JP2004126128A - Optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical module which is increased in coupling efficiency on the whole and can suppress stray light. <P>SOLUTION: In Fig., a clad is indicated by 11-3a. A Y-branch part 13-1a normally branches off into two waveguides, so a stray light is generated differently from a waveguide mode transmitted through one waveguide. In a PD (photo diode) 12-2a, on the other hand, an absorption layer 12-2a-1 is able to receive light even not in single mode and the light need not to be guided to the PD by a single-mode waveguide as an optical waveguide. A multi-mode optical waveguide 11-2a is arranged as one circuit of the Y-branch circuit 13-1a and a photodiode is arranged at its terminal. Further, when the optical waveguide is abruptly changed as the multi-mode optical waveguide, many modes of high order are generated and it becomes difficult to completely confine light, so it is constituted so that the waveguide width is gradually expanded to generate a mode of high order which can be propagated. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical module in which an optical waveguide circuit and an optical semiconductor element are integrated, and more particularly, to an optical module adapted to an optical circuit in which an optical component having a multi-mode optical waveguide structure such as a light receiving element is integrated.
[0002]
[Prior art]
In an optical module in which a single mode optical waveguide and an optical semiconductor element are hybrid-integrated, a structure has been generally adopted in which light is guided to the element by the single mode optical waveguide and the optical waveguide and the optical semiconductor element are optically coupled to the optical semiconductor element ( For example, see Non-Patent Document 1).
[0003]
FIG. 7 is an example of the prior art. In the figure, reference numeral 71-1 denotes a single mode optical waveguide core. A part of the optical waveguide on the optical waveguide substrate is removed, a recess is provided, and a laser diode (hereinafter, also referred to as an LD (laser diode)) 72-1 and a photodiode for receiving (hereinafter, PD (hereinafter, referred to as PD) are provided as optical semiconductor elements. Photo diode 72-2) is fixed on a substrate, and is combined with the Y branch circuit 73-1 of the optical waveguide 71-1 to constitute an optical transceiver.
[0004]
In general, in a single-mode optical waveguide, light is largely radiated to a cladding in an optical circuit portion or an optical coupling portion. Also in FIG. 7 of the conventional example, light emission appears at the Y-branch and causes loss. Symbol 710-2 is stray light.
Also, in the X-crossing waveguide as shown in FIG. 8, when one waveguide light crosses the other waveguide region in the X-crossing circuit 83-2 at the crossing portion, light becomes radiative at that portion. If the optical waveguide ahead has the same structure as the incident side, uncoupled light will be present and inefficient, and extra stray light will be generated in the waveguide. Reference numeral 810-2 is stray light.
[0005]
[Non-patent document 1]
Junichi Yoshida et al., "Technical Perspective of Economicalization of Components for Optical Access Systems", NTT R & D, 1997, Vol. 46, no. 5, pp 467-472
[0006]
[Problems to be solved by the invention]
In the above-described optical module, stray light is generated at the Y-branch of the optical waveguide, at the intersection of the optical waveguide, and at the optical coupling portion between the optical waveguide and the semiconductor element.
[0007]
For this reason, the prior art has a problem to be solved such that light to be received by a PD is reduced or stray light is combined with another PD.
[0008]
The present invention has been made in view of such a problem, and an object of the present invention is to provide an optical module capable of increasing the coupling efficiency of the entire module and suppressing stray light.
[0009]
[Means for Solving the Problems]
In order to achieve such an object, an optical module according to the present invention is an optical module including a single-mode optical waveguide and an optical component corresponding to a multi-mode, and integrating an optical element having a planar element structure. A multi-mode optical waveguide is provided in the vicinity of the optical circuit portion comprising the single-mode optical waveguide, and optically coupled to the optical component via the multi-mode optical waveguide (Embodiments 1, 2, and 4). , FIGS. 1-4, and 6).
[0010]
Here, the vicinity of the optical circuit portion can be characterized in that it is at the subsequent stage of the Y branch circuit (Embodiment 1, FIG. 1).
[0011]
Further, a cross circuit is provided near the optical circuit portion, and light transmitted through the cross circuit is optically coupled to the optical component (Embodiment 2, FIGS. 3, 4).
[0012]
The vicinity of the optical circuit portion is a cross circuit, and the reflected light of the cross circuit is optically coupled to the optical component (Embodiment 4, FIG. 6).
[0013]
Further, the multimode optical waveguide has an opening angle toward the optical component, and the opening angle is tanΘ = λ / (πw) (λ: wavelength in a medium, w; field radius, π; circumference). Rate) that satisfies the relationship (ratio) (Embodiment 2, FIGS. 3, 4).
[0014]
Further, the light to be optically coupled to the optical component may be light leaking from the single mode optical waveguide (Embodiments 1, 2, and 4, FIGS. 1 to 4, and 6).
[0015]
Further, the single mode optical waveguide may be a bent waveguide (Embodiment 1, FIG. 2).
[0016]
Further, a clad structure capable of confining light may be provided instead of the multi-mode optical waveguide (Embodiment 1, FIG. 1, Embodiment 4, FIG. 6).
[0017]
Further, the vicinity of the optical circuit portion may be a stage subsequent to the directional coupler (Embodiment 1, 2, or 4).
In addition, the vicinity of the optical circuit portion can be characterized by being located after the star coupler (Embodiment 1, 2, or 4).
[0018]
In order to achieve the above object, the optical module of the present invention is an optical module that includes a single-mode optical waveguide and an optical component corresponding to multimode, and integrates an optical element having a planar element structure, An optical element having a different field diameter from the single-mode optical waveguide is coupled to the single-mode optical waveguide, and a clad structure capable of confining light in the vicinity of the coupled portion is provided, and the optical component is provided through the clad structure. (Embodiment 3, FIG. 5).
[0019]
Here, the axis of the cladding structure can be characterized by being along a predetermined radiation angle of light from the coupling portion to the optical component (Embodiment 3, FIG. 5).
[0020]
Further, the light to be optically coupled to the optical component may be leak light of the single mode optical waveguide (Embodiment 3, FIG. 5).
[0021]
According to the above configuration, in the optical module having the single-mode main planar optical waveguide circuit and the multi-mode optical waveguide structure in the component, the multi-mode optical waveguide is provided near the multiplexer / demultiplexer or the optical coupling part of the optical waveguide circuit. A structure is formed, and the waveguide is optically coupled to a multimode optical component.
[0022]
A multi-mode optical waveguide generally has a large field diameter, and can transmit light that is not coupled by a single-mode waveguide structure. From this, by using the above configuration, light generated in the optical multiplexing / demultiplexing circuit and which normally leaks light can be easily guided to the optical component, and since the optical component is multi-mode, the efficiency of the entire circuit is improved. Good optical components can be manufactured.
[0023]
In addition, an embodiment and a figure number corresponding to the claims are shown in parentheses. However, the components described in the claims are not limited to the components of the embodiment of the above ().
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the portions having the same functions are denoted by the same reference numerals, and the description thereof will not be repeated.
[0025]
In all the embodiments, the optical waveguide is made of silica, and has a step index type core structure. However, in the present invention, the optical waveguide may not be made of silica, and the structure of the waveguide core may not be a step index type.
[0026]
[Embodiment 1]
1A and 1B show an optical waveguide substrate having a Y-branch circuit, in which a part of the waveguide is removed to provide an optical element mounting portion, and a laser diode (LD) and a photodiode (PD) are hybrid-integrated. It is a figure of an optical module. FIG. 1A is a diagram when a multi-mode waveguide core is used. FIG. 1B is a diagram showing a case where a part of the cladding is removed to form a waveguide structure. In FIG. 1A, a laser diode (LD) 12-1a and a photodiode (PD) 12-2a are hybrid-integrated. In FIG. 1B, a laser diode (LD) 12-1b and a photodiode (PD) 12-2b are hybrid-integrated.
[0027]
In FIGS. 1A and 1B, reference numerals 11-3a and 11-3b denote claddings. In the Y-branching portions 13-1a and 13-1b, the light is normally split into two waveguides, so that unlike the guided mode transmitted by one, light that is not coupled like stray light 710-2 shown in FIG. appear. On the other hand, in the PD 12-2a and PD 12-2b, the absorption layers 12-2a-1 and 12-2b-1 can receive light even if they are not in the single mode, and light is guided to the PD by the single mode waveguide as an optical waveguide. No need.
[0028]
Therefore, in the first embodiment, as shown in FIG. 1A, one circuit of the Y-branch circuit 13-1a is a multi-mode optical waveguide 11-2a, and a photodiode is disposed at the end. Furthermore, when the optical waveguide is rapidly changed as a multi-mode optical waveguide, a large number of higher-order modes are generated, and it becomes difficult to completely confine light. The configuration is such that only higher-order modes occur. As a result, the excess loss in the Y branch, which was about 1 dB in the past, can be suppressed to about 1 dB.
[0029]
As shown in FIG. 1B, the optical module having this configuration may have a structure in which a part of the cladding 11-3b is removed as a structure for guiding stray light. At this time, the waveguide may not be provided as the core 11-4 of the waveguide connected to the PD 12-2b, or may be a single-mode or other-mode waveguide.
[0030]
FIGS. 2A and 2B are diagrams of an optical module using a bent waveguide. FIG. 2A is an explanatory diagram of light emission by a bent waveguide. FIG. 2B is a diagram showing a case where the radiation light from the bent waveguide is guided and incident on the PD.
[0031]
In FIG. 2A, reference numeral 21-1a denotes a single mode optical waveguide core, 21-3a denotes a cladding, and 210-1a denotes a propagating light. When the optical waveguide is sharply bent, stray light 210-2a is generated from a bent portion. I do.
[0032]
In FIG. 2B, reference numeral 21-1a denotes a single mode optical waveguide core, 21-3b denotes a clad, 22-1b-1 denotes a laser diode element active layer, and 22-2b-1 denotes a photodiode element corresponding to a multimode. The absorption layer 220-3 is a conventional optical waveguide trajectory with a radius of curvature. If there is no problem even if the amount of light entering the PD is very small, a multi-mode waveguide structure 21-2b that couples with leaked light may be provided as shown in FIG. 2B to guide the light to the PD. . This makes it possible to reduce the radius of curvature when bending the waveguide. In the first embodiment, it is necessary to provide a distance of about 1 mm between the LD 22-1b and the PD 22-2b in order to obtain an electrode. Required about 3 mm. In the embodiment of FIG. 2 (b), the required horizontal distance on the drawing can be reduced to increase the vertical distance of the distance between the LD and the PD to about 2 mm in the drawing.
[0033]
Although the same applies to the following embodiments 2 to 4 as the branch circuit, a directional coupler or a star coupler may be used instead of the Y branch according to the first embodiment.
[0034]
[Embodiment 2]
FIGS. 3 and 8 show a 1.3 micron 1.55 micron wave filter (33-4, 83-4) composed of a dielectric multilayer film formed on a polyimide film and an X cross circuit 33-X using an X cross optical waveguide. FIG. 2 is a diagram of an optical module in which an optical waveguide having a wavelength branching circuit integrated in 2, 83-2, and LDs 32-1 and 82-1 and PDs 32-2 and 82-2 compatible with multimode are hybrid-integrated.
[0035]
FIG. 8 is a diagram showing a conventional structure of a wavelength division multiplexing optical transceiver using an X-crossing waveguide and a filter. Reference numeral 81-1 denotes a single mode optical waveguide core, and reference numeral 81-3 denotes a cladding. Although the film 83-4 has a thickness of about 20 microns, light is diffracted in this portion, and relatively large diffraction loss occurs in the transmitted light when the output waveguide has the same thickness as the incident optical waveguide. I do.
[0036]
Therefore, FIG. 3 shows a case where the PD emission side optical waveguide is a multi-mode optical waveguide 31-2. Reference numeral 31-1 denotes a single mode optical waveguide core, and 31-3 denotes a clad.
[0037]
Here, the radiation angle is assumed to be a Gaussian beam, and the width w320-2 of the waveguide (field diameter (radiation angle × distance) corresponding to the radiation angle determined by the distance from the radiation part, field radius in the single mode waveguide) is assumed. Is expressed by an angle を 満 た す that satisfies the relationship of tan Θ = λ / (πw) using the wavelength λ in the medium. Was comparable. Thereby, the stray light 810-2 due to the conventional diffraction is confined in the core portion, and the coupling ratio of the PD is improved by about 0.2 dB.
[0038]
FIG. 4 shows the structure of a multi-channel WDM optical transceiver in which a plurality of optical modules having the configuration shown in FIG. 3 are formed on the same substrate. Here, the filter circuit 43-4 is inserted over a plurality of unit modules each including the above-described circuit (the circuit of FIG. 3) as one unit, and suppresses leakage of the LD emission side light to the PD side. Reference numeral 41-3 denotes a clad, 43-2 denotes an X cross circuit, 42-1a to 42-1d denote laser diode elements, and 42-2a to 42-2d denote photodiode elements corresponding to a multi-mode.
[0039]
On the other hand, FIG. 9 shows the structure of a conventional multi-channel WDM optical transceiver in which a plurality of optical modules having the configuration shown in FIG. 8 are formed on the same substrate. Here, the filter circuit 93-4 is inserted over a plurality of unit modules each including the above-described circuit (the circuit in FIG. 8) as one unit, and suppresses leakage of the LD emission side light to the PD side. Reference numeral 91-3 denotes a clad, 93-2 denotes an X cross circuit, 92-1a to 92-1d denote laser diode elements, and 92-2a to 92-2d denote photodiode elements.
[0040]
As for light incident on the PD side, light having substantially the same wavelength is incident on the PD 92-2a via, for example, the optical waveguide core 91-1. Thus, uncoupled light becomes stray light 810-2 and becomes other light. When entering the PDs 92-2b to 92-2d, it becomes crosstalk noise 910-3.
[0041]
However, in FIG. 4 of the second embodiment, in the optical waveguide to the PD 42-2a, the light that was conventionally stray light is confined in the optical waveguide core 41-2 and propagates to the PD (propagating light 410-1). Crosstalk can be suppressed. This makes it possible to suppress the level of light crosstalk from about 30 dB in the past to about 40 dB.
[0042]
[Embodiment 3]
FIG. 10 is a configuration diagram of a conventional LD module with a monitor, and FIG. 5 is a diagram of an optical module in which an LD and a PD are integrated in the optical waveguide of the third embodiment.
[0043]
In FIG. 10, reference numeral 102-2 denotes a photodiode element, reference numeral 1010-1 denotes propagation light, and optical coupling between the optical waveguide 101-1 and the LD 102-1 usually has a different field diameter. A large amount of uncoupled light 1010-2 is generated near the end face.
[0044]
Therefore, as shown in FIG. 5, in the third embodiment, in order to keep the emission intensity of the LD 52-1 constant, the PD 52-2 compatible with the multi-mode is used for output monitoring. In FIG. 5, reference numeral 510-1 denotes a propagation light, 510-2 denotes a non-coupled light, 520-1 denotes a radiation angle, and 51-3 denotes a cladding. Here, a part of the clad was removed as a multi-mode optical waveguide (51-4 or the like) and a light guide structure was provided near the joint between the LD 52-1 and the optical waveguide 51-1.
[0045]
The PD 52-2 used here is called a refraction type PD. The PD 52-2 refracts incident light from the side surface of the chip on an oblique wall surface of the chip, takes out light to the chip surface, and receives the light with a surface type absorption layer. . For this reason, the area of the light receiving portion was large and was approximately 100 μmφ. Since the size of the light guide structure by the cladding is about 20 μm square, the spot becomes a sufficiently small spot with respect to the light receiving diameter of the PD 52-2, and a sufficient output monitor of 100 μA at a module output of 0 dBm was possible.
[0046]
Further, since the optical waveguide cannot be interrupted when the PD 52-2 is arranged, it is necessary to sufficiently separate the optical waveguide from the LD. On the other hand, it is necessary to arrange the PD as close as possible to the LD in order to reduce the decrease due to the scattering of the monitor light. Therefore, in the third embodiment, the direction of the optical waveguide structure is set in a range where light does not decrease in accordance with the radiation angle of the LD, and the distance from the LD is made as short as possible. In this structure, when the end face of the waveguide is slanted in consideration of the return light to the LD due to the end face of the optical waveguide, the end face may be refracted in accordance with Snell's law like the optical axis of the waveguide. In this case, since the emission angle 520-1 of the end face of the LD 52-1 was 25 degrees, it was tilted to about 25 degrees, and the cladding wall was directed toward the PD so that total reflection was established at the interface between glass and air. The structure was narrowed.
[0047]
[Embodiment 4]
FIG. 11 is a configuration example of a conventional optical monitor circuit, and FIG. 6 is a configuration example of an optical monitor circuit according to the fourth embodiment. In the fourth embodiment, in FIG. 6, a part of the light incident on the waveguides 61-1a to 61-1c via the optical fibers 61-5a to 61-5c from the left is reflected by the filter 63-4. , The light intensity is monitored by PDs 62-2a to 62-2c corresponding to the multi-mode.
[0048]
Conventionally, as shown in FIG. 11, a single mode waveguide is used for the waveguide 111-1, the tolerance of the reflection part of the filter 113-4 is strict, and good optical coupling to the PD 112-2a is obtained. Is difficult, and the leaked light is incident on the other optical elements 112-2b to 112-2d to cause crosstalk light 111--3. Reference numeral 1110-1 denotes a propagating light, 113-2 denotes an X cross circuit, and 111-3 denotes a clad.
[0049]
Thus, in the fourth embodiment, as shown in FIG. 6, the PD 62-2a to 62-2b side optical waveguides 61-2a to 61-2b are multimode waveguides (lower waveguide circuit in FIG. 6). . As a result, similarly to the second embodiment, among the light reflected to the PD, the light which has been stray light without being coupled to the conventional optical waveguide is guided by the waveguide and coupled to the PD, resulting in high efficiency. Optical coupling is obtained. Further, since the light 1110-3, which has become stray light and crosstalk light in the related art, is confined in the core portions 61-2a and 61-2b, it is possible to suppress crosstalk to other elements. Reference numeral 610-1 is a propagating light, 63-2a to 63-2c are X cross circuits, and 61-3 is a cladding.
[0050]
Further, as shown in the waveguide circuit on the upper side of FIG. 6, a waveguide structure excluding a part of the clad may be used. Reference numerals 61-4a and 61-4b are clad removing portions. In the fourth embodiment, a refraction type PD having a light receiving surface of about 100 μmφ is used as the PD 62-2c so that there is no problem even if the light spreads to a cladding height of 50 μm.
[0051]
Further, a guide structure is provided from the vicinity of the fiber so that the light leaked due to the coupling between the fiber 61-5c and the optical waveguide 61-1c can be received by the PD 62-2c and reflected by the filter 63-4. When this structure is used, the amount of light entering the PD 62-2c can be adjusted by intentionally shifting the fiber 61-5c from the waveguide 61-1c.
[0052]
[Effects of Embodiment]
As described above, according to the present embodiment, the coupling efficiency of the entire module is increased by using an optical element supporting a multi-mode and a multi-mode optical waveguide for a part of the optical module. Is coupled to the multimode optical waveguide, so that stray light can be suppressed at the same time. Further, by optimizing the structure of the optical waveguide to the field diameter and the emission direction, it becomes possible to enhance the optical coupling between the multimode and the emitted light.
[0053]
【The invention's effect】
As described above, according to the present invention, an optical module that includes a single-mode optical waveguide and an optical component that supports a multi-mode, and that integrates an optical element having a planar element structure, includes a single-mode optical waveguide. A multi-mode optical waveguide is provided near the optical circuit portion, and optically coupled to the optical component via the multi-mode optical waveguide. For this reason, the coupling efficiency of the module as a whole is increased, and stray light can be suppressed.
[0054]
Further, according to the present invention, an optical module including a single-mode optical waveguide and an optical component corresponding to a multi-mode and integrating an optical element having a planar element structure has a single-mode optical waveguide having a field diameter different from that of the single-mode optical waveguide. Different optical elements are coupled, and a cladding structure capable of confining light is provided near the coupling portion, and optically coupled to the optical component via the cladding structure.
For this reason, the coupling efficiency of the module as a whole is increased, and stray light can be suppressed.
[Brief description of the drawings]
FIG. 1 shows a first embodiment of the present invention, in which an optical element mounting portion is provided by removing a part of a waveguide on an optical waveguide substrate having a Y branch circuit, and a laser diode (LD) and a photodiode (PD) are hybrid-integrated. FIG. 3A is a diagram of an optical module in which a multimode waveguide core is used, and FIG. 2B is a diagram of a case where a part of a cladding is removed to form a waveguide structure.
FIGS. 2A and 2B are diagrams of an optical module using a bent waveguide according to the first embodiment of the present invention, wherein FIG. 2A is an explanatory diagram of light emission by the bent waveguide, and FIG. It is a figure in case it makes it wave and makes it incident on PD.
FIG. 3 is a diagram when a multi-mode waveguide is used on the PD side according to the second embodiment of the present invention.
FIG. 4 is a structural diagram of a multi-channel WDM optical transceiver according to a second embodiment of the present invention;
FIG. 5 is a diagram of an LD module with a monitor having a structure in which uncoupled light is guided by a clad according to a third embodiment of the present invention.
FIG. 6 is a diagram collectively showing a configuration example of an optical monitor circuit according to a fourth embodiment of the present invention, in which a case using a waveguide core and a case using a cladding are collectively shown.
FIG. 7 is a diagram of an optical transceiver having a conventional Y branch circuit.
FIG. 8 is a structural diagram of a conventional wavelength multiplexing optical transceiver using an X-crossing waveguide and a filter.
FIG. 9 is a structural diagram of a conventional multi-channel WDM optical transceiver.
FIG. 10 is a configuration diagram of a conventional LD module with a monitor.
FIG. 11 is a diagram illustrating a configuration example of a conventional optical monitor circuit.
[Explanation of symbols]
71-1, 21-1a, 81-1, 31-1, 91-1, 101-1, 51-1, 61-1a to 61-1c, 111-1 Single mode optical waveguide cores 11-2a, 21-1 2b, 31-2, 41-2, 61-2a to 61-2b Multimode optical waveguide core 11-4 Waveguide cores 1-3, 91-3, 51-3, 111-3, 61-3 Cladding 51- 4, 61-4a, 61-4b Cladding removers 61-5a to 61-5c Optical fibers 72-1, 12-1a, 12-1b, 22-1b, 32-1, 82-1, 42-1a to 42 -1d, 92-1a to 92-1d, 102-1 and 52-1 Laser diode element 22-1b-1 Laser diode element active layer 72-2, 12-2a, 12-2b, 22-2b, 32-2 , 82-2, 42-2a to 42-2d, 2-2a to 92-2d, 102-2, 52-2, 62-2a to 62-2c, 112-2a to 112-2d Photodiode elements 12-2a-1, 12-2b-122-2b-1 Photo Diode element absorption layers 73-1, 13-1a, 13-1b Y branch circuits 83-2, 33-2, 43-2, 93-2, 113-2, 63-2a to 63-2c X cross circuits 33- 4, 83-4, 43-4, 93-4, 63-4, 113-4 Dielectric multilayer filter 210-1a, 410-1, 1010-1, 510-1, 1110-1, 610-1 Propagation Light 710-2, 810-2, 210-2a, 1010-2, 510-2 Stray light 910-3, 1110-3 Crosstalk light 520-1 Radiation angle 320-2 Field radius 220-3 in single mode waveguide Conventionally Half curvature The trajectory of the optical waveguide by

Claims (13)

In an optical module including a single-mode optical waveguide and an optical component corresponding to multi-mode, and integrating an optical element having a planar element structure,
A multi-mode optical waveguide is provided in the vicinity of the optical circuit portion comprising the single-mode optical waveguide,
An optical module, which is optically coupled to the optical component via the multimode optical waveguide. The optical module according to claim 1,
The optical module according to claim 1, wherein the vicinity of the optical circuit portion is a stage subsequent to the Y branch circuit. The optical module according to claim 1,
The vicinity of the optical circuit portion is a cross circuit,
An optical module, wherein light transmitted through the crossing circuit is optically coupled to the optical component. The optical module according to claim 1,
The vicinity of the optical circuit portion is a cross circuit,
An optical module, wherein the reflected light of the cross circuit is optically coupled to the optical component. The optical module according to claim 1,
The multimode optical waveguide has an opening angle toward the optical component, and the opening angle is tanΘ = λ / (πw) (λ: wavelength in a medium, w; field radius, π; pi). An optical module characterized by an angle を 満 た す satisfying the following relationship: The optical module according to any one of claims 1 to 5,
An optical module, wherein the light to be optically coupled to the optical component is light leaking from the single mode optical waveguide. The optical module according to claim 6,
The optical module according to claim 1, wherein the single mode optical waveguide is a bent waveguide. The optical module according to claim 1, wherein
An optical module comprising a clad structure capable of confining light instead of the multimode optical waveguide. The optical module according to any one of claims 1 to 8,
The optical module according to claim 1, wherein the vicinity of the optical circuit portion is a stage subsequent to the directional coupler. The optical module according to any one of claims 1 to 8,
The optical module according to claim 1, wherein the vicinity of the optical circuit portion is a stage after the star coupler. In an optical module including a single-mode optical waveguide and an optical component corresponding to multi-mode, and integrating an optical element having a planar element structure,
An optical element having a different field diameter from the single mode optical waveguide is coupled to the single mode optical waveguide,
A clad structure capable of confining light near the coupling portion,
An optical module, which is optically coupled to the optical component via the clad structure. The optical module according to claim 11,
The optical module according to claim 1, wherein an axis of the clad structure is along a predetermined radiation angle of light from the coupling portion to the optical component. The optical module according to claim 11 or 12,
An optical module, wherein the light to be optically coupled to the optical component is light leaking from the single mode optical waveguide.

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