JP2019117258A - Light-emitting device - Google Patents

Abstract

To provide a light-emitting device equipped with a configuration capable of simply and highly accurately controlling a divergence angle of light emitted from an emission end of an optical fiber.SOLUTION: A light-emitting device includes: a laser device 10; a lens 20 with a lens barrel arranged at a light emission side of the laser device 10; a spacer 30 which, between the laser device 10 and the lens 20 with the lens barrel, is arranged in contact with these laser device 10 and the lens 20 with the lens barrel and equipped with an aperture 30a for passing only a part of the light emitted from the laser device 10 therethrough; a holding member 31 for holding the laser device 10, the space 30, and the lens 20 with the lens barrel; and an optical fiber holding member 32 arranged at one end of the holding member 31.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to a light emitting device.

  Generally, in the light emitting element module, it is desirable to take out the light output of the light emitting element as an optical fiber output as much as possible. Therefore, conventionally, the light output of the light emitting element is maximally taken, and the light emitting element module is set to the interval when the optical fiber output is maximized, that is, the optimum distance according to the specifications of the optical system and the light emitting element. It was assembled (for example, patent documents 1-3 etc.).

Japanese Patent Application Publication No. 2003-207696 Japanese Patent Application Laid-Open No. 07-333474 Japanese Patent Application Laid-Open No. 05-033324

However, in recent years where a higher output light emitting element is used, the divergence angle of light emitted from the output end of the optical fiber can be made more accurate than taking out the light output of the light emitting element as it is as the output of the optical fiber. There are also cases where control is required.
An object of the present invention is to provide a light emitting device having a configuration capable of easily and precisely controlling the divergence angle of light emitted from the output end of an optical fiber.

The present application includes the following inventions.
Laser device,
A lens with a lens barrel disposed on the light emission side of the laser device;
A spacer, which is disposed between the laser device and the lens with a lens barrel, is disposed in contact with the laser device and the lens with a lens barrel, and has an aperture that allows only part of the light emitted from the laser device to pass.
A light emitting device comprising: the laser device; a holding member holding the spacer and the lens with a lens barrel; and an optical fiber holding member disposed at one end of the holding member.

  According to the present invention, it is possible to provide a light emitting device having a configuration capable of controlling the divergence angle of the light emitted from the output end of the optical fiber simply and with high precision.

It is a schematic sectional drawing of the light-emitting device of one Embodiment. It is a schematic cross-sectional schematic diagram for demonstrating the definition in the light-emitting device shown to FIG. 1A. It is a schematic sectional drawing of the laser apparatus mounted in FIG. 1A. It is a schematic perspective view for demonstrating the optical fiber connector attached to the light-emitting device shown to FIG. 1A. It is a schematic perspective view for demonstrating the fastening member which fastens the light-emitting device shown to FIG. 1A and an optical fiber connector.

  The form shown below is an illustration for embodying the technical thought of the present invention, and does not limit the present invention to the following. In addition, the size and positional relationship of members shown in each drawing may be exaggerated for the sake of clarity. Furthermore, as for the same name and reference numeral, in principle, the same or the same member is shown, and the duplicated explanation is appropriately omitted.

[Light-emitting device]
As shown in FIGS. 1A and 1B, the light emitting device 40 according to the embodiment of the present application includes the laser device 10, the lens 20 with a lens barrel, and an aperture 30a that allows only part of the light emitted from the laser device 10 to pass. A spacer 30, a holding member 31 and an optical fiber holding member 32 are provided.
With such a configuration, it is possible to easily and reliably control the optical fiber incident angle in the light emitting device, and as a result, to accurately control the divergence angle of the light emitted from the optical fiber output end. It becomes possible. In the present specification, the divergence angle is defined as an angle up to a point at which the intensity is 1 / e 2 (0.10.135) with respect to the maximum beam intensity (on-axis intensity) of light.

(Laser device 10)
As shown in FIG. 2, the laser device 10 mainly includes a laser element 1 and a package 2 for housing the laser element 1.

(Laser element 1)
The laser element 1 is a light emitting element which functions as a light source for emitting a laser beam. The laser device 1 can be controlled to either pulse drive or rated drive, and it is preferable to use a laser device having a large light emission output and high directivity. The output of the laser element may be, for example, an output of 1 W to several hundreds W. The peak wavelength of the laser element may be any of ultraviolet light to infrared light, but for example, one having an emission peak wavelength of 300 nm to 500 nm is mentioned, and one having an emission peak wavelength of 400 nm to 470 nm is preferable.
In the laser device 10, the laser element 1 is generally fixed to a submount 3 provided in the package 2 using a die bonding member. It is preferable to use the solder material excellent in heat dissipation, Au-Sn, Ag paste, In alloy etc. for a die-bonding member.

(Package 2)
The package 2 constituting the laser device 10 is a member for housing the laser element 1.
The laser device 10 may be a transmissive type that extracts the light emitted from the laser element as it is or a reflective type light emitting device that extracts the light emitted from the laser element using a raising mirror or the like, and in FIG. 1 shows a can type laser device of the type.
The package 2 is configured of, for example, a base 2A, a cap 2B, and the like.
In the laser device 10, the submount 3 is mounted on a post which is a columnar member which stands upright from the upper surface of the base 2A. The laser element 1 is fixed to the upper surface of the submount 3. The laser element 1 may be fixed to the upper surface of the submount 3 via a heat sink. As described above, when the laser element 1 is fixed to the side surface of the submount 3 fixed to the upper surface side of the base 2A, the device can be miniaturized.

A hollow cap 2B is bonded to the upper surface side of the base 2A in the vicinity of the periphery of the base 2A so as to cover the laser element 1. On the upper surface of the cap 2B, at the part facing the laser element 1, a window for penetrating light in the thickness direction and extracting light is disposed. A translucent member or the like is fixed and disposed so as to close the window of the cap 2B.
The inner wall of the through hole constituting the window may be inclined so that the size of the hole increases from the laser element side to the upper surface side.

The base 2A and the cap 2B are preferably made of a reflective material that hardly absorbs light. Here, the reflective property is preferably, for example, a material that reflects 50% or more of light emitted from the laser element 1 used, or a material that reflects 60% or more, 70%, or 80% or more.
In this light emitting device, the heat generated from the light transmitting member is transferred to 2A via the cap 2B. On the other hand, the heat generated from the laser element 1 is also transferred to the base 2A via the submount 3. Therefore, it is preferable that the package 2 be used as a heat dissipation member and be made of a material having good thermal conductivity. Here, that the thermal conductivity at 20 ° C. is several W / m · k or more is preferable that the thermal conductivity is good, and 10 W / m · k or more and 25 W / m · k or more are more preferable, 50 W / m More preferably k or more. In this case, the cap 2B is preferably formed of a material having a thermal conductivity larger than that of the light transmitting member. Thereby, the heat of the light transmitting member can be efficiently dissipated. The package 2 is preferably made of a heat-resistant material. Here, that the heat resistance is good means that the melting point is several hundred ° C. or more, more preferably 1000 ° C. or more, and even more preferably 1500 ° C. or more.

The base 2A can be formed of various materials such as conductivity and insulation. For example, metals such as Cu, W, Ta, Mo, Al, Fe, Ag, Au, Rh, Kovar, brass, CuW, CuMo and the like can be used. These metals may be used as a base material, and plating may be performed on the entire surface or a part of the surface with Au, Ag, Al or the like. Especially, what is formed with the copper or copper alloy by which the surface was gold-plated is preferable.
The cap 2B can be made of Ni-Fe alloy, kovar, CuW, Ni, Co, Fe, brass or the like. In particular, Ni, an Fe-Ni alloy, Kovar, etc., which have high thermal conductivity and are capable of resistance welding using a projection, are preferable.

The shape, size, and the like of the package 2 can be appropriately set according to the purpose of use and the intended action or effect.
The submount 3 on which the laser element 1 is mounted is typically a material having high electrical insulation and high thermal conductivity. For example, aluminum nitride and silicon carbide can be mentioned.

(Lead 5)
One end of the lead 5 is electrically connected to the laser element 1 in the package 2, and the other end is mounted on a circuit board or the like and electrically connected to an external power supply.
At least one pair of leads 5 is provided, and is fixed via an insulating member so as to penetrate from the top surface side to the bottom surface side of the base 2A. The inner lead portion disposed on the upper surface side of the base 2A is electrically connected to the laser device 1, and the outer lead portion disposed on the bottom surface is mounted on a circuit board or the like to be electrically connected to an external power supply Be done.

(Lens with lens barrel 20)
The lens 20 with lens barrel is disposed on the light emission side of the laser device 10, and is disposed on the light emission side of the laser device 10 via a spacer 30 described later. The lens with barrel 20 may use any form known in the art. Among them, as the lens 20 with a lens barrel, one in which the lens 20b and the lens barrel 20a are integrated is preferable. For example, the lens 20b and the lens barrel 20a can be integrated with high accuracy by precision glass molding.
The lens with barrel 20 can be fixed with high accuracy by welding the barrel 20 a to the holding member 31. In particular, as described later, when the holding member 31 has a step between the lens 20 with the barrel and the light emitting side, the barrel 20a is brought into contact with the step and welded. It can be fixed easily in place.

(Lens barrel 20a)
The lens barrel 20a is any of titanium, bismuth, thallium, tungsten, tantalum, tin, aluminum, chromium, magnesium, gallium, niobium, zirconium, strontium, molybdenum, iridium, osmium, rhenium, gold, platinum, zinc, silver, copper Or the alloy of two or more of them, the metal, and the metal and the alloy to which an impurity is added, or the like. For example, it is preferable to form with ferritic stainless steel etc.
The barrel may not necessarily be a barrel having a mirror surface, as long as it is a tubular member capable of holding a lens.
The material constituting the lens barrel 20a is preferably such that the difference in thermal expansion coefficient with the lens 20b is 20 × 10 ^-7 / ° C. or less, and the thermal expansion coefficient is larger than that of the lens 20b, and its melting point is higher than the softening point of the lens It is preferable to be large.

(Lens 20b)
The lens 20 b may be a lens of various forms such as a concave lens or a convex lens. The lens 20 b has an optical function such as collimating the light passing through the concave or convex optical surface or condensing the light on a light receiving portion. In particular, the lens 20b is preferably substantially circular as viewed in the optical axis direction. The lens 20 b is preferably formed of, for example, an optical glass such as lead-free glass.

(Spacer 30)
The spacer 30 is a member having an arbitrary thickness and disposed between the laser device 10 and the lens-barrel mounted lens 20 in contact with the laser device 10 and the lens-barrel 20 a. Further, the spacer 30 is provided with an aperture 30 a which allows only a part of the light emitted from the laser device 10 to pass.
The thickness of the spacer 30, coupled with the shape and size of the aperture 30a, enables accurate control of the distance L1 from the light emitting surface Z of the laser device 10 to the incident principal point of the lens 20b, as shown in FIG. 1B. It is set to.
The optical lateral magnification M depends on the distance L1 from the laser light emitting surface of the laser device 10 to the entrance-side principal point of the lens 20b when the focal length EFL of the lens 20b is constant. When the spacer 30 is provided, the optical lateral magnification M is the light incident angle θ1 of the light incident side principal point of the lens of the light emitted from the laser device after passing through the aperture regardless of the divergence angle of the laser device 10 In addition, the incident angle θ2 of the optical fiber, that is, the divergence angle of the light emitted from the output end of the optical fiber can be controlled. That is, by the arrangement of the spacer 30, it is possible to control the optical lateral magnification M with high accuracy, and to accurately control the divergence angle of the light emitted from the output end of the optical fiber.

The thickness of the spacer can be appropriately adjusted according to the type of laser device used, the size and performance of the lens 20 with a lens barrel, the size of the light emitting device, the characteristics of the light emitting device to be obtained, and the like. For example, 1 micrometer-several tens mm are mentioned, 1 micrometer-several mm are preferable, and several micrometers-several tens micrometer are more preferable.
The spacer 30 can be formed of a ceramic, a metal such as stainless steel or an alloy exemplified for the base 2A, the cap 2B and the like described above.

  The aperture 30a refers to an opening formed in the spacer 30, and may be, for example, one having a shape such as a circle or an ellipse. The size is preferably set such that the light incident angle θ1 of the light emitted from the laser device to the light incident side principal point of the lens is a value smaller than 20 ° in cross sectional view. Specifically, those having a diameter or a length of a major axis of 10 μm to 3000 μm can be mentioned, and several μm to several tens μm are preferable. The aperture 30a may be varied in the thickness direction of the spacer 30, but is preferably constant. In other words, the inner wall of the through hole constituting the aperture 30 a is preferably perpendicular or substantially perpendicular (90 ± 5 °) to the surface of the spacer 30. Thus, the light blocking of the light emitted from the laser device can be controlled with high accuracy.

(Holding member 31)
The holding member 31 is a member for holding the laser device 10, the spacer 30, and the lens mounted lens 20 in this order. The holding member 31 further includes an optical fiber holding member 32 for holding an optical fiber at the light emitting side end of the lens-barrel mounted lens 20.
The holding member 31 can be formed, for example, of the ceramic, metal, etc. exemplified for the base 2A, the cap 2B, etc. described above. In particular, it is preferable that the inner wall of the holding member 31 that constitutes the traveling path of light be formed of a material that does not easily absorb light, that is, a material having light reflectivity. Here, light reflectivity means the property of reflecting 60% or more of light and the property of reflecting 70%, 80% or 85% or more of light.

As shown in FIG. 1B, the holding member 31 has a distance L1 from the light exit surface Z of the laser device 10 to the light incident side principal point Y of the lens 20b, and the optical fiber holding member from the light exit side principal point X of the lens 20b. When the distance to the inside of the optical fiber, that is, the distance to the light incident surface Q of the optical fiber is L2, each member is determined by the thickness of the spacer, the size of the aperture 30a, etc. so that L2 has a larger value than L1. The holding position of is set.
Here, the incident-side principal point and the emission-side principal point of the lens 20b indicate meanings generally used in the relevant field.

From another viewpoint, when the light incident angle of the light from the laser device 10 after passing through the aperture to the light incident side principal point Y of the lens 20b is θ1, the angle θ1 is 20 in a cross sectional view The value is preferably set to a value smaller than °, more preferably 17.5 ° or less, 15 ° or less, or 12.5 ° or less, and still more preferably 10 °, 9 ° or 8 °. The angle θ1 is a value obtained by blocking a part of the light emitted from the laser device by the aperture 30a, and thus has a smaller value than the divergence angle of the light emitted from the laser device 10.
Furthermore, when the incident angle of light from the lens 20b light emitting surface side principal point to the optical fiber holding member 32 (that is, the end face of the optical fiber) is θ2, the angle θ2 has a smaller value than the angle θ1 in cross sectional view It is preferable to be set, more preferably set to a value smaller than 20 °, more preferably 15 ° or less, 10 ° or less or 7.5 ° or less, 5 ° or less, 4 ° or less Or 3 ° or less is more preferable.

The light emitting device of the present embodiment is for simply and accurately controlling the divergence angle of the light emitted from the emitting end of the optical fiber attached thereto, and for that purpose, the light emitted from the laser device 10 , That is, components of the incident angle of the optical fiber outside the specified range.
The optical fiber incident angle θ2 in the light emitting device depends on the divergence angle θ1 of the light emitted from the laser device after passing through the aperture and the optical lateral magnification M (M = θ1 / θ2). The optical lateral magnification M depends on the distance L1 from the laser device to the entrance-side principal point of the lens 20b when the focal length EFL of the lens 20b is constant. Therefore, in order to control L1 accurately, a spacer provided with an aperture for adjusting L1 is disposed between the laser device and the lens 20 with a lens barrel, and the optical lateral magnification M is controlled. Then, as described above, by making the spacer function as an aperture, it is possible to remove the non-specified optical fiber incident angle component. This is a problem brought about by the increase in the output of the laser element in the laser device in recent years, and corresponds to the need to set the optical lateral magnification M to a smaller value than in the past. .
Here, the optical lateral magnification M is represented by θ1 / θ2 or L2 / L1, and as described above, can be controlled by adjusting the angle θ1 and the angles θ2 or L1 and L2 according to the method described above . For example, M is preferably 3.5 or less, more preferably 3.0 or less, still more preferably 2.8 or less, and still more preferably 2.8 to 2.5.

(Optical fiber holding member 32)
The optical fiber holding member 32 is disposed at one end of the holding member 31 and is a member for holding an optical fiber. The optical fiber holding member 32 not only can directly hold the optical fiber, but also can hold an optical fiber connector in which a ferrule, a support member and the like are provided at the tip of the optical fiber as described later. Usually, the fastening member is used to fasten to the optical fiber connector. That is, the optical fiber holding member 32 may be either a pigtail type or a receptacle type.
The optical fiber holding member 32 has a predetermined length so that the position of the light incident surface of the optical fiber can be adjusted in order to adjust θ2 or L2 described above.

  The optical fiber holding member 32 can be formed, for example, of the ceramic, metal, etc. exemplified for the base 2A, the cap 2B, etc. described above. The optical fiber holding member 32 can be formed in various shapes depending on the configuration of one end on the optical fiber side. The optical fiber holding member 32 may be configured by one member, but may be configured by combining two or more members. These may be integral or may be removable and / or degradable members.

(Fiber optic connector 54)
The optical fiber connector 54 is a member for supporting the tip of the optical fiber as shown in FIG. 3, and for example, a ferrule 53 and a support member 50 having a flange portion 50a extending outward in the radial direction at one end Prepare.
The ferrule 53 is configured such that the optical fiber 52 is inserted from its end, and the end opposite to the insertion side of the optical fiber 52 is supported by the support member 50 so as to cover the outer periphery thereof . A well-known thing can be used as a ferrule.
The supporting member 50 has a flange portion 50 a that extends outward in the radial direction at an end on the side of supporting the ferrule 53. The flange portion 50a may have an annular shape having a diameter larger than that of the portion covering the ferrule 53, or a portion thereof, for example, a concave portion or a radially recessed portion disposed on the surface thereof One or more recesses 50b may be formed. Although the support member 50 itself, the support member 50, and the collar portion 50a may be configured by one member, a plurality of members may be combined and configured integrally.

(Fastening member)
As a fastening member used to fasten the optical fiber holding member 32 and the optical fiber connector 54, any of those known in the art can be used.
In one embodiment, as shown in FIG. 5, as the fastening member 51, one having a base portion 55 and a locking portion 57 having a spring portion at the tip can be used. The fastening member 51 can be detachably attached to, for example, an optical fiber connector provided with a flange portion that spreads outward in the radial direction.

The base portion 55 supports the optical fiber connector, and has a slit 55a in a plate-like member. The slit 55 a is preferably smaller in diameter than the flange portion 50 a of the optical fiber connector 54 and larger in diameter than the optical fiber connector 54.
The locking portion 57 is a portion bent from the base portion 55. For example, the locking portion 57 is disposed in a pair, and has a spring portion 57a at the tip thereof. The spring portion 57a is preferably inclined further inward than the inclination of the locking portion 57 so as to exert the function of a plate spring. In order to facilitate the engagement with the optical fiber holding member 32, the tip end of the spring portion 57a is preferably bent outward.

  The base 55 preferably further has a hook 56 for fixing the optical fiber connector, which can support and press the support member 50. The claw portion 56 has a bending portion 56a bent from the base portion 55, and the bending portion 56a has a ridge portion 56b whose tip is further bent from the bending portion 56a. The bent portion 56a is preferably wider than the claws 56, and preferably wider than the diameter of the optical fiber connector to be supported. It is preferable that the collar portion 56b extends in the vertical direction with respect to the bending portion 56a. When the flange portion 50a of the optical fiber connector 54 has the recess 50b on the surface, the flange portion 56b can be engaged with the recess 50b, and the fastening member 51 can be firmly fastened to the optical fiber connector 54 it can.

  As described above, by providing the light emitting device of this embodiment, it is possible to easily and reliably control the optical fiber incident angle in the light emitting device, and as a result, the divergence angle of the light emitted from the optical fiber emitting end can be obtained. It becomes possible to control accurately. For this purpose, a part of the light emitted from the laser device 10, that is, the component of the incident angle of the optical fiber outside the specified range is removed, and the problem is brought about by the increase in the output of the laser element in the recent laser device. It becomes possible to set the lateral magnification M to a smaller value.

  The light emitting device of the present invention includes various display devices, lighting devices, displays, back light sources of liquid crystal displays, image reading devices such as copiers and scanners, projector devices, laser displays, endoscopes, headlights for vehicles. And bar code scanner etc. can be used suitably.

Reference Signs List 1 laser element 2 package 2A base 2B cap 3 submount 5 lead 10 laser device 20 lens with lens barrel 20a lens barrel 20b lens 30 spacer 30a aperture 31 holding member 32 optical fiber holding member 40 light emitting device 50 support member 50a ridge 50b recess 51 Fastening member 52 Optical fiber 53 Ferrule 54 Optical fiber connector 55 Base 55a Slit 56 Claw 56a Bend 56b Flange 57 Locking part 57a Spring Q Light entrance surface X Light exit side principal point Y Light entrance side principal point Z Light exit surface

Claims (7)

Laser device,
A lens with a lens barrel disposed on the light emission side of the laser device;
A spacer, which is disposed between the laser device and the lens with a lens barrel, is disposed in contact with the laser device and the lens with a lens barrel, and has an aperture that allows only part of the light emitted from the laser device to pass.
A light emitting device comprising: the laser device; a holding member holding the spacer and the lens with a lens barrel; and an optical fiber holding member disposed at one end of the holding member.   When the distance from the light emission surface of the laser device to the light incident side principal point of the lens is L1, and the distance from the light emission side principal point of the lens to the inside of the optical fiber holding member is L2, L2 is greater than L1 The light emitting device according to claim 1, wherein the light emitting device is set to a large value.   The light emitting device according to claim 2, wherein the optical lateral magnification M of the light emitting device is represented by L2 / L1 and the value is 3.5 or less.   The light incident angle θ1 to the light incident side principal point of the lens of the light emitted from the laser device after passing through the aperture is set to a value smaller than 20 ° in a cross sectional view. Light emitting device.   The light emitting device according to claim 3, wherein a light incident angle θ2 from the light emitting side principal point of the lens into the optical fiber holding member is set to a value smaller than the θ1 in a cross sectional view.   The light emitting device according to claim 4, wherein the optical lateral magnification M of the light emitting device is represented by θ1 / θ2, and the value is 3.5 or less.   The aperture of the spacer is set such that the light incident angle θ1 of the light emitted from the laser device to the light incident side principal point of the lens is a value smaller than 20 ° in a cross sectional view The light-emitting device according to any one of Items 1 to 6.