CN218513862U - Optical device, light source device, and fiber laser - Google Patents

Abstract

The utility model provides an optical device, light source device and fiber laser. For example, an optical device, a light source device, and a fiber laser having more improved and new configurations can be obtained, in which problems due to temperature increases of optical components can be suppressed. The optical device includes, for example: a base; a plurality of light emitting elements provided on the base and outputting laser light; and a plurality of optical members provided on the base and transmitting the laser light output from the light emitting element to the optical fiber, the plurality of optical members including: a first condenser lens that condenses laser light from the plurality of light emitting elements toward an end of the optical fiber; and a second condenser lens for condensing the laser beams from the plurality of light emitting elements toward the first condenser lens, wherein the first condenser lens and the second condenser lens are made of synthetic quartz, and an intermediate member having a thermal expansion coefficient of a value between that of the synthetic quartz and that of the base is provided between the first condenser lens and the base, and between the second condenser lens and the base.

Description

Optical device, light source device, and fiber laser

Technical Field

The utility model relates to an optical device, light source device and fiber laser.

Background

Conventionally, an optical device is known in which laser light output from a plurality of light emitting elements is guided to an end portion of an optical fiber via a plurality of optical members (for example, patent document 1). In the optical device of patent document 1, a plurality of light emitting elements and a plurality of optical components are mounted on a base having heat dissipation properties.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2017/134911

In such an optical device, in order to guide a plurality of laser beams to an end portion of one optical fiber, particularly, in an optical component on the side closer to the end portion of the optical fiber, the temperature rise due to absorption of the laser beams tends to increase as the energy density increases. If the difference in thermal expansion between the optical member and the base is too large due to such a temperature rise of the optical member, a problem such as the optical member being displaced from the base may occur.

SUMMERY OF THE UTILITY MODEL

Therefore, an object of the present invention is to provide an optical device, a light source device, and a fiber laser having a more improved and new configuration, which can suppress a problem caused by a temperature rise of an optical member.

The utility model discloses an optical device possesses for example: a base; a plurality of light emitting elements provided on the base and outputting laser light; and a plurality of optical members provided on the base and transmitting the laser light output from the light emitting element to an optical fiber, the plurality of optical members including: a first condenser lens that condenses the laser light from the plurality of light emitting elements toward an end of the optical fiber; and a second condenser lens that condenses the laser light from the plurality of light emitting elements to the first condenser lens, wherein the first condenser lens and the second condenser lens are made of synthetic quartz, and an intermediate member having a thermal expansion coefficient that is a value between a thermal expansion coefficient of the synthetic quartz and a thermal expansion coefficient of the base is provided between the first condenser lens and the base, and between the second condenser lens and the base.

In the optical device, the first condenser lens and the second condenser lens may be fixed to the intermediate member via an adhesive, respectively.

The optical device may further include a first intermediate member interposed between the first condenser lens and the base as the intermediate member.

The optical device may include: and an end cap integrated with an end portion of the optical fiber and having an end surface with an area larger than a cross-sectional area of the optical fiber, wherein the first intermediate member is a first support member provided on the base and supporting the optical fiber, the end cap, and the first condenser lens.

The optical device may include: and a second supporting member provided on the base and supporting the optical fiber, wherein the first intermediate member is interposed between the second supporting member and the first condensing lens.

The optical device may further include a second intermediate member interposed between the second condenser lens and the base as the intermediate member.

The optical device may further include a third intermediate member interposed between the first and second condenser lenses and the base, as the intermediate member.

The optical device may include: and an end cap integrated with an end portion of the optical fiber and having an end surface with an area larger than a cross-sectional area of the optical fiber, wherein the third intermediate member is a third support member provided in the base and supporting the optical fiber, the end cap, the first condenser lens, and the second condenser lens.

In the optical device, a difference between a thermal expansion coefficient of the synthetic quartz and a thermal expansion coefficient of the intermediate member may be 11 × 10 ^-6 [1/K]The following.

In the optical device, a difference between a coefficient of thermal expansion of the intermediate member and a coefficient of thermal expansion of the mount may be 11 × 10 ^-6 [1/K]The following.

In the optical device, the wavelength of the laser light may be 400[ 2 ] or more and 520[ nm ] or less.

In the optical device, the first condenser lens and the second condenser lens may have an absorptance of 0.1[% ] or less with respect to the laser light.

In the optical device, the light output from the optical fiber may be 100[ W ] or more.

In the optical device, the material constituting the intermediate member may have a lower absorptivity for light having a wavelength of from 400[ nm ] to 520[ nm ] than the material constituting the base.

In the optical device, the intermediate member may be made of a copper-tungsten alloy or aluminum oxide.

The utility model discloses an optical device possesses for example: a base; a plurality of light emitting elements provided on the base and outputting laser light; and a plurality of optical members provided on the base and transmitting the laser light output from the light emitting element to an optical fiber, the plurality of optical members including: and a condensing lens that condenses the laser light from the plurality of light emitting elements, wherein an intermediate member having a thermal expansion coefficient of a value between that of the condensing lens and that of the base is provided between the condensing lens and the base.

In the optical device, the condenser lens may be fixed to the intermediate member via an adhesive.

The optical device may include: a cooling mechanism that cools the intermediate member.

Further, the light source device of the present invention includes the optical device, for example.

Furthermore, the present invention provides a fiber laser, for example, comprising: the light source device; and a light amplification fiber amplifying the laser light output from the light source device.

Effect of the utility model

According to the utility model discloses, can obtain the optical device, light source device and the fiber laser who possesses the new structure of more improving.

Drawings

Fig. 1 is an exemplary and schematic top view of an optical device of embodiment 1.

Fig. 2 is an exemplary and schematic top view of a light emitting module included in the optical device of embodiment 1.

Fig. 3 is an exemplary and schematic perspective view of a mount included in the optical device of embodiment 1.

Fig. 4 is an exemplary and schematic perspective view of a support structure included in the optical device of embodiment 1.

Fig. 5 is an exemplary and schematic top view of an optical fiber and an end cap included in the optical device of embodiment 1.

FIG. 6 shows B contained in the material of the lens contained in the optical device of embodiment 1 ₂ O ₃ A graph showing an example of the correlation between the content of (b) and the temperature of the lens.

Fig. 7 is an exemplary and schematic perspective view of a support structure included in the optical device of embodiment 2.

Fig. 8 is an exemplary and schematic top view of the optical device of embodiment 3.

Fig. 9 is an exemplary and schematic side view of a subassembly included in the optical device of embodiment 3.

Fig. 10 is an exemplary and schematic top view of the optical device of embodiment 4.

Fig. 11 is an exemplary schematic configuration diagram of the light source device according to embodiment 5.

Fig. 12 is an exemplary schematic configuration diagram of the fiber laser according to embodiment 6.

Description of reference numerals

10

20 \ 8230and casing

21 \ 8230and bottom wall

22 \ 8230and front wall

22a (8230); opening part

23-8230and window member

Sub-assembly

A heat sink

Metallization layer

32 method 8230and luminous element

32a 8230and exit surface

41C

41a (8230); incident surface

41b 8230and exit surface

42A, 42C

42a 8230and incident surface

42b 8230and an emergent surface

43A, 43C

43a 8230and incident surface

43b 8230and exit surface

100. 100A-100D 8230and optical device

100a, 100a1, 100a2

A base plate

101b 8230and surface

101b1 (8230); step difference

Mirror (optical component)

A condenser lens (second condenser lens, optical component)

Condenser lens (first condenser lens, optical component)

108% -8230a light synthesis part

Combiner (first optical component, optical component)

108b

108c.. 1/2 wavelength plate (first optical component, optical component)

109 \ 8230and refrigerant channel

109a (8230)

109b (8230); outlet

110 \ 8230and supporting structure

111A-111C 8230and supporting member

111a (8230); noodles

111b (8230); noodles

A cover member

End cap

113a1 (8230); end face

113b 8230and a protrusion

114

116 \ 8230and fixing tool

120. optical fiber

120a 8230and stripped end

120a1 \8230afront end

121 \ 8230and core wire

130A1 (8230); intermediate member (first intermediate member)

130A2 (8230); intermediate member (second intermediate member)

130B 8230a middle component (second middle component)

130C 8230a middle component (third middle component)

140, 8230and a container

Combiner 200

300

310. 320 \ 8230and high reflection FBG

Rare earth-doped optical fiber

Output side optical fiber

1000 of 8230a light source device

Ax (8230); central shaft

A1, a2

Laser

Pcz 8230and convergence point

Pth 823060 threshold value

R8230and accommodating chamber

Tth 823060 threshold value

Vc2 \8230andvirtual central plane

Beam width (in the Z direction)

Wzc. (collimated in Z direction) beam width

X1 (8230); direction

X2 (8230); direction

Y8230j Direction

Z \8230direction

Detailed Description

Exemplary embodiments of the present invention are disclosed below. The structure of the embodiment described below and the operation and result (effect) of the structure are examples. The present invention can be realized by other than the structure disclosed in the following embodiments. Further, according to the present invention, at least one of various effects (including a derivative effect) obtained by the structure can be obtained.

The embodiments described below have the same configuration. Therefore, according to the configurations of the respective embodiments, the same operation and effect can be obtained by the same configuration. In the following, the same reference numerals are given to the same components, and redundant description thereof may be omitted.

In the present specification, ordinal numbers do not indicate priority or order for distinguishing members, portions, and the like and for convenience of assignment.

In each figure, the X1 direction is represented by an arrow X1, the X2 direction is represented by an arrow X2, the Y direction is represented by an arrow Y, and the Z direction is represented by an arrow Z. The X1 direction, the Y direction, and the Z direction intersect and are orthogonal to each other. Further, the X1 direction and the X2 direction are opposite directions to each other.

In fig. 1 and 8 to 10, the optical path of the laser beam L is shown by solid arrows.

[ 1 st embodiment ]

Fig. 1 is a schematic configuration diagram of an optical device 100A (100) according to embodiment 1, and is a plan view of the inside of the optical device 100A viewed in a direction opposite to the Z direction.

As shown in fig. 1, the optical device 100A includes a base 101, a plurality of subassemblies 100A, a light combining unit 108, condenser lenses 104 and 105, and an optical fiber 120. The laser light output from the light emitting module 10 of each sub-assembly 100a is transmitted to an end portion (not shown) of the optical fiber 120 via the mirror 103, the light combining section 108, and the condenser lenses 104 and 105 of each sub-assembly 100a, and is optically coupled to the optical fiber 120. The optical device 100A can also be referred to as a light emitting device.

The base 101 is made of a material having high thermal conductivity, such as a copper-based material or an aluminum-based material. The base 101 may be formed of one member or may be formed of a plurality of members. Further, the base 101 is covered by a cover member (not shown). The plurality of subassemblies 100a, the plurality of mirrors 103, the light combining unit 108, the condenser lenses 104 and 105, and the end portions of the optical fibers 120 are all provided on the base 101, and are accommodated in an accommodating chamber (not shown) formed between the base 101 and the cover. In the present embodiment, the storage chamber is hermetically sealed, but the storage chamber is not limited thereto.

The optical fiber 120 is an output optical fiber and is fixed to the base 101 via a support structure 110 that supports the end thereof. The light output from the optical fiber 120 is, for example, 100[ W ] or more.

The sub-assembly 100a (100 a1, 100a 2) has the light emitting module 10, a lens 43A, and a mirror 103. The lens 43A collimates the laser light of the light emitting module 10 in the Y direction, i.e., in the slow axis.

Fig. 2 is a plan view showing the light emitting module 10. As shown in fig. 2, the light-emitting module 10 has a sub-assembly 30. In fig. 1 and 2, the optical axis of the laser beam is indicated by a dashed line Ax.

The sub-assembly 30 has a heat sink (Submount) 31, a light emitting element 32, and a lens 42A.

The heat sink 31 has a flat rectangular parallelepiped shape that is thin in the Z direction, for example. The heat sink 31 is made of an insulating material such as aluminum nitride (AIN), ceramic, or glass. Further, the material may be made of silicon carbide, diamond, or the like having relatively high thermal conductivity. A metallized layer 31a is formed on the heat sink 31 as an electrode for supplying power to the light emitting element 32.

The light emitting element 32 is, for example, a semiconductor laser element having a Fast Axis (FA) and a Slow Axis (SA) and having an output of 5[ W ] or more. The light emitting element 32 extends in the X1 direction. The light emitting element 32 emits laser light in the X direction from an emission opening (not shown) provided in an emission surface 32a located at an end in the X1 direction orthogonal to the Z direction. In the present embodiment, the fast axis of the light emitting element 32 is along the Z direction, and the slow axis is along the Y direction. Further, the light emitting element 32 outputs laser light of, for example, 400[ 2 ] or more and 520[ nm ] or less.

The lens 42A is attached to an end surface of the heat sink 31 in the X1 direction, and is disposed adjacent to the emission surface 32A of the light emitting element 32 in the X1 direction. The lens 42A refracts and transmits the laser light from the light emitting element 32. The laser light emitted from the light emitting element 32 and transmitted through the lens 42A is directed in the X direction. The lens 42A is, for example, a collimator lens, and collimates the laser light on the fast axis. The lens 42A is an example of an optical member that transmits the laser light from the light emitting module 10 to the optical fiber 120.

Furthermore, the light emitting module 10 may have a housing 20. In the example shown in fig. 2, the housing 20 of the light emitting module 10 is partially broken, and the structure of the inside of the light emitting module 10 is shown. In the example shown in fig. 2, the heat sink 31 is attached to the bottom wall 21 of the case 20, and the light emitting element 32 is provided on the base 101 via the case 20 and the heat sink 31. Further, the lens 42A is provided on the base 101 via the case 20 and the heat sink 31.

The housing 20 has a box-like shape, which can also be referred to as a cabinet. The housing 20 forms a housing chamber R therein. The housing 20 accommodates the sub-assembly 30 in the accommodation chamber R. The housing 20 hermetically seals the housing chamber R, thereby preventing liquid, gas, dust, and the like from acting on the sub-assembly 30 from outside the housing 20. Further, the storage chamber R is filled with, for example, inert gas or dry air.

The case 20 is made of a copper material such as copper or a copper alloy.

The bottom wall 21 of the case 20 is made of a copper material such as copper or a copper alloy, and is located at an end of the case 20 opposite to the Z direction. The bottom wall 21 intersects the Z direction and extends in the X direction and the Y direction. The bottom wall 21 has a quadrangular and plate-like shape.

The bottom wall 21 of the housing 20 is preferably made of a material having high thermal conductivity, and therefore can be made of a material different from the other parts of the housing 20. More specifically, for example, the bottom wall 21 may be made of a copper material having high thermal conductivity, such as copper or a copper alloy, and the side wall and the lid (not shown) of the case 20 may be made of another material, such as an iron-nickel-cobalt alloy.

A front wall 22 of one of the side walls of the housing 20 is located at an end of the housing 20 in the X1 direction. The front wall 22 intersects the X1 direction and extends in the Y direction and the Z direction. The front wall 22 has a quadrangular and plate-like shape.

The front wall 22 is provided with an opening 22a. The window member 23 is fitted into the opening 22a. The window member 23 has a property of transmitting laser light. That is, the window member 23 is transparent to the laser light emitted from the light emitting element 32.

Fig. 3 is a perspective view of the base 101. As shown in fig. 3, on the front surface 101b of the base 101, a plurality of steps 101b1 are provided in which the position of the subassembly 100a is shifted in the direction opposite to the Z direction as it goes in the Y direction. With respect to each of the arrays A1, A2 in which a plurality of subassemblies 100a are arranged at given intervals (e.g., fixed intervals) in the Y direction, the subassemblies 100a are arranged on the respective step differences 101b1. Thus, the position of the sub-assembly 100a included in the array A1 in the Z direction is deviated in the opposite direction to the Z direction as going to the Y direction, and the position of the sub-assembly 100a included in the array A2 in the Z direction is also deviated in the opposite direction to the Z direction as going to the Y direction. With such a configuration, in each of the arrays A1 and A2, laser beams parallel to each other, which travel in the Y direction and are aligned in the Z direction, can be input to the optical combining section 108 from the plurality of mirrors 103. The step 101b1 is offset in a direction inclined in the Y direction or the opposite direction to the Y direction with respect to the Z direction, and the laser light advances from each mirror 103 in a direction having a predetermined angle of elevation with respect to the Y direction.

As shown in fig. 1, the laser beams from the mirrors 103 are input to the light combining unit 108, and combined in the light combining unit 108. The optical combiner 108 includes a combiner 108a, a mirror 108b, and a 1/2 wavelength plate 108c.

The mirror 103, the combiner 108a, the mirror 108b, and the 1/2 wavelength plate 108c are examples of optical components that transmit laser light from the light emitting module 10 to the optical fiber 120. These optical components are provided on the base 101 directly or indirectly via another member.

The mirror 108b causes the laser light from the sub-assembly 100a of the array A1 to travel to the combiner 108a via the 1/2 wavelength plate 108c. The 1/2 wavelength plate 108c rotates the plane of polarization of the light from array A1.

On the other hand, the laser light from the sub-assembly 100a of the array A2 is directly input to the combiner 108a.

The combiner 108a combines the lasers from the two arrays A1, A2. The combiner 108a is also referred to as a polarization combining element.

The laser light from the combiner 108a is condensed by the condenser lenses 104 and 105 to the end (not shown) of the optical fiber 120, optically coupled to the optical fiber 120, and transmitted through the optical fiber 120. The condenser lens 104 condenses the laser beam on the fast axis toward the condenser lens 105. The condenser lens 105 condenses the laser light on the slow axis toward an end portion (end cap, not shown) of the optical fiber 120. The condenser lenses 104 and 105 are examples of optical members for transmitting the laser light from the light emitting module 10 to the optical fiber 120. The condenser lens 104 is an example of a second condenser lens, and the condenser lens 105 is an example of a first condenser lens.

The base 101 is provided with a cooling medium passage 109 for cooling the sub-assembly 100a (light emitting module 10), the support structure 110 (support member 111A), the condenser lenses 104 and 105, the combiner 108a, the intermediate members 130A1 and 130A2, and the like. A refrigerant such as a coolant flows through the refrigerant passage 109. The cooling medium passage 109 passes through, for example, the vicinity of, for example, the mounting surface of each component of the base 101, for example, directly below or in the vicinity thereof, and the inner surface of the cooling medium passage 109 and the cooling medium (not shown) in the cooling medium passage 109 are thermally connected to the component or portion to be cooled, that is, the sub-assembly 100a, the support structure 110, the condenser lenses 104 and 105, the coupling 108a, the intermediate members 130A1 and 130A2, and the like. Heat exchange is performed between the refrigerant and the component or portion via the base 101, thereby cooling the component. The inlet 109a and the outlet 109b of the refrigerant passage 109 are provided at the opposite ends of the base 101 in the Y direction, for example, but may be provided at other positions. The refrigerant passage 109 constitutes a cooling mechanism together with a pump and a valve of the refrigerant, a controller of the pump and the valve, and the like.

As shown in fig. 1 and 3, a support member 111A for supporting the structure 110 is provided on the front surface 101b of the base 101. The support member 111A is fixed to the base 101, and supports the optical fiber 120, the condenser lens 105, and the like. In other words, the support member 111A is interposed between the base 101 and optical components such as the optical fiber 120 and the condenser lens 105. The support member 111A is an intermediate member 130A1, and is an example of a first support member and a first intermediate member.

Fig. 4 is a perspective view of the support structure 110. As shown in fig. 4, the support structure 110 includes a support member 111A, a cover 112, and a holder 114, and supports the optical fiber 120, the end cap 113, and the condenser lens 105.

The support member 111A has a rectangular parallelepiped shape with a catch in the Y direction, and supports the optical fiber 120 extending in the Y direction. The support member 111A has a surface 111A facing the opposite direction of the Z direction and a surface 111b facing the Z direction.

The cover 112 intersects and is orthogonal to the Z-direction. The cover 112 has a rectangular and plate-like shape, and is short in the X1 and X2 directions, long in the Y direction, and thin in the Z direction.

Both the support member 111A and the cover 112 are made of a material having high thermal conductivity.

The optical fiber 120 is provided between the support member 111A and the cover 112, and is partially housed in a housing chamber 140 extending in the X direction. A light processing mechanism for processing the leakage light from the optical fiber 120 may be provided in the housing chamber 140.

The cover 112 is fixed to the support member 111A by a fixing tool 116 such as a screw. The optical fiber 120 is supported by the support member 111A and the cover 112.

The end cap 113 is surrounded by the support member 111A and the retainer 114 on the opposite side of the support member 111A. The anchor 114 is attached to the support member 111A with a fastener 116 such as a screw in a state where the end cap 113 is interposed between the anchor and the support member 111A. The end cap 113 is integrated with the stripped end 120a (core wire 121) of the optical fiber 120 by fusion bonding or the like, for example.

The condenser lens 105 is fixed to the surface 111b of the support member 111A by a bonding material (not shown) such as an adhesive. Examples of the bonding material include an electromagnetic wave curable adhesive, a thermosetting adhesive, and a moisture curable adhesive.

Fig. 5 is a plan view showing the leading end of the optical fiber 120 and the end cap 113. In fig. 5, the optical path of the laser light L from the end cap 113 to the distal end 120a1 of the core wire 121 of the optical fiber 120 is shown by a broken line. If the laser light condensed by the condenser lens 105 or the like reaches the tip 120a1 of the peeling end portion 120a in the configuration without the end cap 113, the power density is excessively increased as the beam diameter becomes smaller at the tip 120a1 serving as the interface, and an excessive temperature rise is generated, and the tip 120a1 may be damaged. In this regard, in the present embodiment, the laser beam L reaches the end face 113a1 of the end cap 113 having an area larger than the distal end 120a1, that is, an area larger than the cross-sectional area of the optical fiber 120 in a state of a larger beam diameter and a smaller power density, and thus, excessive temperature rise can be suppressed at both the end face 113a1 which is an interface and the distal end 120a1 of the core wire 121, and damage can be suppressed. End cap 113 can also be referred to as a moderator member.

In addition, an AR (anti reflection) coating is applied to an end surface 113a1 of the end cap 113 opposite to the protrusion 113 b. Thereby, reflection of light in the end face 113a1 is suppressed.

As shown in fig. 1 and 3, an intermediate member 130A2 is provided on the surface 101b of the base 101. The intermediate member 130A2 is fixed to the base 101 and supports the condenser lens 104. In other words, the intermediate member 130A2 is interposed between the base 101 and the condenser lens 104 as an optical component. The intermediate member 130A2 is fixed to the base 101 by bonding, welding, or the like with a bonding material such as solder, brazing material, or adhesive. The condenser lens 104 is fixed to the intermediate member 130A2 by a bonding material (not shown) such as an adhesive, for example. Examples of the bonding material include an electromagnetic wave curable adhesive, a thermosetting adhesive, and a moisture curable adhesive. The intermediate member 130A2 is an example of a second intermediate member.

The condenser lenses 104 and 105 are made of, for example, synthetic quartz. Synthetic quartz has low laser absorptivity. Therefore, by forming the condenser lenses 104 and 105 from synthetic quartz, the temperature rise of the condenser lenses 104 and 105 due to the absorption of laser light is suppressed. From such a viewpoint, the absorptance of the condenser lenses 104 and 105 to laser light having a wavelength of 400[ nm ] or more and 520[ nm ] or less is preferably 0.1[% ] or less.

The inventors conducted experiments to install boron oxide (B) in each of the optical devices 100A ₂ O ₃ ) Light-collecting member made of materials having different content ratios (mass content ratios)The lens 105 was irradiated with laser light, and optical characteristics such as temperature and light output of the condenser lens 105 in each case were measured. Fig. 6 is a graph showing a correlation between the content of boron oxide and the maximum temperature of the condenser lens 105. The abscissa of the graph represents boron oxide (B) in the condenser lens 105 ₂ O ₃ ) Mass content (mass [% ])]) The vertical axis represents the temperature of the condenser lens 105 [ deg.C ]]. In this experiment, the wavelength of the laser was 465[ nm ]]The sum of the power of the laser light is 220[ W ]]. As is clear from fig. 6, the higher the content of boron oxide, the higher the temperature of the condenser lens 105.

As a result of this experiment, in the optical device 100A, the threshold value Tth (maximum temperature) of the temperature of the condenser lens 105, at which the optical characteristics are within the desired range, is 57[ ° c ], and the threshold value Pth (maximum content) of the mass content of boron oxide corresponding to the threshold value Tth is 2[% ]. That is, it can be seen that the mass content of boron oxide in the material of the condenser lenses 104 and 105 is preferably 2[% ] (mass [% ]) or less.

In the above configuration, it is preferable that the intermediate member 130A1 is made of a material having a thermal expansion coefficient between the thermal expansion coefficient of the condenser lens 105 and the thermal expansion coefficient of the base 101, and the intermediate member 130A2 is made of a material having a thermal expansion coefficient between the thermal expansion coefficient of the condenser lens 104 and the thermal expansion coefficient of the base 101. If the condenser lenses 104 and 105 are directly attached to the base 101, the difference in volume change due to temperature change between the condenser lenses 104 and 105 and the base 101 becomes large due to the difference between the coefficient of thermal expansion of the base 101 made of, for example, copper-based metal and the coefficient of thermal expansion of the condenser lenses 104 and 105 made of, for example, synthetic quartz. If the difference in volume change exceeds a range in which the bonded state of the adhesive for fixing the condenser lenses 104 and 105 to the base 101 can be maintained, for example, the condenser lenses 104 and 105 may be displaced from the base 101, tilted, and come off, and desired optical characteristics may not be obtained in the optical device 100A. In this regard, in the present embodiment, since the condenser lenses 104 and 105 are fixed to the base 101 via the intermediate members 130A1 and 130A2, the difference in volume change due to temperature change can be made smaller between the condenser lenses 104 and 105 and the intermediate members 130A1 and 130A2, and the difference in volume change due to temperature change can be made smaller between the intermediate members 130A1 and 130A2 and the base 101. Therefore, the fixed state of the condenser lenses 104 and 105 via the intermediate members 130A1 and 130A2 by the base 101 can be easily maintained in a desired state, and further, it is possible to suppress a situation in which desired optical characteristics cannot be obtained in the optical device 100A due to changes in the relative positions and postures of the condenser lenses 104 and 105 with respect to the base 101.

As the material of the intermediate members 130A1 and 130A2, for example, a copper-tungsten alloy (for example, an alloy containing Cu in an amount of about 10 to 20[% ] by mass), alumina, or the like is preferable. In order to suppress heat generation due to stray light (leakage light) in the optical device 100A, the intermediate members 130A1 and 130A2 are preferably made of a material having a lower absorptivity of laser light having a wavelength of 400[ nm ] or more and 520[ nm ] or less than that of the material (copper in the present embodiment) constituting the base 101.

Further, the inventors have made extensive studies and confirmed that: when the difference between the thermal expansion coefficient of the condenser lens 104 made of synthetic quartz and the thermal expansion coefficient of the intermediate member 130A2, the difference between the thermal expansion coefficient of the condenser lens 105 made of synthetic quartz and the thermal expansion coefficient of the intermediate member 130A1, the difference between the thermal expansion coefficient of the intermediate member 130A2 and the thermal expansion coefficient of the base 101, and the difference between the thermal expansion coefficient of the intermediate member 130A1 and the thermal expansion coefficient of the base 101 are all 11 × 10 ^-6 [1/K]Hereinafter, desired reliability can be secured with respect to the fixed state of the condenser lenses 104 and 105 with respect to the base 101, and deterioration of the optical characteristics of the optical device 100A due to deviation of the positions and postures of the condenser lenses 104 and 105 does not occur or is reduced to a level that does not become a problem.

As described above, in the present embodiment, the condenser lenses 104 and 105 are made of synthetic quartz. Since the condenser lenses 104, 105 are inputted with a plurality of laser lights, and particularly the condenser lens 105 is inputted with the light condensed from the condenser lens 104, the laser lights are inputted with a relatively high energy density. For this reason, the temperature of the condenser lenses 104 and 105, particularly the condenser lens 105, is more likely to rise than that of the optical components other than the end cap 113. If an excessive temperature rise occurs in the condenser lenses 104 and 105, the reliability of the fixed state of the condenser lenses 104 and 105 to the base 101 may be reduced, and the reliability of the optical characteristics of the optical device 100A may be reduced accordingly. In this regard, in the present embodiment, since the condenser lenses 104 and 105 are made of synthetic quartz having a low laser light absorptance, excessive temperature rise of the condenser lenses 104 and 105 can be suppressed, and thus a decrease in reliability of the fixed state of the condenser lenses 104 and 105 to the base 101 and a decrease in reliability of the optical characteristics of the optical device 100A associated therewith can be suppressed.

In the present embodiment, the condenser lenses 104 and 105 are fixed to the base 101 via the intermediate members 130A1 and 130A2, and the thermal expansion coefficients of the intermediate members 130A1 and 130A2 are values between the thermal expansion coefficients of the condenser lenses 104 and 105 and the thermal expansion coefficient of the base 101. With such a configuration, it is easier to maintain a desired fixed state of the condenser lenses 104 and 105, compared to a case where the condenser lenses 104 and 105 are directly fixed to the base 101.

[ 2 nd embodiment ]

Fig. 7 is a perspective view of the support structure 110 of embodiment 2. The optical device 100B (100) of the present embodiment has the same configuration as the optical device 100A of embodiment 1, except that the support structure 110 is different.

In the support structure 110 of the present embodiment, the plate-shaped intermediate member 130B is interposed between the support member 111B and the condenser lens 105. Intermediate member 130B is not present between support member 111B and end cap 113. In the present embodiment, the intermediate member 130B is also made of a material having a thermal expansion coefficient between the thermal expansion coefficient of the condenser lens 105 and the thermal expansion coefficient of the base 101, and specifically made of copper-tungsten alloy or alumina. In the optical device 100B having such a configuration, the intermediate member 130B is provided between the base 101 and the condenser lens 105, whereby the same effects as those of embodiment 1 can be obtained. The intermediate member 130B is an example of a first intermediate member, and the support member 111B is an example of a second support member.

The thermal expansion coefficient of the support member 111B may be a value between that of the base 101 and that of the intermediate member 130B, or may be a value close to or equal to that of the base 101. The support member 111B may be formed as a member separate from the base 101 and fixed to the base 101, or may be a part of the base 101.

[ embodiment 3 ]

Fig. 8 is a plan view of the optical device 100C according to embodiment 3. In an optical device 100C of the present embodiment, the structure of a subassembly 100a is different from that of embodiment 1, and the structure of a support structure 110 is different from that of embodiment 1. Except for these, the optical device 100C has the same configuration as the optical device 100A of embodiment 1 described above.

Fig. 9 is a side view showing the structure of the subassembly 100a1 (100 a). As shown in fig. 9, in the sub-assembly 100a1, the laser light L output from the light emitting element 32 passes through the lens 41C, the lens 42C, and the lens 43C in this order, and is collimated at least in the Z direction and the Y direction. The lens 41C, the lens 42C, and the lens 43C are all provided outside the housing 20.

In the present embodiment, the lens 41C, the lens 42C, and the lens 43C are arranged in this order in the X1 direction. The laser light L output from the light emitting element 32 passes through the lens 41C, the lens 42C, and the lens 43C in this order. The optical axis of the laser light L is linear, the fast axis direction of the laser light L is along the Z direction, and the slow axis direction of the laser light L is along the Y direction, between the light emitted from the light emitting element 32 and passing through the lens 41C, the lens 42C, and the lens 43C.

The lens 41C is slightly spaced from the window member 23 in the X1 direction, or is in contact with the window member 23 in the X1 direction. The lens 41C may be fixed to the housing 20 via an adhesive or the like.

The laser light L passing through the window member 23 is incident on the lens 41C. The lens 41C is a lens having an axially symmetric shape with respect to a central axis Ax along the optical axis, and is configured as a rotating body around the central axis Ax. The lens 41C is disposed such that the central axis Ax is along the X1 direction and overlaps the optical axis of the laser light L. The incident surface 41a and the emission surface 41b of the lens 41C each have a rotation surface around the central axis Ax extending in the X1 direction. The emission surface 41b is a convex curved surface convex in the X1 direction. The emission surface 41b protrudes more than the incident surface 41 a. The lens 41C is a so-called convex lens.

The beam width of the laser beam L emitted from the lens 41C becomes narrower as it goes in the X1 direction. The beam width is a width of a region in which the light intensity is equal to or higher than a predetermined value in the beam profile of the laser beam. The given value being, for example, 1/e of the light intensity of the peak ² . The lens 41C focuses the laser light L in the Z direction, the Y direction, and a direction between the Z direction and the Y direction, and therefore, an effect of reducing aberration of the laser light L can be obtained.

The lens 42C has a plane-symmetric shape with respect to a virtual center plane Vc2 which is a plane intersecting and orthogonal to the Z direction. The incident surface 42a and the exit surface 42b of the lens 42C have generatrices along the Y direction, and have cylindrical surfaces extending in the Y direction. The incident surface 42a is a convex curved surface that is convex in the direction opposite to the X1 direction. The emission surface 42b is a concave curved surface that is concave in the X1 direction.

The lens 42C collimates the laser light L in the Z direction, i.e., the fast axis, in a state where the beam width Wzc in the Z direction is smaller than the beam width Wza in the Z direction on the incident surface 41a of the lens 41C. The lens 42C is a concave lens in a cross section orthogonal to the Y direction. Lens 42C can also be referred to as a collimating lens.

The lens 42C is disposed closer to the lens 41C than a convergence point Pcz of the laser light L in the Z direction by the lens 41C. Assuming that the lens 42C is disposed farther away from the lens 41C than the convergence point Pcz in the Z direction, the convergence point Pcz in the Z direction appears on the optical path of the laser light L between the lens 41C and the lens 42C. In this case, there is a possibility that dust may accumulate at the accumulation point Pcz in the Z direction where the energy density is high. In this regard, in the present embodiment, since the lens 42C is located closer to the lens 41C than the convergence point Pcz in the Z direction, the laser light L is collimated by the lens 42C before reaching the convergence point Pcz. That is, according to the present embodiment, since the convergence point Pcz in the Z direction does not appear on the optical path of the laser light L, a problem caused by the convergence point Pcz can be avoided.

Further, although a convergence point (not shown) of the laser light L in the Y direction is present between the lens 41C and the lens 42C, the energy density at the convergence point in the Y direction is not so high, and there is no problem of dust accumulation.

The beam width of the laser light L in the Y direction, which is output from the light emitting element 32 and passes through the lens 41C and the lens 42C, increases as it goes in the X1 direction. The laser light L having a thick tip and expanded in the Y direction through the lens 42C enters the lens 43C.

The lens 43C has a plane-symmetrical shape with respect to a virtual center plane which is a plane intersecting and orthogonal to the Y direction. The incident surface 43a and the exit surface 43b of the lens 43C have generatrices along the Z direction, and have cylindrical surfaces extending in the Z direction. The incident surface 43a is a plane orthogonal to the X1 direction. The emission surface 43b is a convex curved surface convex in the X1 direction.

The lens 43C collimates the laser light L in the Y direction, i.e., the slow axis. The lens 43C is a convex lens in a cross section orthogonal to the Z direction. The lens 43C can also be referred to as a collimating lens.

In the present embodiment, as shown in fig. 8, the support member 111C supports the condenser lenses 104 and 105. The support member 111C is an intermediate member 130C. The intermediate member 130C is made of a material having a thermal expansion coefficient between the thermal expansion coefficients of the condenser lenses 104 and 105 and the base 101, specifically, a copper-tungsten alloy or alumina.

In the optical device 100C having such a configuration, the intermediate member 130C is provided between the base 101 and the condenser lenses 104 and 105, whereby the same effects as those of embodiment 1 can be obtained. The intermediate member 130C is an example of a third intermediate member, and the support member 111C is an example of a third support member.

In the optical device 100C of the present embodiment, compared with the optical device 100A of embodiment 1 and the optical device 100B of embodiment 2, the number of intermediate members 130C, and hence the number of components of the optical device 100C can be reduced by providing one intermediate member 130C for two condenser lenses 104 and 105, and therefore, for example, the manufacturing labor and cost can be reduced. Such a configuration is particularly advantageous when the condenser lenses 104 and 105 are arranged relatively close to each other. On the other hand, when the condenser lenses 104 and 105 are arranged relatively far, as in the above-described embodiment 1 and embodiment 2, the configuration in which the different intermediate members 130A1 (130B) and 130A2 are provided for the condenser lenses 104 and 105, respectively, may be advantageous in that the intermediate members can be made smaller, and an increase in the mass of the optical device 100 can be suppressed.

[ 4 th embodiment ]

Fig. 10 is a plan view of the optical device 100D according to embodiment 4. The optical device 100D of the present embodiment has the same configuration as the optical device 100 of the above embodiment except that the plurality of light emitting elements 32 output laser light of different wavelengths (λ 1, λ 2, \ 8230;, λ n-1, λ n), and that the 1/2 wavelength plate 108c is not provided and the sub-assembly 30 is not housed in the case 20. The interval of the plurality of wavelengths is, for example, 5[ nm ] to 20[ nm ] in terms of the central wavelength interval. The light synthesized here may include blue laser light.

In the optical device 100D having such a configuration, the intermediate member 130C is provided between the base 101 and the condenser lenses 104 and 105, whereby the same effects as those of embodiment 1 can be obtained.

[ 5 th embodiment ]

Fig. 11 is a configuration diagram of a light source device 1000 according to embodiment 5 on which the optical device 100 (light-emitting device) according to any one of embodiments 1 to 4 is mounted. The light source apparatus 1000 includes a plurality of optical devices 100 as excitation light sources. The laser light output from the plurality of optical devices 100 is transmitted to the combiner 200 as an optical coupling section via the optical fiber 120. The output end of the optical fiber 120 is coupled to a plurality of input ports of the multi-input 1-output combiner 200, respectively. The light source device 1000 is not limited to having a plurality of optical devices 100, and may have at least 1 optical device 100.

[ 6 th embodiment ]

Fig. 12 is a structural diagram of the fiber laser 300 to which the light source apparatus 1000 of fig. 11 is attached. The fiber laser 300 includes the light source device 1000 and the combiner 200 shown in fig. 11, the rare-earth-doped fiber 330, and the output-side fiber 340. The input end and the output end of the rare earth-doped fiber 330 are respectively provided with a high-reflection FBG310, 321 (fiber Bragg grating).

The input end of the rare earth-doped fiber 330 is connected to the output end of the combiner 200, and the input end of the output-side fiber 340 is connected to the output end of the rare earth-doped fiber 330. The input unit for inputting the laser light output from the plurality of optical devices 100 to the rare-earth-doped fiber 330 may have another configuration instead of the combiner 200. For example, the optical fibers 120 of the output units in the optical device 100 may be arranged in a row, and the laser light output from the optical fibers 120 may be input to the input end of the rare-earth-doped fiber 330 using an input unit such as an optical system including a lens. The rare earth-doped fiber 330 is an example of a light amplification fiber.

According to the light source apparatus 1000 of embodiment 5 or the fiber laser 300 of embodiment 6, the same effects as those of embodiments 1 to 4 can be obtained by including the optical device 100 of embodiments 1 to 4.

The embodiments of the present invention have been described above, but the above embodiments are examples and are not intended to limit the scope of the present invention. The above embodiments may be implemented in other various forms, and various omissions, substitutions, combinations, and changes may be made without departing from the spirit of the invention. Further, specifications such as the structure and shape (structure, type, direction, pattern, size, length, width, thickness, height, number, arrangement, position, material, and the like) can be appropriately changed and implemented.

For example, in the above embodiments, the optical device has a configuration having two condenser lenses, but the present invention is not limited thereto. More specifically, the optical device may include three or more condenser lenses instead of two condenser lenses, or may include one condenser lens that condenses the laser light toward the end of the optical fiber in both the fast axis and the slow axis.

The structure, arrangement, and combination of the sub-assembly, the light emitting module, the optical members, the protruding portion, the shielding portion, and the like are not limited to the above embodiments. The traveling direction of the stray light is not limited to the above-described direction.

Claims (20)

1. An optical device is provided with:

a base;

a plurality of light emitting elements provided on the base and outputting laser light; and

a plurality of optical members provided on the base and transmitting laser light output from the light emitting element to an optical fiber,

the plurality of optical members includes:

a first condenser lens that condenses the laser light from the plurality of light emitting elements toward an end of the optical fiber; and

a second condenser lens that condenses the laser light from the plurality of light emitting elements toward the first condenser lens,

the first condenser lens and the second condenser lens are made of synthetic quartz,

an intermediate member having a thermal expansion coefficient of a value between the thermal expansion coefficients of the synthetic quartz and the base is provided between the first condenser lens and the base and between the second condenser lens and the base.

2. The optical device according to claim 1,

the first condenser lens and the second condenser lens are fixed to the intermediate member via an adhesive, respectively.

3. The optical device according to claim 1,

the optical device includes a first intermediate member interposed between the first condenser lens and the base as the intermediate member.

4. The optical device of claim 3,

the optical device includes: an end cap integrated with an end portion of the optical fiber and having an end face with an area larger than a cross-sectional area of the optical fiber,

the first intermediate member is a first support member provided on the base and supporting the optical fiber, the end cap, and the first condenser lens.

5. The optical device according to claim 3,

the optical device includes a second support member provided on the base and supporting the optical fiber,

the first intermediate member is present between the second support member and the first condenser lens.

6. The optical device according to claim 3,

the optical device includes a second intermediate member interposed between the second condenser lens and the base as the intermediate member.

7. The optical device according to claim 1,

the optical device includes a third intermediate member interposed between the first and second condenser lenses and the base, as the intermediate member.

8. The optical device according to claim 7,

the optical device includes: an end cap integrated with an end portion of the optical fiber and having an end face with an area larger than a cross-sectional area of the optical fiber,

the third intermediate member is a third supporting member provided on the base and supporting the optical fiber, the end cap, the first condenser lens, and the second condenser lens.

9. The optical device according to any one of claims 1 to 8,

the difference between the thermal expansion coefficient of the synthetic quartz and the thermal expansion coefficient of the intermediate member is 11X 10 ^-6 [1/K]The following.

10. The optical device according to any one of claims 1 to 8,

the difference between the thermal expansion coefficient of the intermediate member and the thermal expansion coefficient of the base is 11 × 10 ^-6 [1/K]The following.

11. The optical device according to any one of claims 1 to 8,

the wavelength of the laser is from 400[ 2 ] to 520[ nm ].

12. The optical device of claim 11,

the absorptance of the first condenser lens and the second condenser lens with respect to the laser light is 0.1[% ] or less.

13. The optical device according to any one of claims 1 to 8,

the light output from the optical fiber is 100[ 2 ], [ W ] or more.

14. The optical device according to any one of claims 1 to 8,

the absorptance of light having a wavelength of 400[ nm ] or more and 520[ nm ] or less of a material constituting the intermediate member is lower than the absorptance of a material constituting the chassis.

15. The optical device according to any one of claims 1 to 8,

the intermediate member is made of copper-tungsten alloy or aluminum oxide.

16. An optical device is characterized by comprising:

a base;

a plurality of light emitting elements provided on the base and outputting laser light; and

a plurality of optical members provided on the base and transmitting laser light output from the light emitting element to an optical fiber,

the plurality of optical members includes: a condensing lens that condenses the laser light from the plurality of light emitting elements,

an intermediate member having a thermal expansion coefficient of a value between that of the condenser lens and that of the base is provided between the condenser lens and the base.

17. The optical device of claim 16,

the condenser lens is fixed to the intermediate member via an adhesive.

18. The optical device according to any one of claims 1 to 8, 16 and 17,

the optical device includes: a cooling mechanism that cools the intermediate member.

19. A light source device comprising the optical device according to any one of claims 1 to 18.

20. A fiber laser comprising:

the light source device of claim 19; and

and a light amplification fiber for amplifying the laser light output from the light source device.

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