Optical element assembly, method of manufacturing an optical element assembly, optical module, optical engine, and XR glasses

Abstract

The present application relates to an optical element assembly, a manufacturing method of an optical element assembly, an optical module, an optical engine, and an XR glasses. The optical element assembly includes: a plurality of laser diode assemblies; and a substrate for an optical waveguide provided with an optical waveguide layer on a main surface, the optical waveguide layer having an optical waveguide that guides laser light emitted from the plurality of laser diode assemblies, the laser diode assembly having a submount and a laser diode formed on the submount, and at least one of the plurality of laser diode assemblies is disposed apart from an adjacent laser diode assembly at a mounting pitch that satisfies formula (1). P ≥ W + 0.9T … (1) (P is the mounting pitch, W is the width of the submount, and T is the thickness of the submount.)

Description

Technical Field

[0001] This invention relates to an optical element assembly, a method for manufacturing the optical element assembly, an optical module, an optical engine, and XR glasses. Background Technology

[0002] AR (Augmented Reality) glasses, VR (Virtual Reality) glasses, and XR glasses with multiple laser light sources are expected to be miniaturized wearable devices. In wearable devices like AR and VR glasses, miniaturizing various functions within the size of typical eyeglasses is key to their widespread adoption.

[0003] As an optical element assembly, it is generally formed by guiding light from a laser diode to the optical element using optical fibers, aligning the optical fibers, and bonding them together using resins, etc. (e.g., Patent Document 1, Patent Document 2). For optical elements having multiple waveguides, in optical element assemblies having a structure such as directly bonding a laser diode, the following method is used: after bonding the laser diode to a subcarrier, one side of the subcarrier is used as the bonding surface, and bonding is performed using an adhesive.

[0004] In addition, there is a known device that, for an optical element having multiple optical waveguides and performing some form of optical or photoelectric conversion, optical coupling is achieved by directly aligning a laser diode with the waveguides and bonding them together. In such devices, a structure using eutectic bonds such as AuSn junctions for bonding has been proposed (e.g., Patent Document 3).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2019 / 239839

[0008] Patent Document 2: Japanese Patent Application Publication No. 2024-58375

[0009] Patent Document 3: Japanese Patent Application Publication No. 2024-147277 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] In structures like those in Patent Documents 1 and 2, when bonding is performed, gaps are created between laser diode components based on requirements such as coating methods and bonding fixtures in the bonding process, thereby determining the waveguide spacing.

[0012] Even when using eutectic bonding, the reflow soldering method still has limitations. Specifically, during reflow soldering, it is necessary to consider preventing the unbonded laser diode units from being affected by the heat of the nearby bonded laser diodes.

[0013] Furthermore, when multiple laser fibers are joined together, the spacing of the waveguides is constrained by processes and components such as the size of the coupler at the joined part, the configuration of the clamps, and the method of applying the adhesive.

[0014] The present invention was made in view of the above circumstances, and its object is to provide an optical element assembly, a method for manufacturing the optical element assembly, an optical module, an optical engine, and XR glasses, which can mount the laser diode assembly with high precision in a manner that does not affect the heat of other laser diode assemblies when the base on which the laser diode is formed is bonded to the substrate for optical waveguide.

[0015] Technical means for solving technical problems

[0016] In order to solve the above-mentioned technical problems, the present invention provides the following technical means.

[0017] [1] One aspect of the present invention relates to an optical element assembly comprising:

[0018] Multiple laser diode components; and

[0019] An optical waveguide substrate has an optical waveguide layer disposed on its main surface, the optical waveguide layer having an optical waveguide for guiding laser light emitted from the plurality of laser diode components.

[0020] The laser diode assembly has a base and a laser diode formed on the base.

[0021] At least one of the plurality of laser diode assemblies is spaced apart from the adjacent laser diode assembly in such a way that the mounting spacing satisfies equation (1).

[0022] P≥W+0.9T……(1)

[0023] (P is the installation spacing, W is the width of the base, and T is the thickness of the base.)

[0024] [2] In the optical element assembly described in [1] above, the plurality of laser diode assemblies may also be arranged in a non-equidistant manner.

[0025] [3] In the optical element assemblies of [1] and [2] above, the plurality of laser diode assemblies may also be arranged at intervals such that adjacent laser diode assemblies are arranged at a mounting spacing that satisfies formula (1).

[0026] [4] In the optical element assemblies described above [1] to [3], the plurality of laser diode assemblies may also be arranged in such a way that the interval between them and the adjacent laser diode assemblies is equal.

[0027] [5] In the optical element assemblies described above [1] to [4], the plurality of laser diode assemblies may be bonded to the optical waveguide substrate via a plurality of metal films.

[0028] [6] In the optical element assemblies described above [1] to [5], the plurality of metal films may also contain Sn and Au.

[0029] [7] In the optical element assemblies described above [1] to [6], the plurality of laser diode assemblies may also be formed in such a way that the mounting spacing satisfies formula (2).

[0030] P≤Wo-nW……(2)

[0031] (Wo is the width of the optical element assembly, and n is the number of laser diode assemblies contained in the optical element assembly.)

[0032] [8] In the optical element assemblies described in [1] to [7] above, it is also possible that,

[0033] The plurality of laser diode assemblies includes: at least two first laser diode assemblies disposed adjacently, which are bonded to the optical waveguide substrate via a plurality of metal films; and at least one second laser diode assembly bonded to the optical waveguide substrate via an adhesive layer.

[0034] The adjacent first laser diode assemblies of the plurality of laser diode assemblies are arranged with a spacing P between them in a manner that satisfies the mounting spacing of equation (1).

[0035] The distance between the second laser diode assembly and the adjacent laser diode assembly is less than the distance P.

[0036] [9] In the optical element assembly described above [1] to [8], the plurality of metal films may also include a eutectic film of Sn and Au, or a eutectic film of Sn and Pt.

[0037]

[10] The optical element assembly described above [1] to [9] may also include: a base for bonding the base and the optical waveguide substrate via an adhesive layer, wherein the thermal conductivity of the adhesive layer is 0.5 W / m·K or higher.

[0038]

[11] In one aspect of the present invention, the optical module includes the optical element assemblies described above [1] to

[10] within a package.

[0039]

[12] One aspect of the present invention relates to an optical engine comprising: the optical module described above

[11] ; and a light scanning mirror that changes angle to reflect light emitted from the optical module for image display.

[0040]

[13] One aspect of the present invention relates to XR glasses that are equipped with the optical engine described above

[12] .

[0041]

[14] One aspect of the present invention relates to a method for manufacturing an optical element assembly, comprising: a bonding step of bonding a plurality of laser diode assemblies to an optical waveguide substrate via a plurality of metal films.

[0042] The optical waveguide substrate includes a substrate and an optical waveguide layer having an optical waveguide formed on the main surface of the substrate.

[0043] The laser diode assembly includes a base and a laser diode formed on the base.

[0044] In the bonding process, a laser is irradiated to heat the substrate in a manner that satisfies the mounting spacing of formula (1), with at least one of the plurality of laser diode assemblies abutting against the adjacent laser diode assembly at a distance.

[0045] P≥W+0.9T……(1)

[0046] (P is the installation spacing, W is the width of the base, and T is the thickness of the base.)

[0047]

[15] In the manufacturing method of the optical element assembly described in

[14] above, it is also possible that, in the bonding process, the substrate on which a first metal film containing Au is formed is brought into contact with the substrate on which a second metal film containing Sn is formed and heated to form a eutectic film of Au and Sn.

[0048]

[16] In the manufacturing methods of the optical element assembly described in

[13] and

[14] above, a Si substrate may be used as the base, and a YAG laser may be used in the bonding process.

[0049]

[17] The manufacturing method of the optical element assembly described in

[13] to

[16] above may also be that, in the bonding process, the plurality of laser diode assemblies are heated by irradiating a laser in a manner that satisfies the mounting spacing of formula (2), such that at least one of the plurality of laser diode assemblies is spaced apart from the adjacent laser diode assembly and abuts against the substrate.

[0050] P≤Wo-nW……(2)

[0051] (Wo is the width of the optical element assembly, and n is the number of laser diode assemblies contained in the optical element assembly.)

[0052]

[18] The manufacturing method of the optical element assembly described in

[13] to

[17] above may also be that, in the bonding process, adjacent laser diode assemblies among the plurality of laser diode assemblies are spaced apart by a mounting spacing that satisfies formula (1).

[0053] The effects of the invention

[0054] According to the present invention, it is possible to provide an optical element assembly, a method for manufacturing the optical element assembly, an optical module, an optical engine, and XR glasses, which can be provided with high precision in mounting a laser diode assembly without causing thermal effects on a base on which other laser diodes are formed when a base on which a laser diode is formed is joined to an optical waveguide substrate, and have a high degree of freedom in mounting position that matches the shape of the laser diode assembly. Attached Figure Description

[0055] Figure 1 This is a perspective view illustrating an example of the structure of an optical element assembly according to one embodiment of the present invention.

[0056] Figure 2 yes Figure 1 A top view of the optical component assembly.

[0057] Figure 3A It is a three-dimensional view of a laser source base that carries three laser sources.

[0058] Figure 3B This is a three-dimensional view of a substrate for an optical waveguide.

[0059] Figure 4 yes Figure 1 The optical element assembly shown is a cross-sectional view along line A-A'.

[0060] Figure 5 yes Figure 2 The optical element assembly shown is a cross-sectional view along line B-B'.

[0061] Figure 6A This is a schematic diagram showing the structure of the first metal film 74 and the second metal film 72 compared to each other.

[0062] Figure 6B This diagram schematically illustrates the structure of the first metal film 74 and the second metal film 72 being integrally alloyed to form a eutectic layer.

[0063] Figure 7This is a schematic diagram illustrating the structure of a method for manufacturing an optical element assembly according to one embodiment of the present invention, and a cross-sectional view showing the bonding process.

[0064] Figure 8 This is a schematic diagram illustrating the structure of a method for manufacturing an optical element assembly according to one embodiment of the present invention, and a cross-sectional view showing the bonding process.

[0065] Figure 9 It means Figure 1 The diagram shows a top view of an example of the structure of an optical element assembly, and is an enlarged view of the peripheral structure of multiple laser diode assemblies.

[0066] Figure 10 It means Figure 1 A cross-sectional view of an example of the structure of an optical element assembly of other variations.

[0067] Figure 11 This is a top view illustrating an example of the structure of an optical module according to one embodiment of the present invention.

[0068] Figure 12 yes Figure 11 A cross-sectional view of the optical module.

[0069] Figure 13 This is an explanation Figure 11 A top view of the structure within the package of the optical module.

[0070] Figure 14 This is a conceptual diagram illustrating one embodiment of XR glasses according to the present invention.

[0071] Figure 15 This is a conceptual diagram illustrating a scenario where an image is directly projected onto the retina using a laser emitted from an optical module according to one embodiment of the present invention.

[0072] Explanation of reference numerals in the attached figures:

[0073] 3, 3-1, 3-2, 3-3, 3-4… Laser diode assembly

[0074] 20, 20-1, 20-2, 20-3, 20-4… Base (base and subcarrier for laser light source)

[0075] 20a… Upper surface (surface)

[0076] 20b… Bottom surface (base bottom)

[0077] 21… Upper surface

[0078] 21-1, 21-2, 21-3…main side

[0079] 22, 22-1, 22-2, 22-3… Base side joint surfaces

[0080] 23…Bottom

[0081] 30, 30-1, 30-2, 30-3… Laser diodes (laser light sources)

[0082] 30-1…Red laser light source

[0083] 30-2…Green laser light source

[0084] 30-3… Blue laser light source

[0085] 31, 31-1, 31-2, 31-3… Projection surfaces

[0086] 33, 33-1… lower surface

[0087] 35…Near-infrared laser source

[0088] 40…Substrate for optical waveguides (substrate)

[0089] 41… Upper surface (surface)

[0090] 42…Matching surface

[0091] 42-1, 42-2, 42-3… Substrate-side joint

[0092] 43… Bottom surface (bottom surface of substrate)

[0093] 50… Optical waveguide layer

[0094] 50A…incident surface

[0095] 51, 51-1, 51-2, 51-3… Optical waveguides (core layer)

[0096] 51A-1, 51A-2, 51A-3… Inlet

[0097] 52…cladding

[0098] 57-1, 57-2... Meeting point

[0099] 61…incident surface

[0100] 64…Ejection surface

[0101] 72, 73, 74...metal film

[0102] 72, 72-1, 72-2, 72-3… Second metal film

[0103] 73…Third metal film (eutectic film)

[0104] 74, 74-1, 74-2, 74-3… First Metal Film

[0105] 75…First Metal Layer

[0106] 76…Second Metal Layer

[0107] 77… Adhesive layer

[0108] 81, 82... Anti-reflective film

[0109] 90… laser

[0110] 100, 100B, 100C… Optical Component Assembly

[0111] 101…Light-transmitting window (opening)

[0112] 102…Main Body

[0113] 102a…wall (sidewall)

[0114] 105…cover

[0115] 107…Storage Department

[0116] 108…Electrode section

[0117] 110… package

[0118] 140…Substrate for optical waveguides

[0119] 151-1, 151-1, 151-2, 151-3… Optical waveguide (ridge)

[0120] 157-1, 157-2... Meeting point

[0121] 180…base

[0122] 180a… Upper surface

[0123] 182… Adhesive layer

[0124] 1000, 1001, 2000… Optical modules

[0125] 1100… Laser Driver

[0126] 1200… Optical Scanning Mirror Driver

[0127] 1300…Video Controller

[0128] 2001a…collimating lens

[0129] 2001b…slit

[0130] 2001c…ND filter

[0131] 3001…Light Scanning Mirror

[0132] 4001…Reflector

[0133] 5001… Optical Engine

[0134] 10000…XR Glasses

[0135] 10010… box Detailed Implementation

[0136] Hereinafter, embodiments will be described in detail with appropriate reference to the accompanying drawings. In the drawings used in the following description, for ease of understanding, some features are sometimes shown as enlarged portions, and the size ratios of the constituent elements may sometimes differ from the actual dimensions. The materials, dimensions, etc., illustrated in the following description are examples, and the present invention is not limited to these examples; appropriate modifications can be made to achieve the effects of the present invention.

[0137] [Optical Component Assembly]

[0138] Figure 1 This is a perspective view illustrating an example of the structure of an optical element assembly according to one embodiment of the present invention. Figure 2 yes Figure 1 A top view of the optical component assembly. Figure 3A This is a three-dimensional view of a laser source base that houses three laser light sources. Figure 3B This is a three-dimensional view of a substrate for an optical waveguide. Figure 4 yes Figure 1 The optical element assembly shown is a cross-sectional view along line A-A'.

[0139] Figures 1-4 The optical element assembly 100 shown includes a plurality of laser diode assemblies 3 (3-1, 3-2, 3-3) and an optical waveguide substrate 40 on which an optical waveguide layer 50 is provided on the main surface. The optical waveguide layer 50 has an optical waveguide 51 for guiding laser light emitted from the plurality of laser diode assemblies 3. The laser diode assembly 3 has a base 20 (20-1, 20-2, 20-3) and laser diodes 30 (30-1, 30-2, 30-3) formed on the base 20. At least one of the plurality of laser diode assemblies 3 is formed at a distance from the adjacent laser diode assembly 3 such that a mounting spacing satisfying equation (1) is achieved.

[0140] P≥W+0.9T……(1)

[0141] (P is the installation spacing, W is the width of the base, and T is the thickness of the base.)

[0142] In this embodiment, regarding the components indicated by reference numeral 0, when different features are illustrated by reference numerals 0-1, 0-2, and 0-3, they are described separately using reference numerals 0-1, 0-2, and 0-3. However, for features common to all components, only reference numeral 0 is used for general description. Furthermore, in this embodiment, the base 20 is also referred to as a laser light source base or subcarrier. Additionally, the laser diode 30 is also referred to as a laser light source.

[0143] Figure 1 The optical element assembly 100 shown includes: three laser diodes 30; three laser source bases 20 (20-1, 20-2, 20-3) on main surfaces 21-1, 21-2, and 21-3 respectively and arranged at intervals between them; an optical waveguide layer 50 having at least one optical waveguide 51 for guiding the laser light emitted from the three laser diodes 30 (30-1, 30-2, 30-3); an optical waveguide substrate 40 on which the optical waveguide layer 50 is provided; and a substrate for bonding the laser source bases 20 (20-1, 20-2, 20-3) to the optical waveguide substrate 40. Metal films M (72, 73, 74) are disposed between the base-side bonding surfaces 22 (22-1, 22-2, 22-3) of the laser source bases 20 (20-1, 20-2, 20-3) and the plurality of substrate-side bonding portions 42-1, 42-2, 42-3, thereby bonding the laser source bases 20-1, 20-2, 20-3 to the optical waveguide substrate 40. The plurality of substrate-side bonding portions 42-1, 42-2, 42-3 are disposed on the bonding surfaces 42 of the optical waveguide substrate 40 at intervals from each other corresponding to the base-side bonding surfaces 22-1, 22-2, 22-3. In this way, in the optical element assembly 100, the plurality of laser diode assemblies 3 are bonded to the optical waveguide substrate 40 via the metal films M composed of the plurality of metal films.

[0144] <Laser Diodes and Laser Diode Bases>

[0145] As the laser diode 30, various laser elements can be used. For example, commercially available laser diodes (LDs) for red, green, blue, near-infrared, and ultraviolet light can be used. For red light, a peak wavelength of 600 nm or higher and 780 nm or lower can be used; for green light, a peak wavelength of 500 nm or higher and 560 nm or lower can be used; and for blue light, a peak wavelength of 430 nm or higher and 500 nm or lower can be used. Furthermore, for near-infrared light, a peak wavelength of 830 nm or higher and 2000 nm or lower can be used.

[0146] exist Figure 1In the optical element assembly 100 shown, laser diodes 30-1, 30-2, and 30-3 are used as LDs emitting red light, green light, and blue light, respectively. LDs 30-1, 30-2, and 30-3 can be mounted, for example, as bare chips (unpackaged chips) on various laser source substrates (subcarriers; hereinafter sometimes referred to as subcarriers). Subcarriers 20-1, 20-2, and 20-3 are, for example, made of aluminum nitride (AlN), silicon (Si), etc.

[0147] A first metal layer 75 and a second metal layer 76 are disposed between the subcarrier 20 and the LD30 (see reference). Figure 4 The subcarrier 20 and LD30 are connected via a first metal layer 75 and a second metal layer 76. The first metal layer 75 and the second metal layer 76 can be formed using known methods, without particular limitation, such as sputtering, vapor deposition, or coating with a slurry of metal. The first metal layer 75 and the second metal layer 76 may contain, for example, one or more metals selected from gold (Au), platinum (Pt), silver (Ag), lead (Pb), indium (In), nickel (Ni), titanium (Ti), tantalum (Ta), tungsten (W), gold (Au), and tin (Sn), tin (Sn)-silver (Ag)-copper (Cu) solder alloys (SAC), SnCu, InBi, SnPdAg, SnBiIn, and PbBiIn, and may be composed of one or more of these metals.

[0148] like Figure 2 , Figure 4 As shown, the base 20 has a width W corresponding to the length in the x-direction and a thickness T corresponding to the length in the z-direction. Additionally, the length in the y-direction of the base 20 is sometimes referred to as its depth.

[0149] exist Figure 3A In the image, the structure of LD30 formed on the base 20 is shown in magnified form. For example... Figure 3A As shown, the LD30, along with the active layer corresponding to the emission portion, and the electrode portions of the cathode and anode electrically connected to the active layer, are formed on the base 20. The mounting spacing P in equation (1) above is the interval between adjacent laser diode components 3 among the plurality of laser diode components 3, corresponding to the interval of the laser light irradiated from the LD30. That is, in Figure 3A In each of LD30-1, LD30-2, and LD30-3, laser light is emitted parallel to the width direction centers C30-1, C30-2, and C30-3 of the emission section. In the laser diode assembly 3 with the above structure, the mounting spacing P is the distance between the width direction centers C30-1 and C30-2 of the emission section, and the distance between C30-2 and C30-3. Figure 3AThe width W and thickness T of the base 20 are shown. Additionally, in Figure 3B The width Wo of the optical waveguide layer 50 is shown. The width of the optical waveguide layer 50 is, for example, the same as the width of the substrate 40. Figure 3B The diagram shows substrate-side bonding portions 42-1, 42-2, and 42-3, and second metal films 72-1, 72-2, and 72-3 disposed in this region. However, the positions and spacing of these portions can be adjusted according to the positions and spacing of the sub-carriers 20-1, 20-2, and 20-3. The substrate-side bonding portions 42-1, 42-2, and 42-3 are disposed opposite to the first metal films 74-1, 74-2, and 74-3 disposed on the sub-carriers 20-1, 20-2, and 20-3.

[0150] exist Figures 1-4 In the optical element assembly 100 shown, all of the multiple laser diode assemblies 3 are arranged at intervals from the adjacent laser diode assemblies in such a way that they satisfy the mounting spacing of equation (1). Figures 1-4 In the optical element assembly 100 shown, the thickness T and width W of the bases of multiple laser diode assemblies 3 are fixed, and adjacent laser diode assemblies 3 are arranged at equal intervals. As an example, the base 20 can have a width W of 0.37 mm, a thickness T of 0.40 mm, and a depth of 0.40 mm. As the optical functional layer 50, an optical functional layer with a width of 2.25 mm, a height of 3.42 mm, and a depth of 0.415 mm can be used. When using such a base 20, W + 0.9T = 0.37 + 0.90 × 0.40 = 0.73 (mm). Therefore, according to equation (1), the mounting spacing P can be set to a size greater than 0.73 mm, for example, it can be set to 0.75 mm. In this case, the mounting spacing P satisfies the relationship W + 0.9T + 0.02 (mm). For example, the adjacent laser diode assemblies 3 in the three laser diode assemblies 3 can be installed at equal intervals with the mounting distance P between them set to the above value.

[0151] In the optical element assembly 100, from the viewpoint of ensuring sufficient positional accuracy and miniaturization, the plurality of laser diode assemblies 3 are preferably arranged at intervals from the adjacent laser diode modules in such a way that the mounting spacing satisfies the following formula (2).

[0152] P≤Wo―nW……(2)

[0153] (Wo is the width of the optical element assembly, and n is the number of laser diode assemblies contained in the optical element assembly.)

[0154] <Optical waveguide layers and substrates for optical waveguides>

[0155] The optical waveguide layer 50 has at least an optical waveguide for guiding laser light emitted from the laser source. There are no particular limitations on this optical waveguide layer; for example, a known structure can be used. The following shows an example of an optical waveguide layer.

[0156] The optical waveguide layer 50 is referred to as PLC (Planar lightwave circuit). Hereinafter, the optical waveguide layer 50 is sometimes referred to as PLC50. In addition, optical waveguides 51-1, 51-2, and 51-3 are sometimes referred to as core layers 51-1, 51-2, and 51-3.

[0157] An optical waveguide layer 50 is formed on an optical waveguide substrate 40. Furthermore, as described above, a laser source 30 is mounted on a subcarrier 20. The optical waveguide substrate 40 and the subcarrier 20 are integrated by a metal bonding process. This metal bonding enables precise optical axis configuration and also achieves miniaturization.

[0158] Figure 5 It is Figure 2 The diagram shows a cross-sectional view of the optical element assembly 100 cut along line B-B'. The optical waveguide substrate 40 is made of, for example, silicon (Si). The PLC 50 is fabricated on the upper surface 41 in an integral manner with the optical waveguide substrate 40 using known semiconductor processes including photolithography or dry etching used in forming microstructures such as integrated circuits. Figure 2 As shown, the PLC50 has the same number of core layers 51-1, 51-2, and 51-3 as LD30-1, 30-2, and 30-3, and a cladding layer 52 surrounding the core layers 51-1, 51-2, and 51-3. There are no particular limitations on the thickness of the cladding layer 52 or the width dimension of the core layers 51-1, 51-2, and 51-3. For example, core layers 51-1, 51-2, and 51-3 with width dimensions of several micrometers can be arranged within a cladding layer 52 with a thickness of approximately 50 μm.

[0159] The core layers 51-1, 51-2, 51-3 and the cladding layer 52 are, for example, made of quartz. Hereinafter, it is sometimes referred to as a quartz-based PLC 50. The refractive indices of the core layers 51-1, 51-2, and 51-3 are higher than the refractive index of the cladding layer 52 by a specified value. Thus, light incident on each core layer 51-1, 51-2, and 51-3 undergoes total internal reflection at the interface between each core layer and the cladding layer 52, and then propagates within each core layer. The core layers 51-1, 51-2, and 51-3 are, for example, doped with impurities such as germanium (Ge) in an amount corresponding to the aforementioned specified value.

[0160] like Figure 1 , Figure 2 and Figure 4As shown, core layers 51-1, 51-2, and 51-3 converge into one core layer 51-4 at the front side of the emission surface 64 of the PLC 50. That is, core layers 51-1, 51-2, and 51-3 gradually merge forward in the x-direction, merging into a single core layer 51-4. To prevent light leakage from core layers 51-1, 51-2, and 51-3, it is preferable that core layers 51-1, 51-2, and 51-3 are connected to core layer 51-4 with a radius of curvature greater than a specified radius of curvature.

[0161] By metal bonding between the optical waveguide substrate 40 and the subcarrier 20, each core layer and its corresponding LD are configured relative to each other in such a way that the center of the entrance port of each core layer 51-1, 51-2, 51-3 of the PLC 50 is approximately aligned with the optical axis of the emitted light from each corresponding LD 30-1, 30-2, 30-3.

[0162] like Figure 4 As shown, the incident surface 50A of PLC 50 is configured opposite to the exit surface 31 of LD 30. Specifically, the exit surface 31 of LD 30-1 is opposite to the incident port 51A-1 of optical waveguide 51. In the x and z directions, the optical axis of the red light emitted from LD 30-1 approximately overlaps with the center of the incident port 51A-1. Similarly, the exit surface 31-2 of LD 30-2 is opposite to the incident port 51A-2 of optical waveguide 51-2. In the x and z directions, the optical axis of the green light emitted from LD 30-2 approximately overlaps with the center of the incident port 51A-2. The exit surface 31-3 of LD 30-3 is opposite to the incident port 51A-3 of optical waveguide 51-3. In the x and z directions, the optical axis of the blue light emitted from LD 30-3 approximately overlaps with the center of the incident port 51A-3. With this structure and configuration, at least a portion of the red, green, and blue light emitted from LD30-1, LD30-2, and LD30-3 can be incident on optical waveguides 51-1, 51-2, and 51-3.

[0163] like Figure 2 As shown, red, green, and blue light emitted from LD30-1, 30-2, and 30-3, respectively, are incident on core layers 51-1, 51-2, and 51-3, and then propagate within each core layer. The red and green light propagating in core layers 51-3 and 51-2 converge at a predetermined convergence position 57-1, located behind the convergence position 57-2 in the y-direction. The converged red and green light then merges with the blue light propagating in 51-2 at the convergence position 57-2. The RGB light that converges at the convergence position 57-2 propagates in core layer 51-4, reaches the emission surface 64, and is emitted from the emission surface 64.

[0164] <Joint>

[0165] Three separate laser light source bases 20-1, 20-2, and 20-3 are bonded to the optical waveguide substrate 40 via a metal film M.

[0166] The metal film M is disposed between the base-side bonding surfaces 22-1, 22-2, and 22-3 of the three separate laser light source bases 20-1, 20-2, and 20-3 and the bonding surfaces 42 of the optical waveguide substrate 40 corresponding to these base-side bonding surfaces 22-1, 22-2, and 22-3, which are respectively arranged separately on the bonding surfaces 42-1, 22-2, and 22-3.

[0167] The metal film M is only disposed on the separately disposed substrate-side bonding portions 42-1, 42-2, and 42-3. It is not a continuously formed film, but a separate film, which can suppress the generation of capacitive coupling and prevent crosstalk.

[0168] Figure 2 and Figure 4 For simplicity, the metal film M shown is depicted as a three-layer structure to reflect the fabrication process of the metal film M (or, more specifically, the bonding process between the laser light source substrate and the optical waveguide substrate). Furthermore, when describing the metal film M, each of the three layers is sometimes also described.

[0169] That is, for convenience, the metal film M in the figure is depicted as consisting of three layers: a first metal film 74 (74-1, 74-2, 74-3), a second metal film 72 (72-1, 72-2, 72-3), and a eutectic layer 73. The first metal films 74 (74-1, 74-2, 74-3) are disposed on the respective base-side bonding surfaces 22-1, 22-2, 22-3 of each laser light source base 20-1, 20-2, 20-3. The second metal films 72 (72-1, 72-2, 72-3) are respectively disposed on three substrate-side bonding portions 42-1, 42-2, 42-3 on the bonding surface 42 of the optical waveguide substrate 40, which are respectively corresponding to the base-side bonding surfaces 22-1, 22-2, 22-3. The eutectic layer 73 is disposed between the first metal film 74 and the second metal film 72.

[0170] In actual bonding, when the first and second metal films are sufficiently thin, an alloy layer (eutectic layer) is formed, leaving no residue of the first or second metal films. On the other hand, when either the first or second metal film is thicker, sometimes only the surface side of the thicker metal film is eutecticized, leaving a portion on the laser source substrate side or the optical waveguide substrate side, while the other metal film is completely eutecticized, making it difficult to clearly distinguish the layers (interfaces).

[0171] Thus, in actual bonding, the membrane structure of the metal membrane M varies depending on the fabrication process conditions. In addition, the attached figure conceptually depicts the characteristic surfaces of the membrane structure.

[0172] For example, a structure can be formed by using one of the first metal film 74 and the second metal film 72, or a structure where the first metal film 74 and the second metal film 72 are integrally alloyed to form a eutectic layer. Figure 6A It is the structure of the former, and is a schematic diagram showing the residual structure of the first metal film 74 and the second metal film 72. Figure 6B It is the structure of the latter, and is a schematic diagram showing the structure of the first metal film 74 and the second metal film 72 being integrally alloyed to form a eutectic layer.

[0173] The first metal film 74 is formed, for example, entirely on the bonding surface 22 of the substrate 20 or entirely except for the ends. In order to achieve bonding by heating the first metal film 74 to form a eutectic with the second metal film 72, it is necessary to heat in a manner that fully melts the first metal film 74 and the second metal film 72 as a whole. This needs to be considered in order to specify the mounting spacing P of the laser diode assembly 3.

[0174] The first metal film 74 and the second metal film 72 are aligned in an overlapping manner. When the laser directly irradiates the sub-carrier 20 or directly irradiates through the sub-carrier, the first metal film 74 and the second metal film 72 are heated, thereby melting the first metal film 74 and the second metal film 72. When the first metal film 74 and the second metal film 72 are heated by the laser while in contact, the composition of the second metal film 72 eutecticizes and diffuses into the first metal film 74.

[0175] The second metal film 72 disposed on the substrate-side bonding portions 42-1, 42-2, and 42-3 is preferably composed of Sn or an alloy containing Sn, such as Sn-Ag-Cu. Furthermore, the first metal film 74 disposed on the abutment-side bonding surfaces 22-1, 22-2, and 22-3 is preferably a metal capable of eutectic formation with Sn, for example, containing one or an alloy of Au, Si, Al, Ni, Pb, Zn, and Pt. The first metal film 74 is preferably Au or Pt among the aforementioned metals capable of eutectic formation with Sn. These metals are those that require high-temperature treatment during the bonding process when forming a eutectic with Sn through reflow. Therefore, there is a tendency to easily influence components located nearby, such as the metal film of the laser diode assembly adjacent to the laser diode assembly 3 bonded to the optical waveguide substrate 40. However, in this embodiment, by setting adjacent laser diode assemblies 3 of the object to be joined at intervals of mounting distance P, it is possible to suppress the heat generated on the laser diode assemblies 3 located in the periphery, thus creating an optical element assembly with highly precise mounting position adjustment.

[0176] Alternatively, the three-layer structure of the metal films M (72, 73, 74) shown in Figure 6 can also be arranged in reverse. That is, it can also be a structure in which the second metal film 72 is disposed on the laser source base 20 side and the first metal film 74 is provided on the optical waveguide substrate 40 side.

[0177] [Manufacturing method of optical component assemblies]

[0178] Hereinafter, a method for manufacturing an optical element assembly according to an embodiment of the present invention will be described using the method of manufacturing the optical element assembly 100 of the above embodiment as an example. Figure 7 and Figure 8 This is a schematic diagram illustrating the structure of a method for manufacturing an optical element assembly according to one embodiment of the present invention, and a cross-sectional view showing the bonding process.

[0179] One embodiment of the present invention provides a method for manufacturing an optical element assembly, comprising a bonding step of bonding a plurality of laser diode assemblies 3 to an optical waveguide substrate 40 via a plurality of metal films 72, 74. In the bonding step, a laser is irradiated to heat the substrate such that at least one of the plurality of laser diode assemblies 3 is in contact with the substrate at a distance from the adjacent laser diode assembly 3, such that the mounting spacing satisfies formula (1).

[0180] P≥W+0.9T……(1)

[0181] (P is the installation spacing, W is the width of the base, and T is the thickness of the base.)

[0182] The laser diode assembly 3 is formed by mounting a bare LD30 chip on the upper surface of the substrate 20 using a known method. For example, a first metal layer 75 is formed on the upper surface 21 of the substrate 20 using sputtering or evaporation. Then, a second metal layer 76 is formed on the lower surface 33 of the LD30 (e.g., the lower surface 33-1 of LD30-1) using sputtering or evaporation. Next, the substrate 20 is irradiated with a laser, heating it only to a degree that it does not melt or deform. Through heat transfer from the substrate 20, the first metal layer 75 and the second metal layer 76 are softened or melted, and then cooled. Thus, the LD30 is bonded to the upper surface 21 of the substrate 20 via the first metal layer 75 and the second metal layer 76, forming the laser diode assembly 3.

[0183] Furthermore, before or after mounting the LD30 onto the base 20, a first metal film 74 is formed on the base-side mating surface 22 of the base 20. The formation of the first metal film 74 can be performed using methods such as sputtering or vapor deposition.

[0184] Next, a PLC 50 is formed on the upper surface 41 of the substrate 40 using a known semiconductor process. Then, a second metal film 72 is formed on the substrate-side bonding portions 42-1, 42-2, and 42-3 of the substrate 40 by sputtering or vapor deposition.

[0185] Next, the LD30s corresponding to each other in the x and z directions and the emission surfaces 31 and incident surfaces 61 of the core layers 51-1, 51-2, and 51-3 are positioned at a distance in the y direction. The optical axes of the various colors of light emitted from the LD30 are made to approximately overlap with the center of the incident surface 61 of the corresponding core layer, and the base 20 on which the first metal film 74 is formed and the substrate 40 on which the second metal film 72 is formed are brought into contact. Here, the laser diode assembly 3 on which the LD30 is formed is joined to the adjacent laser diode assembly 3 at a distance from each other, as described later, in a manner that satisfies the mounting spacing of Equation (1).

[0186] Specifically, such as Figure 7 and Figure 8 As shown, laser light is irradiated from laser 90 onto the subcarrier 20, and the first metal film 74, the second metal film 72, and the third metal film (eutectic film) 73 are softened or melted through heat transfer from the subcarrier 20. The relative positions of LD30 and PLC50 are adjusted, and the subcarrier 20 on which LD30 is mounted is bonded to the substrate 40 on which PLC50 is formed, such that the bottom surface 23 of the subcarrier 20 and the bottom surface 43 of the substrate 40 are substantially flush.

[0187] As the laser 90, any known laser capable of heating the first metal film 74 and the second metal film 72 to the eutectic temperature can be used, but a laser capable of irradiating wavelengths of 1064 nm or higher, such as a YAG laser, is preferred. In the bonding process, when irradiating a short-wavelength laser, the metal film M is indirectly heated via the substrate 20. In this embodiment, a substrate 20 made of Si is preferably used, and a laser with a wavelength of 1064 nm or higher, such as a YAG laser, is used in the bonding process. When a substrate 20 made of Si is used and a laser with a wavelength of 1064 nm or higher, such as a YAG laser, is used in the bonding process, the laser irradiated by the laser 90 passes through the substrate 20 and can directly heat the metal film M. Therefore, the influence of thermal radiation from the substrate 20 to the adjacent laser diode assembly 3 can be further suppressed.

[0188] The method for manufacturing the optical element assembly of this embodiment is particularly effective when using a metal film containing Au as the first metal film 74 and a metal film containing Sn as the second metal film 72. When eutecticizing Sn and Au in such a metal film, a higher temperature is achieved, raising concerns that the temperature of the laser diode assembly 3 adjacent to the laser diode assembly 3 to be bonded may easily rise. However, according to this embodiment, by spacing the gaps in a manner that satisfies the mounting spacing of the above formula (1), the substrate 20 and the substrate 40 are bonded in the laser diode assembly 3 to be bonded by forming a eutectic film of Au and Sn. This suppresses the metal film M of the adjacent laser diode assembly 3 from reaching a high temperature, enabling the manufacture of an optical element assembly 100 with high-precision alignment.

[0189] (Modified example)

[0190] The optical element assembly of one embodiment of the present invention is not limited to the structure of the above-described embodiment and can be modified in various ways. For example, the optical element assembly of one embodiment of the present invention can adopt the structure shown below. Figure 9 It means Figure 1 The diagram shows a top view of an example of the structure of a modified optical element assembly, and is an enlarged view showing the peripheral structure of multiple laser diode assemblies. Figure 9 In the optical element assembly 100B shown, the same reference numerals are used for structures that are the same as those in the optical element assembly of the above embodiment, and descriptions are omitted.

[0191] Figure 9 The optical element assembly 100B shown includes laser diode assembly 3-4 in addition to laser diode assemblies 3-1, 3-2, and 3-3. Like the other laser diode assemblies 3, laser diode assembly 3-4 has an LD 30 disposed on the base 20, for example via a first metal layer 75 and a second metal layer 76. The base and LD of laser diode assembly 3-4 are referred to as base 20-4 and LD 30-4, respectively. Laser diode assembly 3-4 is bonded to the optical waveguide substrate 40, for example, via an adhesive layer 77. The adhesive layer 77 is, for example, made of an adhesive.

[0192] In the optical element assembly 100B, considering the distance between the laser diode assemblies described later, the laser diode assembly bonded to the optical waveguide substrate via a metal film is sometimes referred to as the first laser diode assembly, and the laser diode assembly bonded to the optical waveguide substrate 40 via an adhesive layer is referred to as the second laser diode assembly. The optical element assembly 100B of this modified example includes at least two first laser diode assemblies and at least one second laser diode assembly. Laser diode assemblies 3-1, 3-2, and 3-3 correspond to the first laser diode assemblies, and laser diode assembly 3-4 corresponds to the second laser diode assembly.

[0193] In the optical element assembly 100B, the first laser diode assembly is spaced apart from the adjacent laser diode assembly 3 at a mounting spacing that satisfies equation (1). The optical element assembly 100B is arranged with a plurality of laser diode assemblies 3-1, 3-2, 3-3, and 3-4 at non-equidistant spacings. That is, the distance between at least one laser diode assembly 3 and the adjacent laser diode assembly 3 is different from the distance between other adjacent laser diode assemblies 3. In the optical element assembly 100B, the adjacent laser diode assemblies, i.e., the first laser diode assemblies, are spaced apart from each other at a mounting spacing that satisfies equation (1). The distance P1 between laser diode assemblies 3-1 and 3-2, and the distance P2 between laser diode assemblies 3-2 and 3-3, for example, are of the same length, and the laser diode assemblies 3-1, 3-2, and 3-3 are equally spaced. On the other hand, the distance P3 between the adjacent first laser diode assembly and the second laser diode assembly, i.e., the distance between laser diode assemblies 3-3 and 3-4, does not satisfy equation (1), and is, for example, shorter than the aforementioned distances P1 and P2. In addition, distance P3 can also be greater than or equal to distance P1 or P2.

[0194] The first laser diode assembly is bonded to the optical waveguide substrate using a metal film M and is formed using the same bonding process as in the manufacturing method of the optical element assembly described in the above embodiment. Therefore, from the viewpoint of suppressing positional misalignment of non-bonded laser diode assemblies during the bonding process, the distance between these laser diode assemblies is preferably formed to satisfy the mounting spacing P. On the other hand, since the second laser diode assembly is bonded to the optical waveguide substrate 40 via the adhesive layer 77, the impact of bonding adjacent first laser diode assemblies to the optical waveguide substrate 40 is minimal, and vice versa. Therefore, even with the optical element assembly 100B, the alignment of laser diode assemblies 3-1, 3-2, and 3-3 can be performed with high precision. Furthermore, the possibility of positional misalignment of laser diode assembly 3-4 during the bonding of laser diode assembly 3-3 is minimal, and a structure in which all laser diode assemblies 3 are mounted on the optical waveguide substrate 40 with high precision can be formed.

[0195] Furthermore, in the optical element assembly of the above embodiment, a structure in which all bases 20 have the same size is illustrated, but it is also possible for at least one base to have a different size from the other bases. In such a structure, in equations (1) and (2), the width W and thickness T of the bases 20 of adjacent laser diode assemblies 3 are used with larger values. The optical element assembly of this embodiment does not make the distance between the laser diode assemblies 3 a specific value, but is designed according to the size of the laser diode assemblies 3, thereby becoming a structure with a high degree of freedom.

[0196] Furthermore, according to the optical element assembly of the above embodiment, by providing multiple independent laser diode assemblies 3, the effects of separation of electrical influences and heat between the individual laser diode assemblies 3 can be eliminated. For example, it can also eliminate the effects of strict precision management of each component and electrothermal and optical influences that occur when multiple laser diodes are mounted on a subcarrier and further bonded to the substrate 40. Here, when separate and independent laser diode assemblies as in this embodiment are mounted on the substrate 40, various dimensions are affected by the reflow soldering method and bonding process. The optical element assembly of this embodiment specifies the size of the subcarrier and the waveguide spacing considering this situation.

[0197] in addition, Figure 10 It means Figure 1 A cross-sectional view of an example of the structure of an optical element assembly in other variations. Figure 10 In the optical element assembly 100C shown, an anti-reflective film 81 is provided between the LD30 and the PLC50. For example, the anti-reflective film 81 is integrally formed on the bonding surface 42 of the substrate 40 and the incident surface 50A of the PLC50. However, the anti-reflective film 81 may also be formed only on the incident surface 50A of the PLC50.

[0198] exist Figure 10 In the optical element assembly 100C shown, in addition to the anti-reflective film 82 provided on the incident surface 50A, an anti-reflective film 82 is also provided on the exit surface 64.

[0199] Antireflective films 81 and 82 are used to prevent incident or emitted light to the PLC 50 from being reflected in a direction opposite to the direction from which it enters the surface from the incident surface 50A or the emitted surface 64, and to improve the transmittance of the incident or emitted light. Antireflective films 81 and 82 are, for example, multilayer films formed by alternately stacking various dielectrics at predetermined thicknesses corresponding to the wavelengths of red, green, and blue light, which are incident light. Examples of such dielectrics include titanium oxide (TiO2), tantalum oxide (Ta2O5), silicon oxide (SiO2), and aluminum oxide (Al2O3).

[0200] The exit surface 31 of LD30 and the incident surface 50A of PLC50 are arranged at a specified interval. The incident surface 50A is opposite to the exit surface 31, and there is a gap K between the exit surface 31 and the incident surface 50A in the x-direction. Considering that the optical element assembly 100C is used for XR glasses and the amount of light required by the XR glasses, the size of the gap (interval) K in the x-direction is, for example, greater than 0 μm and less than 5 μm.

[0201] The following is about Figure 10 The optical element assembly 100C shown is described, but the same principle applies to the optical element assembly 100.

[0202] The optical element assembly 100C is arranged such that its bottom surface (base bottom surface) 20b, which faces the upper surface (surface) 20a of the subcarrier (laser source base) 20 (20-1, 20-2, 20-3), and its bottom surface (substrate bottom surface) 43, which faces the upper surface 41 of the substrate 40, are located on approximately the same plane S. In the optical element assemblies 100 and 100C, since the subcarrier 20 and the substrate 40 are connected via a metal film, the occurrence of positional displacement caused by the bonding process can be significantly suppressed compared to the case where adhesive bonding is used.

[0203] Furthermore, the generally identical plane S mentioned here allows for slight offsets between the bottom surface (base bottom surface) 20b and the bottom surface (substrate bottom surface) 43. Specifically, an offset of less than 20 μm relative to the thickness of the substrate 40 along the z-direction is allowed, but the smaller the offset, the better, more preferably less than 10 μm, and even more preferably less than 5 μm.

[0204] If, as shown in the optical element assembly 100C, the bottom surface 20b of the subcarrier 20 and the bottom surface 43 of the substrate 40 are formed to be located on approximately the same plane S, then the subcarrier 20 and the substrate 40 can be bonded to a plane, for example, a package or heat sink. Thus, compared to the case where the bottom surfaces of the subcarrier and the substrate are not on approximately the same plane and can only be bonded to one of them, the optical element assembly 100C can efficiently dissipate heat generated by the operation of the LD (optical semiconductor element) 30 on both the bottom surface 20b of the subcarrier 20 and the bottom surface 43 of the substrate 40.

[0205] Furthermore, by setting the bottom surface 20b of the subcarrier 20 and the bottom surface 43 of the optical waveguide substrate 40 on approximately the same plane S, as shown in the optical element assembly 100C, when the optical module is bonded to a plane of other substrates, the bottom surface 20b of the subcarrier 20 and the bottom surface 43 of the optical waveguide substrate 40 can be bonded to a plane of the substrate, thus maintaining high bonding strength and realizing an optical element assembly 100C with excellent impact resistance.

[0206] For example, when the bottom surface of the subcarrier is located in the +z direction relative to the bottom surface of the substrate, that is, when the bottom surface of the subcarrier moves upward away from the base 180 of the package 110 relative to the bottom surface of the substrate (see reference). Figure 12In the previous configuration, the size of the first side of the subcarrier was relatively small, resulting in ineffective heat dissipation. Furthermore, if wire bonding (described later) was performed with insufficient bonding strength to the substrate, the subcarrier could sometimes slip off. However, in the illustrated optical element assemblies 100 and 100C, the size of the side of the base 20 is adequately ensured, allowing for sufficient heat dissipation from the bottom surface 20b and sides of the base 20, as well as adequate bonding with the optical waveguide substrate 40. Therefore, heat dissipation and shock resistance are improved. By improving shock resistance, for example, the LD30 can be maintained in an optimal position relative to the PLC50. Therefore, the optical element assembly 100C can achieve the desired light utilization efficiency and optical characteristics, improving the reliability of the optical element assemblies 100 and 100C.

[0207] [Optical Module]

[0208] Figure 11 This is a top view schematic diagram of the optical module in this embodiment. Figure 12 It is Figure 11 The diagram shows a cross-sectional view of the optical module cut along the XZ plane.

[0209] Figure 11 The optical module 1000 shown contains the optical element assembly of the above embodiment within the package 110. Figure 11 The optical component assembly shown is also known as a laser assembly.

[0210] In addition to the optical element assembly described in the above embodiment, the package 110 may also include known constituent elements. For example, it may be able to house a photodetector (PD).

[0211] If a photodiode (PD) is included, variations in the light output of the LD can be detected by observing the current flowing through the PD. Furthermore, the current flowing through the PD can be monitored and the drive current of the LD controlled to maintain a constant output.

[0212] The package 110 includes a body 102 having a cavity structure and a cover 105 covering the body 102.

[0213] The main body 102 has: a bottom on which the internally housed components are placed; and a wall portion (side wall portion) 102a arranged to surround these components from the side.

[0214] A light-transmitting window 101 is formed in the wall portion (side wall portion) 102a arranged along the direction of laser emission, through which the laser L emitted from the laser source 30 can optically pass.

[0215] A light-transmitting window (opening) 101 is formed on the side wall 102a near the emission portion of the laser L emitted from the optical module 1000 in the side wall portion of the storage section 107. The opening 101 is formed approximately at the center of the side wall 102a at a position intersecting the optical axis of the emitted laser. The opening 101 is covered without gap by a glass plate 220 from the outside of the side wall 102a. That is, the storage section 107 is hermetically sealed by the cover 105 and the glass plate 220. Although the glass plate 220 is used for hermetical sealing, any material that the laser can pass through is acceptable, and it is not limited to a glass plate. An anti-reflective film (not shown) may also be provided on both surfaces of the glass plate 220.

[0216] The electrode portion 108 is disposed in the x-direction, at the front side, i.e., at the rear in the x-direction, of the housing portion 107. The upper surface of the electrode portion 108 is located below the upper surface of the housing portion 107. The bottom surface of the electrode portion 108 is located at approximately the same height as the bottom surface of the housing portion 107. On the upper surface of the electrode portion 108, a plurality of external electrode pads 210 are provided at intervals in the y-direction.

[0217] like Figure 10 As shown, a base 180 for mounting an optical module is provided at a predetermined position at the bottom of the storage section 107. The optical module includes an LD30 and a sub-carrier 20 on which the LD30 is mounted, a PLC50 and a waveguide substrate 40 on which the PLC50 is formed. The optical module is mounted on the base 180. That is, the optical module is disposed in the internal space of the storage section 107. The bottom surface (base bottom surface) 20b of the sub-carrier (laser source base) 20 and the bottom surface (substrate bottom surface) 43 of the waveguide substrate 40 are located on approximately the same plane S. Therefore, both the sub-carrier 20 and the waveguide substrate 40 of the optical module are bonded to the upper surface 180a (an inner surface) of the base 180.

[0218] The bottom surface (base bottom surface) 20b of the subcarrier 20 and the bottom surface (substrate bottom surface) 43 of the optical waveguide substrate 40 can be bonded to the upper surface 180a (an inner surface) of the base 180 via the adhesive layer 182. To improve thermal conductivity, the adhesive layer 182 uses a material in which filler is mixed into a resin. Examples of resins constituting the adhesive layer 182 include epoxy resin. Additionally, copper powder, aluminum powder, alumina powder, etc., can be used as fillers to improve the thermal conductivity of the resin.

[0219] In addition, in order to maintain a certain level of thermal conductivity, the thermal conductivity of such adhesive layer 182 is preferably 0.5 W / m·K or higher, more preferably 1 W / m·K or higher, and even more preferably 4 W / m·K or higher.

[0220] In this way, by bonding both the carrier 20 of the optical module and the optical waveguide substrate 40 to the upper surface 180a of the base 180 of the package 110, heat generated by the operation of the LD30 can be efficiently dissipated from the bottom surface (base bottom surface) 20b of the carrier 20 and the bottom surface (substrate bottom surface) 43 of the optical waveguide substrate 40 toward the base 180. Furthermore, by bonding the bottom surface 20b of the sub-carrier 20 and the bottom surface 43 of the optical waveguide substrate 40 together with an adhesive layer made of a resin mixed with filler, heat can be efficiently transferred from the bottom surface 20b of the sub-carrier 20 and the bottom surface 43 of the optical waveguide substrate 40 toward the base 180.

[0221] Figure 13 This is a conceptual diagram of an optical module with an optical waveguide layer, representing... Figure 11 The optical module is illustrated by a top view showing the structure within the package.

[0222] For components common to the optical element assemblies described above, the same reference numerals are sometimes used and descriptions are omitted. Figure 13 The image shows an example of an optical component assembly that, in addition to an RGB laser light source, also has a near-infrared laser light source. Near-infrared lasers are invisible, therefore, they can be used for eye tracking.

[0223] exist Figure 13 In the optical module 2000 shown, an optical element assembly 100B is housed within the package 110. The optical element assembly 100B includes: an RGB laser light source 30 and a laser light source base 20 for mounting the RGB laser light source 30; a near-infrared laser light source 35 and a laser light source base 20-4 for mounting the near-infrared laser light source 35; an optical waveguide substrate 140 on which a PLC 150 is formed; and metal films 72, 73, and 74 for bonding the laser light source base 20 and the laser light source base 20-4 to the optical waveguide substrate 140.

[0224] Near-infrared laser source 35 is mounted on subcarrier 20-4 in the same manner as laser source 30. In addition, PLC 150 is formed on optical waveguide substrate 140.

[0225] The optical module 2000 has a PLC 150 within the package 110. The PLC 150 includes: optical waveguides 151 (151-1, 151-2, 151-3) for guiding the laser emitted from the laser source 30 and optical waveguides 152 for guiding the near-infrared laser emitted from the near-infrared laser source 35.

[0226] In the optical module 2000, the optical waveguide substrate 140 on which the PLC150 is formed, the subcarrier 20 on which the laser light source 30 is mounted, and the subcarrier 20-4 on which the near-infrared laser light source 35 is mounted are also integrated by metal bonding.

[0227] This metal bonding allows for precise optical axis configuration and also enables miniaturization.

[0228] Examples of substrates 140 used for optical waveguides include sapphire substrates, Si substrates, and thermally oxidized silicon substrates.

[0229] like Figure 13 As shown, optical waveguides 151-1, 151-2, and 151-3 converge into one at the front side of the emission surface of PLC 150. That is, optical waveguides 151-1, 151-2, and 151-3 gradually merge forward in the x-direction, merging into one optical waveguide 151-4. Preferably, optical waveguides 151-1, 151-2, and 151-3 are connected to optical waveguide 151-4 with a radius of curvature greater than a specified radius of curvature to prevent light leakage from optical waveguides 151-1, 151-2, and 151-3.

[0230] By metal bonding between the optical waveguide substrate 140 and the subcarrier 20, and with the optical axis accurately aligned in such a way that the center of the entrance port of each ridge 151-1, 151-2, 151-3, 152 of the PLC50 is approximately aligned with the optical axis of the emitted light from each corresponding LD 30-1, 30-2, 30-3, 35, each ridge is arranged opposite to each corresponding LD.

[0231] The entrance ports of each optical waveguide 151-1, 151-2, 151-3, and 152 are opposite to the exit ports of each LD30-1, 30-2, 30-3, and 35, and are positioned so that light emitted from the exit ports of each LD30-1, 30-2, 30-3, and 35 can enter each entrance port. Each LD30-1, 30-2, 30-3, and 35 is optically connected to each optical waveguide 151-1, 151-2, 151-3, and 152.

[0232] like Figure 13 As shown, red, green, and blue light emitted from LD30-1, 30-2, and 30-3 are incident on the entrances of optical waveguides (ridges) 151-1, 151-2, and 151-3, respectively, and propagate within each ridge. The red and green light propagating in ridges 151-3 and 151-2 converge at a predetermined convergence position 157-1, located behind the convergence position 157-2 in the x-direction. The converged red and green light then merges with the blue light propagating in 151-2 at convergence position 57-2. The RGB light, after converging at convergence position 57-2, propagates in ridge 151-4, reaches the exit surface, and is emitted from the exit surface.

[0233] In addition, the near-infrared light emitted from the LD35 propagates in the ridge 152, reaches the emission surface, and is emitted from the emission surface.

[0234] The optical waveguides 151-1, 151-2, 151-3, and 152 in the PLC150 can also be Mach-Zehnder type optical waveguides.

[0235] [XR Glasses]

[0236] The XR glasses of this embodiment incorporate the optical module described in the above embodiment into the glasses.

[0237] XR glasses (glasses) are glasses-type terminals. XR is a general term for Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality.

[0238] Figure 15 A conceptual diagram of XR glasses used to illustrate this embodiment is shown.

[0239] Figure 15 The XR glasses 10000 shown have an optical module 1001 mounted on a frame 10010. The reference numeral L indicates the image display light.

[0240] exist Figure 15 In this specification, the optical module 1001, the optical scanning mirror 3001, and the optical system 2001 connecting the optical module 1001 and the optical scanning mirror 3001 are collectively referred to as the optical engine 5001. The optical module 1001 is any of the optical modules described in the above embodiments. The optical engine is also referred to as an optical engine module.

[0241] As a light source in the optical module 1001, for example, an RGB laser light source with a red laser light source 30-1, a green laser light source 30-2 and a blue laser light source 30-3, and a near-infrared laser light source 35 can be used.

[0242] As a light source in the optical module 1001, for example, an RGB laser light source with a red laser light source 30-1, a green laser light source 30-2 and a blue laser light source 30-3, and a near-red laser light source 35 can be used.

[0243] like Figure 15 As shown, the laser light irradiated from the optical module 1001 mounted on the eyeglass frame is reflected by the optical scanning mirror 3001. The reflected light is then reflected by the mirror 4001, which reflects the light in the direction of the human eyeball E, and enters the human eyeball E, where it can directly project an image (picture) onto the retina M.

[0244] By incorporating an eye-tracking mechanism, images are projected directly onto the retina while simultaneously tracking the eye movements. Known mechanisms can be used as eye-tracking mechanisms.

[0245] The optical scanning mirror 3001 is, for example, a MEMS mirror. In order to project a 2D image, a biaxial MEMS mirror that vibrates in a manner that changes the angle of the laser in the horizontal direction (X direction) and the vertical direction (Y direction) is preferred.

[0246] The optical system 2001, which performs optical processing on the laser emitted from the optical module 1001, includes a collimating lens 2001a, a slit 2001b, and an ND filter 2001c. This optical system is one example, but other structures are also possible.

[0247] The optical engine 5001 has a laser driver 1100, an optical scanning mirror driver 1200, and a video controller 1300 that controls these drivers.

[0248] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Within the scope of the spirit of the present invention as set forth in the claims, various omissions, substitutions, modifications, and alterations are possible. These embodiments and their modifications are included in the scope and spirit of the invention, and similarly included in the scope of the invention as set forth in the claims and its equivalents.

Claims

1. An optical element assembly, characterized in that, have: Multiple laser diode components; and An optical waveguide substrate has an optical waveguide layer disposed on its main surface, the optical waveguide layer having an optical waveguide for guiding laser light emitted from the plurality of laser diode components. The laser diode assembly has a base and a laser diode formed on the base. At least one of the plurality of laser diode assemblies is spaced apart from the adjacent laser diode assembly in such a way that the mounting spacing satisfies equation (1). P≥W+0.9T……(1) Where P is the installation spacing, W is the width of the base, and T is the thickness of the base.

2. The optical element assembly according to claim 1, characterized in that, The plurality of laser diode assemblies are arranged in a non-equidistant manner.

3. The optical element assembly according to claim 1, characterized in that, The plurality of laser diode assemblies are spaced apart by means of an installation spacing that satisfies equation (1) between adjacent laser diode assemblies.

4. The optical element assembly according to claim 3, characterized in that, The plurality of laser diode assemblies are arranged at equal intervals with adjacent laser diode assemblies.

5. The optical element assembly according to claim 1, characterized in that, The laser diode assembly is bonded to the optical waveguide substrate via multiple metal films.

6. The optical element assembly according to claim 5, characterized in that, The plurality of metal films contain Sn and Au.

7. The optical element assembly according to claim 1, characterized in that, The plurality of laser diode assemblies are formed in such a way that they satisfy the mounting spacing of equation (2). P≤Wo-nW……(2) Where Wo is the width of the optical element assembly, and n is the number of laser diode assemblies contained in the optical element assembly.

8. The optical element assembly according to claim 2, characterized in that, The plurality of laser diode assemblies includes: at least two first laser diode assemblies disposed adjacently, which are bonded to the optical waveguide substrate via a plurality of metal films; and at least one second laser diode assembly bonded to the optical waveguide substrate via an adhesive layer. The adjacent first laser diode assemblies of the plurality of laser diode assemblies are arranged with a spacing P between them in a manner that satisfies the mounting spacing of equation (1). The distance between the second laser diode assembly and the adjacent laser diode assembly is less than the distance P.

9. An optical module, characterized in that, The package contains the optical element assembly as described in any one of claims 1 to 8.

10. An optical engine, characterized in that, have: The optical module as described in claim 9; and A light scanning mirror, which changes its angle to reflect light emitted from the optical module for image display.

11. An XR pair of glasses, characterized in that, It is equipped with the optical engine as described in claim 10.

12. A method for manufacturing an optical element assembly, characterized in that, It has a bonding process that bonds multiple laser diode components to an optical waveguide substrate via multiple metal films. The optical waveguide substrate includes a substrate and an optical waveguide layer having an optical waveguide formed on the main surface of the substrate. The laser diode assembly includes a base and a laser diode formed on the base. In the bonding process, at least one of the plurality of laser diode assemblies is irradiated with a laser to heat the substrate, with the mounting spacing satisfying equation (1) and at least one of the laser diode assemblies being spaced apart from the adjacent laser diode assembly. P≥W+0.9T……(1) Where P is the installation spacing, W is the width of the base, and T is the thickness of the base.

13. The method for manufacturing an optical element assembly according to claim 12, characterized in that, In the bonding process, the substrate on which a first metal film containing Au is formed is brought into contact with the substrate on which a second metal film containing Sn is formed and heated to form a eutectic film of Au and Sn.

14. The method for manufacturing an optical element assembly according to claim 12 or 13, characterized in that, The substrate is a Si substrate. A YAG laser is used in the joining process.

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