JP2008170797A - Lens assembly and optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device by which high reliability is obtained in optical characteristics and performance such as weather resistance and which can lower the manufacturing cost. <P>SOLUTION: A lens assembly 4 has a first lens 12 and a second lens 13, each having a spherical surface section 12b, 13b at its one end surface, a band-pass filter 14, and a sleeve 15 for receiving the band-pass filter 14. In the lens assembly 4, the first lens 12 is fixed to one-end side of the sleeve 15 while the spherical surface section 12b is made to be in contact with an opening edge on the one-end side of the sleeve 15, and the second lens 13 is fixed to the other-end side of the sleeve 15 while the spherical surface section 13b is made to be in contact with the opening edge on the other side of the sleeve 15. An optical device 1 is constructed by assembling the lens assembly 4 in it. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical device such as an optical multiplexer / demultiplexer, an optical isolator, an optical circulator, an optical switch, and an optical gain equalizer used in an optical communication system, and a lens assembly used in the optical device.

  As this type of optical device, a lens assembly fixed with an adhesive or the like so that two lenses face each other through an optical functional component (optical filter, optical isolator core, etc.) inside a cylindrical housing sleeve. It is customary to be incorporated. In addition, a capillary tube in which an end portion of an optical fiber is fixed is fixed with an adhesive or the like in a state of being inserted into an accommodation sleeve of the lens assembly (for example, Patent Document 1 below). ). The lens has a function of converting light emitted from the optical fiber into parallel light, and condensing the parallel light so as to enter the optical fiber. As a lens, a gradient-index cylindrical lens (so-called GRIN lens: one end is a vertical surface orthogonal to the optical axis and the other end is often an inclined surface), two partial spherical shapes having the same center of curvature A cylindrical lens with a uniform refractive index (so-called drum lens) having a lens surface at both ends, a cylindrical lens with a uniform refractive index having a partially spherical lens surface at one end (so-called C lens: the other end on an inclined surface) In many cases, an aspherical lens or the like is used.

JP 2002-182061 A

  As disclosed in the above-mentioned Patent Document 1, in an optical device including a lens assembly that is fixed inside a housing sleeve (protective tube) so that lenses are opposed to each other via an optical functional component, good optical characteristics are obtained. Therefore, it is necessary to adjust the positions of the lens assembly and the capillary tube fixed to the lens assembly so as to obtain an optimum optical alignment state. In particular, in the lens assembly, in order to achieve an optimum optical alignment state from the relationship with the optical fiber, it is necessary to accurately position and fix the two lenses with respect to the housing sleeve. Therefore, in order to make it possible to adjust the position of the lens, it is usual to secure a relatively large gap (diameter difference) between the inner peripheral surface of the housing sleeve and the outer peripheral surface of each lens. . As a result, when the outer periphery of each lens is fixed to the inner peripheral surface of the housing sleeve with an adhesive, a relatively large amount of adhesive enters the gap, resulting from curing shrinkage and deterioration over time of the adhesive. In some cases, the fixed position of the lens whose position has been adjusted is displaced, and high reliability cannot be obtained in terms of performance such as optical characteristics and weather resistance of the optical device as a finished product.

  In particular, in recent years, in the field of optical communication, with the progress of the multimedia information society, the need for high-speed optical communication, wavelength division multiplexing (WDM), high density wavelength division multiplexing (DWDM), etc. is increasing. There has been a demand for an optical device used in a communication system to improve reliability under conditions where higher energy light is input and output. The use of a relatively large amount of adhesive in this type of optical device increases the concern about thermal degradation of the adhesive as the temperature of the optical device rises due to high energy input / output light. Therefore, the problem that the displacement occurs at the fixed position of the lens becomes more prominent.

  In addition, the work itself of adjusting the position of the lens inside the housing sleeve and fixing the lens to the inner periphery of the housing sleeve with an adhesive itself is also troublesome and complicated. Accordingly, the number of steps until the lens is fixed to the inner peripheral surface of the housing sleeve is unreasonably increased, and as a result, the manufacturing cost of the optical device as a finished product increases.

  An object of the present invention is to provide an optical device capable of obtaining high reliability in terms of performance such as optical characteristics and weather resistance.

  Another object of the present invention is to provide an optical device capable of reducing manufacturing costs.

  The first lens assembly according to the present invention, which has been created to solve the above-described problems, contains a first lens and a second lens each having a spherical surface on one end surface, an optical functional component, and the optical functional component. A lens assembly including a housing sleeve, wherein the first lens is fixed to the housing sleeve in a state where a spherical surface portion thereof is in contact with an opening edge portion on one end side of the housing sleeve, and the second lens The lens is characterized in that the spherical portion is fixed to the receiving sleeve in a state where the spherical portion is in contact with the opening edge of the other end side of the receiving sleeve. Here, the optical functional component means an optical filter (bandpass filter, long wavelength transmission / reflection filter, short wavelength transmission / reflection filter, correction gain equivalent filter, etc.), optical isolator core, etc. The same).

  According to such a configuration, the centers of curvature of the spherical portions of the first lens and the second lens can be easily matched with the central axis of the inner periphery of the housing sleeve. That is, the center of curvature of the spherical surface portion can be accurately aligned on the central axis of the inner periphery of the housing sleeve only by bringing the spherical surface portion of each lens into contact with the opening edge of the housing sleeve. In addition, the amount of adhesive required to fix the lens is greatly reduced compared to when aligning with a large gap between the inner peripheral surface of the housing sleeve and the outer peripheral surface of the lens. Can do. Therefore, by incorporating such a lens assembly into an optical device, it is possible to secure an optimal optical alignment state while suppressing a decrease in the optical characteristics and weather resistance of the optical device due to curing shrinkage of the adhesive and deterioration over time. A highly reliable optical device can be constructed. That is, when such a lens assembly is incorporated in an optical device such as an optical multiplexer / demultiplexer, optical isolator, optical circulator, optical switch, optical gain equalizer, etc., it has high reliability in terms of performance such as optical characteristics and weather resistance. Can be obtained.

  In addition, each lens is aligned at an optimal position by simply abutting the respective spherical surface with the opening edge of the housing sleeve, so that the lens alignment operation is not complicated and complicated. . Therefore, by incorporating such a lens assembly into an optical device, it is possible to simultaneously reduce the manufacturing cost in addition to the high reliability in terms of the performance described above.

  In this case, since the first lens and the second lens are fixed to the opening edges of both ends of the common housing sleeve, the axial dimension of the housing sleeve is managed. The distance between the first lens and the second lens can be set easily and accurately.

  In the above-described configuration, an inner sleeve is fitted to the inner periphery of the housing sleeve, and the inner sleeve has an opening edge on one end side of the spherical surface of either the first lens or the second lens. It is preferable that the optical functional component is fixed to at least one of the spherical surface portion or the inner peripheral surface of the housing sleeve in a contact state, and the optical functional component is fixed to the other end surface of the inner sleeve.

  In this way, each of the first lens, the second lens, and the optical functional component can be managed only by managing the dimensions of the receiving sleeve, the inner sleeve, and the optical functional component (the axial dimension of the receiving sleeve). The distance between each other can be set easily and accurately. Since the inner space of the inner sleeve serves as an optical path of light, even when the optical functional component is fixed to the end surface of the inner sleeve with an adhesive, it is possible to suppress the adhesive from entering the optical path as much as possible. it can.

  The second lens assembly according to the present invention, which has been created to solve the above problems, includes a first lens and a second lens each having a spherical surface on one end surface, a first inner sleeve, a second inner sleeve, A lens assembly comprising: an optical functional component; and at least the first inner sleeve, the second inner sleeve, and an accommodating sleeve for accommodating the optical functional component among these components, the first inner sleeve and the second inner sleeve Are fitted and fixed coaxially to the inner periphery of the housing sleeve with the optical functional component interposed between the respective one end faces facing each other, and the first lens is The spherical portion is fixed to the first inner sleeve in a state in which the spherical portion is in contact with the opening edge on the one end side of the first inner sleeve, and the second lens has its spherical portion on the other end side opening of the second inner sleeve. Edge Characterized in that it is fixed to the second sleeve in a state of being contact.

  According to such a configuration, the center of curvature of the spherical portion of the first lens can be easily matched with the central axis of the inner periphery of the first inner sleeve, and the center of curvature of the spherical portion of the second lens is the second. It can be easily aligned with the central axis of the inner periphery of the inner sleeve. Since the first inner sleeve and the second inner sleeve are coaxially fitted and fixed to the inner circumference of the common housing sleeve, the center of curvature of each spherical surface portion of the first lens and the second lens. Will coincide with the central axis of the inner periphery of the receiving sleeve. That is, the center of curvature of each spherical surface can be accurately aligned on the central axis of the inner circumference of the housing sleeve simply by bringing the spherical surface of each lens into contact with the opening edge of the corresponding inner sleeve. In addition, the amount of adhesive required to fix the lens is greatly reduced compared to when aligning with a large gap between the inner peripheral surface of the housing sleeve and the outer peripheral surface of the lens. Can do. Therefore, by incorporating such a lens assembly into an optical device, it is possible to secure an optimal optical alignment state while suppressing a decrease in the optical characteristics and weather resistance of the optical device due to curing shrinkage of the adhesive and deterioration over time. A highly reliable optical device can be constructed. That is, when such a lens assembly is incorporated in an optical device such as an optical multiplexer / demultiplexer, optical isolator, optical circulator, optical switch, optical gain equalizer, etc., it has high reliability in terms of performance such as optical characteristics and weather resistance. Can be obtained. Since each inner sleeve is fitted and fixed to the inner peripheral surface of the receiving sleeve, it is not necessary to form a large gap between the inner peripheral surface of each inner sleeve and the receiving sleeve, and these members are mutually connected. The amount of the adhesive can be reduced also when fixing to.

  In addition, each lens is centered at an optimal position simply by abutting each spherical surface against the opening edge of each inner sleeve, so that it is difficult to align the lens with a troublesome and complicated task. Absent. Therefore, by incorporating such a lens assembly into an optical device, it is possible to simultaneously reduce the manufacturing cost in addition to the high reliability in terms of the performance described above.

  Said structure WHEREIN: It is preferable that the said 1st inner sleeve, the said 2nd inner sleeve, and the said optical functional component are connected within the said accommodation sleeve.

  In this way, the first lens, the second lens, and the optical function can be managed by managing the dimensions of the first inner sleeve, the second inner sleeve, and the optical functional component (the dimensions of the housing sleeve in the axial direction). The distance between the parts can be set easily and accurately. Since the inner space of the inner sleeve serves as an optical path of light, even when the optical functional component is fixed to the end surface of the inner sleeve with an adhesive, it is possible to suppress the adhesive from entering the optical path as much as possible. it can.

  In the above configuration, the first lens and the second lens may be the above-described drum lens or C lens, but are manufactured by processing a part of a spherical lens into a flat portion (hereinafter, referred to as a “lens”). It is preferable that the lens thus manufactured is referred to as a “hemispherical lens”.

  In this way, the spherical portion of the first lens and the spherical portion of the second lens can be processed relatively easily and accurately, and the optimum optical alignment state of each lens can be obtained more reliably. .

  This hemispherical lens has the above-described plane portion and a spherical portion (partial spherical surface) in which a part of the spherical surface of the spherical lens is left as it is. The length (L) of the line segment from the spherical vertex of the spherical portion to the flat portion through the center of curvature (O: the spherical center of the original spherical lens) is the curvature radius of the spherical portion (R: the original spherical lens) It is preferable that it is equal to or larger than the radius. In this way, since an acute angle portion is not formed at the boundary between the spherical surface portion and the flat surface portion, the hemispherical lens is less likely to be damaged such as a chip. In addition, a plane part turns into a surface orthogonal to said line segment.

  The above hemispherical lens has a lens shape such as the radius of curvature of the spherical portion (R: radius of the original spherical lens) and the length of the line segment (L), as compared with a GRIN lens, etc. There is an advantage that the optical characteristics can be easily changed by simply changing the composition. In addition, since a spherical lens as a material can be manufactured with high accuracy, a hemispherical lens obtained by processing the spherical lens has high accuracy and can be manufactured at a relatively low cost.

  A first optical device according to the present invention, which was created to solve the above problems, includes the first lens assembly described above, and optical fibers are inserted into one end surface and the other end surface of the housing sleeve in the lens assembly. It is characterized in that the capillary holding members holding the fixed capillaries are respectively fixed.

  According to such a configuration, it is possible to similarly enjoy the operational effects of the first lens assembly described above.

  The other end surfaces of the first lens and the second lens in the first lens assembly are plane portions, and a capillary holding member holding a capillary tube into which an optical fiber is inserted and fixed is fixed to the flat portion. An optical device may be configured.

  The second optical device according to the present invention, which has been created to solve the above-mentioned problems, includes an end face of the second inner lens assembly on the side where the first lens of the first inner sleeve is fixed, and the second optical device. 2. Capillary holding members holding capillaries with optical fibers inserted and fixed thereto are fixed to end faces of the inner sleeve on the side where the second lens is fixed, respectively.

  According to such a configuration, it is possible to enjoy the operational effects of the second lens assembly already described.

  A third optical device according to the present invention, which has been created to solve the above-described problems, includes the second lens assembly described above, and is provided on each of the other end surfaces of the first lens and the second lens in the lens assembly. It is characterized in that a capillary holding member holding a capillary tube into which an optical fiber is inserted and fixed is fixed to the provided flat portion.

  According to such a configuration, it is possible to enjoy the operational effects of the second lens assembly already described.

  In the above configuration, it is preferable that the first lens and the second lens are hemispherical lenses.

  In this way, the hemispherical lens increases the amount of gap between the tip of the optical fiber and the lens assembly in an optical device, as compared with a drum lens having the same refractive index and the same focal length. This is effective in reducing the influence of reflected return light on the optical fiber. Further, by arranging the hemispherical lens so that the plane portion is orthogonal to the optical axis of the optical fiber, it is possible to prevent or suppress the optical axis tilt deviation due to the refraction of light transmitted through the lens in the plane portion. .

  ADVANTAGE OF THE INVENTION According to this invention, in terms of performance, such as an optical characteristic and a weather resistance, the optical device which can obtain high reliability can be provided.

  Further, according to the present invention, it is possible to provide a cheaper optical device at a reduced manufacturing cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1A is a transverse sectional view showing a schematic configuration of the optical device 1 according to the first embodiment, and FIG. 1B is a longitudinal sectional view showing a schematic configuration of the optical device 1. . As shown in the figure, the optical device 1 is a combination of a two-core collimator and a single-core collimator, and can be used for wavelength division multiplexing (WDM) or the like.

  The optical device 1 includes a first capillary assembly 2, a second capillary assembly 3, and a lens assembly 4 as main elements.

  The first capillary assembly 2 is composed of a glass capillary 7 in which two optical fibers 5 and 6 are fixed to an inner hole of two cores with an adhesive, and an outer periphery of the capillary 7 coaxially. And a glass holding sleeve (capillary holding member) 8 fixed by, for example. The front end surfaces 5a and 6a of the optical fibers 5 and 6 and the front end surface 7a of the capillary tube 7 are polished to the same inclined surface that is inclined with respect to the optical axis of the optical fibers 5 and 6, whereby the front ends of the optical fibers 5 and 6 are polished. The reflected return light is suppressed (see FIG. 1A). Further, antireflection films are formed on the end faces 5a and 6a of the optical fibers 5 and 6, respectively. One end face 8a of the holding sleeve 8 is formed in a plane perpendicular to the optical axis of the optical fibers 5 and 6, and the perpendicularity thereof is, for example, a geometrical line with the optical axis of the optical fibers 5 and 6 as a normal line. It is controlled with an accuracy of ± 0.5 degrees or less, preferably ± 0.2 degrees or less with respect to the ideal plane.

  The second capillary assembly 3 includes a glass capillary tube 10 in which a single optical fiber 9 is fixed to an inner hole of a single core with an adhesive, and is coaxially extrapolated to the outer periphery of the capillary tube 10 and fixed with an adhesive or the like. And a holding sleeve 11 made of glass. The distal end surface 9a of the optical fiber 9 and the distal end surface 10a of the capillary tube 10 are polished to the same inclined surface that is inclined with respect to the optical axis of the optical fiber 9, thereby suppressing reflected return light at the distal end of the optical fiber 9. (See FIG. 1 (a)). Further, an antireflection film is formed on the distal end surface 9 a of the optical fiber 9. One end face 11a of the holding sleeve 11 is formed in a plane orthogonal to the optical axis of the optical fiber 9, and the perpendicularity thereof is, for example, with respect to a geometric ideal plane having the optical axis of the optical fiber 9 as a normal line. Is controlled with an accuracy of ± 0.5 degrees or less, preferably ± 0.2 degrees or less.

  The lens assembly 4 includes a first lens 12 facing the front end surfaces 5a and 6a of the optical fibers 5 and 6 of the first capillary assembly 2 via a gap, and a front end surface 9a and a gap of the optical fiber 9 of the second capillary assembly 3. A second lens 13 that is opposed to each other, an optical functional part interposed between the first lens 12 and the second lens 13, for example, an optical filter, in particular, a bandpass filter 14, and a glass that houses these parts. The housing sleeve 15 is configured as a main element.

  As shown in FIG. 2 in an enlarged manner, in this embodiment, the first lens 12 is a lens manufactured by processing a part of a spherical lens into a flat part (hemispherical lens), and a part of the spherical lens. Has a flat surface portion 12a formed by cutting the surface by polishing or the like, and a spherical surface portion 12b which is the remaining portion of the spherical lens. The length (L1) of the line segment from the spherical vertex of the spherical surface portion 12b to the flat surface portion 12a through the center of curvature (O1: spherical surface center of the original spherical lens) is the radius of curvature of the spherical surface portion 12b (R1: original and Larger than the radius of the spherical lens. The second lens 13 is also a lens manufactured by processing a part of a spherical lens into a flat part (hemispherical lens), and a flat part formed by cutting a part of the spherical lens by polishing or the like. 13a and a spherical surface portion 13b which is the remaining portion of the spherical lens. The length (L2) of the line segment from the spherical vertex of the spherical surface portion 13b to the flat surface portion 13a through the center of curvature (O2: the spherical surface center of the original spherical lens) is the curvature radius (R2: original and Larger than the radius of the spherical lens. In this embodiment, the first lens 12 and the second lens 13 have the same length (L1, L2) and radius of curvature (R1, R2) (L1 = L2, R1 = R2). The lengths of the line segments (L1, L2) and the radii of curvature (R1, R2) have a relationship of L1 (L2) = 1.2 × R1 (R2).

  The first lens 12 and the second lens 13 are made of, for example, an optical glass having a uniform refractive index. As such an optical glass, MK-18 (manufactured by Nippon Electric Glass Co., Ltd.) having a refractive index of 1.7 or more is used. RH-21 (Nippon Electric Glass Co., Ltd.) etc. with a rate of 1.9 or more can be mentioned. For example, the first lens 12 and the second lens 13 formed of MK-18 and having a relationship of L1 (L2) = 1.2 × R1 (R2) have the same refractive index and the same focal length. As compared with the above, the amount of the gap between the optical fiber and the tip of the optical fiber can be increased by about 3.7 times, so that the reflected return light to the optical fiber can be reduced to about 1/10 or less. In addition, an antireflection film is formed on a portion of the first lens 12 and the second lens 13 where light passes through the flat portions 12a and 13a and the spherical portions 12b and 13b.

  The first lens 12 is fixed to the one end side of the housing sleeve 15 with an adhesive in a state where the spherical surface portion 12 b is in contact with the opening edge portion on the one end side of the housing sleeve 15. The second lens 13 is fixed to the other end side of the housing sleeve 15 with an adhesive in a state where the spherical surface portion 13 b is in contact with the opening edge of the other end side of the housing sleeve 15.

  In this embodiment, the bandpass filter 14 as an optical functional component is fixed to the inner peripheral surface of the housing sleeve 15 via the inner sleeve 16. The inner sleeve 16 is formed in a circular ring shape or a cylindrical shape from glass, metal, ceramics, or the like (in this embodiment, from glass). More specifically, the inner sleeve 16 is fitted to the inner circumference of the accommodation sleeve 15, and the inner circumferential surface of the accommodation sleeve 15 is in a state where the opening edge of the one end side is in contact with the spherical surface portion 12 b of the first lens 12. It is fixed with an adhesive. The inner sleeve 16 may be fixed to the spherical surface portion 12b of the first lens with an adhesive instead of the inner peripheral surface of the housing sleeve 15. The bandpass filter 14 is fixed to the other end surface 16b of the inner sleeve 16 with an adhesive. In this state, the band-pass filter 14 faces the spherical surface portion 12b of the first lens 12 through the internal space of the inner sleeve 16, and also contacts the spherical surface portion 13b of the second lens 13 through the internal space of the housing sleeve 15. It comes to oppose. That is, the distances between the first lens 12, the second lens 13, and the bandpass filter 14 are set easily and accurately by managing the axial dimensions of the housing sleeve 15 and the inner sleeve 16. be able to. The other end side opening of the inner sleeve 16 is fixed to the inner peripheral surface of the housing sleeve 15 with an adhesive while being in contact with the spherical surface portion 13b of the second lens 13, and one end surface of the inner sleeve 16 is fixed. You may make it fix the band pass filter 14 to 16a with an adhesive agent. In this case, the inner sleeve 16 may be fixed to the spherical surface portion 13b of the second lens instead of the inner peripheral surface of the housing sleeve 15 with an adhesive.

  Both end faces 15a and 15b of the housing sleeve 15 are formed in planes orthogonal to the central axis of the inner circumference of the housing sleeve 15, and the perpendicularity thereof is, for example, a geometrical line with the central axis of the inner circumference as a normal line. It is controlled with an accuracy of ± 0.5 degrees or less, preferably ± 0.2 degrees or less with respect to an ideal plane. The flat surface portion 12 a of the first lens 12 and the flat surface portion 13 a of the second lens 13 are parallel to both end surfaces 15 a and 15 b of the housing sleeve 15.

  Further, both end surfaces 16a and 16b of the inner sleeve 16 are formed in a plane orthogonal to the inner peripheral center axis of the inner sleeve 16, and the perpendicularity thereof is, for example, a geometry having the inner peripheral center axis as a normal line. It is controlled with an accuracy of ± 0.5 degrees or less, preferably ± 0.2 degrees or less with respect to a theoretical ideal plane.

  As shown in FIGS. 1 (a) and 1 (b), the first capillary assembly 2 and the lens assembly 4 are made of an adhesive with one end surface 8a of the holding sleeve 8 and one end surface 15a of the housing sleeve 15 butted together. The second capillary assembly 3 and the lens assembly 4 are fixed with an adhesive such that one end face 11a of the holding sleeve 11 and the other end face 15b of the housing sleeve 15 are butted together. The flat surface portion 12 a of the first lens 12 faces the front end surfaces 5 a and 6 a of the optical fibers 5 and 6 of the first capillary assembly 2 via a gap, and the flat surface portion 13 a of the second lens 13 is light of the second capillary assembly 3. It opposes the front end surface 9a of the fiber 9 through a gap. Note that, on the inner peripheral surface of the holding sleeve 8 of the first capillary assembly 2, a large diameter portion and a small diameter portion having a relatively smaller diameter than the large diameter portion are provided in this order from the lens assembly 4 side. . The capillary 7 is inserted and fixed in the small diameter portion, and the first lens 12 is accommodated in the large diameter portion via a gap. Similarly, a large-diameter portion and a small-diameter portion are also provided on the inner peripheral surface of the holding sleeve 11 of the second capillary assembly 3, and the capillary tube 10 is inserted and fixed in the small-diameter portion. Two lenses 13 are accommodated.

  The optical device 1 of this embodiment can be assembled as follows, for example.

  First, the first lens 12 is fixed to one end side of the housing sleeve 15 with an adhesive in the manner described above. At that time, the flat surface portion 12a of the first lens 12 is appropriately pressed by a positioning jig, and the one end surface 15a and / or the other end surface 15b in which the perpendicularity to the central axis of the housing sleeve 15 is controlled are parallel. Or fix so as to be substantially parallel. Thereafter, the inner sleeve 16 to which the band-pass filter 14 is bonded and fixed is inserted into the inner circumference from the other end side of the housing sleeve 15, and the opening edge of the inner sleeve 16 is connected to the spherical surface portion 12 b of the first lens 12. The outer peripheral surface of the inner sleeve 16 is fixed to the inner peripheral surface of the housing sleeve 15 with an adhesive in a state of being in contact with the inner sleeve 16. The inner sleeve 16 may be fixed to the spherical surface portion 12b of the first lens 12 with an adhesive instead of the inner peripheral surface of the housing sleeve 15. In addition, the outer diameter of the inner sleeve 16 and the inner diameter of the housing sleeve 15 are substantially matched so that the inner sleeve 16 can be smoothly inserted into the inner periphery of the housing sleeve 15. Specifically, the clearance between the inner peripheral surface of the housing sleeve 15 and the outer peripheral surface of the inner sleeve 16 is set to 0.030 mm or less, preferably 0.015 mm or less, for example.

  Then, the second lens 13 is fixed with an adhesive in the above-described manner to the other end side of the accommodation sleeve 15 to which the first lens 12, the inner sleeve 16, and the bandpass filter 14 are fixed in this way, so that the lens assembly is obtained. 4 can be produced. At that time, the flat surface portion 13a of the second lens 13 is appropriately pressed with a positioning jig, and the other end surface 15b and / or the one end surface 15a in which the perpendicularity to the central axis of the housing sleeve 15 is controlled are parallel. Or fix so as to be substantially parallel.

  In this way, the center of curvature O1 of the spherical surface portion 12b of the first lens 12 can be easily or substantially matched with the central axis of the inner periphery of the housing sleeve 15. In addition, the center of curvature O2 of the spherical surface portion 13b of the second lens 13 can coincide with or substantially coincide with the central axis of the inner periphery of the housing sleeve 15. Since the first lens 12 and the second lens 13 are respectively fixed to the opening edges of the both ends of the common housing sleeve 15, the first lens 12 can be managed by managing the axial dimension of the housing sleeve 15. And the distance between the second lens 13 can be set easily and accurately. The bandpass filter 14 is fixed to the other end surface 16b of the inner sleeve 16 with the opening edge of the inner sleeve 16 in contact with the spherical surface portion 12b of the first lens 12. If the axial dimension of the sleeve 16 is managed, the distance between the bandpass filter 14 and the first lens 12 can be set easily and accurately. Therefore, if the axial dimensions of the housing sleeve 15, the inner sleeve 16 and the band pass filter 14 are managed, the distances between the first lens 12, the second lens 13 and the band pass filter 14 can be easily and accurately determined. Can be set well.

  Next, one end surface 8a of the holding sleeve 8 of the first capillary assembly 2 is abutted against the one end surface 15a of the housing sleeve 15 of the lens assembly 4 manufactured as described above, and the relative position of the two is determined by the optical fiber 8. , 9 in the direction perpendicular to the optical axis direction (Z-axis direction) (X-axis, Y-axis direction), and the capillary tube 7 is moved in the optical-axis direction (Z-axis) within the holding sleeve 8 of the first capillary assembly 2 abutted. The position of the tip surfaces 5a and 6a of the optical fibers 5 and 6 fixed to the capillary tube 7 is adjusted, for example, the light emitted from one of the optical fibers 5 is reflected by the bandpass filter 14. Then, it is bonded and fixed in an optimal optical alignment state so as to return to the other optical fiber 6.

  Furthermore, one end surface 11a of the holding sleeve 11 of the second capillary assembly 3 is abutted against the other end surface 15b of the housing sleeve 15 of the lens assembly 4 described above, and the relative position between them is determined in the direction of the optical axis of the optical fiber 9 (Z-axis). Direction) and the capillary 10 is moved in the optical axis direction (Z-axis direction) within the holding sleeve 11 of the second capillary assembly 3 that has been abutted. The position of the tip surface 9a of the optical fiber 9 fixed to 10 is adjusted, and the capillary tube 10 is rotated so that the tilt direction of the tip surface 9a tilted with respect to the optical axis of the optical fiber 9 fixed to the capillary tube 10 is changed. For example, so that light emitted from one optical fiber 5 of the first capillary assembly 2 passes through the bandpass filter 14 and enters the optical fiber 9. Bonded and fixed with a suitable optical alignment state.

  In the method for assembling the optical device 1 described above, if all the members constituting the optical device 1 are formed of a transparent material (for example, resin, glass, etc.), it becomes possible to use a UV curable adhesive as the adhesive. As a result, workability of assembly work is improved. Further, in the adhesion between the holding sleeve 8 (11) and the capillary 7 (10) and / or the adhesion between the capillary assembly 2 (3) and the lens assembly 4, the reliability is secured after temporarily fixing with a UV curable adhesive. It may be fixed with a high thermosetting adhesive.

  Next, an example of use of the optical device 1 of this embodiment will be described by taking a case where it is used as an optical demultiplexer.

  For example, light having different wavelengths λ 1 and λ 2 is emitted from one optical fiber 5 of the first capillary assembly 2. The bandpass filter 14 has an optical characteristic of reflecting light having a wavelength λ1 and transmitting light having a wavelength λ2. The light having the wavelength λ1 emitted from the optical fiber 5 of the first capillary assembly 2 is collimated into parallel light by the first lens 12 and reflected by the bandpass filter 14. The light of wavelength λ 1 reflected by the band pass filter 14 is collected by the first lens 12 and returned to the other optical fiber 6 of the first capillary assembly 2. On the other hand, the light of wavelength λ 2 emitted from the optical fiber 5 of the first capillary assembly 2 is collimated into parallel light by the first lens 12 and enters the band pass filter 14. Then, the light passes through the bandpass filter 14, is collected by the second lens 13, and enters the optical fiber 9 of the second capillary assembly 3.

  FIG. 3A is a transverse sectional view showing a schematic configuration of the optical device 21 according to the second embodiment, and FIG. 3B is a longitudinal sectional view thereof. Note that substantially the same parts and portions as those of the optical device 1 according to the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The optical device 21 of this embodiment is different from the optical device 1 according to the first embodiment described above in that the configuration of the lens assembly 22 and the first capillary assembly 2 and the second capillary assembly to the lens assembly 22 are provided. 3 fixing method. That is, as shown in FIGS. 3A and 3B, in the lens assembly 22, the first inner sleeve 23 and the second inner sleeve 24 are coaxially fitted and fixed to the inner periphery of the housing sleeve 15. The bandpass filter 14 is fixed between the other end surface 23b of the first inner sleeve 23 and the one end surface 24a of the second inner sleeve 24, which are fixedly fitted to each other, in contact with the end surfaces 23b and 24a. Has been. At this time, the band-pass filter 14 is fixed to at least one of the other end surface 23b of the first inner sleeve 23 and one end surface 24a of the second inner sleeve 24 with an adhesive (in this embodiment, other than the first inner sleeve 23). It is fixed to the end face 23b with an adhesive). The first lens 12 is fixed to one end side of the first inner sleeve 23 with an adhesive in a state where the spherical surface portion 12b is in contact with the opening edge of the first inner sleeve 23, and the second lens 12b. The lens 13 is fixed to the other end side of the second inner sleeve 24 with an adhesive in a state where the spherical surface portion 13b is in contact with the opening edge of the second inner sleeve 24 on the other end side.

  Further, one end surface 23 a of the first inner sleeve 23 and the other end surface 24 b of the second inner sleeve 24 slightly protrude outward from both ends of the housing sleeve 15. The holding sleeve 8 in the first capillary assembly 2 is fixed to one end surface 23a of the first inner sleeve 23 with an adhesive. The holding sleeve 11 in the second capillary assembly 3 is fixed to the other end surface 24b of the second inner sleeve 24 with an adhesive. It should be noted that both end faces 23a, 23b of the first inner sleeve 23 and both end faces 24a, 24b of the second inner sleeve 24 are in a plane orthogonal to the central axis of the inner periphery of the first inner sleeve 23 and the second inner sleeve 24, respectively. The perpendicularity of the first inner sleeve 23 and the second inner sleeve 24 is, for example, ± 0.5 degrees or less with respect to a geometrical ideal plane whose normal is the central axis of the inner periphery of the first inner sleeve 23 and the second inner sleeve 24, preferably It is managed with an accuracy of ± 0.2 degrees or less.

  In this way, the center of curvature of the spherical surface portion 12b of the first lens 12 can be easily matched with the central axis of the inner periphery of the first inner sleeve 23, and the center of curvature of the spherical surface portion 13b of the second lens 13 can be achieved. Can be easily aligned with the central axis of the inner periphery of the second inner sleeve 24. Since these inner sleeves 23 and 24 are coaxially fitted and fixed to the inner circumference of the common housing sleeve 15, the spherical portions 12 b and 13 b of the first lens 12 and the second lens 13 are respectively fixed. The center of curvature can be easily matched with the central axis of the inner periphery of the storage sleeve 15. Since the first lens 12, the second lens 13, and the band pass filter 14 are continuous in the axial direction via the first inner sleeve 23 and the second inner sleeve 24, the first inner sleeve 23, By managing the axial dimensions of the inner sleeve 24 and the bandpass filter 14, the distances between the first lens 12, the second lens 13, and the bandpass filter 14 can be set easily and accurately.

  The optical device 21 of this embodiment can be assembled as follows, for example.

  First, the first lens 12 and the band-pass filter 14 are fixed to the first inner sleeve 23 with an adhesive in the manner described above, and an assembly including these three parts is produced. At this time, the flat surface portion 12a of the first lens 12 and the one end surface 23a and / or the other end surface 23b in which the perpendicularity with respect to the central axis of the first inner sleeve 23 is controlled by appropriately pressing with a positioning jig, Are fixed to be parallel or substantially parallel. The assembled body is inserted into the inner periphery of the housing sleeve 15 and the position thereof is adjusted, and then the outer periphery of the first inner sleeve 23 is fixed to the inner periphery of the housing sleeve 15 with an adhesive. In addition, the outer diameter of the first inner sleeve 23 and the inner diameter of the housing sleeve 15 are substantially matched so that the first inner sleeve 23 of the assembly can be smoothly inserted into the inner circumference of the housing sleeve 15. Specifically, the clearance between the inner peripheral surface of the housing sleeve 15 and the outer peripheral surface of the first inner sleeve 23 is set to 0.030 mm or less, preferably 0.015 mm or less, for example. In this way, the flat surface portion 12a of the first lens 12 is parallel to the one end surface 23a and / or the other end surface 23b of the first inner sleeve 23 and orthogonal to the central axis of the inner periphery of the housing sleeve 15. The assembly can be fixed to the housing sleeve 15 so as to be in a state or a state close thereto.

  Next, the first lens 13 is fixed to the second inner sleeve 24 with an adhesive in the manner described above, and an assembly including these two parts is produced. At that time, by pressing with a positioning jig as appropriate, the flat surface portion 13a of the second lens 13, the other end surface 24b in which the perpendicularity to the central axis of the second inner sleeve 24 is managed, and / or the one end surface 24a Are fixed to be parallel or substantially parallel. Then, this assembled body is inserted into the inner periphery of the housing sleeve 15, the one end surface 24 a of the second inner sleeve 24 of the assembled body is brought into contact with the band pass filter 14, and then the outer periphery of the second inner sleeve 24 is moved. The lens assembly 22 can be manufactured by fixing the inner sleeve 15 with an adhesive. The outer diameter of the second inner sleeve 24 and the inner diameter of the housing sleeve 15 are substantially matched so that the second inner sleeve 24 of the assembled body can be smoothly inserted into the inner circumference of the housing sleeve 15. Specifically, the clearance between the inner peripheral surface of the housing sleeve 15 and the outer peripheral surface of the second inner sleeve 24 is set to 0.030 mm or less, preferably 0.015 mm or less, for example. In this way, the flat surface portion 13a of the second lens 13 is parallel to the other end surface 24b and / or the one end surface 24a of the second inner sleeve 24 and orthogonal to the central axis of the inner periphery of the housing sleeve 15. The assembly can be fixed to the housing sleeve 15 so as to be in a state or a state close thereto.

  Next, the holding sleeve 8 of the first capillary assembly 2 is fixed to one end surface 23a of the first inner sleeve 23 in the lens assembly 22 manufactured as described above with an adhesive, and the other end surface 24b of the second inner sleeve 24 is fixed. The holding sleeve 11 of the second capillary assembly 3 is fixed with an adhesive. At this time, the positioning method of the two capillary assemblies 2 and 3 with respect to the lens assembly 22 is performed by the same method as in the first embodiment.

  FIG. 4A is a transverse sectional view showing a schematic configuration of the optical device 31 according to the third embodiment, and FIG. 4B is a longitudinal sectional view thereof. Note that substantially the same parts and portions as those of the optical devices 1 and 21 according to the first and second embodiments are denoted by the same reference numerals, and redundant description is omitted.

  The optical device 31 of this embodiment is different from the optical device 21 according to the second embodiment in the configuration of the lens assembly 32. More specifically, the first difference is that the accommodating sleeve 15 is extended in the axial direction, and the first inner sleeve 23 and the second inner sleeve 24 are completely accommodated in the inner periphery of the accommodating sleeve 15. It is. The second difference is that the front end portion (one end surface 8a) of the holding sleeve 8 of the first capillary assembly 2 is bonded to the one end surface 23a of the first inner sleeve 23 in a state where it is inserted into the inner periphery of the housing sleeve 15. In the state where the distal end portion (one end surface 11 a) of the holding sleeve 11 of the second capillary assembly 3 is inserted into the inner periphery of the housing sleeve 15, the adhesive is applied to the other end surface 24 b of the second inner sleeve 24. This is a fixed point. A gap (for example, an optical alignment state between the capillary assemblies 2 and 3 and the lens assembly 32 can be adjusted between the outer peripheral surfaces of the holding sleeves 8 and 11 and the inner peripheral surface of the housing sleeve 15 (for example, , A gap of about 0.125 mm to 0.25 mm) is formed. In this embodiment, the holding sleeves 8 and 11 are fixed to a part of the inner periphery of the housing sleeve 15 with an adhesive in order to reinforce the fixing force and / or further improve the weather resistance. .

  FIG. 5A is a transverse sectional view showing a schematic configuration of the optical device 41 according to the fourth embodiment, and FIG. 5B is a longitudinal sectional view thereof. It should be noted that substantially the same parts and portions as those of the optical devices 1, 21, and 31 according to the first to third embodiments are denoted by the same reference numerals, and redundant description is omitted.

  The optical device 41 according to this embodiment differs from the optical devices 21 and 31 according to the second and third embodiments described above in that the configuration of the lens assembly 42 and the first capillary assembly 2 to the lens assembly 42 are provided. And a method of fixing the second capillary assembly 3. More specifically, the first difference is that the flat portion 12a of the first lens 12 and the flat portion 13a of the second lens 13 are slightly protruded outward from both ends of the housing sleeve 15. The second difference is that one end face 8a of the holding sleeve 8 of the first capillary assembly 2 is fixed to the flat portion 12a of the first lens 12 with an adhesive, and the holding sleeve 11 of the second capillary assembly 3 is fixed. One end surface 11a is fixed to the flat portion 13a of the second lens 13 with an adhesive.

  FIG. 6A is a transverse sectional view showing a schematic configuration of an optical device 51 according to the fifth embodiment, and FIG. 6B is a longitudinal sectional view thereof. Note that substantially the same parts and portions as those of the optical devices 1, 21, 31, and 41 according to the first to fourth embodiments are denoted by the same reference numerals, and redundant description is omitted.

  The optical device 51 according to this embodiment is different from the optical device 41 according to the fourth embodiment in the configuration of the lens assembly 52 and the first capillary assembly 2 and the second capillary assembly 3 to the lens assembly 52. And fixing method. More specifically, the first difference is that the axial dimension of the housing sleeve 15 is extended so that the first lens 12 and the second lens 13 are completely housed in the inner periphery of the housing sleeve 15. The second difference is that the flat portion 12 a of the first lens 12 is inserted in the state where the distal end portion (one end surface 8 a) of the holding sleeve 8 of the first capillary assembly 2 is inserted into the inner periphery of the housing sleeve 15. To the flat surface portion 13a of the second lens 13 with the distal end portion (one end surface 11a) of the holding sleeve 11 of the second capillary assembly 3 being inserted into the inner periphery of the housing sleeve 15. It is in the point fixed with the adhesive. A gap (for example, an optical alignment state between the capillary assemblies 2 and 3 and the lens assembly 52 can be adjusted between the outer peripheral surface of each holding sleeve 8 and 11 and the inner peripheral surface of the housing sleeve 15 (for example, , A gap of about 0.125 mm to 0.25 mm) is formed. In this embodiment, the holding sleeves 8 and 11 are fixed to a part of the inner periphery of the housing sleeve 15 with an adhesive in order to reinforce the fixing force and / or further improve the weather resistance. .

  In addition, this invention is not limited to the said embodiment, For example, while combining single core collimators, it is good also as a structure which uses an optical isolator core as an optical functional component. That is, in the above first to fifth embodiments, similarly to the second capillary assembly, one optical fiber is fixed to the inner hole of the capillary of the first capillary assembly with an adhesive, and the bandpass filter is used. The optical isolator core may be fixed.

  In the above embodiment, the holding sleeve having the large diameter portion and the small diameter portion on the inner peripheral surface may be changed to a holding sleeve having a substantially constant inner diameter. Conversely, the holding sleeve having a substantially constant inner diameter may be changed to a holding sleeve having a large diameter portion and a small diameter portion on the inner peripheral surface.

(A) is a cross-sectional view showing a schematic configuration of the optical device according to the first embodiment, and (b) is a vertical cross-sectional view thereof. It is a longitudinal cross-sectional view which shows schematic structure of the lens assembly of the optical device which concerns on 1st Embodiment. (A) is a cross-sectional view which shows schematic structure of the optical device which concerns on 2nd Embodiment, (b) is the longitudinal cross-sectional view. (A) is a cross-sectional view which shows schematic structure of the optical device which concerns on 3rd Embodiment, (b) is the longitudinal cross-sectional view. (A) is a cross-sectional view which shows schematic structure of the optical device which concerns on 4th Embodiment, (b) is the longitudinal cross-sectional view. (A) is a cross-sectional view showing a schematic configuration of the optical device according to the fifth embodiment, and (b) is a vertical cross-sectional view thereof.

Explanation of symbols

1, 2, 31, 41, 51 Optical device 2 First capillary assembly 3 Second capillary assembly 4, 22, 32, 42, 52 Lens assembly 5, 6, 9 Optical fiber 5a, 6a, 9a Tip surface 7, 10 Capillary 7a, 10a Tip surfaces 8, 11 Holding sleeve (capillary holding member)
8a, 11a One end surface 12 First lens 12a Plane portion (other end surface)
12b Spherical surface (one end)
O1 Center of curvature L1 Length of a line segment from the top of the spherical surface through the center of curvature to the flat surface portion R1 Radius of curvature of the spherical surface portion 13 Second lens 13a
13b Spherical surface (one end)
O2 Center of curvature L2 Length of the line segment from the top of the spherical surface through the center of curvature to the plane portion R2 Radius of curvature of the spherical portion 14 Band pass filter (optical functional component)
15 receiving sleeve 15a one end face 15b other end face 16 inner sleeve 16a one end face 16b other end face 23 first inner sleeve 23a one end face 23b other end face 24 second inner sleeve 24a one end face 24b other end face

Claims (9)

A lens assembly comprising a first lens and a second lens each having a spherical surface on one end surface, an optical functional component, and an accommodating sleeve for accommodating the optical functional component,
The first lens is fixed to the receiving sleeve in a state where the spherical portion is in contact with the opening edge on one end side of the receiving sleeve, and the second lens has its spherical portion other than the receiving sleeve. A lens assembly, wherein the lens assembly is fixed to the receiving sleeve while being in contact with an end opening edge.   An inner sleeve is fitted to the inner periphery of the housing sleeve, and the inner sleeve is in a state in which an opening edge portion on one end side is in contact with the spherical surface portion of either the first lens or the second lens. The optical functional component is fixed to the other end surface of the inner sleeve, and is fixed to at least one of the spherical portion or the inner peripheral surface of the receiving sleeve. Lens assembly. A first lens and a second lens each having a spherical surface on one end surface, a first inner sleeve, a second inner sleeve, an optical functional component, and at least the first inner sleeve, the second inner sleeve, and the like among these components; A lens assembly including a housing sleeve for housing an optical functional component,
The first inner sleeve and the second inner sleeve are fitted and fixed coaxially to the inner periphery of the receiving sleeve in a state where the optical functional parts are interposed between the respective one end surfaces facing each other. The first lens is fixed to the first inner sleeve in a state in which the spherical portion is in contact with the opening edge on the one end side of the first inner sleeve, and the second lens is fixed to the spherical portion. The lens assembly is fixed to the second sleeve while being in contact with the opening edge on the other end side of the second inner sleeve.   4. The lens assembly according to claim 3, wherein the first inner sleeve, the second inner sleeve, and the optical functional component are connected in the housing sleeve. 5.   5. The lens assembly according to claim 1, wherein the first lens and the second lens are manufactured by processing a part of a spherical lens into a flat portion.   3. The lens assembly according to claim 1 or 2, comprising a capillary holding member holding a capillary tube into which an optical fiber is inserted and fixed to one end surface and the other end surface of the receiving sleeve in the lens assembly. An optical device characterized by that.   5. The lens assembly according to claim 3, wherein an end face of the lens assembly on the side where the first lens of the first inner sleeve is fixed, and the second lens of the second inner sleeve are provided. An optical device, wherein a capillary holding member holding a capillary tube into which an optical fiber is inserted and fixed is fixed to an end face on a fixed side.   A capillary tube comprising the lens assembly according to claim 3 or 4, wherein an optical fiber is inserted and fixed in a flat portion provided on each of the other end surfaces of the first lens and the second lens in the lens assembly. An optical device, wherein the held capillary holding members are respectively fixed.   The optical device according to claim 6, wherein the first lens and the second lens are manufactured by processing a part of a spherical lens into a flat portion.

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