JP2005241998A - Optical filter unit and optical filter module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem; a conventional optical filter module is configured so that a beam of light is made slantingly incident to an optical filter unit, and a refractive angle of the incident beam of light is different by wavelengths, thereby making adjustment at the time of manufacturing the optical filter module difficult. <P>SOLUTION: The optical filter unit 30 which constitutes the optical filter module 100 is provided with a 1st plane 3 to/from which two or more beams of light 11 of different wavelngth bands are made incident or reflected, a 2nd plane 2 to/from which a single beam of light 12 including two or more wavelength bands is made incident or reflected, and a filter part which multiplexes the two or more beams of light 11 of the different wavelength bands into a single beam of light including the two or more wavelength bands, or demultiplexes the single beam of light 12 including the two or more wavelength bands into the two or more beams of light 11 of the different wavelength bands, and all the two or more beams of light 11 of the different wavelength bands are made incient or reflected almost vertically to/from the 1st plane 3 from different positions 24, 25, 26 on the same 1st plane 3, and the single beam of light 12 including the two or more wavelength bands is made incident or reflected to/from the 2nd plane 2 almost vertically to the 2nd plane 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical filter unit having an optical filter function, in particular, a multiplexed beam having multiplexed light for optical communication is separated into a plurality of demultiplexed beams, or conversely, a plurality of demultiplexed beams in different wavelength bands. The present invention relates to an optical filter unit for combining the optical filter unit into one combined light beam and an optical filter module including the optical filter unit.

  Conventionally, as shown in FIG. 4, an optical filter module for multiplexing or demultiplexing light for optical communication is known.

  In FIG. 4, such an optical filter module transmits a combined beam including a plurality of wavelength bands transmitted through a combined beam optical fiber and emitted through a combined beam collimator lens. Incidently incident on the emission plane and incident on the optical multilayer film, it is demultiplexed into a plurality of rays for each wavelength band, and demultiplexed rays are emitted obliquely from the optical filter unit to the incident / exit plane. In order to transmit, the light is incident on the optical fiber for demultiplexed light via the collimator lens for demultiplexed light. Or, conversely, the demultiplexed light beam transmitted through the demultiplexed light beam optical fiber and emitted through the demultiplexed light beam collimator lens is incident obliquely on the incident / output plane of the optical filter unit and incident on the optical multilayer film. Then, the combined light beam is emitted obliquely from the optical filter unit to the incident / exit plane, and is incident on the optical fiber for the combined light beam via the collimator lens in order to transmit the combined light beam.

  Further, in such an optical filter module, the optical fiber for combined light, the collimator lens thereof, the optical fiber for demultiplexed light, and the collimator lens thereof are shaped like an optical fiber unit, for example. It was integrated with.

  In manufacturing such an optical filter module, it is necessary to adjust the mutual position of the optical filter unit and the optical fiber unit at the stage where the optical filter unit and the optical fiber unit as the constituent elements are manufactured. .

  By this mutual position adjustment operation, the combined light beam emitted from the combined light beam optical fiber via the combined light beam collimator lens enters the accurate position of the optical filter unit, and is accurately demultiplexed to be optical filter unit. , And the emitted demultiplexed light beam enters the correct position of the demultiplexing light beam collimator lens and enters the demultiplexed light beam optical fiber via the demultiplexing light beam collimator lens, or vice versa. The demultiplexed light beam emitted from the optical fiber for demultiplexed light beam via the collimator lens is incident on the correct position of the optical filter unit, and is accurately combined and emitted from the optical filter unit. In this case, the light beam can be incident on the correct position of the collimating lens for the combined light beam and can enter the optical fiber for the combined light beam via the optical fiber for the combined light beam.

  In such a conventional optical filter module, the combined light beam and the demultiplexed light beam emitted from the optical fiber unit are incident obliquely on the incident / exit plane of the optical filter unit. Further, the combined light beam and the demultiplexed light beam emitted from the optical filter unit are emitted obliquely from the incident / exit plane of the optical filter unit. A member having an incident / exit plane generally has refractive index dispersion. Then, the combined light beam and the demultiplexed light beam are refracted at different angles depending on the light wavelength when entering or exiting the incident / exit plane obliquely.

  For example, in an optical filter module as shown in FIG. 4, a combined beam obtained by multiplexing a plurality of light beams having different wavelengths exits the collimating lens for the combined beam and enters the incident / output plane of the optical filter unit obliquely. Then, in order to receive the refractive action of different magnitude depending on the wavelength at the entrance / exit plane due to the refractive index dispersion, the light is refracted in different directions depending on the wavelength, and then enters the reflection plane at an incident angle different depending on the wavelength and is reflected. Therefore, the combined light beam enters the optical multilayer film at an incident angle that varies depending on the wavelength and is demultiplexed. As a result, a plurality of demultiplexed light beams having different wavelengths emitted after being demultiplexed from the optical filter unit are emitted from the incident and output planes at different intervals.

  Then, the optical fibers for demultiplexing light beams that enter these plural demultiplexing light beams for transmission must be arranged in the optical fiber unit at unequal intervals. In this way, in order to arrange the demultiplexed light fibers at unequal intervals in the optical fiber unit, the unequal between the demultiplexed light beams adjacent to each other is based on the refractive index dispersion and the optical path length through which the light passes. The mutual spacing must be calculated. In order to arrange the optical fibers for demultiplexing light beams at intervals equal to the unequal mutual spacing between the adjacent demultiplexing light beams calculated in this way, it is generally troublesome and difficult to adjust. Furthermore, light rays are incident on the two types of optical multilayer films provided in FIG. 4 at different incident angles depending on the wavelength. The optical multilayer film has a film configuration determined for a specified incident angle. Therefore, light rays incident on the optical multilayer film at an incident angle different from the specified incident angle are reflected or transmitted with spectral optical characteristics different from the designed optical characteristics, so that the designed optical characteristics cannot be obtained, and as a result, sufficient separation is achieved. There is a risk that the wave cannot be generated and the S / N ratio of the demultiplexed light beam decreases. This characteristic problem is difficult to solve.

  The above describes the problem when the combined light beam is incident on the incident / exit plane obliquely. On the contrary, when the split light beams parallel to each other are incident on the incident / exit plane obliquely, for example, they are combined. Since the combined beam is not emitted as a single beam, the optical coupling efficiency when entering the combined beam optical fiber from the combined beam collimator lens for transmission decreases, and the amount of the combined beam to be transmitted is reduced. Various problems occur, such as a problem of reducing the amount of noise, but detailed description thereof is omitted.

  In summary, if the optical filter unit that constitutes the optical filter module is configured so that the combined light beam or the demultiplexed light beam is incident obliquely, the problem of difficulty in adjusting the optical filter module, combined light beam, Various problems occur, such as a problem that the optical coupling efficiency is lowered when the light enters the optical fiber, a problem of demultiplexing characteristics, and a problem of degradation of the multiplexing characteristics.

  The present invention solves at least one of the problems listed above and solves the problem of difficulty in adjusting the optical filter module caused by refractive index dispersion, and an optical filter module including the optical filter unit. It is to provide.

  In order to solve the above-described problems, the optical filter unit according to the first aspect of the present invention includes a first plane on which a plurality of light beams having different wavelength bands enter or exit, and a single light beam including a plurality of wavelength bands. Alternatively, the second plane to be emitted and a plurality of light beams having different wavelength bands are combined into one light beam including the plurality of wavelength bands, or one light beam including the plurality of wavelength bands is combined with a plurality of light beams having different wavelength bands. A plurality of light beams incident on or exiting the first plane from different positions on the same first plane substantially perpendicularly to the first plane. Is incident or exited substantially perpendicularly to the second plane from the second plane.

  An optical filter unit according to a second aspect of the present invention is the optical filter unit according to the first aspect, wherein the filter unit supports the optical filter and the optical filter on one surface and reflects on the other surface. A substrate having a surface; and an optical member having the first plane and the second plane on a side opposite to the substrate side of the optical filter.

  An optical filter unit according to a third aspect of the present invention is the optical filter unit according to the first or second aspect, wherein the first plane and the second plane are on a common plane.

  An optical filter unit according to a fourth aspect of the present invention is the optical filter unit according to the third aspect, wherein the optical filter includes a plurality of optical filter elements having different spectral characteristics arranged on one surface of the substrate. Have.

  An optical filter unit according to a fifth aspect of the present invention is the optical filter unit according to the third or fourth aspect, wherein the optical member changes the direction of one light beam including the plurality of wavelength bands. Further includes a reflective surface.

  An optical filter module according to a sixth aspect of the present invention includes an optical filter unit according to any one of the first to fourth aspects, and a plurality of different wavelength bands that are emitted from the optical filter unit or incident on the optical filter unit. A plurality of first optical systems for entering or emitting light rays, and a second optical system for entering or emitting one light beam including the plurality of wavelength bands that are emitted from the optical filter unit or incident on the optical filter unit; With

  An optical filter module according to a seventh aspect of the present invention is the optical filter module according to the sixth aspect, wherein the plurality of first optical systems includes a plurality of first optical fibers and end faces of the plurality of first optical fibers. A plurality of first lenses disposed in the vicinity, wherein the one second optical system includes one second optical fiber and one second lens disposed in the vicinity of an end surface of the one second optical fiber. The plurality of first lenses receive a plurality of light beams in different wavelength bands that exit the end faces of the plurality of first optical fibers to make each light beam a parallel light flux, or emit the light from the first plane. A plurality of light beams having different wavelength bands are incident and condensed on the end surfaces of the plurality of first optical fibers, and the one second lens emits an end surface of the one second optical fiber. Multiple wavelength bands A single light beam is made into a parallel light beam, or a single light beam including the plurality of wavelength bands exiting from the second plane is incident and condensed on an end face of the one second optical fiber, The optical axes of the plurality of first lenses are arranged substantially perpendicular to the first plane, and the optical axis of the one second lens is arranged substantially perpendicular to the second plane.

  An optical filter module according to an eighth aspect of the present invention is the optical filter module according to the seventh aspect, wherein at least the plurality of first lenses includes a lens array formed of the same member, and the plurality of the first lenses. It has a coupling member that holds one optical fiber at a predetermined interval.

  An optical filter module according to a ninth aspect of the present invention includes an optical filter unit according to any one of the third to fifth aspects, and a plurality of different wavelength bands that are emitted from the optical filter unit or incident on the optical filter unit. A plurality of first optical fibers that enter or emit light, and a second optical fiber that inputs or emits one light including the plurality of wavelength bands that exit from or enter the optical filter unit. And a lens group for condensing a plurality of light beams of the different wavelength bands or a single light beam including the plurality of wavelength bands in the vicinity of end faces of the plurality of first optical fibers and the one second optical fiber.

  An optical filter module according to a tenth aspect of the present invention is the optical filter module according to the ninth aspect, comprising a plurality of first optical fibers and a coupling member that holds the one second optical fiber at a predetermined position. Have.

  The optical filter unit according to the present invention is a combined light beam obtained by combining the divided light beam or the demultiplexed light beam obtained by separating the combined light beam when the combined light beam or the demultiplexed light beam is substantially perpendicularly incident on the respective incident surfaces. Are emitted almost perpendicularly to the respective exit surfaces, so that there is almost no problem that the refraction angle varies depending on the wavelength at the time of incidence or emission, so that the position adjustment work when the optical filter module is manufactured by combining the optical fiber units is not necessary. It is easy and an optical filter module can be easily manufactured.

  In addition, the optical filter module of the present invention includes the optical filter unit and an optical fiber unit suitable for the optical filter unit, so that the operation of adjusting the position of the optical filter unit and the optical fiber unit is easy and can be manufactured. Easy.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic view showing a cross section of the optical filter module of the present embodiment.

  In FIG. 1, the optical filter module 100 of this embodiment includes an optical filter unit 30 and an optical fiber unit 40.

  The optical filter unit 30 constituting the optical filter module 100 according to the present embodiment includes a first member 13, a second member 14, and optical multilayer films 21 and 22.

  The optical multilayer films 21 and 22 are multilayer films that do not have a substrate in which a plurality of layers having two or more different refractive indexes are stacked, and preferably a plurality of layers in which a high refractive index film and a low refractive index film are alternately stacked. And have the desired optical properties obtained by the thin film interference effect. Here, the high refractive index film means a film having a refractive index higher than that of the low refractive index film, and the low refractive index film means a film having a refractive index lower than that of the high refractive index film. As the material of the high refractive index film, one or more selected from niobium oxide, neodymium oxide, tantalum oxide, zirconium oxide, titanium oxide, hafnium oxide, cerium oxide, zinc oxide, etc. can be used. As the substance, one or more selected from silicon oxide, magnesium fluoride, aluminum fluoride, calcium fluoride and the like can be used, and the substance is not particularly limited as long as it is transparent to the wavelength used.

  The film configurations of the optical multilayer films 21 and 22 are determined by using a known optical thin film design method with respect to the desired spectral characteristics, the incident angle θ, and the refractive index of the incident / exit medium. It is determined by designing the film thickness and the required number of layers. The incident / exit medium is originally the adhesive layers 17 and 18, but the incident angle and the emission angle with respect to the optical multilayer films 21 and 22 are the first member 13 and the second member 14 for convenience in this specification. The incident angle and the exit angle are taken as the inside. Further, the desired spectral characteristic is to demultiplex a predetermined combined light beam, reflect a light beam in a certain predetermined wavelength band and combine a light beam in another predetermined wavelength band to combine the predetermined demultiplexed light beam. It is determined to be transparent.

  The optical multilayer film is preferably formed by a vacuum film formation method such as sputtering.

  The optical multilayer film may be formed by forming an optical multilayer film on a soluble substrate surface and then dissolving the substrate, or forming a thin film of a soluble material such as aluminum on the glass substrate surface. An optical multilayer film may be formed on the surface of the soluble material thin film, and then the soluble material thin film is dissolved and the optical multilayer film is peeled off.

The optical multilayer film is produced, for example, as follows.
(1) A glass substrate is prepared. This glass substrate has at least a film forming surface polished.
(2) An aluminum film having a thickness of 50 nm is formed on the glass substrate surface.
(3) A glass substrate on which an aluminum film is formed is set in a sputtering apparatus, and an alternating layer of a high refractive index film and a low refractive index film is formed by sputtering a target under predetermined substrate temperature and pressure conditions.
(4) When film formation of a predetermined number of layers is completed, the glass substrate is cooled, the inside of the vacuum chamber of the sputtering apparatus is returned to atmospheric pressure, and the glass substrate is taken out. Thereafter, in order to obtain the optical multilayer films 21 and 22 having desired dimensions and shapes as shown in FIG. 1, the film surface is divided by cutting the film surface into the glass substrate with a dicing saw. .
(5) The glass substrate is immersed in a 10% by weight NaOH aqueous solution, the aluminum film is dissolved, and the optical multilayer film is peeled from the glass substrate.

  In this way, rectangular optical multilayer films 21 and 22 having no substrate are produced.

  Here, since the optical multilayer film 21 and the optical multilayer film 22 are configured to have different wavelength bands for transmission and reflection, both the optical multilayer film 21 and the optical multilayer film 22 are manufactured in order to produce the optical multilayer films 21 and 22. It is necessary to form a film twice.

  The first member 13 and the second member 14 are members in which the optical multilayer films 21 and 22 are sandwiched.

  As the material of the first member 13, optical glass such as BK7 is preferable. The first member 13 may be made of synthetic resin other than optical glass as long as it is transparent to the light used. As shown in FIG. 1, the first member 13 includes a side surface, a bottom surface, and a top surface, and the side surface has a polygonal column shape perpendicular to the bottom surface or the top surface, and the side surface has a plane portion 15 that forms a predetermined angle with each other; A second entrance / exit plane 2 and a first entrance / exit plane 3 are provided. The plane portion 15 and the first incident / exit plane 3 form an angle β, and the first incident / exit plane 3 and the second incident / exit plane 2 form an angle α.

  The material of the second member 14 is selected in the same manner as the first member 13, preferably a material having the same refractive index as that of the first member 13, more preferably the same material. When the refractive index of the 1st member 13 and the 2nd member 14 differs, it is preferable to make refractive index dispersion | distribution of both materials equal. The second member 14 has a parallel plate shape, and includes a plane portion 16 and a reflection plane 4 parallel to the plane portion 16 with a predetermined distance therebetween. The predetermined distance is determined based on a predetermined interval of the demultiplexed light beam 11 exiting the optical filter unit 30. The first reflection plane 4 is configured to reflect light in all wavelength bands of incident light including the wavelength band of combined light from the inside of the second member 14 toward the first reflection plane 4, Either a metal film reflecting surface such as a gold film or a dielectric multilayer reflecting surface may be used.

  The optical multilayer films 21 and 22 are bonded by the adhesive layer 17 and the adhesive layer 18 between the flat portion 15 of the first member 13 and the flat portion 16 of the second member 14, respectively. That is, the optical multilayer films 21 and 22 are formed between the bottom surface of the first member 13 and the planar portion 15 with a narrow gap between the planar portion 15 and the planar portion 16 opposed to the planar portion 15. 1, that is, in the x-axis direction in FIG. 1, the upper surfaces of the optical multilayer films 21 and 22 are bonded in parallel to the flat portion 15 via the adhesive layer 17, and the optical multilayer films 21 and 22 are The lower surface is bonded in parallel to the flat portion 16 via the adhesive layer 18.

  Here, as the material of the adhesive layers 17 and 18, a thermosetting resin such as an epoxy resin, an ultraviolet curable resin, or the like can be used. The optical multilayer films 21 and 22 can be bonded to the flat portion 15 of the first member 13 and the flat portion 16 of the second member 14 and are not particularly limited as long as they are transparent to the light used. It is preferable that the refractive index of the second member 14 is close. If necessary, the optical multilayer films 21 and 22 may be directly joined to the flat portions 15 and 16 by optical contact without using an adhesive.

  As described above, the optical multilayer films 21 and 22 are bonded to the respective surfaces between the flat portion 15 of the first member 13 and the flat portion 16 of the second member 14 with the adhesive layer 17 and the adhesive layer 18. Thus, the optical filter unit 30 is manufactured. As shown in FIG. 1, the manufactured optical filter unit 30 includes a second member 14 having a first reflecting surface 4 parallel to the film surface 10 on one surface side of the optical multilayer films 21 and 22, and the other member. On the surface side, a first incident / exit plane 3 forming an angle β with the film surface 10 and a first member 13 having a first incident / exit plane 3 forming an angle α with the first incident / exit plane 3 are provided.

  Here, in FIG. 1, the angle α and the angle β of the optical filter unit 30 indicate that the light incident on the optical filter unit 30 perpendicular to the second incident / exit plane 2 is reflected by the first reflecting plane 4, 21 and 22 so that the light incident on the optical filter unit 30 perpendicularly to the first entrance / exit plane 3 is incident on the optical multilayer film 21 so as to be emitted perpendicularly to the first entrance / exit plane 3. 22 is reflected so as to be reflected by the first reflection plane 4 and emitted perpendicularly to the second incident / exit plane 2.

  In general, when the refractive index is different between adjacent members, the light beam traveling beyond the boundary is refracted.

  In the optical filter unit 30 constituting the optical filter module 100 of the present embodiment, the first member 13 and the first member 13 are prevented from being refracted in order to eliminate the adverse effect caused by the light beams having different wavelength bands being refracted at different refraction angles. The second member 14 is preferably made of a material having the same refractive index, and more preferably made of the same member. In this case, the angle β is equal to the incident angle θ to the optical multilayer films 21 and 22, and the angle α is equal to π−2θ. When the first member 13 and the second member 14 have different refractive indexes, even if refraction occurs, the first member 13 and the second member 14 are dispersed in refractive index so that the refraction angles are equal to each other between different wavelength bands. Are preferably made of the same material.

  FIG. 3 shows the spectral transmission characteristics and spectral reflection characteristics of the optical multilayer films 21 and 22 constituting the optical filter unit 30, and the spectra of the target demultiplexed light beams W1, W2, and W3. In order to make it easier to understand the difference between the cutoff wavelengths of the optical multilayer films 21 and 22, the relative light intensity levels of the spectral transmission characteristics and the spectral reflection characteristics are shifted from each other. Is irrelevant to the essence of the invention.

  3 and 1, the optical multilayer film 21 constituting the optical filter unit 30 receives incident light at an incident angle θ and reflects light in the wavelength band indicated by the spectral reflection characteristic R1 at a reflection angle θ. Light in the wavelength band indicated by the spectral transmission characteristic T1 is transmitted at a predetermined emission angle. As described above, in the present embodiment, as shown in FIG. 1, the incident angle is defined as an angle θ in the second member 14. Similarly, the optical multilayer film 22 is configured such that incident light is incident at an incident angle θ, the light in the wavelength band R2 is reflected at the reflection angle θ, and the light in the wavelength band T2 is transmitted at a predetermined emission angle. Yes. Here, the wavelength at which the reflected light shifts from the wavelength band in which the reflected light is remarkable to the wavelength band in which the transmitted light is significant is called a cutoff wavelength. The optical multilayer films 21 and 22 are configured such that Λ1 <Λ2 when the cutoff wavelengths are Λ1 and Λ2, respectively.

  Further, assuming that the principal wavelengths of the demultiplexed rays W1, W2, and W3 are λ1, λ2, and λ3, respectively, the optical multilayer films 21 and 22 are configured to satisfy the relationship of λ1 <Λ1 <λ2 <Λ2 <λ3. Yes.

  Furthermore, the optical filter unit 30 is configured as follows. When a combined light beam W1 + W2 + W3 including a light beam W1 having a main wavelength λ1, a light beam W2 having a main wavelength λ2, and a light beam W3 having a main wavelength λ3 is perpendicularly incident on the surface from the second predetermined position 23 on the second incident / exit plane 2, The wave beam is reflected by the first reflection plane 4 via the first member 13 and the second member 14, enters the optical multilayer film 21 at the incident angle θ, and transmits the transmitted demultiplexed beam W 1. The light exits from the first predetermined position 24 on the first incident / exit plane 3 perpendicularly to the surface. Further, the remaining light beam W2 + W3 reflected by the optical multilayer film 21 is reflected by the first reflection plane 4 and incident on the optical multilayer film 22 at an incident angle θ, and the transmitted demultiplexed light beam W2 passes through the first member 13 to the first. The light exits perpendicularly to the surface from the first predetermined position 25 on the one entrance / exit plane 3. Further, the demultiplexed light beam W 3 reflected by the optical multilayer film 22 is reflected by the first reflection plane 4, passes through the second member 14 and the first member 13, and is surfaced from the first predetermined position 26 on the first incident / exit plane 3. Injected perpendicularly to On the contrary, the demultiplexed light beams W1, W2, and W3, which are parallel to each other and whose distance between the light beams is a predetermined distance 27, are optically perpendicular to the surface from the first predetermined positions 24, 25, and 26 on the first incident / exit plane 3, respectively. When entering the filter unit 30, a combined beam W 1 + W 2 + W 3 that combines them is emitted from the second predetermined position 23 on the second incident / exit plane 2 perpendicularly to the surface via the second member 14 and the first member 13. . The first predetermined positions 24, 25, and 26 and the second predetermined position 23 are provided on one plane parallel to the bottom surface or the upper surface of the first member 13, and the first predetermined positions 24, 25, and 26 are equally spaced. In addition, it is provided at a predetermined interval 27. Further, the demultiplexed light beam that enters or exits at the first predetermined position 24, 25, 26 and the combined light beam that enters or exits at the second predetermined position 23 form an angle of π−α. This angle π-α is twice the incident angle θ when the refractive indexes of the first member 13 and the second member 14 are equal.

  In FIG. 1, an optical fiber unit 40 constituting the optical filter module 100 of the present embodiment includes a first collimator lens 6, a second collimator lens 7, a first optical fiber 8, a second optical fiber 9, and these collimator lenses 6. , 7 and optical fibers 8 and 9 are disposed and fixed to a coupling member 19.

  The coupling member 19 arranges and fixes the components positioned relative to each other so that the components function as follows.

  The second optical fiber 9 is configured to transmit the combined light beam and emit it toward the second collimator lens 7, and conversely, transmit the combined light beam incident from the second collimator lens 7.

  The second collimator lens 7 enters the combined light beam emitted from the second optical fiber 9 into a parallel light beam, emits it in a predetermined direction, and conversely, enters the combined light beam from the predetermined direction and enters the second optical fiber. It is comprised so that it may condense toward 9 cores.

  The first optical fiber 8 is configured to transmit a demultiplexed light beam and emit it toward the first collimator lens 6, and conversely, to transmit a demultiplexed light beam incident from the first collimator lens 6.

  The first collimator lens 6 enters the demultiplexed light beam emitted from the first optical fiber 8 into a parallel light beam, emits it in a predetermined direction, and conversely, enters the demultiplexed light beam from the predetermined direction, and enters the first optical fiber. It is configured to collect light toward the eight cores.

  Further, the first collimator lens 6 and the first optical fiber 8 are fixed on the coupling member 19 by adjusting their positions and directions so that demultiplexed light beams that are parallel to each other at regular intervals 27 can enter and exit. . For this purpose, the position and direction are adjusted and fixed so that the optical axis direction of the first collimator lens 6 and the extending direction of the first optical fiber 8, that is, the core axis direction, coincide with the direction of the incident light beam. It is preferable. Furthermore, the second collimator lens 7 and the second optical fiber 9 are separated from the first collimator lens 6 and the first optical fiber 8 so that a combined light beam that forms a predetermined angle π-α with the demultiplexed light beam can enter and exit. The position and direction are adjusted and fixed at a predetermined distance. For this reason, the optical axis direction of the second collimator lens 7 and the extending direction of the second optical fiber 9, that is, the core axis direction coincide with the direction of the combined light beam that enters or exits, and the optical axis direction of the first collimator lens 6 and It is preferable that the position and direction are adjusted and fixed so as to form a predetermined angle π-α with the extending direction of the first optical fiber 8. The optical axes of the first collimator lens 6 and the second collimator lens 7 are arranged on the same plane. The demultiplexed light beam incident or emitted by the first collimator lens 6 of the optical fiber unit 40 and the combined light beam incident or emitted by the second collimator lens 7 are configured to be on the same plane.

  The optical fiber unit 40 which comprises the optical filter module 100 of this embodiment is produced as mentioned above.

  After the optical filter unit 30 and the optical fiber unit 40 constituting the optical filter module 100 of the present embodiment are manufactured as described above, the optical filter unit 30 and the optical fiber unit 40 in FIG. As described, they are positioned with respect to each other and fixed with a coupling member (not shown).

  That is, the demultiplexed light beam 11 is emitted from the first collimator lens 6 of the optical fiber unit 40, and the demultiplexed light beam 11 is surfaced from the first predetermined positions 24 to 26 on the first incident / exit plane 3 of the optical filter unit 30. Incident perpendicularly. In this state, the optical filter unit 30 is configured such that the combined light beam 12 obtained by combining the demultiplexed light beam 11 is emitted perpendicularly to the surface from the second predetermined position 23 on the second incident / exit plane 2 of the optical filter unit 30. It had been. Since the combined light beam 12 to be emitted is not parallel to the incident demultiplexed light beam 11, the combined light beam 12, the demultiplexed light beam 11, and the like are determined according to the distance between the position on the combined light beam 12 and the second incident / exit plane 2. The distance of changes. Therefore, the demultiplexed light beam 11 is incident perpendicularly to the surface from the first predetermined positions 24 to 26 on the first incident / exit plane 3 surface, and the combined light beam 12 is input to the second predetermined position 23 on the second incident / exit plane surface 2. From the first collimator lens 6 from which the demultiplexed light beam 11 is emitted, the mutual distance between the optical filter unit 30 and the optical fiber unit 40 is adjusted. So as to correctly enter the second collimator lens 7. In this state, the optical fiber unit 40 and the optical filter unit 30 are fixed by a coupling member (not shown). In the optical filter module 100 of this embodiment, as shown in FIG. 1, both the demultiplexed light beam 11 and the combined light beam 12 are on the xy plane.

  The optical filter module 100 of this embodiment is produced as described above.

  The optical filter module 100 according to the present embodiment transmits the demultiplexed light beam 11 that has been transmitted through the optical fiber unit 40 and emitted to the optical filter unit 30 to be combined, and emitted the combined light beam 12 to be incident on the optical fiber unit. Then transmit. On the other hand, the optical filter module 100 transmits the multiplexed light beam 12 transmitted through the optical fiber unit 40 and splits it, enters the optical filter unit 30, splits it, and emits the split light beam 11 to output the optical fiber unit. 40 is incident for transmission.

  In the optical filter module 100 of the present embodiment, the combined light beam 12 is perpendicularly incident on the second entrance / exit plane 2 of the optical filter unit 30 and therefore is not refracted at the second entrance / exit plane 2, and thus is refracted. Since there is no influence of the rate dispersion, there is no problem that the incident angle of the combined beam incident on the optical multilayer films 21 and 22 varies depending on the light wavelength. Therefore, there is no problem that the demultiplexing characteristics are deteriorated when light enters the optical multilayer films 21 and 22 at an incident angle different from the design. Alternatively, it is not necessary to design the optical multilayer films 21 and 22 at different incident angles depending on the wavelength. Further, since the demultiplexed light beams 11 are emitted from the optical filter unit 30 at equal intervals, it is not necessary to arrange the first optical fibers 8 on the coupling member 19 while adjusting the first optical fibers 8 at unequal intervals. Further, since the demultiplexed light beam 11 is perpendicularly incident on the first incident / exit plane 3, it is not refracted by the first incident / exit plane 3, and thus is not affected by the refractive index dispersion. There is no problem that the incident angle of the incident demultiplexed light beam varies depending on the light wavelength. Therefore, there is no problem that the multiplexing characteristics are deteriorated when light is incident on the optical multilayer films 21 and 22 at an incident angle different from the designed angle. Alternatively, it is not necessary to design the optical multilayer films 21 and 22 at different incident angles depending on the wavelength. Furthermore, since the combined light beam 12 becomes one and exits from the optical filter unit 30, the coupling efficiency does not decrease due to the spread of the combined light beam incident on the second optical fiber 9.

  Further, the optical filter module 100 of the present embodiment vertically enters a plurality of light beams of different wavelength bands emitted from the optical fiber unit 40 at a plurality of different predetermined positions on the same first incident / exit plane 3 of the optical filter unit 30. The combined light beam 11 emitted from the second incident / exit plane 2 can be made incident on a predetermined position of the optical fiber unit 40 only by adjusting the mutual distance between the optical fiber unit 40 and the optical filter unit 30. The adjustment work is easy.

Furthermore, in the optical filter module 100 of the present embodiment, the optical multilayer films 21 and 22 having no substrate are joined along the flat portions of the first member 13 and the second member 14, so that the film stress Even if the thickness of the second member 14 and the first member 13 is reduced, the deflection of the film surfaces of the optical multilayer films 21 and 22 can be reduced. For this reason, it is possible to reduce the deviation of the wave fronts of the combined light beam and the demultiplexed light beam, so that the coupling efficiency to the optical fiber into which the combined light beam and the demultiplexed light beam are incident is high, and the size reduction is easy.
[Second Embodiment]
FIG. 2 is a schematic view showing a cross section of the optical filter module of the present embodiment. In addition, the same code | symbol is attached | subjected about the component of the function corresponding to the component of the optical filter module of 1st Embodiment, and the overlapping description is abbreviate | omitted.

  In FIG. 2, the optical filter module 100 of the present embodiment includes an optical filter unit 30 and an optical fiber unit 40.

  The optical filter unit 30 constituting the optical filter module 100 according to the present embodiment includes a first member 13, a second member 14, and optical multilayer films 21 and 22.

  The optical multilayer films 21 and 22 are the same as those in the first embodiment.

  As a material of the first member 13, optical glass such as BK7 is preferable. As a material of the first member, a synthetic resin other than optical glass may be used as long as it is transparent to the light used. As shown in FIG. 2, the first member 13 has a side surface, a bottom surface, and a top surface. The side surface has a polygonal column shape perpendicular to the bottom surface or the top surface. An emission plane 1 and a second reflection plane 5 are provided. The plane portion 15 and the incident / exit plane 1 form an angle β, and the incident / exit plane 1 and the second reflection plane form an angle α. The second reflection plane 5 is configured to reflect light in all the wavelength bands of the incident light including the wavelength band of the combined light incident from the incident / output plane 1, and reflects the metal film such as a total reflection surface and a gold film. Either a surface or a dielectric multilayer film reflecting surface may be used.

  The material of the second member 14 is selected in the same manner as the first member 13, preferably a material having the same refractive index as that of the first member 13, more preferably the same material. When the refractive index of the 1st member 13 and the 2nd member 14 differs, it is preferable to make refractive index dispersion | distribution of both materials equal. The second member 14 has a parallel plate shape, and includes a plane portion 16 and a reflection plane 4 parallel to the plane portion 16 with a predetermined distance therebetween. The predetermined distance is determined based on a predetermined interval of the demultiplexed light beam 11 exiting the optical filter unit 30. The first reflection plane 4 is configured to reflect light in all the wavelength bands of incident light including the wavelength band of the combined light directed from the inside of the second member 14 toward the first reflection plane 4, Either a metal film reflecting surface such as a gold film or a dielectric multilayer reflecting surface may be used. Alternatively, the second member 14 may be further provided with a third reflection plane 28 perpendicular to the first reflection plane 5 as an alternative to the second reflection plane 5 of the first member 13.

  The optical multilayer films 21 and 22 are bonded by the adhesive layer 17 and the adhesive layer 18 between the flat portion 15 of the first member 13 and the flat portion 16 of the second member 14, respectively. That is, the optical multilayer films 21 and 22 are formed between the bottom surface of the first member 13 and the planar portion 15 with a narrow gap between the planar portion 15 and the planar portion 16 opposed to the planar portion 15. 2, that is, in the x-axis direction in FIG. 2, the upper surfaces of the optical multilayer films 21 and 22 are bonded in parallel to the planar portion 15 via the adhesive layer 17, and the optical multilayer films 21 and 22 are The lower surface is bonded in parallel to the flat portion 16 via the adhesive layer 18. When the third reflection plane 28 is provided on the second member 14, the third reflection plane 28 is joined in parallel to the normal direction of the bottom surface or the top surface of the first member 13.

  Here, the adhesive layers 17 and 18 are the same as those in the first embodiment.

  As described above, the optical multilayer films 21 and 22 are bonded to the respective surfaces between the flat portion 15 of the first member 13 and the flat portion 16 of the second member 14 with the adhesive layer 17 and the adhesive layer 18. Thus, the optical filter unit 30 is manufactured. As shown in FIG. 2, the produced optical filter unit 30 includes a second member 14 having a first reflecting surface 4 parallel to the film surface 10 on one surface side of the optical multilayer films 21 and 22, and the other member. On the surface side, a first member 13 having an incident / exit plane 1 that forms an angle β with the film surface and a second reflection plane 5 that forms an angle α with the incident / exit plane 1 is provided.

  Here, in FIG. 2, the angles α and β of the optical filter unit 30 indicate that the light rays incident on the optical filter unit 30 perpendicular to the incident / exit plane 1 pass through the second reflection plane 5 and the first reflection plane 4 in order. Reflected light passes through the optical multilayer films 21, 22 and exits perpendicularly to the incident / exit plane 1, and conversely, light rays incident on the optical filter unit 30 perpendicular to the incident / exit plane 1 are reflected in the optical multilayer film The first reflection plane 4 and the second reflection plane 5 are sequentially reflected through the light beams 21 and 22 and emitted perpendicularly to the incident / exit plane 1.

  As described above, in order for light rays to enter or exit, the first reflection plane 4 and the second reflection plane 5 need to be vertical.

Accordingly, the optical filter unit 3 constituting the optical filter module 100 of the present embodiment is configured such that the relationship α + β = π is established between the angle α and the angle β of the first member 13, and the optical multilayer The angle β is determined depending on the designed incident angle θ of the films 21 and 22. For example, when the first member 13 and the second member 14 have the same refractive index, β = θ, and when the first member 13 has a refractive index n1 and the second member 14 has a refractive index n2, β = sin ⁻¹ {( n2 / n1) sin θ}.

  The spectral transmission characteristics and spectral reflection characteristics of the optical multilayer films 21 and 22 constituting the optical filter unit 30 of the optical filter module 100 of the present embodiment and the spectra of the target demultiplexed light beams W1, W2, and W3 are shown in FIG. These are the same as those provided in the optical filter unit of the first embodiment, and will not be described repeatedly.

  The optical filter unit 30 is configured as follows. When a combined light beam W1 + W2 + W3 including a light beam W1 having a main wavelength λ1, a light beam W2 having a main wavelength λ2, and a light beam W3 having a main wavelength λ3 is incident perpendicularly to the surface from the second predetermined position 23 on the incident / exit plane 1, Is incident on the optical multilayer film 21 at an incident angle θ through the first member 13 and the second member 14 while being reflected by the second reflection plane 5 and the first reflection plane 4, and is transmitted. W1 exits perpendicularly to the surface from the first predetermined position 24 on the incident / exit plane 1 via the first member 13. Further, the remaining light beam W2 + W3 reflected by the optical multilayer film 21 is reflected by the first reflection plane 4 and enters the optical multilayer film 22 at an incident angle θ, and the transmitted demultiplexed light beam W2 enters through the first member 13. The light is ejected from the first predetermined position 25 on the ejection plane 1 perpendicular to the surface. Further, the demultiplexed light beam W 3 reflected by the optical multilayer film 22 is reflected by the first reflection plane 4, passes through the second member 14 and the first member 13, and is perpendicular to the surface from the first predetermined position 26 on the incident / exit plane 1. To ejaculate. On the contrary, the demultiplexed light beams W1, W2, and W3, which are parallel to each other and whose distance between the light beams is a predetermined distance 27, are optical filter units perpendicular to the surface from the first predetermined positions 24, 25, and 26 on the entrance / exit plane 1, respectively. When the light is incident on 30, the combined light beam W <b> 1 + W <b> 2 + W <b> 3 is reflected on the first reflection plane 4 and the second reflection plane 5 while passing through the second member 14 and the first member 13. The light is ejected from the second predetermined position 23 perpendicular to the surface. The first predetermined positions 24, 25, 26 and the second predetermined position 23 are on a straight line parallel to the bottom surface or the top surface of the first member 13, and the first predetermined positions 24, 25, 26 are equally spaced and the first The predetermined interval 27 and the interval between the second predetermined position 23 and the first predetermined position 24 are determined as a second predetermined interval 29. Further, the demultiplexed light beam that is incident or emitted at the first predetermined position 24, 25, or 26 and the combined light beam that is incident or emitted at the second predetermined position 23 are on the same plane and are parallel to each other.

  In FIG. 2, the optical fiber unit 40 constituting the optical filter module 100 of the present embodiment includes a first collimator lens 6, a second collimator lens 7, a first optical fiber 8, a second optical fiber 9, and these collimator lenses 6. , 7 and optical fibers 8 and 9 are disposed and fixed to a coupling member 19.

  Since the functions of these components, the collimator lenses 6 and 7, the optical fibers 8 and 9, and the coupling member 19 are the same as those of the first embodiment, they will not be described repeatedly.

  Since the coupling member 19 of the optical fiber unit 40 constituting the optical filter module 100 of the present embodiment is the same as that of the first embodiment except for the following points, the repeated description of the parts having common functions is omitted. To do.

  In the first embodiment, the coupling member 19 includes the first collimator so that the combined beam incident or emitted from the second collimator lens forms a predetermined angle π-α with the demultiplexed beam incident or emitted from the first collimator lens. The position, direction of the lens, the first optical fiber, the second collimator lens, and the second optical fiber are adjusted and fixed. On the other hand, the coupling member 19 of the optical fiber unit 40 constituting the optical filter module 100 of the present embodiment is the amount that the combined light beam incident or emitted by the second collimator lens 7 is incident or emitted by the first collimator lens 6. Positions of the first collimator lens 6, the first optical fiber 8, the second collimator lens 7, and the second optical fiber 9 so that they can enter or exit in parallel with the wave ray at a second predetermined interval 29. And the direction is adjusted and fixed. In the optical filter module 100 of the present embodiment, as shown in FIG. 2, the demultiplexed light beam 11 and the combined light beam 12 are on the xy plane.

  The optical fiber unit 40 which comprises the optical filter module 100 of this embodiment is produced as mentioned above.

  After the optical filter unit 30 and the optical fiber unit 40 constituting the optical filter module 100 of the present embodiment are manufactured as described above, the optical filter unit 30 and the optical fiber unit 40 in FIG. As described, they are positioned with respect to each other and fixed with a coupling member (not shown).

  That is, the demultiplexed light beam 11 is emitted from the first collimator lens 6 of the optical fiber unit 40, and the demultiplexed light beam 11 is perpendicular to the surface from the first predetermined positions 24 to 26 on the incident / exit plane 1 of the optical filter unit 30. To enter. In this state, the optical filter unit 30 is configured such that the combined light beam 12 obtained by combining the demultiplexed light beam 11 is emitted perpendicularly to the surface from the second predetermined position 23 on the incident / exit plane 1 of the optical filter unit 30. . The interval between the second predetermined position 23 and the first predetermined position 24 is set at a second predetermined interval 29, and the first collimator lens 6 and the second collimator lens 7 are separated from the demultiplexed light beam 11 at the second predetermined interval 29. Since the combined light beam 12 is configured to enter or exit, the combined light beam 12 exiting the second predetermined position 23 is correctly incident on the second collimator lens 7. In this state, the optical fiber unit 40 and the optical filter unit 30 are fixed by a coupling member (not shown).

The optical filter module 100 of the present embodiment is manufactured as described above. The optical filter module 100 of the present embodiment transmits the demultiplexed light beam 11 transmitted through the optical fiber unit 40 and emitted to the optical filter unit 30. Then, the combined light beam 12 is emitted and incident on the optical fiber unit 30 for transmission. On the other hand, the optical filter module 100 transmits the multiplexed light beam 12 transmitted through the optical fiber unit 40 and splits it, enters the optical filter unit 30, splits it, and emits the split light beam 11 to output the optical fiber unit. Incident for transmission.

  The optical filter module 100 of the present embodiment has the same effects as the optical filter module 100 of the first embodiment, and the optical filter unit 30 has a plurality of demultiplexed light beams 11 and a plurality of wavelength bands in different wavelength bands. The combined light beam 12 includes the same incident / exit plane 1 on which the incident / exit plane 12 is incident or exited in a direction perpendicular to the surface. The second predetermined position 23 is provided at a second predetermined interval 29 from the first predetermined position 24, 25, 26, and a plurality of demultiplexed light beams 11 having different wavelength bands are respectively supplied to the first predetermined positions 24, 25, 26. When the light is incident perpendicularly to the incident / exit plane 1, the combined light beam 12 is emitted perpendicularly to the incident / exit plane 1 from the second predetermined position 23. In addition, the optical fiber unit 40 emits the demultiplexed light beams 11 that are spaced apart from each other by a predetermined distance 27 on the same plane and are parallel to each other from the first collimator lens 6, and the demultiplexed light beams 11 emitted from the optical fiber unit 40 and the second demultiplexed light beams 11. A combined light beam 12 that is parallel to each other and is on the same plane as the demultiplexed light beam 11 is made incident on the second collimator lens 7. Accordingly, the optical filter is arranged so that the demultiplexed light beam 11 emitted from the first collimator lens 6 of the optical fiber unit 40 enters or exits the incident / emission plane 1 perpendicularly at the first predetermined positions 24, 25, and 26 of the incident / emission plane 1. By simply moving the unit 30 and the optical fiber unit 40 relative to each other in the direction of the entrance / exit plane 1, the optical filter unit 30 and the optical fiber unit 40 are not affected by the mutual distance between the optical filter unit 30 and the optical fiber unit 40. Thus, the position can be adjusted so that the demultiplexed light beam 11 and the combined light beam 12 can be exchanged accurately. If the position is adjusted as described above, conversely, when the combined light beam 12 is emitted from a predetermined position of the optical fiber unit 40 and is incident on the second predetermined position 23 of the incident / exit surface 1 of the optical filter unit 30, There is no doubt that the plurality of demultiplexed light beams 11 exit from the first predetermined positions 24, 25, and 26 and accurately enter the predetermined positions of the optical fiber unit 40.

  As described above, according to the optical filter module 100 of the present embodiment, the same effects as those of the optical filter module 100 of the first embodiment can be obtained, and in addition, the manufacturing can be adjusted more than the optical filter module 10 of the first embodiment. Easy.

  In the above description, the example in which the combined light beam 12 is reflected by the second reflection plane 5 of the first member 13 has been described, but may be reflected by the third reflection plane 28 of the second member 14.

  In the above description of the optical filter module of the first and second embodiments, the case where the number of demultiplexed light beams 11 is three has been described. However, the number of demultiplexed light beams 11 may be two, or any number of four or more.

  In the optical filter modules of the first and second embodiments, the example in which the optical multilayer film is bonded between the first member and the second member has been described. However, the optical multilayer film itself has a predetermined refraction at a predetermined position. The configuration is not limited to this configuration as long as it is arranged in the medium of the rate, and a third member, a fourth member or more may be used in addition to this. The optical multilayer films 21 and 22 are not limited to those having no substrate, but may be those having a film-forming substrate using a lithography method or the like. In this case, the first member 13 or the second member 14 is a substrate for forming an optical multilayer film.

  Although the predetermined positions 23, 24, 25, and 26 on the incident / exit plane have been described as points, it goes without saying that there is an allowable range according to the effective dimensions of the optical multilayer films 21 and 22.

The optical filter module of 1st Embodiment is shown. The optical filter module of 2nd Embodiment is shown. It is a figure explaining the function of the optical filter module of 1st, 2nd embodiment. 1 shows a conventional optical filter module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Entrance / exit plane 2 2nd entrance / exit plane 3 1st entrance / exit plane 4 1st reflection plane 5 2nd reflection plane 6 1st collimator lens 7 2nd collimator lens 8 1st optical fiber 9 2nd optical fiber 10 Film surface 11 Demultiplexed light beam 12 Combined light beam 13 First member 14 Second member 15, 16 Planar portion 17, 18 Adhesive layer 19 Bonding member 21, 22 Optical multilayer film 23 Second predetermined position 24, 25, 26 First predetermined position 27 Predetermined interval 28 Third reflection plane 29 Second predetermined interval 30 Optical filter unit 40 Optical fiber unit 100 Optical filter module

Claims (10)

A first plane on which a plurality of light beams having different wavelength bands are incident or emitted;
A second plane on which one light beam including a plurality of wavelength bands enters or exits;
A filter unit that combines a plurality of light beams of different wavelength bands into one light beam including the plurality of wavelength bands, or separates one light beam including the plurality of wavelength bands into a plurality of light beams of different wavelength bands; Prepared,
All of the plurality of light beams in the different wavelength bands are incident or exited substantially perpendicularly to the first plane from different positions on the same first plane, and one light beam including the plurality of wavelength bands is the second light beam. An optical filter unit, wherein the optical filter unit is incident or exited from a plane substantially perpendicularly to the second plane. The optical filter unit according to claim 1,
The filter unit includes an optical filter, a substrate that supports the optical filter on one surface and a reflective surface on the other surface, the first plane and the first surface on the opposite side of the optical filter from the substrate side. An optical filter unit comprising an optical member having two planes. The optical filter unit according to claim 1 or 2,
The optical filter unit, wherein the first plane and the second plane are on a common plane. The optical filter unit according to claim 3,
The optical filter unit includes a plurality of optical filter elements having different spectral characteristics arranged on one surface of the substrate. The optical filter unit according to claim 3 or 4,
The optical filter unit, wherein the optical member further includes a second reflecting surface that changes the direction of one light beam including the plurality of wavelength bands. The optical filter unit according to any one of claims 1 to 5,
A plurality of first optical systems that emit or emit a plurality of light beams of the different wavelength bands that are emitted from or incident on the optical filter unit;
An optical filter module comprising: a second optical system that inputs or emits one light beam including the plurality of wavelength bands that are emitted from the optical filter unit or incident on the optical filter unit. The optical filter module according to claim 6,
The plurality of first optical systems includes a plurality of first optical fibers and a plurality of first lenses disposed in the vicinity of end surfaces of the plurality of first optical fibers,
The one second optical system includes one second optical fiber and one second lens disposed in the vicinity of an end surface of the one second optical fiber,
The plurality of first lenses receive a plurality of light beams in different wavelength bands that exit the end faces of the plurality of first optical fibers to convert each light beam into a parallel light flux, or the different wavelengths that exit from the first plane. A plurality of light beams in a band are incident and each light beam is condensed on the end faces of the plurality of first optical fibers;
The one second lens is configured to enter one light beam including a plurality of wavelength bands that exit the end face of the one second optical fiber to make the light beam a parallel light beam, or to emit the plurality of light beams from the second plane. One light beam including a wavelength band is incident and condensed on an end surface of the one second optical fiber, and an optical axis of the plurality of first lenses is substantially perpendicular to the first plane and the second light beam. An optical filter module, wherein an optical axis of the lens is disposed substantially perpendicular to the second plane. The optical filter module according to claim 7,
At least the plurality of first lenses are made of a lens array formed of the same member, and have a coupling member that holds the plurality of first optical fibers at a predetermined interval. The optical filter unit according to any one of claims 3 to 5,
A plurality of first optical fibers that emit or emit a plurality of light beams of the different wavelength bands that are emitted from or incident on the optical filter unit;
One second optical fiber that enters or emits one light beam including the plurality of wavelength bands that are emitted from or incident on the optical filter unit;
A lens group for condensing a plurality of light beams of the different wavelength bands or a single light beam including the plurality of wavelength bands in the vicinity of end faces of the plurality of first optical fibers and the one second optical fiber. An optical filter module. The optical filter module according to claim 9,
An optical filter module comprising: a plurality of first optical fibers; and a coupling member that holds the one second optical fiber at a predetermined position.

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