JP5324371B2 - Optical connection component and optical connection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical connecting component in which stress given to optical fibers is relaxed, insertion loss, break of the optical fibers and polarized wave extinction ratio are improved and an array composing is easy. <P>SOLUTION: The optical connecting component separates an inner space from outside with a housing (10), a lid (12) and a transmission window (600) provided on the housing. The transmission window is composed so that the optical fiber (200) or a planar light wave circuit (300) may be connected to the inner space side, a second optical fiber (202) or a second planar light wave circuit may be connected to the out part side, the light which propagates in the optical fiber or the planar light wave circuit may be connected to the second optical fiber or the second planar light wave circuit via the transmission window, or the light which propagates in the second optical fiber or the second planar light wave circuit may be connected to the optical fiber or the planar light wave circuit via the transmission window. The thickness of the transmission window is such that the coupling loss of light is within 0.5 dB, and the thermal expansion/contraction coefficient of the transmission window is smaller than the thermal expansion/contraction rate of the housing. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an optical connection component and an optical connection method, and more specifically, a component for connecting an optical element installed in an internal space surrounded by a casing, a lid, and a transmission window to an external optical fiber or a planar lightwave circuit, and Regarding the method.

  With the recent increase in the amount of data communication, optical elements used for optical fiber communication are required to cope with the increase in the number of channels. Accordingly, it has become more important to miniaturize the optical element package. In addition, optical elements using semiconductor materials such as laser diodes, photodiodes, and optical modulators are worried about characteristic deterioration due to moisture. Therefore, when an optical element is packaged, the optical element is mounted in an internal space sealed with a housing and a lid in order to isolate the optical element from moisture. Conventionally, when connecting input / output light from an optical element installed in an internal space to an external optical fiber, the following optical connection parts have been used.

(Prior art 1)
By passing a metallized fiber sealed in advance in the inner diameter part of the optical fiber holding part through the opening of the case and sealing the case and the optical fiber holding part, input / output light from the internal optical element is received. An optical connection component that connects to an external optical fiber is known (see, for example, Patent Document 1).

  FIG. 1 shows the configuration of a conventional optical connection component. In this optical connection component, a metallized fiber 20 is used for internal and external optical connection in a package having an internal space surrounded by a housing 10 and a lid 12. The metallized fiber 20 is held on the inner diameter part of the optical fiber holding part 22. The casing 10 and the lid 12 are made of an iron-nickel alloy. The metallized fiber 20 is manufactured by plating nickel and gold around the strand portion of a single mode fiber made of quartz glass. Here, the diameter of the strand is 125 μm, and the thickness of the plating is about 5 μm.

  The internal space of the package is sealed by sealing the inner diameter portions of the metallized fiber 20 and the optical fiber holding portion 22 in advance, penetrating the optical fiber holding portion 22 through the opening of the housing 10, and the housing 10 and the optical fiber holding portion. This is done by sealing 22. For the sealing, a brazing material such as gold-tin alloy solder is used. The reflow temperature at the time of sealing is 280 degrees or more.

(Conventional technology 2)
In addition, in a package having an internal space surrounded by a housing 10 and a lid 12 as shown in FIG. 2, an optical connection component having a configuration in which a transmission window 60 and a lens 40 are used for internal and external optical connection is known. (For example, refer to Patent Document 2). At least one lens 40 of the optical connection component shown in FIG. 2 is installed between the optical element 30 installed in the internal space and the external optical fiber 20. The configuration example shown in FIG. 2 is a collimating optical system in which lenses 40-1 and 40-2 are installed one by one near the optical element 30 and the optical fiber 20, respectively. The lens 40 is fixed to the housing 10 using lens holding portions 42 and 43. The optical element 30 is fixed to the housing 10 via an element mount 32. The optical fiber 20 is fixed in advance to a ferrule that is an optical fiber holding portion 22. Further, the ferrule is fixed to the metal sleeve 24.

  The internal space of the package is sealed by previously sealing the transmission window 60 and the housing 10 and attaching the lid 12. Unlike the prior art 1, the optical fiber and the optical fiber holding part are not penetrated into and out of the housing. Further, welding with YAG light is used for fixing the housing 10 and the lens holding portions 42 and 43, fixing the lens holding portions 42 and 43 and the metal sleeve 24, and fixing the metal sleeve 24 and the optical fiber holding portion 22.

JP 2005-055475 A (paragraph 0019, FIG. 1) JP 2005-338434 A (paragraph 0018, FIG. 1)

  However, the conventional optical connection parts and optical connection methods have the following problems. First, in the optical connection component using the metallized fiber shown in FIG. 1 as an optical fiber, stress and cracks are likely to occur in the optical fiber because the metallization is performed on the thin optical fiber. Therefore, there has been a problem that the insertion loss of the optical fiber is increased and disconnection is likely to occur. Further, when a polarization maintaining fiber is used as the optical fiber, there has been a problem that the polarization extinction ratio is deteriorated due to non-uniformity in stress on the optical fiber due to uneven thickness of the plating. Further, when brazing the metallized fiber to the optical fiber holding part, there is a concern about an increase in loss due to stress generated by the brazing material, disconnection, and deterioration of the polarization extinction ratio. Furthermore, the optical element may deteriorate due to heat generated during brazing. In order to avoid this, the sealing portion and the optical element have to be installed at a sufficient distance, and there is a problem that the package becomes large.

  In addition, in the optical connection component using the lens coupling shown in FIG. 2, due to thermal expansion and contraction of the package, a positional shift occurs between the optical element and the lens, or between the optical fiber and the lens, and the coupling loss increases. There was a problem. In addition, when multi-channel optical connection is performed by arraying optical elements, there is a problem in that the spherical aberration of the lens is generated, so that coupling loss varies depending on the channel.

  The present invention has been made in view of such a problem. The object of the present invention is to relieve stress on an optical fiber, improve insertion loss, disconnection, and polarization extinction ratio, and can be easily arrayed. An optical connection component and an optical connection method are provided.

  In the optical connecting component according to the present invention, the optical signal input / output end of an optical element such as an optical fiber or a planar lightwave circuit in the internal space of the casing is directly connected to a transmission window provided in the casing.

  The optical connection component according to the first aspect of the present invention has an internal space separated from the outside by a casing, a lid, and a transmission window provided in the casing, and the transmission window is formed of the transmission window. An optical fiber or a planar lightwave circuit is connected to the internal space side, and a second optical fiber or a second planar lightwave circuit is connected to the outside of the transmission window, and light propagates through the optical fiber or the planar lightwave circuit. Is coupled to the second optical fiber or the second planar lightwave circuit through the transmission window, or the light propagating through the second optical fiber or the second planar lightwave circuit is transmitted through the transmission window It is configured to be coupled to an optical fiber or a planar lightwave circuit.

  In one embodiment, the optical fiber and the second optical fiber are each mounted on an optical fiber holding portion and maintained in a state of being connected to the transmission window. The optical fiber is connected to the transmission window so as to have a buckling portion in the internal space.

  In one embodiment, the transmission window has a lens function. A part of the transmission window can be constituted by a lens.

  In one embodiment, the internal space is hermetically sealed.

  An optical connection method for an optical connection component according to a second aspect of the present invention is an optical connection component having an internal space separated from the outside by a casing, a lid, and a transmission window provided in the casing. After connecting the external optical fiber or planar lightwave circuit to the external side of the transmission window, connecting the optical fiber or planar lightwave circuit of the internal space to the internal space side of the transmission window, or (2) An optical fiber or a planar lightwave circuit in an internal space is connected to the internal space side of the transmission window, and then the external optical fiber or a planar lightwave circuit is connected to the external side of the transmission window.

  In one embodiment, after the optical fiber holding part having a hollow is bonded to the inner space side of the transmission window and the optical fiber of the inner space is passed through the hollow and connected to the inner space side of the transmission window The external optical fiber or the planar lightwave circuit is connected to the external side of the transmission window.

  As described above, according to the present invention, an increase in optical loss and a deterioration in the polarization extinction ratio are suppressed even when the optical element is displaced due to thermal expansion and contraction of the casing. In addition, it is possible to increase the number of arrays using a small casing.

It is a block diagram of the conventional optical connection component. It is another block diagram of the conventional optical connection component. It is a figure which shows the optical connection component in 1st Embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a general view of the package using the optical connection component in 1st Embodiment, (a) is sectional drawing, (b) is a top view. It is a figure for demonstrating the connection method about the optical connection part of the package in 1st Embodiment, (a) And (b) is a figure for demonstrating each process. It is a figure for demonstrating the connection method about the optical connection part of the package in 1st Embodiment, (a) And (b) is a figure for demonstrating each process. It is a figure for demonstrating the relationship regarding the thickness of a transmissive window, and a coupling loss. It is a general view of the optical connection component and package in 2nd Embodiment, (a) is sectional drawing, (b) is a top view. It is a figure for demonstrating the connection method about the optical connection part which connected the planar lightwave circuit to the transmission window of the package in 2nd Embodiment, (a) And (b) is a figure for demonstrating each process. It is. It is a figure for connecting the connection method about the optical connection part in the transmission window of the package in 2nd Embodiment, (a), (b) and (c) are the figures for demonstrating each process. . It is a figure which shows the optical connection component in 3rd Embodiment. It is a figure which shows the optical connection component in 4th Embodiment.

  The optical connection component according to the present invention has an internal space separated from the outside by a housing, a lid, and a transmission window provided in the housing. In the transmission window, the optical input / output end of an optical element such as an optical fiber or a planar lightwave circuit is connected to the transmission window provided in the housing, and an optical signal propagating through the optical fiber or the planar lightwave circuit passes through the transmission window. To be coupled to another optical fiber or a planar lightwave circuit. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or similar reference numerals are used for the same or similar elements, and repeated description is omitted.

(First embodiment)
FIG. 3 shows an optical connection component according to the first embodiment of the present invention. This optical connection component packages an optical element (not shown) in an internal space surrounded by the casing 10 and the lid 12. The casing 10 is provided with a transmissive window 600. The housing 10, the transmission window 600, and the lid 12 divide the inside and outside of the optical connection component to form an internal space. In FIG. 3, the light input / output end of the optical fiber 200 inside the optical connecting component faces the transmission window 600 and is connected by bonding using an adhesive (light-transmitting resin) 500. Similarly, the light input / output end of the optical fiber 202 outside the optical connection component is connected to the transmission window 600 so as to face it. As a result, the optical fiber 200 and the optical fiber 202 face the transmission window 600, and light propagating through them is connected (coupled) through the transmission window 600.

  More specifically, the optical fibers 200 and 202 are connected to the transmission window 600 while being held by the optical fiber holding portions 220 and 222, respectively. The optical fiber holding portions 220 and 222 are ferrules having a multi-core hollow, and an optical fiber strand is bonded and fixed to the hollow portion with a resin. For adhesion, the resin is temporarily fixed by irradiation with ultraviolet rays, and then annealed at around 60 ° C. for permanent fixing.

  The casing 10 and the lid 12 are made of an iron-nickel alloy. As the optical fibers 200 and 202, single mode fibers made of quartz glass are used.

  4 (a) and 4 (b) show an overall view of a package using optical connection components. FIG. 4A is a cross-sectional view of the package as viewed from the side, and FIG. 4B is a top view of the package without the lid 12. In this package, a planar lightwave circuit (PLC) 300 as an optical element is fixed to the housing 10 via a PLC mount 320 in an internal space surrounded by the housing, the transmission window, and the lid. The planar lightwave circuit 300 is manufactured by depositing quartz on a silicon substrate. By performing deposition while changing the refractive index, an optical waveguide having a core and a clad is produced on the substrate. The thickness of the planar lightwave circuit 300 is about 1 mm.

  In FIG. 4, drawing of a circuit diagram is omitted. The light input / output ends of the optical fibers 200-1 and 200-2 held by the optical fiber holding portions 224-1 and 224-2 are connected to the two light input / output ends of the optical waveguide of the planar lightwave circuit 300, respectively. Yes. Here, for reinforcement, connection portion reinforcing plates 322-1 and 322-2 are installed on the planar lightwave circuit 300. In the present embodiment, four array optical fibers are used as the optical fibers 200-1 and 200-2. Although not shown, the optical waveguides on the planar lightwave circuit are also arranged in an array.

  The other light input / output end of the optical fiber 200-1 connected to the planar lightwave circuit 300 is held by the optical fiber holding unit 220-1, and is connected to the inside of the casing of the transmission window 600-1. Similarly, the other end of the optical fiber 200-2 is held by the optical fiber holding unit 220-2 and connected to the inside of the casing of the transmission window 600-2.

  Furthermore, the optical fiber 202-1 held by the optical fiber holding part 222-1 is connected to the outside of the casing of the transmission window 600-1. Similarly, the optical fiber 202-2 held by the optical fiber holder 222-2 is connected to the outside of the casing of the transmission window 600-2. The optical fibers 200-1 and 200-2 are provided with a gentle buckling portion with respect to the height direction of the package, and the radius thereof is 15 mm.

  The internal space of the package is sealed by previously sealing the transmission window 600 and the housing 10 and attaching the lid 12.

  Next, the optical connection method will be described with reference to FIGS. FIG. 5 shows one connection method for the optical connection portion of the package shown in FIG. The connection procedure is as follows: (1) As shown in FIG. 5A, first, the optical fiber 202 outside the housing is connected to the transmission window 600 by bonding. The bonding position at that time may be bonded with a loose accuracy, for example, within ± 1 mm. (2) Next, as shown in FIG. 5B, the optical fiber 200 in the housing is bonded to the transmission window 600. At that time, the optical fibers are input and adjusted so that the cores of the two optical fibers 200 and 202 are aligned. The bonding position of the fiber 200 needs to be bonded with strict accuracy such as within ± 1 μm with respect to the bonding position of the optical fiber 202.

  FIG. 6 shows another connection method for the optical connection portion of the package shown in FIG. The connection procedure is as follows: (1) First, as shown in FIG. 6A, the optical fiber 200 in the housing is connected to the transmission window 600 by bonding. The bonding position at that time may be bonded with a loose accuracy, for example, within ± 1 mm. (2) Next, as shown in FIG. 6B, the optical fiber 202 outside the housing is connected to the transmission window 600 by bonding. At that time, the optical fibers are input and adjusted so that the cores of the two optical fibers 200 and 202 are aligned. The bonding position of the optical fiber 202 needs to be bonded with strict accuracy such as within ± 1 μm with respect to the bonding position of the optical fiber 200.

  Here, the thickness of the transmission window 600 will be described with reference to FIG. FIG. 7 is a diagram showing the relationship between the thickness of the transmission window 600 and the coupling loss. For the transmission window 600, sapphire or quartz glass is usually used, and in these cases, the relationship between the thickness and the coupling loss was obtained by calculation. For comparison, the calculated value of the air layer is also added to FIG. From this result, when the transmission window 600 is configured using a sapphire window or quartz glass, the coupling loss can be suppressed to within 0.5 dB by setting the thickness of the transmission window 600 to 50 μm or less.

  As described above, when the optical device in the internal space is packaged using the optical connection component of the present embodiment, even if the housing 10 expands or contracts due to heat, an increase in loss due to a shift in the connection position of the optical fiber is unlikely to occur. That is, as shown in FIG. 3, the optical connection between the inside and the outside of the housing 10 is performed by the optical fibers 200 and 202 that are directly connected to both the internal space side and the outside side of the transmission window 600. The thermal expansion / contraction of the transmission window is small compared to the thermal expansion / contraction of the optical connection, and the positional displacement amount of the optical connection is reduced. In FIG. 4, the connection between the planar lightwave circuit 300 and the optical fibers 200-1 and 200-2 is not provided with a space, and the optical waveguide of the planar lightwave circuit 300 and the cores of the optical fibers 200-1 and 200-2 are bonded. Because of the direct connection, the displacement can be ignored regardless of the thermal expansion and contraction of the housing. In addition, since the optical fiber is not subjected to metallization, stress and cracks on the optical fiber can be reduced. Therefore, there is an effect that an increase in insertion loss or disconnection of the optical fiber and deterioration of the polarization extinction ratio are unlikely to occur. Further, the optical fibers 200 and 202 can be bonded to the transmission window 600 in a low temperature environment of about 60 degrees using a resin. Therefore, damage to the optical element 300 inside the package is reduced, and the size of the package can be reduced. In addition, since no lens is used, for example, a multi-channel connection of about 40 channels can be mounted with little loss variation.

  Although the transmission window 600 is an isotropic medium here, it is possible to improve the coupling loss by processing at least one of the transmission windows 600-1 and 600-2 into a lens shape such as a Fresnel lens. is there. Further, since the optical fiber 200 inside the housing is buckled, stress on the fiber 200 due to expansion and contraction of the housing 10 due to heat can be avoided. Furthermore, since the core of the fiber 200 is directly connected to the optical waveguide of the planar lightwave circuit 300, the optical fiber 200 can be routed even if the mounting direction of the optical element 300 is changed. improves. Moreover, although the optical fiber holding | maintenance parts 220 and 222 were made into the ferrule which has a multi-core hollow, you may use the member which mounted the strand fiber on the glass plate which performed V-groove processing. In the case of using a ferrule or a V-grooved part, the resistance of the connecting portion to vibration and impact is improved as compared with the case where only the optical fibers 200 and 202 are connected to the transmission window. Further, by using a resin adhesive in the method of mounting the optical fiber on the optical fiber holding portions 220 and 222, it is possible to fix the optical fiber with less stress, and to prevent deterioration of the characteristics of the optical fiber. is there.

  Although two different methods described with reference to FIGS. 5 and 6 were used as the optical connection method, the optical fibers 200 and 202 may be connected to the two transmission windows 600 in the package by any one method. The connection may be made by different methods. The difference between the two is the order of the optical fibers 200 and 202 attached to the transmission window 600. When both are compared, it can be said that the method of FIG. 6 is more effective. This is because the connection accuracy to the transmission window inside the housing may be loose. In the case of the connection method of FIG. 5 where the connection accuracy is strict, high rigidity and accuracy are required for the device and jig required for attachment. Therefore, since it is necessary to insert such a device or jig into the housing, the size of the housing is likely to increase. On the other hand, in the case of FIG. 6, the apparatus and the jig may be simple and the housing can be miniaturized.

(Second Embodiment)
8A and 8B are general views of the optical connection component and the package according to the second embodiment of the present invention. FIG. 8A is a cross-sectional view of the package viewed from the side, and FIG. 8B is a top view of the package without a lid. In this optical connection component, a planar lightwave circuit (PLC) 300 is packaged as an optical element in an internal space surrounded by the casing 10 and the lid 12. The casing 10 is provided with a transmissive window 600. The housing 10, the transmission window 600, and the lid 12 divide the inside and outside of the optical connection component to form an internal space. Similar to the above embodiment, the transmission windows 600-1 and 600-2 are used for optical connection between the inside and the outside of the housing 10. The optical fibers 200-1 and 202-1 are connected to one transmission window 600-1 so as to face each other, and the optical fiber 202-2 and the planar lightwave circuit 300 are connected to the other transmission window 600-2. The optical fibers 200 and 202 and the planar lightwave circuit 300 are connected to the transmission window by bonding using a light-transmitting resin. The optical fibers 200 and 202 are held by optical fiber holding portions 220 and 222. The optical fiber holding part 222 is a ferrule having a multi-core hollow, and an optical fiber strand is bonded and fixed to the hollow part with a resin. For adhesion, the resin is temporarily fixed by irradiation with ultraviolet rays, and then annealed at around 60 degrees to be permanently fixed. The casing 10 and the lid 12 are made of an iron-nickel alloy. As the optical fibers 200 and 202, single mode fibers made of quartz glass are used.

  In this package, a planar lightwave circuit 300 is mounted as an optical element in an internal space surrounded by the housing 10 and the lid 12, but the main fixing portion is not used as the housing 10 via the PLC mount. Is a bonding portion with the transmission window 600-2. The planar lightwave circuit 300 is manufactured by depositing quartz on a silicon substrate. By performing deposition while changing the refractive index, an optical waveguide having a core and a clad is produced on the substrate. The thickness of the planar lightwave circuit 300 is about 1 mm. In FIG. 8, drawing of a circuit diagram is omitted. One end of the optical waveguide of the planar lightwave circuit 300 is connected to the inner space side of the transmission window 600-2, and the other end is connected to one end of the optical fiber 20-1 held by the optical fiber holding unit 224-1. In FIG. 8, four array optical fibers are used. Although not shown, the optical waveguides on the planar lightwave circuit 300 are also arranged in an array. In order to reinforce the optical waveguide of the planar lightwave circuit 300, connection portion reinforcing plates 322-1 and 322-2 are installed on the planar lightwave circuit 300. The other end of the optical fiber 200-1 connected to the planar lightwave circuit 300 is connected to the housing internal space side of the transmission window 600-1. Furthermore, the optical fibers 202-1 held by the optical fiber holders 222-1 are connected to the outside of the casing of the transmission window 600-1. The optical fiber 200-1 between the planar lightwave circuit 300 and the transmission window 600-1 is provided with a gentle buckling portion in the package width direction, and its radius is 15 mm.

  The internal space of the package is sealed by previously sealing the transmission window 600 and the housing 10 and attaching the lid 12.

  Next, the optical connection method will be described with reference to FIGS. FIG. 9 shows a connection method for the optical connection part in which the planar lightwave circuit 300 is connected to the transmission window 600-2 in the package shown in FIG. The connection procedure is as follows: (1) First, as shown in FIG. 9A, the planar lightwave circuit 300 in the housing is connected to the transmission window 600-2 by bonding. The bonding position at that time may be bonded with a loose accuracy, for example, within ± 1 mm. (2) Next, as shown in FIG. 9B, the optical fiber 202-2 outside the housing is bonded to the transmission window 600-2. At this time, adjustment is performed by inputting light into the optical fiber so that the position of the core of the optical fiber 202-2 on the outside of the housing matches the position of the optical waveguide of the planar lightwave circuit 300. The bonding position of the optical fiber 202-2 needs to be bonded with strict accuracy such as within ± 1 μm with respect to the position of the optical waveguide of the planar lightwave circuit 300 in the housing.

  FIG. 10 shows a connection method for the optical connection portion in the transmission window 600-1 of the package shown in FIG. The connection procedure is as follows: (1) As shown in FIG. 10A, first, the optical fiber holding part 220-1 having a hollow is bonded to the transmission window 600-2. The bonding position at that time may be bonded with a loose accuracy, for example, within ± 1 mm. (2) Next, as shown in FIG. 10B, the optical fiber 200-1 is passed through the hollow portion of the optical fiber holding portion 220-1 in the housing. (3) Further, as shown in FIG. 10C, the optical fiber 202-1 outside the housing is bonded to the transmission window 600-1. At that time, the optical fibers 200-1 and 202-1 are adjusted by inputting light to the optical fibers so that the positions of the cores are aligned. The bonding position of the optical fiber 202-1 needs to be bonded with strict accuracy such as within ± 1 μm with respect to the bonding position of the optical fiber optical fiber 200-1 in the housing.

  As described above, when the optical device in the internal space is packaged by using the optical connection component of this embodiment, even if expansion or contraction occurs in the housing due to heat as in the first embodiment, the optical connection portion is displaced. Loss increase is unlikely to occur. That is, the optical connection between the inside and the outside of the casing is performed by the optical fibers 200 and 202 and the planar lightwave circuit 300 directly connected to both the internal space side and the outside side of the transmission window 600. In comparison, the thermal expansion and contraction of the transmission window is small, and the effect of reducing the displacement of the optical connection is obtained. Further, in FIG. 8, the connection between the planar lightwave circuit 300 and the optical fiber 200-1 is made by directly connecting the optical waveguide of the planar lightwave circuit 300 and the core of the optical fiber 200-1 with an adhesive or the like without providing a space. Here too, the displacement is negligible regardless of the thermal expansion and contraction of the housing. In addition, since the optical fiber is not subjected to metallization, stress and cracks on the optical fiber can be reduced. Therefore, there is an effect that an increase in insertion loss or disconnection of the optical fiber and deterioration of the polarization extinction ratio are unlikely to occur. Further, the optical fibers 200 and 202 can be bonded to the transmission window 600 in a low temperature environment of about 60 degrees using a resin. Therefore, damage to the optical element 300 inside the package is reduced, and the size of the package can be reduced. In addition, since no lens is used, for example, a multi-channel connection of about 40 channels can be mounted with little loss variation.

  Furthermore, in this embodiment, since the planar lightwave circuit 300 is directly bonded to the transmission window 600-2, the number of components of the optical fiber and the optical fiber holding portion can be reduced as compared with the first embodiment. In addition, since a mount for fixing the planar lightwave circuit to the housing 10 is not used, the mounting process on the mount can be eliminated, and simpler mounting becomes possible. Here, the optical fiber 202 is used for the optical connection method outside the housing, but a planar lightwave circuit may be directly connected to the outside of the housing of the transmission window 600. That is, a planar lightwave circuit may be connected to face the transmission window. As a result, the optical waveguide can be connected at a narrow pitch, which is impossible with an optical fiber array, such as a pitch between optical waveguides of 10 μm, so that the package can be further miniaturized.

(Third embodiment)
FIG. 11 shows an optical connection component according to the third embodiment of the present invention. This optical connection component packages the optical element 300 in an internal space surrounded by the housing 10 and the lid 12. The casing 10 is provided with a transmissive window 600. The housing 10, the transmission window 600, and the lid 12 divide the inside and outside of the optical connection component to form an internal space. In FIG. 11, the light input / output end of the optical fiber 204 inside the optical connection component faces the transmission window 600 and is connected by bonding using an adhesive (light-transmitting resin) 500. The lens 400 is connected to the outer side of the casing of the transmission window 600, and the light input / output end of the optical fiber 202 outside the optical connection component is bonded to the transmission window 600 using an adhesive (light-transmitting resin) 500. It is connected. As a result, the optical fiber 200 and the optical fiber 202 face the transmission window 600 and the lens 400, and light propagating through the optical fiber 200 and the optical fiber 202 is connected (coupled) via the transmission window 600 and the lens 400. The optical fibers 204 and 202 are held by optical fiber holding portions 220 and 222, respectively. The optical fiber holding portion is a ferrule having a multi-core hollow, and an optical fiber strand is bonded and fixed to the hollow portion with a resin. For adhesion, the resin is temporarily fixed by irradiation with ultraviolet rays, and then annealed at around 60 ° C. for permanent fixing. The casing 10 and the lid 12 are made of an iron-nickel alloy. As the optical fibers 200 and 202, single mode fibers made of quartz glass are used.

  Further, a laser diode 300 as an optical element is mounted via an element mount 320 in an internal space surrounded by the casing 10 and the lid 12. The other end of the optical fiber 204 bonded to the transmission window 600 on the inside of the housing is processed into a tip and performs optical coupling with the laser diode 300.

  The internal space of the package is sealed by previously sealing the transmission window 600 and the housing 10 and attaching the lid 12.

  As described above, when the optical device (laser diode) 300 in the internal space is packaged by using the optical connecting component of this embodiment, the metallization process is not performed on the optical fiber as in the first and second embodiments. Therefore, stress and cracks on the optical fiber can be reduced. Therefore, there is an effect that an increase in insertion loss or disconnection of the optical fiber and deterioration of the polarization extinction ratio are unlikely to occur. Further, the coupling loss can be reduced by the lens 400 attached to the outside of the casing of the transmission window 600 as compared with the case where the lens is not used. Further, as in the first and second embodiments, even if expansion and contraction occur in the housing 10 due to heat, an increase in loss due to the displacement of the optical connection portion is unlikely to occur, and thus good optical coupling with the laser diode 300 is achieved. Can be held. In particular, since the lens 400 is directly connected to both the transmission window 600 and the optical fiber 202, the positional deviation is less likely to occur than in the prior art.

  Although a laser diode is used here as the optical element, other semiconductor optical elements such as a photodiode and an optical modulator can be applied in the same manner. In this embodiment, the lens is attached to the outside of the housing, but it may be attached directly to the inner space side of the transmission window 600 or directly to both the inner space side and the outer side of the transmission window 600.

(Fourth embodiment)
FIG. 12 shows an optical connecting component according to the fourth embodiment of the present invention. This optical connection component is packaged as an optical element (not shown) in an internal space surrounded by the casing 10 and the lid 12. The casing 10 is provided with a transmissive window 600. The housing 10, the transmission window 600, and the lid 12 divide the inside and outside of the optical connection component to form an internal space. In FIG. 12, the light input / output end of the optical fiber 200 inside the optical connection component faces the transmission window 600 and is connected by bonding using an adhesive (light-transmitting resin) 500. A lens 400 held by a lens holding portion 43 fixed to the housing 10 is disposed on the outside of the housing of the transmission window 600, and the light input / output end of the optical fiber 202 outside the optical connection component is the transmission window 600. Are connected to each other via a lens 402. As a result, the optical fiber 200 and the optical fiber 202 face the transmission window 600 and the lens 402, and light propagating through the optical fiber 200 and the optical fiber 202 is connected (coupled) via the transmission window 600 and the lens 402. The optical element is fixed to the housing 10 via an element mount (not shown). The optical fiber 202 is fixed in advance to the ferrule 22 which is an optical fiber holding unit. Further, the ferrule 22 is fixed to the metal sleeve 24. Welding with YAG light is used for fixing the housing 10 and the lens holding portion 43, fixing the lens holding portion 43 and the metal sleeve 24, and fixing the metal sleeve 24 and the optical fiber holding portion 22.

  The light input / output end of the optical fiber 200 inside the housing is connected to the transmission window 600 by bonding using an adhesive (light-transmitting resin) 500. The optical fiber 200 is held by an optical fiber holding unit 220. For adhesion, the resin is temporarily fixed by irradiation with ultraviolet rays, and then annealed at around 60 ° C. for permanent fixing. The casing 10 and the lid 12 are made of an iron-nickel alloy. As the optical fibers 200 and 202, single mode fibers made of quartz glass are used.

  The internal space of the package is sealed by previously sealing the transmission window 600 and the housing 10 and attaching the lid 12.

  As described above, when the optical device in the internal space is packaged using the optical connecting component of the present embodiment, the optical fiber and the optical fiber holding unit 2 are penetrated into and out of the housing as in the first to third embodiments. There is nothing. Since the optical fiber is not metallized, stress and cracks on the optical fiber can be reduced. Therefore, there is an effect that an increase in insertion loss or disconnection of the optical fiber and deterioration of the polarization extinction ratio are unlikely to occur. Further, the coupling loss can be reduced by the lens 402 attached to the outside of the casing of the transmission window 600 as compared with the case where no lens is used. Similarly to the first to third embodiments, even if expansion and contraction occur in the housing 10 due to heat, an increase in loss due to displacement of the optical connection portion is unlikely to occur. Bonds can be retained.

  While the present invention has been described with respect to several specific embodiments, the embodiments described herein are merely illustrative in view of the many possible embodiments to which the principles of the present invention can be applied. It is not intended to limit the scope of the invention.

For example, an optical fiber with an obliquely polished end face may be connected to the transmission window. Thereby, it is possible to reduce the reflected return light at the connection portion. It is also possible to further improve the connection loss in the optical connection by changing the spot size by expanding or reducing the core diameter of the optical fiber connected to the transmission window and the planar lightwave circuit. In the present invention, the internal space surrounded by the casing and the lid is airtight. The value is preferably 1 × 10 ⁶ Pa · m ³ / s or less as the amount of leak of He gas.

DESCRIPTION OF SYMBOLS 10 Case 12 Lid 20 Metallized fiber 22 Optical fiber holding | maintenance part 24 Metal sleeve 200,202 Optical fiber 220,222,224 Optical fiber holding | maintenance part 30 Optical element 32 Element mount 300 Planar optical circuit (PLC)
320 PLC mount 322 Connection portion reinforcing plate 40 Lens 42, 43 Lens holding portion 400, 402 Lens 50 Sealant 500 Adhesive 60 Transmission window

Claims (11)

An optical connecting component having an internal space separated from the outside by a housing, a lid, and a transmission window having a thermal expansion / shrinkage rate smaller than the thermal expansion / shrinkage rate of the housing ,
The transmission window, the tip of the optical fiber or a planar lightwave circuit in the internal space side of the transmission window is directly connected by bonding, the second optical fiber or the second planar lightwave circuit to the external side of the transmission window And light propagating through the optical fiber or planar lightwave circuit is coupled to the second optical fiber or second planar lightwave circuit via the transmission window, or the second optical fiber or second An optical connection part configured to couple light propagating through a planar lightwave circuit to the optical fiber or the planar lightwave circuit through the transmission window. 2. The optical connection component according to claim 1, wherein a tip end portion of the second optical fiber or the second planar lightwave circuit is directly connected to the outer side of the transmission window by bonding. 3. The optical connection component according to claim 1, wherein the thickness of the transmission window is such that the coupling loss of the light is within 0.5 dB. Said optical fibers or mounting the second optical fiber, so as to maintain a state of the optical fiber or the second optical fiber is connected directly to the transmission window, adapted to be adhered to the transparent window The optical connection component according to claim 1, further comprising an optical fiber holding portion. The optical connection component according to claim 1, wherein the optical fiber is directly connected to the transmission window so as to have a buckling portion in the internal space.   The optical connection component according to claim 1, wherein the transmission window has a lens function.   The optical connection component according to claim 6, wherein a part of the transmission window is configured by a lens.   The optical connection component according to claim 1, wherein the internal space is hermetically sealed. An optical connection method for an optical connection component having an internal space separated from the outside by a housing, a lid, and a transmission window having a thermal expansion / shrinkage rate that is smaller than the thermal expansion / shrinkage rate of the housing The tip of the external optical fiber or the planar lightwave circuit is directly connected to the outside of the transmission window by an adhesive, and then the tip of the optical fiber or the planar lightwave circuit in the internal space is connected to the inside of the transmission window. An optical connection method for an optical connection component, wherein the optical connection component is directly connected to the space side by an adhesive . An optical connection method for an optical connection component having an internal space separated from the outside by a housing, a lid, and a transmission window having a thermal expansion / shrinkage rate that is smaller than the thermal expansion / shrinkage rate of the housing After the optical fiber in the internal space or the front end portion of the planar lightwave circuit is directly connected to the inner space side of the transmission window by an adhesive, the front end portion of the external optical fiber or the planar lightwave circuit is connected to the transmission window. An optical connection method for an optical connection component, wherein the optical connection component is directly connected to an external side with an adhesive . An optical connection method for an optical connection component having an internal space separated from the outside by a housing, a lid, and a transmission window having a thermal expansion / shrinkage rate that is smaller than the thermal expansion / shrinkage rate of the housing , bonding the optical fiber holder having a hollow in the internal space side of the transmission window, and connecting the tip of the optical fiber of the inner space directly into the inner space side of the transmission window by passing adhered to the hollow An optical connection method for an optical connection component, wherein the external optical fiber or the distal end portion of the planar lightwave circuit is directly connected to the external side of the transmission window with an adhesive .

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