  • Optical fiber incident surface condensing member incident surface
  • Core 13 Clad 20
  • Semiconductor laser (light source) 30A prism (optical member) 30B Prism (optical member) 30C prism (optical member) 31A Light entrance surface 31B
  • Light entrance surface 32
  • Light exit surface L1 Optical axis (optical axis of light emitted from the light source)
  • L2 optical axis optical axis of the outgoing light from the light exit surface)
  • Optical fiber incident angle condensed member incident angle

Abstract

Each semiconductor laser (20) in an optical unit (1A) according to the present invention is provided such that the optical axes (L1) of the emitted light are respectively inclined relative to the line (Z) normal to an optical fiber incidence surface (11). A prism (30A) is formed such that an optical fiber incidence angle (θ2) between the optical axis (L2) of the emission light from the light emission surface (32) and the line (Z) normal to the optical fiber incidence surface (11) is smaller than an incidence light inclination angle (θ1) between the optical axis (L1) of the light emitted from the semiconductor laser (20) toward the light incidence surface (31A) and the line (Z) normal to the optical fiber incidence surface (11).

Description

光学ユニットOptical unit
　本発明は、光ファイバー等の被集光部材に複数の光源から光を入射させる光学ユニットに関するものである。 The present invention relates to an optical unit that allows light from a plurality of light sources to enter a light collecting member such as an optical fiber.
　光ファイバー等の被集光部材にレーザー光を効率よく入射させるには、光を入射する面に対して垂直に近い角度で入射させる必要がある。しかし、複数のレーザー光源を単純に光ファイバー等の被集光部材における光入射面に垂直な方向に配置しようとすると、レーザー光源同士や光路が重なってしまい、干渉することによって上手く配置できないという問題がある。 In order for the laser light to be efficiently incident on a light collecting member such as an optical fiber, it is necessary to make the light incident at an angle close to perpendicular to the light incident surface. However, if a plurality of laser light sources are simply arranged in a direction perpendicular to the light incident surface of a light collecting member such as an optical fiber, the laser light sources overlap with each other and the optical path overlaps, causing a problem that they cannot be arranged well due to interference. is there.
　これらの問題を解決する方法として、例えば、特許文献１に開示されたハーフミラーによる方法が最も一般的である。上記特許文献１に開示されている光モジュール１００では、図７に示すように、筐体１０１に第１発光素子１０２と第２発光素子１０３とが直交して設けられ、第１発光素子１０２と第２発光素子１０３とから出射されたそれぞれの光が、ハーフミラー１０４・１０５を介して１つの光ファイバー１０６に入射されるようになっている。 As a method for solving these problems, for example, a method using a half mirror disclosed in Patent Document 1 is the most common. In the optical module 100 disclosed in Patent Document 1, as shown in FIG. 7, a first light emitting element 102 and a second light emitting element 103 are provided orthogonally to a housing 101, and the first light emitting element 102 Each light emitted from the second light emitting element 103 is incident on one optical fiber 106 via the half mirrors 104 and 105.
　しかしながら、この入射方法では、ハーフミラー１０４・１０５による光損失により、光効率が低下してしまう。また、２つの光源を互いに９０°曲げた方向に向けて配置するので、全体として装置が大型化してしまう傾向がある。 However, in this incident method, light efficiency is reduced due to light loss by the half mirrors 104 and 105. Further, since the two light sources are arranged in a direction bent by 90 ° from each other, the apparatus tends to be large as a whole.
　一方、他の入射方法として、例えば、特許文献２に開示されたレーザーモジュール２００では、図８に示すように、同一の平面上に２次元に配置されて複数のレーザービームをそれぞれ発する複数のレーザー光源２０１…と、複数のレーザービームを受ける光ファイバー２０２と、複数のレーザー光源２０１…に対応してそれぞれ設けられて、対応するレーザー光源から受けるレーザービームを集光して光ファイバー２０２の端面に結合させる複数のレンズ２０３…とを備えている。 On the other hand, as another incident method, for example, in the laser module 200 disclosed in Patent Document 2, as shown in FIG. 8, a plurality of lasers that are two-dimensionally arranged on the same plane and emit a plurality of laser beams, respectively. A light source 201, an optical fiber 202 that receives a plurality of laser beams, and a plurality of laser light sources 201, respectively. The laser beams received from the corresponding laser light sources are condensed and coupled to the end face of the optical fiber 202. And a plurality of lenses 203.
日本国公開特許公報「特開２０１３－４５０９２号公報（２０１３年３月４日公開）」Japanese Patent Publication “JP 2013-45092 A” (published March 4, 2013) 日本国公開特許公報「特開２００７－２４８５８１号公報（２００７年９月２７日公開）」Japanese Patent Publication “Japanese Patent Laid-Open No. 2007-244851” (published on September 27, 2007)
　しかしながら、上記従来の特許文献２に開示されたレーザーモジュール２００では、垂直方向に向けた複数のレーザー光源２０１…を横方向にずらして並べて配置している。このため、屈折により進行方向を光ファイバー２０２の方向に導く方法を採用しているものの、光ファイバー２０２への入射角度が大きい状態にて光ファイバー２０２に斜めに光が入射する。この結果、光ファイバー２０２に光が入射する表面での光損失により、光効率が低下してしまうという問題を有している。 However, in the laser module 200 disclosed in the above-mentioned conventional patent document 2, a plurality of laser light sources 201... Oriented in the vertical direction are arranged side by side in a lateral direction. For this reason, although a method of guiding the traveling direction to the direction of the optical fiber 202 by refraction is adopted, light is incident on the optical fiber 202 obliquely with a large incident angle to the optical fiber 202. As a result, there is a problem that light efficiency is reduced due to light loss at the surface where light enters the optical fiber 202.
　本発明は、上記従来の問題点に鑑みなされたものであって、複数の光源から被集光部材への光入射効率を向上し得る光学ユニットを提供することにある。 The present invention has been made in view of the above-described conventional problems, and is to provide an optical unit capable of improving the light incident efficiency from a plurality of light sources to a light collecting member.
　本発明の一態様における光学ユニットは、上記課題を解決するために、被集光部材と、複数の光源と、上記被集光部材と複数の光源との間に位置し、各光源から発せられた光を光入射面から入射して屈折により進行方向を変化させて光出射面から出射させて上記被集光部材の被集光部材入射面に導く光学部材とを備えた光学ユニットにおいて、上記各光源は、該各光源における出射光の光軸が上記被集光部材における被集光部材入射面の法線に対してそれぞれ傾斜するように設けられていると共に、上記光学部材は、該光学部材の光出射面からの出射光の光軸と上記被集光部材における被集光部材入射面の法線とのなす角度である被集光部材入射角度が、該光学部材の光入射面への上記各光源から発せられた光の光軸と上記被集光部材における被集光部材入射面の法線とのなす入射光傾斜角度よりも小さくなるように形成されていることを特徴としている。 In order to solve the above-described problem, an optical unit according to an aspect of the present invention is positioned between a light collecting member, a plurality of light sources, and the light collecting member and the plurality of light sources, and is emitted from each light source. An optical unit including an optical member that enters the light incident surface from the light incident surface, changes the traveling direction by refraction, and emits the light from the light emitting surface to guide the light collecting member incident surface of the light collecting member. Each light source is provided such that the optical axis of the emitted light from each light source is inclined with respect to the normal of the incident surface of the light collecting member in the light collecting member, and the optical member includes the optical member The incident angle of the light collecting member, which is an angle formed by the optical axis of the light emitted from the light emitting surface of the member and the normal line of the light incident surface of the light collecting member, is the light incident surface of the optical member. The optical axis of the light emitted from each of the light sources and the light collecting member It is characterized in that it is formed to be smaller than the incident light angle of inclination formed by the normal line of the light collector incident surface that.
　本発明の一態様によれば、複数の光源から被集光部材への光入射効率を向上し得る光学ユニットを提供するという効果を奏する。 According to one aspect of the present invention, there is an effect of providing an optical unit that can improve the light incident efficiency from a plurality of light sources to a light collecting member.
本発明の実施形態１における光学ユニットの構成を示す正面図である。It is a front view which shows the structure of the optical unit in Embodiment 1 of this invention. 上記光学ユニットの半導体レーザーからの出射光のビーム形状を示す斜視図である。It is a perspective view which shows the beam shape of the emitted light from the semiconductor laser of the said optical unit. 上記光学ユニットにおいて、レーザー光が屈折率の高い物資から屈折率の低い物資へ透過するときのｐ波偏光とｓ波偏光との関係を示す断面図である。In the said optical unit, it is sectional drawing which shows the relationship between p wave polarized light and s wave polarized light when a laser beam permeate | transmits from a material with a high refractive index to a material with a low refractive index. 上記レーザー光が屈折率の高い物資から屈折率の低い物資へ透過する場合のｐ波偏光及びｓ波偏光における入射角と反射率との関係を示すグラフである。It is a graph which shows the relationship between the incident angle and reflectance in p wave polarization | polarized-light and s wave polarization | polarized-light when the said laser beam permeate | transmits the material with a high refractive index to a material with a low refractive index. 本発明の実施形態２における光学ユニットの構成を示す正面図である。It is a front view which shows the structure of the optical unit in Embodiment 2 of this invention. 本発明の実施形態３における光学ユニットの構成を示す斜視図である。It is a perspective view which shows the structure of the optical unit in Embodiment 3 of this invention. 従来の光モジュールの構成を示す断面図である。It is sectional drawing which shows the structure of the conventional optical module. 従来のレーザーモジュールの構成を示す断面図である。It is sectional drawing which shows the structure of the conventional laser module.
　　〔実施の形態１〕
　本発明の一実施形態について図１～図４に基づいて説明すれば、以下のとおりである。 [Embodiment 1]
One embodiment of the present invention will be described below with reference to FIGS.
　本実施の形態の光学ユニットの構成について、図１及び図２に基づいて説明する。図１は、光学ユニットの構成を示す正面図である。図２は半導体レーザーからの出射光のビーム形状を示す斜視図である。 The configuration of the optical unit according to the present embodiment will be described with reference to FIGS. FIG. 1 is a front view showing the configuration of the optical unit. FIG. 2 is a perspective view showing a beam shape of light emitted from the semiconductor laser.
　本実施の形態の光学ユニット１Ａは、図１に示すように、被集光部材としての光ファイバー１０と、複数の光源としての半導体レーザー２０…と、光ファイバー１０と複数の半導体レーザー２０…との間に位置し、各半導体レーザー２０…から発せられた光を光入射面３１Ａから入射して屈折により進行方向を変化させて光出射面３２から出射させて光ファイバー１０の被集光部材入射面としての光ファイバー入射面１１に導く光学部材としてのプリズム３０Ａとを備えている。 As shown in FIG. 1, the optical unit 1A of the present embodiment includes an optical fiber 10 as a light collecting member, semiconductor lasers 20 as a plurality of light sources, and an optical fiber 10 and a plurality of semiconductor lasers 20. The light emitted from each of the semiconductor lasers 20... Enters the light incident surface 31A, changes the traveling direction by refraction and is emitted from the light emitting surface 32, and is used as the focused member incident surface of the optical fiber 10. And a prism 30 </ b> A as an optical member that guides the optical fiber incident surface 11.
　上記光ファイバー１０は、離れた場所に光を伝える伝送路であり、コア（core）１２と呼ばれる芯とその外側のクラッド（clad）１３と呼ばれる部分との２重構造になっている。尚、クラッド（clad）１３を覆う図示しない被覆が設けられていてもよい。上記コア１２の屈折率はクラッド１３の屈折率よりも高くなっており、これによって、全反射や屈折によりできるだけ光を中心部のコア１２にだけ伝播させる構造になっている。上記コア１２とクラッド１３とは、いずれも光に対して透過率が非常に高い石英ガラス又はプラスチックにてなっている。尚、本実施の形態では、被集光部材としての光ファイバー１０への適用例について説明しているが、本発明の被集光部材は、必ずしもこれに限らず、例えばレンズ又は他の受光体であってもよい。 The optical fiber 10 is a transmission path for transmitting light to a distant place, and has a double structure of a core called a core 12 and a portion called a clad 13 outside the core. A coating (not shown) for covering the clad 13 may be provided. The refractive index of the core 12 is higher than the refractive index of the clad 13, so that light is propagated only to the core 12 at the central portion as much as possible by total reflection and refraction. Both the core 12 and the clad 13 are made of quartz glass or plastic having a very high transmittance with respect to light. In this embodiment, the application example to the optical fiber 10 as a light collecting member is described. However, the light collecting member of the present invention is not necessarily limited to this, for example, a lens or other light receiving body. There may be.
　上記半導体レーザー２０は、本実施の形態では、複数としての例えば２個設けられている。ただし、本発明では、必ずしもこれに限らず、複数としての例えば３個以上設けることも可能である。このように、半導体レーザー２０の個数を増加すればする程、大きな出力を光ファイバー１０に集光させることができる。 In the present embodiment, for example, two semiconductor lasers 20 are provided as a plurality. However, the present invention is not necessarily limited to this, and a plurality of, for example, three or more may be provided. As described above, as the number of the semiconductor lasers 20 is increased, a larger output can be condensed on the optical fiber 10.
　本実施の形態では、各半導体レーザー２０は、該各半導体レーザー２０における出射光の光軸Ｌ１・Ｌ１が光ファイバー１０における光ファイバー入射面１１の法線Ｚに対してそれぞれ傾斜するように設けられている。 In the present embodiment, each semiconductor laser 20 is provided such that the optical axes L1 and L1 of the emitted light from each semiconductor laser 20 are inclined with respect to the normal Z of the optical fiber incident surface 11 of the optical fiber 10, respectively. .
　これにより、各半導体レーザー２０を配設するときに、各半導体レーザー２０を、該各半導体レーザー２０における出射光の光軸Ｌ１・Ｌ１が光ファイバー入射面１１の法線Ｚに対して平行となるように設ける場合に比べて、横方向への距離が長くなることを抑制することができる。また、光ファイバー１０への入射効率の低下を防止することができる。 Thereby, when each semiconductor laser 20 is disposed, each of the semiconductor lasers 20 is arranged so that the optical axes L1 and L1 of the emitted light from each of the semiconductor lasers 20 are parallel to the normal line Z of the optical fiber incident surface 11. Compared with the case where it provides in, it can suppress that the distance to a horizontal direction becomes long. Further, it is possible to prevent the incidence efficiency on the optical fiber 10 from being lowered.
　すなわち、各半導体レーザー２０を、該各半導体レーザー２０における出射光の光軸Ｌ１・Ｌ１が光ファイバー入射面１１の法線Ｚに対して平行となるように設けるということは、各半導体レーザー２０を平行方向にずらして配置することになる。その結果、光ファイバー入射面１１の法線から遠い位置に存在する半導体レーザー２０から発せられた光における、プリズム３０Ａを通した光ファイバー入射面１１への入射角度が大きくなり、光ファイバー１０の開口数ＮＡよりも大きくなる。このため、光ファイバー１０への入射効率を低下させることになる。また、この問題を解消しようとすると、複数の半導体レーザー２０を互いに重ねて配置する必要があり、その結果、一部の光路が他の半導体レーザー２０によって塞がれることになるので、光利用効率が低下することになる。尚、光ファイバー１０の開口数ＮＡとは、入射光線がコア１２内で内部全反射するために持てる最大角の正弦として定義されるものである。 That is, providing each semiconductor laser 20 so that the optical axes L1 and L1 of the emitted light from each semiconductor laser 20 are parallel to the normal Z of the optical fiber incident surface 11 means that each semiconductor laser 20 is parallel. It will be shifted in the direction. As a result, the incident angle of the light emitted from the semiconductor laser 20 existing at a position far from the normal line of the optical fiber incident surface 11 to the optical fiber incident surface 11 through the prism 30A becomes larger than the numerical aperture NA of the optical fiber 10. Also grows. For this reason, the incident efficiency to the optical fiber 10 is reduced. Further, in order to solve this problem, it is necessary to arrange a plurality of semiconductor lasers 20 so as to overlap each other. As a result, some of the optical paths are blocked by other semiconductor lasers 20, so that the light utilization efficiency is increased. Will drop. The numerical aperture NA of the optical fiber 10 is defined as the sine of the maximum angle that an incident light beam can have for total internal reflection within the core 12.
　また、本実施の形態では、上述したように、半導体レーザー２０を斜めに配置しているので、光学ユニット１Ａの装置長さを短くすることができ、光学ユニット１Ａのコンパクト化を図ることができる。例えば、本実施の形態では、光学ユニット１Ａの大きさを例えば直径１５ｍｍ×高さ１３ｍｍ内に抑えることができる。尚、高さ１３ｍｍとは、半導体レーザー２０の後端から、光ファイバー入射面１１までの寸法である。 In the present embodiment, as described above, since the semiconductor laser 20 is disposed obliquely, the apparatus length of the optical unit 1A can be shortened, and the optical unit 1A can be made compact. . For example, in the present embodiment, the size of the optical unit 1A can be suppressed within, for example, a diameter of 15 mm and a height of 13 mm. The height 13 mm is a dimension from the rear end of the semiconductor laser 20 to the optical fiber incident surface 11.
　また、後述するように、半導体レーザー２０のビーム形状は、長軸と短軸とが異なる非対称の楕円となる。これに対して、各半導体レーザー２０を光ファイバー入射面１１の法線Ｚに対して傾斜して配置することにより、ビーム形状を非対称である楕円から対称である真円に近づけることができる。この結果、光ファイバー１０への入射効率を高めることができる。 As will be described later, the beam shape of the semiconductor laser 20 is an asymmetric ellipse having a major axis and a minor axis different from each other. On the other hand, by arranging each semiconductor laser 20 so as to be inclined with respect to the normal line Z of the optical fiber incident surface 11, the beam shape can be approximated from an asymmetric ellipse to a symmetric perfect circle. As a result, the efficiency of incidence on the optical fiber 10 can be increased.
　ここで、半導体レーザー２０は、直線偏光の光を出力するが、拡がり角が直交方向において互いに異なっている。例えば、半導体レーザー２０として、光が通過する経路の両端に結晶の劈開等で形成した２枚の反射面を対向させた一般的なファブリペロー共振器を備えたファブリペロー型半導体レーザーを用いた場合には、拡がり角は通常３０°程度と１０°程度となっている。その結果、半導体レーザー２０のビーム形状は、図２に示すように、楕円形状になる。尚、偏光方向は、図２において矢印で示す直線偏光である。また、楕円形状の長軸を照射平面に対して傾斜させて半導体レーザー２０を配置することによって、ビーム形状を新円に近づける補正が可能となる。 Here, the semiconductor lasers 20 output linearly polarized light, but the divergence angles are different from each other in the orthogonal direction. For example, when the semiconductor laser 20 is a Fabry-Perot type semiconductor laser having a general Fabry-Perot resonator in which two reflecting surfaces formed by crystal cleavage or the like are opposed to each other at both ends of a path through which light passes The divergence angle is usually about 30 ° and about 10 °. As a result, the beam shape of the semiconductor laser 20 becomes an elliptical shape as shown in FIG. The polarization direction is linearly polarized light indicated by an arrow in FIG. Further, by arranging the semiconductor laser 20 so that the major axis of the elliptical shape is inclined with respect to the irradiation plane, it becomes possible to correct the beam shape closer to a new circle.
　次に、本実施の形態のプリズム３０Ａは、図１に示すように、該プリズム３０Ａの光出射面３２からの出射光の光軸Ｌ２・Ｌ２と光ファイバー１０における光ファイバー入射面１１の法線Ｚとのなす角度である被集光部材入射角度としての光ファイバー入射角度θ２が、該プリズム３０Ａの光入射面３１Ａへの各半導体レーザー２０から発せられた光の光軸Ｌ１・Ｌ１と光ファイバー入射面１１の法線Ｚとのなす入射光傾斜角度θ１よりも小さくなるように形成されている。尚、本実施の形態のプリズム３０Ａは、一体に形成されているが、本発明においては、必ずしもこれに限らず、それぞれの半導体レーザー２０毎に別体に形成されていてもよい。 Next, as shown in FIG. 1, the prism 30 </ b> A of the present embodiment includes optical axes L <b> 2 and L <b> 2 of light emitted from the light emission surface 32 of the prism 30 </ b> A and a normal line Z of the optical fiber incident surface 11 in the optical fiber 10. The incident angle θ2 of the optical fiber as the incident angle of the light collecting member, which is an angle between the optical axes L1 and L1 of the light emitted from each semiconductor laser 20 on the light incident surface 31A of the prism 30A and the optical fiber incident surface 11 It is formed to be smaller than the incident light inclination angle θ1 formed with the normal line Z. The prism 30A of the present embodiment is integrally formed. However, in the present invention, the prism 30A is not necessarily limited thereto, and may be formed separately for each semiconductor laser 20.
　これにより、光ファイバー入射面１１の法線Ｚに対して斜めに向けられた半導体レーザー２０・２０からの光の光軸Ｌ１・Ｌ１をプリズム３０Ａにて該法線Ｚに近い方向に曲げて、効率よく光ファイバー１０に光を入射させることができる。 As a result, the optical axes L1 and L1 of the light from the semiconductor lasers 20 and 20 directed obliquely with respect to the normal line Z of the optical fiber incident surface 11 are bent in a direction close to the normal line Z by the prism 30A, thereby improving efficiency. Light can be incident on the optical fiber 10 well.
　また、本実施の形態の光学ユニット１Ａでは、プリズム３０Ａの光入射面３１Ａが平面状となっている。これにより、半導体レーザー２０から平行光が出射された場合に、その平行光を維持して光入射面３１Ａからプリズム３０Ａに入射させることができる。 In addition, in the optical unit 1A of the present embodiment, the light incident surface 31A of the prism 30A is planar. Thereby, when parallel light is emitted from the semiconductor laser 20, the parallel light can be maintained and incident on the prism 30A from the light incident surface 31A.
　さらに、本実施の形態の光学ユニット１Ａでは、プリズム３０Ａの光出射面３２が平面状となっている。これにより、後述するように、プリズム３０Ａの光出射面３２での光損失を低減することができる。 Furthermore, in the optical unit 1A of the present embodiment, the light emission surface 32 of the prism 30A is planar. Thereby, as will be described later, it is possible to reduce light loss at the light exit surface 32 of the prism 30A.
　さらに、本実施の形態の光学ユニット１Ａでは、各半導体レーザー２０・２０から発せられる光は、プリズム３０Ａの光出射面３２に対してｐ波偏光となっている。このｐ波偏光について、図３及び図４に基づいて説明する。図３は、レーザー光が屈折率の高い物資から屈折率の低い物資へ透過するときのｐ波偏光とｓ波偏光との関係を示す断面図である。また、図４は、レーザー光が屈折率の高い物資から屈折率の低い物資へ透過する場合のｐ波偏光及びｓ波偏光における入射角と反射率との関係を示すグラフである。具体的には、アクリル樹脂（ＰＭＭＡ）の入射角と反射率との関係を示すものである。 Furthermore, in the optical unit 1A of the present embodiment, the light emitted from each of the semiconductor lasers 20 and 20 is p-wave polarized with respect to the light exit surface 32 of the prism 30A. This p-wave polarization will be described with reference to FIGS. FIG. 3 is a cross-sectional view showing the relationship between p-wave polarized light and s-wave polarized light when laser light passes from a material with a high refractive index to a material with a low refractive index. FIG. 4 is a graph showing the relationship between the incident angle and the reflectance in p-wave polarized light and s-wave polarized light when laser light is transmitted from a material with a high refractive index to a material with a low refractive index. Specifically, the relationship between the incident angle of acrylic resin (PMMA) and the reflectance is shown.
　すなわち、本実施の形態では、光源として半導体レーザー２０を使用している。ここで、半導体レーザー２０は、一般的に直線偏光であり、該直線偏光をプリズム３０Ａの光出射面３２に対して平行か又は垂直かのいずれに向けるかによってｐ波偏光とｓ波偏光とが選択可能である。そこで、本実施の形態では、図３に示すように、レーザー光が屈折率の高いプリズム３０Ａの界面である光出射面３２に入射して屈折率の低い空気層へ出射する場合、空気層へ出射される光をｐ波偏光とし、界面である光出射面３２にて反射してプリズム３０Ａ側に戻る光をｓ波偏光とするようにしている。 That is, in this embodiment, the semiconductor laser 20 is used as the light source. Here, the semiconductor laser 20 is generally linearly polarized light, and p-wave polarized light and s-wave polarized light are changed depending on whether the linearly polarized light is parallel or perpendicular to the light exit surface 32 of the prism 30A. Selectable. Therefore, in the present embodiment, as shown in FIG. 3, when the laser light is incident on the light emitting surface 32 that is the interface of the prism 30A having a high refractive index and is emitted to the air layer having a low refractive index, the air layer is entered. The emitted light is made p-wave polarized light, and the light reflected by the light emitting surface 32 which is an interface and returning to the prism 30A side is made s-wave polarized light.
　ここで、ｓ波偏光及びｐ波偏光は、図４に示すように、プリズム３０Ａの光出射面３２への入射角度θ’によって光透過率、反射率が変化するが、基本的には、ｐ波偏光の方が広い角度範囲で透過率が高くなる。 Here, as shown in FIG. 4, the light transmittance and the reflectance of the s-wave polarized light and the p-wave polarized light change depending on the incident angle θ ′ to the light exit surface 32 of the prism 30A. Wave polarization has a higher transmittance over a wider angle range.
　この結果、本実施の形態では、各半導体レーザー２０・２０から発せられる光が、プリズム３０Ａの光出射面３２に対してｐ波偏光となるように選択する。これによって、プリズム３０Ａの光出射面３２での反射による光損失を低減し、光利用率を向上することができるものとなっている。 As a result, in this embodiment, the light emitted from each of the semiconductor lasers 20 and 20 is selected so as to be p-wave polarized with respect to the light exit surface 32 of the prism 30A. As a result, light loss due to reflection on the light exit surface 32 of the prism 30A can be reduced, and the light utilization rate can be improved.
　特に、本実施の形態の光学ユニット１Ａでは、各半導体レーザー２０・２０から発せられた光における、プリズム３０Ａの光入射面３１Ａに入射した後の光軸の方向は、プリズム３０Ａの光出射面３２に対してブリュースター角をなしている。すなわち、図４に示すように、各半導体レーザー２０・２０から発せられる光が、プリズム３０Ａの光出射面３２に対してｐ波偏光である場合に、プリズム３０Ａの光出射面３２への入射角度がブリュースター角度であるときに、プリズム３０Ａの光出射面３２での反射による光損失が最少となる。具体的には、ブリュースター角度は、図４から読み取れるように、光出射面３２への入射角度θ’が約３５°の場合であり、このとき、プリズム３０Ａの光出射面３２でのｐ波偏光の反射率が略０となる。 In particular, in the optical unit 1A of the present embodiment, the direction of the optical axis of the light emitted from each of the semiconductor lasers 20 and 20 after entering the light incident surface 31A of the prism 30A is the light emitting surface 32 of the prism 30A. The Brewster angle is made. That is, as shown in FIG. 4, when the light emitted from each of the semiconductor lasers 20 and 20 is p-wave polarized with respect to the light exit surface 32 of the prism 30A, the incident angle to the light exit surface 32 of the prism 30A. Is the Brewster angle, the light loss due to reflection at the light exit surface 32 of the prism 30A is minimized. Specifically, as can be seen from FIG. 4, the Brewster angle is when the incident angle θ ′ to the light emitting surface 32 is about 35 °, and at this time, the p-wave on the light emitting surface 32 of the prism 30A. The reflectance of the polarized light becomes substantially zero.
　上記構成を備えた光学ユニット１Ａにおける各部材の作用について説明する。 The operation of each member in the optical unit 1A having the above configuration will be described.
　まず、本実施の形態に光学ユニット１Ａでは、ハーフミラーを用いない構成となっているので、部品点数が少ないものとなっている。また、半導体レーザー２０・２０からの光線の光軸Ｌ１・Ｌ１が光ファイバー１０の光ファイバー入射面１１の法線Ｚに対して傾斜するように半導体レーザー２０・２０を配置しているので、光学ユニット１Ａの寸法をコンパクトにすることができるものとなっている。 First, the optical unit 1A according to the present embodiment has a configuration that does not use a half mirror, so that the number of parts is small. Further, since the semiconductor lasers 20 and 20 are arranged so that the optical axes L1 and L1 of the light beams from the semiconductor lasers 20 and 20 are inclined with respect to the normal line Z of the optical fiber incident surface 11 of the optical fiber 10, the optical unit 1A. The dimensions can be made compact.
　そして、本実施の形態の光学ユニット１Ａでは、図１に示すように、一つの半導体レーザー２０からレーザー光が出射されると、楕円形状のビーム形状を有するレーザー光は、光入射面３１Ａにてプリズム３０Ａに入射される。 In the optical unit 1A of the present embodiment, as shown in FIG. 1, when laser light is emitted from one semiconductor laser 20, laser light having an elliptical beam shape is incident on the light incident surface 31A. The light enters the prism 30A.
　次いで、本実施の形態では、プリズム３０Ａの光出射面３２は平面になっており、かつこの平面は光ファイバー１０の光ファイバー入射面１１に対して傾斜している。具体的には、平面からなる光出射面３２の傾斜角度は、レーザー光の楕円形状のビーム形状が、真円となる傾斜角度となっている。すなわち、光出射面３２は、レーザー光の楕円形状のビーム形状の短軸を中心として長軸回りに回転させる方向に傾斜している。これにより、プリズム３０Ａの光出射面３２から出射されたレーザー光のビーム形状は、真円となって、光ファイバー１０の光ファイバー入射面１１に入射される。 Next, in the present embodiment, the light exit surface 32 of the prism 30A is a flat surface, and this flat surface is inclined with respect to the optical fiber incident surface 11 of the optical fiber 10. Specifically, the inclination angle of the planar light emitting surface 32 is such that the elliptical beam shape of the laser light is a perfect circle. That is, the light emitting surface 32 is inclined in a direction to rotate around the major axis about the minor axis of the elliptical beam shape of the laser light. Thereby, the beam shape of the laser light emitted from the light emitting surface 32 of the prism 30 </ b> A becomes a perfect circle and is incident on the optical fiber incident surface 11 of the optical fiber 10.
　この結果、光ファイバー１０に入射されるレーザー光は、光ファイバー１０の断面真円のコア１２の内部に収まるようになるので、全ての光が光ファイバー１０のコア１２に入射され、入射効率が高いものとなる。 As a result, the laser light incident on the optical fiber 10 is contained within the core 12 having a perfect cross section of the optical fiber 10, so that all the light is incident on the core 12 of the optical fiber 10 and the incident efficiency is high. Become.
　また、レーザー光がプリズム３０Ａの光出射面３２から出射するときに、本実施の形態では、レーザー光のｐ波偏光が透過されるようになっている。さらに、レーザー光における、平面からなる光出射面３２への入射光の光軸の入射角度がブリュースター角度となっているので、光出射面３２から出射されるｐ波偏光のレーザー光の反射率は０である。したがって、プリズム３０Ａ内において、最も光損失が小さい状態でプリズム３０Ａから出射される。 Further, when the laser beam is emitted from the light emitting surface 32 of the prism 30A, in this embodiment, the p-wave polarization of the laser beam is transmitted. Furthermore, since the incident angle of the optical axis of the incident light on the light emitting surface 32 formed of a plane in the laser light is a Brewster angle, the reflectance of the p-wave polarized laser light emitted from the light emitting surface 32 Is 0. Therefore, the light is emitted from the prism 30A with the least light loss in the prism 30A.
　したがって、本実施の形態における光学ユニット１Ａでは、複数の半導体レーザー２０・２０を用いて、小型、高効率かつ低コストにて光ファイバー１０に集光させることができる。 Therefore, in the optical unit 1A in the present embodiment, the plurality of semiconductor lasers 20 and 20 can be used to focus on the optical fiber 10 in a small size, high efficiency, and low cost.
　すなわち、光損失等について整理すると、複数の半導体レーザー２０・２０のレーザー光の波長が互いに異なる場合は、通常、ダイクロイックフィルタを用いるが、集光レンズが別途に１つ以上必要となり、部品点数が増える。また、光損失についても、ダイクロイックフィルタでの光損失に加え、集光レンズの両面での光損失が積算される。具体的には、図４から読み取れるように、反射防止膜を施していない面に垂直に入射した場合、一つの面で約４％の光損失となる。 In other words, when arranging the optical loss and the like, when the wavelengths of the laser beams of the plurality of semiconductor lasers 20 and 20 are different from each other, usually, a dichroic filter is used. However, one or more condensing lenses are required separately, and the number of parts is reduced. Increase. As for the optical loss, in addition to the optical loss at the dichroic filter, the optical loss at both surfaces of the condenser lens is integrated. Specifically, as can be seen from FIG. 4, when the light is incident perpendicularly to the surface not provided with the antireflection film, the light loss is about 4% on one surface.
　また、半導体レーザー２０のように、ビーム形状が楕円として射出されるレーザー光に関しては、通常の対称のレンズを使用すると光ファイバー入射面１１でも楕円形状となるため、光ファイバー１０のコア１２の内部に入らず損失となる場合がある。 In addition, laser light emitted as an ellipse beam like the semiconductor laser 20 has an elliptical shape on the optical fiber incident surface 11 when a normal symmetric lens is used, and therefore enters the core 12 of the optical fiber 10. There may be a loss.
　さらに、平面状に半導体レーザー２０…を配置しようとすると、光ファイバー１０の開口数ＮＡ内に入れるためには、開口数ＮＡの寸法を長くしなければならない。例えば、φ５．６ｍｍサイズの半導体レーザー２０…を複数個平面状に並べると、開口数ＮＡの寸法が短いと、光ファイバー入射面１１への入射光が開口数ＮＡの内部に収まらず、光がクラッド１３に抜けて光損失となってしまう。 Furthermore, if the semiconductor lasers 20 are arranged in a planar shape, the size of the numerical aperture NA must be increased in order to be within the numerical aperture NA of the optical fiber 10. For example, when a plurality of semiconductor lasers 20 having a diameter of 5.6 mm are arranged in a plane, if the numerical aperture NA is short, the light incident on the optical fiber incident surface 11 does not fit within the numerical aperture NA, and the light is clad. 13 will result in light loss.
　したがって、光ファイバー１０に高効率にて結合させるためには、
（１）プリズム３０Ａの光入射面３１Ａ及び光出射面３２での損失を減らす。
（２）光ファイバー１０のコア１２のよりも小さなスポットサイズに絞る。
（３）光ファイバー１０の開口数ＮＡ内に入射させる。
ことが重要である。 Therefore, in order to couple to the optical fiber 10 with high efficiency,
(1) The loss at the light incident surface 31A and the light emitting surface 32 of the prism 30A is reduced.
(2) The spot size is narrower than that of the core 12 of the optical fiber 10.
(3) Incidence is made within the numerical aperture NA of the optical fiber 10.
This is very important.
　そこで、本実施の形態では、プリズム３０Ａの光出射面３２を光軸Ｌ１・Ｌ１に対して斜めに配置している。これにより、反射の少ないｐ波偏光のブリュースター角を利用することによって、透過率の向上を図ることができる。また、非対称であるビーム形状を対称に近づけることができるので、結合効率を向上させることができる。さらに、光ファイバー１０に対する光ファイバー入射角度θ２が小さくなるので、光ファイバー１０の開口数ＮＡ外への光入射による光損失を低下することができるものとなっている。 Therefore, in the present embodiment, the light emission surface 32 of the prism 30A is disposed obliquely with respect to the optical axes L1 and L1. Thereby, the transmittance can be improved by using the Brewster angle of p-wave polarized light with less reflection. In addition, since the asymmetric beam shape can be made closer to symmetry, the coupling efficiency can be improved. Furthermore, since the optical fiber incident angle θ2 with respect to the optical fiber 10 is reduced, it is possible to reduce light loss due to light incident outside the numerical aperture NA of the optical fiber 10.
　以上のように、本実施の形態における光学ユニット１Ａは、光ファイバー１０と、複数の半導体レーザー２０・２０と、光ファイバー１０と複数の半導体レーザー２０・２０との間に位置し、各半導体レーザー２０・２０から発せられた光を光入射面３１Ａから入射して屈折により進行方向を変化させて光出射面３２から出射させて光ファイバー１０の光ファイバー入射面１１に導くプリズム３０Ａとを備えている。そして、各半導体レーザー２０・２０は、該各半導体レーザー２０・２０における出射光の光軸Ｌ１・Ｌ１が光ファイバー１０における光ファイバー入射面１１の法線Ｚに対してそれぞれ傾斜するように設けられていると共に、プリズム３０Ａは、該プリズム３０Ａの光出射面３２からの出射光の光軸Ｌ２・Ｌ２と光ファイバー１０における光ファイバー入射面１１の法線Ｚとのなす角度である光ファイバー入射角度θ２が、該プリズム３０Ａの光入射面３１Ａへの上記各半導体レーザー２０・２０から発せられた光の光軸Ｌ１・Ｌ１と光ファイバー１０における光ファイバー入射面１１の法線Ｚとのなす入射光傾斜角度θ１よりも小さくなるように形成されている。 As described above, the optical unit 1A according to the present embodiment is located between the optical fiber 10, the plurality of semiconductor lasers 20 and 20, and the optical fiber 10 and the plurality of semiconductor lasers 20 and 20. The prism 30A is provided with the light 30 emitted from the light incident surface 31A, changed in the traveling direction by refraction, emitted from the light emitting surface 32, and guided to the optical fiber incident surface 11 of the optical fiber 10. The semiconductor lasers 20 and 20 are provided such that the optical axes L1 and L1 of the emitted light from the semiconductor lasers 20 and 20 are inclined with respect to the normal line Z of the optical fiber incident surface 11 of the optical fiber 10, respectively. At the same time, the prism 30A has an optical fiber incident angle θ2, which is an angle formed between the optical axes L2 and L2 of the light emitted from the light emitting surface 32 of the prism 30A and the normal Z of the optical fiber incident surface 11 of the optical fiber 10. The incident light inclination angle θ1 formed by the optical axes L1 and L1 of the light emitted from the semiconductor lasers 20 and 20 on the light incident surface 31A of 30A and the normal Z of the optical fiber incident surface 11 of the optical fiber 10 is smaller. It is formed as follows.
　上記の構成により、本実施の形態では、プリズム３０Ａとして屈折を利用するものとなっており、光学ユニットとしてのハーフミラーを用いないので、ハーフミラー使用時における反射光と透過光とのいずれか一方による光損失を防止することができる。また、ハーフミラーを用いないので、部品点数が少なくなり、小型化を図り得る光学ユニット１Ａを提供することができる。 With the above configuration, in this embodiment, refraction is used as the prism 30A, and a half mirror as an optical unit is not used, so either one of reflected light and transmitted light when using the half mirror is used. Can prevent light loss. Further, since the half mirror is not used, the optical unit 1A can be provided which can reduce the number of components and can be miniaturized.
　ところで、このような光学ユニットでは、各半導体レーザー２０・２０を、該各半導体レーザー２０・２０における出射光の光軸Ｌ１・Ｌ１が光ファイバー入射面１１の法線Ｚに対して平行となるように設けたのでは、各半導体レーザー２０・２０を平行方向にずらして配置する結果、光ファイバー入射面１１の法線から遠い位置に存在する半導体レーザー２０から発せられた光における、プリズム３０Ａを通した光ファイバー入射角度θ２が大きくなり、光ファイバー１０の開口数ＮＡよりも大きくなるので、光ファイバー１０への入射効率を低下させることになる。また、この問題を解消しようとすると、複数の半導体レーザー２０・２０を互いに重ねて配置する必要があり、その結果、一部の光路が他の光源によって塞がれることになるので、光利用効率が低下することになる。 By the way, in such an optical unit, the semiconductor lasers 20 and 20 are arranged so that the optical axes L1 and L1 of the emitted light from the semiconductor lasers 20 and 20 are parallel to the normal line Z of the optical fiber incident surface 11. By providing the semiconductor lasers 20 and 20 while being shifted in the parallel direction, the optical fiber that has passed through the prism 30A in the light emitted from the semiconductor laser 20 located far from the normal line of the optical fiber incident surface 11 is arranged. Since the incident angle θ2 increases and becomes larger than the numerical aperture NA of the optical fiber 10, the incident efficiency to the optical fiber 10 is lowered. Further, in order to solve this problem, it is necessary to arrange a plurality of semiconductor lasers 20 and 20 so as to overlap each other. As a result, a part of the optical path is blocked by another light source. Will drop.
　そこで、本実施の形態では、各半導体レーザー２０・２０は、該各半導体レーザー２０・２０における出射光の光軸Ｌ１・Ｌ１が光ファイバー１０における光ファイバー入射面１１の法線Ｚに対してそれぞれ傾斜するように設けられている。 Therefore, in the present embodiment, the semiconductor lasers 20 and 20 are such that the optical axes L1 and L1 of the emitted light from the semiconductor lasers 20 and 20 are inclined with respect to the normal Z of the optical fiber incident surface 11 of the optical fiber 10, respectively. It is provided as follows.
　この結果、各半導体レーザー２０・２０を配設するときに、各半導体レーザー２０・２０を、該各半導体レーザー２０・２０における出射光の光軸Ｌ１・Ｌ１が光ファイバー入射面１１の法線Ｚに対して平行となるように設ける場合に比べて、横方向への距離が長くなることを抑制することができ、光ファイバー１０への光入射効率の低下を防止し、光利用効率の低下を防止することができる。 As a result, when the semiconductor lasers 20 and 20 are disposed, the optical axes L1 and L1 of the emitted light from the semiconductor lasers 20 and 20 are set to the normal line Z of the optical fiber incident surface 11, respectively. Compared with the case of providing parallel to each other, it is possible to suppress an increase in the distance in the lateral direction, preventing a decrease in light incidence efficiency to the optical fiber 10 and preventing a decrease in light utilization efficiency. be able to.
　また、本実施の形態では、プリズム３０Ａは、該プリズム３０Ａの光出射面３２からの出射光の光軸Ｌ２・Ｌ２と光ファイバー１０における光ファイバー入射面１１の法線Ｚとのなす角度である光ファイバー入射角度θ２が、該プリズム３０Ａの光入射面３１Ａへの上記各半導体レーザー２０・２０から発せられた光の光軸Ｌ１・Ｌ１と光ファイバー１０における光ファイバー入射面１１の法線Ｚとのなす入射光傾斜角度θ１よりも小さくなるように形成されている。 Further, in the present embodiment, the prism 30A has an optical fiber incident angle that is an angle formed by the optical axes L2 and L2 of the light emitted from the light emitting surface 32 of the prism 30A and the normal Z of the optical fiber incident surface 11 of the optical fiber 10. The angle θ2 is the incident light inclination formed by the optical axes L1 and L1 of the light emitted from the semiconductor lasers 20 and 20 with respect to the light incident surface 31A of the prism 30A and the normal line Z of the optical fiber incident surface 11 of the optical fiber 10. It is formed to be smaller than the angle θ1.
　この結果、光ファイバー入射面１１の法線Ｚに対して斜めに向けられた半導体レーザー２０・２０からの光の光軸Ｌ１・Ｌ１をプリズムの機能を有する光学部材にて該法線Ｚに近い方向つまり光ファイバー入射面１１の垂直方向に近づくように曲げて、効率よく光ファイバー１０に光を入射させることができる。 As a result, the optical axes L1 and L1 of the light beams from the semiconductor lasers 20 and 20 directed obliquely with respect to the normal line Z of the optical fiber incident surface 11 are directions close to the normal line Z by an optical member having a prism function. That is, the light can be efficiently incident on the optical fiber 10 by being bent so as to approach the vertical direction of the optical fiber incident surface 11.
　したがって、複数の半導体レーザー２０・２０を配置するときの重なりを防止して該光学ユニット１Ａをコンパクトにし、かつハーフミラーを用いずに光を光ファイバー入射面１１の法線Ｚに近い方向から光ファイバー１０に入射させることにより光入射効率を向上し得る光学ユニット１Ａを提供することができる。 Therefore, the optical unit 1A is made compact by preventing overlap when the plurality of semiconductor lasers 20 and 20 are arranged, and the optical fiber 10 is transmitted from a direction close to the normal line Z of the optical fiber incident surface 11 without using a half mirror. It is possible to provide the optical unit 1A that can improve the light incident efficiency by being incident on the optical unit.
　また、本実施の形態の光学ユニット１Ａでは、各半導体レーザー２０・２０から発せられる光は、プリズム３０Ａの光出射面３２に対してｐ波偏光である。すなわち、半導体レーザー２０は、一般的に直線偏光であり、該直線偏光をプリズム３０Ａの光出射面３２に対して平行か又は垂直かのいずれに向けるかによってｐ波偏光とｓ波偏光とが選択可能である。この場合、ｓ波偏光及びｐ波偏光は、プリズム３０Ａの光出射面３２への入射角度によって光透過率、反射率が変化するが、基本的には、ｐ波偏光の方が広い角度範囲で透過率が高くなる。 Further, in the optical unit 1A of the present embodiment, the light emitted from each of the semiconductor lasers 20 and 20 is p-wave polarized with respect to the light exit surface 32 of the prism 30A. That is, the semiconductor laser 20 is generally linearly polarized light, and p-wave polarized light and s-wave polarized light are selected depending on whether the linearly polarized light is parallel or perpendicular to the light exit surface 32 of the prism 30A. Is possible. In this case, the light transmittance and the reflectance of the s-wave polarized light and the p-wave polarized light change depending on the incident angle to the light exit surface 32 of the prism 30A. Basically, the p-wave polarized light has a wider angle range. Increases transmittance.
　この結果、本実施の形態では、各半導体レーザー２０・２０から発せられる光が、プリズム３０Ａの光出射面３２に対してｐ波偏光となるように選択することにより、プリズム３０Ａの光出射面３２での反射による光損失を低減し、光利用率を向上することができる。 As a result, in the present embodiment, the light emitting surface 32 of the prism 30A is selected by selecting the light emitted from each of the semiconductor lasers 20 and 20 to be p-wave polarized with respect to the light emitting surface 32 of the prism 30A. It is possible to reduce light loss due to reflection at the light source and improve the light utilization rate.
　さらに、本実施の形態における光学ユニット１Ａでは、各半導体レーザー２０・２０から発せられた光における、プリズム３０Ａの光出射面３２に入射した後の光軸の方向は、プリズム３０Ａの光出射面３２に対してブリュースター角をなしている。 Furthermore, in the optical unit 1A according to the present embodiment, the direction of the optical axis of the light emitted from each of the semiconductor lasers 20 and 20 after entering the light exit surface 32 of the prism 30A is the light exit surface 32 of the prism 30A. The Brewster angle is made.
　すなわち、各半導体レーザー２０・２０から発せられる光が、プリズム３０Ａの光出射面３２に対してｐ波偏光である場合に、プリズム３０Ａの光出射面３２への入射角度がブリュースター角度であるときに、プリズム３０Ａの光出射面３２での反射による光損失が最少となる。 That is, when the light emitted from each of the semiconductor lasers 20 and 20 is p-wave polarized with respect to the light exit surface 32 of the prism 30A, the incident angle to the light exit surface 32 of the prism 30A is a Brewster angle. In addition, light loss due to reflection at the light exit surface 32 of the prism 30A is minimized.
　したがって、本実施の形態の構成を採用することにより、プリズム３０Ａの光出射面３２での反射による光損失を最大限に低減し、光利用率をさらに向上することができる。 Therefore, by adopting the configuration of the present embodiment, light loss due to reflection on the light exit surface 32 of the prism 30A can be reduced to the maximum, and the light utilization rate can be further improved.
　尚、本実施の形態では、光源として半導体レーザー２０を採用しているが、必ずしもこれに限らず、他の光源でもよい。 In the present embodiment, the semiconductor laser 20 is employed as the light source, but the present invention is not limited to this, and other light sources may be used.
　　〔実施の形態２〕
　本発明の他の実施の形態について図５に基づいて説明すれば、以下のとおりである。尚、本実施の形態において説明すること以外の構成は、前記実施の形態１と同じである。また、説明の便宜上、前記の実施の形態１の図面に示した部材と同一の機能を有する部材については、同一の符号を付し、その説明を省略する。 [Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIG. The configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment are given the same reference numerals, and explanation thereof is omitted.
　前記実施の形態１の光学ユニット１Ａでは、プリズム３０Ａは、光入射面３１Ａが平面となっていた。しかし、本実施の形態の光学ユニット１Ｂでは、プリズム３０Ｂの光入射面３１Ｂが凸形状となっている点が異なっている。 In the optical unit 1A of the first embodiment, the light incident surface 31A of the prism 30A is a flat surface. However, the optical unit 1B of the present embodiment is different in that the light incident surface 31B of the prism 30B has a convex shape.
　本実施の形態の光学ユニット１Ｂの構成について、図５に基づいて説明する。図５は本実施の形態の光学ユニット１Ｂの構成を示す正面図である。 The configuration of the optical unit 1B of the present embodiment will be described with reference to FIG. FIG. 5 is a front view showing the configuration of the optical unit 1B of the present embodiment.
　本実施の形態の光学ユニット１Ｂは、図５に示すように、プリズム３０Ｂの光入射面３１Ｂが凸形状となっている。尚、これ以外の構成は、前記実施の形態１にて説明した光学ユニット１Ａの構成と同じであるので、その説明を省略する。 In the optical unit 1B of the present embodiment, the light incident surface 31B of the prism 30B has a convex shape as shown in FIG. Since the other configuration is the same as that of the optical unit 1A described in the first embodiment, the description thereof is omitted.
　すなわち、光学ユニット１Ｂのプリズム３０Ｂは、光入射面３１Ｂと光出射面３２とのいずれか一方が凸形状となっており、かつ１つの半導体レーザー２０に対して１つの該凸形状が対応しているとすることが可能である。 That is, in the prism 30B of the optical unit 1B, one of the light incident surface 31B and the light emitting surface 32 has a convex shape, and one convex shape corresponds to one semiconductor laser 20. It is possible to be.
　これにより、光学部材としてのプリズム３０Ｂの光入射面３１Ｂと光出射面３２とのいずれか一方が凸形状となっているので、光学部材は、プリズムとしての機能だけでなく、凸レンズとしての機能も有している。この結果、光ファイバー１０の光ファイバー入射面１１に対して十分に小さいスポットサイズに絞って入射することができるので、光ファイバー１０への光入射効率をさらに高めることができる。 Accordingly, since either one of the light incident surface 31B and the light emitting surface 32 of the prism 30B as an optical member has a convex shape, the optical member functions not only as a prism but also as a convex lens. Have. As a result, the light can be incident on the optical fiber incident surface 11 of the optical fiber 10 with a sufficiently small spot size, so that the light incident efficiency on the optical fiber 10 can be further increased.
　特に、本実施の形態の光学ユニット１Ｂでは、プリズム３０Ｂは、光入射面３１Ｂが凸形状となっている。具体的には、光入射面３１Ｂは、凸形状に突出した曲面となっている。これにより、光入射面３１Ｂが凸レンズとしての機能を有するので、プリズム３０Ｂに入射した光の光路を集中させることができ、光束を絞ることができる。このため、光ファイバー入射面１１の一点に集光させることが可能となる。したがって、半導体レーザー２０等の光源から放射状に光が出射される場合に、光を束ねつつ、光ファイバー１０の光ファイバー入射面１１に対して垂直に光を入射できるという効果がある。 In particular, in the optical unit 1B of the present embodiment, the light incident surface 31B of the prism 30B has a convex shape. Specifically, the light incident surface 31B is a curved surface protruding in a convex shape. Thereby, since the light incident surface 31B has a function as a convex lens, the optical path of the light incident on the prism 30B can be concentrated, and the light flux can be reduced. For this reason, it becomes possible to focus on one point of the optical fiber incident surface 11. Therefore, when light is emitted radially from a light source such as the semiconductor laser 20, there is an effect that light can be incident perpendicularly to the optical fiber incident surface 11 of the optical fiber 10 while bundling the light.
　そして、本実施の形態の光学ユニット１Ｂでは、図５に示すように、一つの半導体レーザー２０からレーザー光が出射されると、楕円形状のビーム形状を有するレーザー光は、光入射面３１Ｂにてプリズム３０Ｂに入射される。このとき、プリズム３０Ｂの光入射面３１Ｂは、断面円弧状に突出する凸形状となっているので、凸レンズの機能により、レーザー光の楕円形状のビーム形状は収束される。このため、プリズム３０Ｂ内で、レーザー光が光入射面３１Ｂから光出射面３２に推移するに伴って、レーザー光の楕円形状のビーム形状は小さくなる。 In the optical unit 1B according to the present embodiment, as shown in FIG. 5, when laser light is emitted from one semiconductor laser 20, the laser light having an elliptical beam shape is emitted from the light incident surface 31B. The light enters the prism 30B. At this time, since the light incident surface 31B of the prism 30B has a convex shape protruding in a circular arc shape in cross section, the elliptical beam shape of the laser light is converged by the function of the convex lens. For this reason, the elliptical beam shape of the laser light becomes smaller as the laser light transitions from the light incident surface 31B to the light emitting surface 32 in the prism 30B.
　このように、本実施の形態の光学ユニット１Ｂでは、プリズム３０Ｂは、光入射面３１Ｂと光出射面３２とのいずれか一方が凸形状となっており、かつ１つの半導体レーザー２０に対して１つの該凸形状が対応している。 As described above, in the optical unit 1 </ b> B of the present embodiment, the prism 30 </ b> B has one of the light incident surface 31 </ b> B and the light emitting surface 32 having a convex shape, and is 1 for one semiconductor laser 20. The two convex shapes correspond to each other.
　これにより、光学部材としてのプリズム３０Ｂの光入射面３１Ｂと光出射面３２とのいずれか一方が凸形状となっているので、光学部材は、プリズムとしての機能だけでなく、凸レンズとしての機能も有している。この結果、光ファイバー１０の光ファイバー入射面１１に対して十分に小さいスポットサイズに絞って入射することができるので、光ファイバー１０への光入射効率をさらに高めることができる。 Accordingly, since either one of the light incident surface 31B and the light emitting surface 32 of the prism 30B as an optical member has a convex shape, the optical member functions not only as a prism but also as a convex lens. Have. As a result, the light can be incident on the optical fiber incident surface 11 of the optical fiber 10 with a sufficiently small spot size, so that the light incident efficiency on the optical fiber 10 can be further increased.
　また、本実施の形態における光入射面３１Ｂでは、プリズム３０Ｂは、光入射面３１Ｂが凸形状となっているので、プリズム３０Ｂに入射した光の光路を集中させることができる。また、プリズム３０Ｂの光出射面３２が平面状となっているので、該光出射面３２での光損失を低減することができる。 Further, in the light incident surface 31B in the present embodiment, the light incident surface 31B of the prism 30B has a convex shape, so that the optical path of the light incident on the prism 30B can be concentrated. In addition, since the light exit surface 32 of the prism 30B is planar, light loss at the light exit surface 32 can be reduced.
　尚、本実施の形態では、プリズム３０Ｂには、光入射面３１Ｂが凸形状となっている場合について説明したが、本発明においては、必ずしもこれに限らず、プリズム３０Ｂの光出射面３２が凸形状となっている構成であってもよい。 In the present embodiment, the case where the light incident surface 31B has a convex shape has been described in the prism 30B. However, the present invention is not limited to this, and the light emitting surface 32 of the prism 30B is convex. The configuration may be a shape.
　　〔実施の形態３〕
　本発明のさらに他の実施の形態について図５に基づいて説明すれば、以下のとおりである。尚、本実施の形態において説明すること以外の構成は、前記実施の形態１及び実施の形態２と同じである。また、説明の便宜上、前記の実施の形態１及び実施の形態２の図面に示した部材と同一の機能を有する部材については、同一の符号を付し、その説明を省略する。 [Embodiment 3]
The following will describe still another embodiment of the present invention with reference to FIG. The configurations other than those described in the present embodiment are the same as those in the first embodiment and the second embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiment 1 and Embodiment 2 are given the same reference numerals, and explanation thereof is omitted.
　前記実施の形態１の光学ユニット１Ａ及び実施の形態２の光学ユニット１Ｂでは、光源は複数としての２個の半導体レーザー２０・２０からなっていた。この点、本実施の形態の光学ユニット１Ｃでは、光源は複数としての４個の半導体レーザー２０・２０からなっている点が異なっている。 In the optical unit 1A of the first embodiment and the optical unit 1B of the second embodiment, the light source is composed of two semiconductor lasers 20 and 20 as a plurality. In this respect, the optical unit 1C of the present embodiment is different in that the light source is composed of a plurality of four semiconductor lasers 20 and 20.
　本実施の形態の光学ユニット１Ｃの構成を図６に基づいて説明する。図６は、本実施の形態の光学ユニット１Ｃの構成を示す斜視図である。 The configuration of the optical unit 1C according to the present embodiment will be described with reference to FIG. FIG. 6 is a perspective view showing a configuration of the optical unit 1C of the present embodiment.
　本実施の形態の光学ユニット１Ｃは、図６に示すように、複数としての４個の半導体レーザー２０・２０・２０・２０を備えている。そして、プリズム３０Ｃには、上記４個の半導体レーザー２０・２０・２０・２０に対応して、４個の光入射面３１Ｂと４個の光出射面３２とが備えられている。 As shown in FIG. 6, the optical unit 1C of the present embodiment includes a plurality of four semiconductor lasers 20, 20, 20, and 20. The prism 30C is provided with four light incident surfaces 31B and four light emitting surfaces 32 corresponding to the four semiconductor lasers 20, 20, 20, 20.
　したがって、本実施の形態のプリズム３０Ｃの形状は、上から見ると四角錐状となっている。 Therefore, the shape of the prism 30C of the present embodiment is a quadrangular pyramid when viewed from above.
　この構成により、本実施の形態の光学ユニット１Ｃでは、４個の半導体レーザー２０・２０・２０・２０からのレーザー光を光ファイバー１０の光ファイバー入射面１１に入射させるので、高出力の光を光ファイバー１０に入射させることができるものとなっている。 With this configuration, in the optical unit 1C of the present embodiment, the laser light from the four semiconductor lasers 20, 20, 20, and 20 is incident on the optical fiber incident surface 11 of the optical fiber 10, so that high output light is transmitted to the optical fiber 10. It can be made to enter.
　尚、その他の構成は、実施の形態１及び実施の形態２にて説明したことと同じであるので、その説明を省略する。 Other configurations are the same as those described in the first embodiment and the second embodiment, and thus description thereof is omitted.
　〔まとめ〕
　本発明の態様１における光学ユニット１Ａ・１Ｂ・１Ｃは、被集光部材（光ファイバー１０）と、複数の光源（半導体レーザー２０）と、上記被集光部材（光ファイバー１０）と複数の光源（半導体レーザー２０）との間に位置し、各光源（半導体レーザー２０）から発せられた光を光入射面３１Ａ・３１Ｂから入射して屈折により進行方向を変化させて光出射面３２から出射させて上記被集光部材（光ファイバー１０）の被集光部材入射面（光ファイバー入射面１１）に導く光学部材（プリズム３０Ａ・３０Ｂ・３０Ｃ）とを備えた光学ユニットにおいて、上記各光源（半導体レーザー２０）は、該各光源（半導体レーザー２０）における出射光の光軸Ｌ１が上記被集光部材（光ファイバー１０）における被集光部材入射面（光ファイバー入射面１１）の法線Ｚに対してそれぞれ傾斜するように設けられていると共に、上記光学部材（プリズム３０Ａ・３０Ｂ・３０Ｃ）は、該光学部材（プリズム３０Ａ・３０Ｂ・３０Ｃ）の光出射面３２からの出射光の光軸Ｌ２と上記被集光部材（光ファイバー１０）における被集光部材入射面（光ファイバー入射面１１）の法線Ｚとのなす角度である被集光部材入射角度（光ファイバー入射角度θ２）が、該光学部材（プリズム３０Ａ・３０Ｂ・３０Ｃ）の光入射面３１Ａ・３１Ｂへの上記各光源（半導体レーザー２０）から発せられた光の光軸Ｌ１と上記被集光部材（光ファイバー１０）における被集光部材入射面（光ファイバー入射面１１）の法線Ｚとのなす入射光傾斜角度（入射光傾斜角度θ１）よりも小さくなるように形成されていることを特徴としている。 [Summary]
The optical units 1A, 1B, and 1C according to the first aspect of the present invention include a light collecting member (optical fiber 10), a plurality of light sources (semiconductor laser 20), the light collecting member (optical fiber 10), and a plurality of light sources (semiconductors). The light emitted from each light source (semiconductor laser 20) is incident from the light incident surfaces 31A and 31B, is changed in the traveling direction by refraction, and is emitted from the light emitting surface 32. In the optical unit including optical members ( prisms 30A, 30B, and 30C) that lead to the light collecting member incident surface (optical fiber incident surface 11) of the light collecting member (optical fiber 10), each of the light sources (semiconductor lasers 20) is The optical axis L1 of the emitted light from each light source (semiconductor laser 20) is the light collecting member incident surface (optical fiber) of the light collecting member (optical fiber 10). The optical members ( prisms 30A, 30B, and 30C) are provided so as to be inclined with respect to the normal line Z of the incident surface 11), and the light emitting surfaces of the optical members ( prisms 30A, 30B, and 30C) are provided. The incident angle of the focused member (optical fiber), which is an angle formed by the optical axis L2 of the emitted light from the beam 32 and the normal Z of the focused member incident surface (optical fiber incident surface 11) of the focused member (optical fiber 10). Incident angle θ2) is an optical axis L1 of light emitted from each of the light sources (semiconductor laser 20) to the light incident surfaces 31A and 31B of the optical members ( prisms 30A, 30B, and 30C) and the focused member ( The optical fiber 10) is formed so as to be smaller than the incident light inclination angle (incident light inclination angle θ1) formed with the normal line Z of the light collecting member incident surface (optical fiber incident surface 11). It is characterized by a door.
　上記の発明によれば、光学部材として屈折を利用するものとなっており、光学部材としてのハーフミラーを用いないので、ハーフミラー使用時における反射光と透過光とのいずれか一方による光損失を防止することができる。 According to the above invention, since refraction is used as an optical member and a half mirror as an optical member is not used, light loss due to either reflected light or transmitted light when using the half mirror is reduced. Can be prevented.
　また、本発明では、各光源は、該各光源における出射光の光軸が上記被集光部材における被集光部材入射面の法線に対してそれぞれ傾斜するように設けられている。 In the present invention, each light source is provided such that the optical axis of the emitted light from each light source is inclined with respect to the normal line of the light collecting member incident surface of the light collecting member.
　この結果、各光源を配設するときに、各光源を、該各光源における出射光の光軸が上記被集光部材入射面の法線に対して平行となるように設ける場合に比べて、横方向への距離が長くなることを抑制することができ、被集光部材への光入射効率の低下を防止し、光利用効率の低下を防止することができる。 As a result, when each light source is disposed, each light source is provided so that the optical axis of the emitted light from each light source is parallel to the normal line of the light collecting member incident surface, It can suppress that the distance to a horizontal direction becomes long, can prevent the fall of the light incidence efficiency to a condensing member, and can prevent the fall of light utilization efficiency.
　また、本発明では、光学部材は、該光学部材の光出射面からの出射光の光軸と上記被集光部材における被集光部材入射面の法線とのなす角度である被集光部材入射角度が、該光学部材の光入射面への上記各光源から発せられた光の光軸と上記被集光部材における被集光部材入射面の法線とのなす入射光傾斜角度よりも小さくなるように形成されている。 In the present invention, the optical member is an angled member formed by an optical axis of light emitted from the light emitting surface of the optical member and a normal line of the light collecting member incident surface of the light collecting member. The incident angle is smaller than the incident light inclination angle formed by the optical axis of the light emitted from each light source on the light incident surface of the optical member and the normal line of the light collecting member incident surface of the light collecting member. It is formed to become.
　この結果、被集光部材入射面の法線に対して斜めに向けられた光源からの光の光軸をプリズムの機能を有する光学部材にて該法線に近い方向つまり被集光部材入射面の垂直方向に近づくように曲げて、効率よく被集光部材に光を入射させることができる。 As a result, the optical axis of the light from the light source directed obliquely with respect to the normal line of the light collecting member incident surface is a direction close to the normal line by the optical member having a prism function, that is, the light collecting member incident surface. The light can be efficiently incident on the light collecting member by being bent so as to approach the vertical direction.
　したがって、複数の光源から被集光部材への光入射効率を向上し得る光学ユニットを提供することができる。 Therefore, it is possible to provide an optical unit that can improve the light incident efficiency from a plurality of light sources to the light collecting member.
　本発明の態様２における光学ユニット１Ｂ・１Ｃは、態様１の光学ユニットにおいて、前記光学部材（プリズム３０Ｂ・３０Ｃ）は、前記光入射面３１Ｂと光出射面３２とのいずれか一方が凸形状となっており、かつ１つの光源（半導体レーザー２０）に対して１つの該凸形状が対応していることが好ましい。 The optical units 1B and 1C according to the second aspect of the present invention are the optical units according to the first aspect, and the optical member (the prisms 30B and 30C) has either one of the light incident surface 31B and the light emitting surface 32 having a convex shape. It is preferable that one convex shape corresponds to one light source (semiconductor laser 20).
　これにより、光学部材は、凸レンズとしての機能をも有している。この結果、被集光部材の光入射面に対して十分に小さいスポットサイズに絞って入射することができるので、被集光部材への光入射効率をさらに高めることができる。 Thereby, the optical member also has a function as a convex lens. As a result, it is possible to make the incident light with a sufficiently small spot size with respect to the light incident surface of the light collecting member, so that the light incident efficiency to the light collecting member can be further increased.
　本発明の態様３における光学ユニット１Ｂ・１Ｃは、態様１又は２の光学ユニットにおいて、前記光学部材（プリズム３０Ｂ・３０Ｃ）は、前記光入射面３１Ｂが凸形状となっており、かつ前記光出射面３２が平面状となっていることが好ましい。 The optical units 1B and 1C according to the third aspect of the present invention are the optical units according to the first and second aspects, wherein the optical member ( prisms 30B and 30C) has a convex light incident surface 31B and the light emission surface. The surface 32 is preferably flat.
　これにより、光学部材の光入射面が凸形状となっているので、光学部材に入射した光の光路を集中させることができる。また、光学部材の光出射面が平面状となっているので、後述する構成を有する場合に、特に、該光出射面での光損失を低減することができる。 Thereby, since the light incident surface of the optical member has a convex shape, the optical path of the light incident on the optical member can be concentrated. In addition, since the light emission surface of the optical member has a flat shape, the light loss on the light emission surface can be reduced particularly when the optical member has a configuration described later.
　本発明の態様４における光学ユニット１Ａ・１Ｂ・１Ｃは、態様１，２又は３の光学ユニットにおいて、前記各光源（半導体レーザー２０）から発せられる光は、前記光学部材（プリズム３０Ａ・３０Ｂ・３０Ｃ）の光出射面３２に対してｐ波偏光であることが好ましい。 The optical units 1A, 1B, and 1C according to the fourth aspect of the present invention are the optical units according to the first, second, and third aspects, in which the light emitted from each light source (semiconductor laser 20) is the optical member (the prisms 30A, 30B, and 30C). ) Is preferably p-wave polarized light.
　すなわち、ｓ波偏光及びｐ波偏光は、光学部材の光出射面への入射角度によって光透過率、反射率が変化するが、基本的には、ｐ波偏光の方が広い角度範囲で透過率が高くなる。この結果、本発明では、各光源から発せられる光が、光学部材の光出射面に対してｐ波偏光となるように選択することにより、光学部材の光出射面での反射による光損失を低減し、光利用率を向上することができる。 That is, s-wave polarized light and p-wave polarized light change in light transmittance and reflectance depending on the incident angle to the light exit surface of the optical member. Basically, p-wave polarized light has transmittance in a wider angle range. Becomes higher. As a result, in the present invention, light loss from reflection on the light exit surface of the optical member is reduced by selecting the light emitted from each light source to be p-wave polarized with respect to the light exit surface of the optical member. In addition, the light utilization rate can be improved.
　本発明の態様５における光学ユニット１Ａ・１Ｂ・１Ｃは、態様４の光学ユニットにおいて、前記各光源（半導体レーザー２０）から発せられた光における、前記光学部材（プリズム３０Ａ・３０Ｂ・３０Ｃ）の光入射面３１Ａ・３１Ｂに入射した後の光軸Ｌ１の方向は、上記光学部材（プリズム３０Ａ・３０Ｂ・３０Ｃ）の光出射面３２に対してブリュースター角をなしていることが好ましい。 The optical units 1A, 1B, and 1C according to Aspect 5 of the present invention are the light of the optical members ( prisms 30A, 30B, and 30C) in the light emitted from each light source (semiconductor laser 20) in the optical unit according to Aspect 4. The direction of the optical axis L1 after entering the entrance surfaces 31A and 31B preferably forms a Brewster angle with respect to the light exit surface 32 of the optical member ( prisms 30A, 30B, and 30C).
　これにより、光学部材の光出射面での反射による光損失を最大限に低減し、光利用率をさらに向上することができる。 Thereby, light loss due to reflection on the light exit surface of the optical member can be reduced to the maximum, and the light utilization rate can be further improved.
　尚、本発明は、上述した各実施形態に限定されるものではなく、請求項に示した範囲で種々の変更が可能であり、異なる実施形態にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施形態についても本発明の技術的範囲に含まれる。 The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.
　本発明は、光ファイバー又はレンズ等の被集光部材に複数の例えば半導体レーザー等の光源からの光を集光させる光学ユニットに利用することができる。 The present invention can be used for an optical unit that condenses light from a plurality of light sources such as semiconductor lasers on a light collecting member such as an optical fiber or a lens.
１Ａ　　　　光学ユニット
１Ｂ　　　　光学ユニット
１Ｃ　　　　光学ユニット
１０　　　　光ファイバー（被集光部材）
１１　　　　光ファイバー入射面（被集光部材入射面）
１２　　　　コア
１３　　　　クラッド
２０　　　　半導体レーザー（光源）
３０Ａ　　　プリズム（光学部材）
３０Ｂ　　　プリズム（光学部材）
３０Ｃ　　　プリズム（光学部材）
３１Ａ　　　光入射面
３１Ｂ　　　光入射面
３２　　　　光出射面
Ｌ１　　　　光軸（光源から発せられた光の光軸）
Ｌ２　　　　光軸（光出射面からの出射光の光軸）
ＮＡ　　　　開口数
Ｚ　　　　　法線
θ’　　　　入射角度
θ１　　　　入射光傾斜角度
θ２　　　　光ファイバー入射角度（被集光部材入射角度） 1A Optical unit 1B Optical unit 1C Optical unit 10 Optical fiber (condensed member)
11 Optical fiber incident surface (condensing member incident surface)
12 Core 13 Clad 20 Semiconductor laser (light source)
30A prism (optical member)
30B Prism (optical member)
30C prism (optical member)
31A Light entrance surface 31B Light entrance surface 32 Light exit surface L1 Optical axis (optical axis of light emitted from the light source)
L2 optical axis (optical axis of the outgoing light from the light exit surface)
NA Numerical aperture Z Normal θ ′ Incident angle θ1 Incident light tilt angle θ2 Optical fiber incident angle (condensed member incident angle)

Claims (5)

  1. 　被集光部材と、複数の光源と、上記被集光部材と複数の光源との間に位置し、各光源から発せられた光を光入射面から入射して屈折により進行方向を変化させて光出射面から出射させて上記被集光部材の被集光部材入射面に導く光学部材とを備えた光学ユニットにおいて、
    　上記各光源は、該各光源における出射光の光軸が上記被集光部材における被集光部材入射面の法線に対してそれぞれ傾斜するように設けられていると共に、
    　上記光学部材は、該光学部材の光出射面からの出射光の光軸と上記被集光部材における被集光部材入射面の法線とのなす角度である被集光部材入射角度が、該光学部材の光入射面への上記各光源から発せられた光の光軸と上記被集光部材における被集光部材入射面の法線とのなす入射光傾斜角度よりも小さくなるように形成されていることを特徴とする光学ユニット。     Positioned between the light collecting member, a plurality of light sources, and the light collected from the light collecting member and the plurality of light sources. In an optical unit comprising an optical member that is emitted from a light exit surface and led to a light collection member incident surface of the light collection member,
    Each light source is provided such that the optical axis of the emitted light from each light source is inclined with respect to the normal line of the light collecting member incident surface of the light collecting member,
    The optical member has an incident angle of the light collecting member, which is an angle formed by an optical axis of light emitted from the light emitting surface of the optical member and a normal line of the light collecting member incident surface of the light collecting member. It is formed to be smaller than the incident light inclination angle formed by the optical axis of the light emitted from each of the light sources on the light incident surface of the optical member and the normal line of the light collecting member incident surface of the light collecting member. An optical unit characterized by that.
  2. 　前記光学部材は、前記光入射面と光出射面とのいずれか一方が凸形状となっており、かつ１つの光源に対して１つの該凸形状が対応していることを特徴とする請求項１記載の光学ユニット。 The optical member is characterized in that one of the light incident surface and the light emitting surface has a convex shape, and one convex shape corresponds to one light source. The optical unit according to 1.
  3. 　前記光学部材は、前記光入射面が凸形状となっており、かつ前記光出射面が平面状となっていることを特徴とする請求項１又は２記載の光学ユニット。 3. The optical unit according to claim 1, wherein the light incident surface of the optical member has a convex shape, and the light emission surface has a flat shape.
  4. 　前記各光源から発せられる光は、前記光学部材の光出射面に対してｐ波偏光であることを特徴とする請求項１，２又は３記載の光学ユニット。 4. The optical unit according to claim 1, wherein the light emitted from each of the light sources is p-wave polarized light with respect to a light exit surface of the optical member.
  5. 　前記各光源から発せられた光における、前記光学部材の光入射面に入射した後の光軸の方向は、上記光学部材の光出射面に対してブリュースター角をなしていることを特徴とする請求項４に記載の光学ユニット。 The direction of the optical axis of light emitted from each light source after entering the light incident surface of the optical member forms a Brewster angle with respect to the light emitting surface of the optical member. The optical unit according to claim 4.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9645313B2 (en) 2015-05-22 2017-05-09 Corning Optical Communications LLC Quantum cascade laser devices and methods for optical-fiber processing for connector applications

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62104204U (en) * 1985-12-18 1987-07-03

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62104204U (en) * 1985-12-18 1987-07-03

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9645313B2 (en) 2015-05-22 2017-05-09 Corning Optical Communications LLC Quantum cascade laser devices and methods for optical-fiber processing for connector applications

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