WO2010140453A1

WO2010140453A1 - Optical module and optical component for the optical module

Info

Publication number: WO2010140453A1
Application number: PCT/JP2010/058157
Authority: WO
Inventors: 秀樹浅野
Original assignee: 日本電気硝子株式会社
Priority date: 2009-06-04
Filing date: 2010-05-14
Publication date: 2010-12-09
Also published as: TW201106030A; JP2011013665A

Abstract

Provided is an optical module in which light can be certainly attenuated without increasing the number of the components. An optical component (1) for an optical module, comprising a spherical lens (9), a guide sleeve (3) for holding a ferrule (6) in which an optical fiber (5) is inserted and secured, in a bore, and a glass stub (4) which is arranged in the bore of the guide sleeve (3) and which has a spherically convex surface which is in contact with an end surface of the ferrule (6) on the optical element (10) side is fabricated. When the optical component is fabricated, a dopant is contained in the glass stub (4) to provide a light attenuating function. An optical module assembled from the optical component (1) is fabricated.

Description

Optical module and optical component for optical module

The present invention relates to an optical module used in the fields of optical communication, optical measurement, CATV system, and the like, and an optical component for the optical module, and more specifically, an optical module having a function of attenuating light on the optical path, and The present invention relates to an optical component for the optical module.

As is well known, an optical module used in the fields of optical communication, optical measurement, CATV system, and the like transmits light between an optical element that emits or receives light and an optical fiber continuous on the network side. It is a device that transmits information contained in light by performing propagation. In this optical module, an optical component including one or a plurality of glass components (for example, a lens) is incorporated on the optical path between the optical element and the optical fiber.

By the way, this type of optical module is required to increase long-distance transmission and communication capacity in optical communication applications. Along with this, higher output of light used as a transmission medium is being promoted. Similarly, in an optical module used for other purposes, the actual situation is that high output of light is promoted for various reasons.

However, when high-power light is used in short-distance communication in this way, unless measures are taken, light exceeding the level that can be received by an optical element having a light-receiving function is received and the optical element is damaged. End up. Therefore, it is customary to take measures to attenuate light to a predetermined level on the optical path in advance, and as a specific measure, a method of connecting two optical fibers through a resin filter, A method of adding a dopant having a function of attenuating light in an optical fiber is known.

When these known methods are described in detail, as disclosed in Patent Document 1, the former method separates the optical fiber into two in the middle, and separates the separated optical fibers into separate ferrules. In the state where the end faces of the ferrules are aligned with the optical axes of the optical fibers, they are brought into contact with each other through a resin filter (light attenuation film) deposited with a metal film, A filter is interposed between them.

In the latter method, as disclosed in Patent Document 2, an optical fiber containing a dopant is held in the inner hole of the ferrule, and both ends of the optical fiber are held in the inner hole of another ferrule. The end of the optical fiber and the optical axis are matched to each other, and an optical fiber having an attenuation function is interposed in the middle of the optical fiber.

Japanese Utility Model Publication No. 63-130702 Japanese Utility Model Publication No. 63-96504

However, both of the methods disclosed in

Patent Documents

1 and 2 attenuate the light by using a ferrule or the like that does not originally exist in the optical path in order to interpose an optical fiber containing a resin filter or a dopant in the optical path. Therefore, an increase in the number of parts is inevitable. If the number of parts increases in this way, an extra man-hour is imposed on the assembling work, and the manufacturing cost increases.

In particular, when an optical fiber is separated in the middle and an optical fiber containing a resin filter or a dopant is interposed, a great deal of labor is imposed on the connection, and connection failure is caused by an increase in extra connection points. This is likely to occur and may cause a significant reduction in light coupling efficiency.

An object of the present invention is to provide an optical module capable of reliably attenuating light without increasing the number of parts.

In order to solve the above problems, the present invention provides an optical element that performs at least one of light emission and light reception, and an end face of the optical fiber that is inserted and fixed in the optical fiber holding member and is closest to the optical element. In the optical part for an optical module provided with one or a plurality of glass parts on the optical path, at least one of the one or the plurality of glass parts is characterized by being provided with a light attenuation function.

According to such a configuration, since a function of attenuating light is imparted to the glass parts previously arranged on the optical path, it is not necessary to separately arrange a new member on the optical path only for attenuating the light. Therefore, if an optical module is manufactured by incorporating the optical component for the optical module, the number of parts does not increase in order to attenuate the light, so that the number of assembly steps does not increase and the manufacturing cost is reduced. Can contribute.

In the above configuration, it is preferable that the glass component having the light attenuating function contains a dopant that attenuates light.

In this way, it is possible to easily give the glass part a function of attenuating light. In addition, when the glass part is provided with a dopant and has a function of attenuating light, the light attenuation characteristic is hardly changed by heat. For this reason, when the glass component attenuates light, even if the glass component generates heat due to absorption of light, the light attenuation characteristic hardly changes. Therefore, it is possible to provide an optical module with high reliability by manufacturing the optical module by incorporating the optical component for the optical module.

On the other hand, in the conventional attenuation method using a resin filter, when strong light is incident on the filter, the filter is deteriorated due to heat generated by the light attenuated (absorbed) by the filter, and the attenuation characteristic of the filter is large. Since there is a risk of change, it is practically impossible to provide a highly reliable optical module.

It should be noted that the amount of light attenuation can be easily adjusted by adjusting the unit optical path length (sphere diameter, length, thickness) of the glass component containing the dopant.

In the above configuration, the dopant is preferably at least one ion selected from Co, Mn, Ni, Cr, V, Fe, and Cu. Note that the dopant is an ion means that the dopant in the glass component is contained in an ionized state. When doping in the manufacturing stage, for example, the dopant is oxidized. Doping in the state of an object or the like is also allowed.

By selecting an appropriate dopant as described above, an appropriate attenuation characteristic can be obtained at a desired wavelength by the absorption characteristic specific to the dopant. That is, for example, when Co ions are used as the dopant, the wavelength dependence of the light attenuation characteristic is reduced in the wavelength band of 1300 to 1600 nm, so that the wavelength band mainly used in the field of long-distance optical communication ( 1310 nm to 1550 nm), it becomes possible to attenuate light at a constant level.

In the above configuration, two or more glass parts containing the dopant may be disposed on an optical path between the optical element and an end face of the optical fiber closest to the optical element.

In this way, since a dopant that attenuates light is contained in two or more glass parts, the total amount of light attenuation can be easily adjusted by combining the glass parts. Become. Also, the light attenuation function is given to two or more glass parts to achieve the predetermined light attenuation, compared to the case where the same attenuation is realized by giving the light attenuation function to one glass part. Thus, the amount of light absorbed by each glass component can be reduced. Therefore, there also exists an advantage that the heat_generation | fever for every glass component can be suppressed.

In the above configuration, the glass component having the light attenuation function may be a lens that collects light passing on an optical path between the optical element and an end face of the optical fiber closest to the optical element. Good. Further, in the case where a glass stub having a convex spherical surface that comes into contact with the end face closest to the optical element of the optical fiber holding member is provided, even if the glass component having the light attenuation function is the glass stub Good.

In the above configuration, the glass component having the light attenuation function is directly fixed to the holding member for holding the glass component on the optical path by heat treatment, or indirectly fixed to the low melting point glass. Is preferred.

In this way, even when the glass component having the function of attenuating light attenuates the light, even if the glass component generates heat due to the absorption of light, the fixing portion of the glass component is formed of glass, so Since it is difficult for the fixing force to decrease, it is very advantageous in practice.

On the other hand, in the conventional attenuation method using an optical fiber containing a dopant, the ferrule and the optical fiber are usually bonded by a resin adhesive. When the optical fiber generates heat due to absorption, the adhesive that bonds the optical fiber gradually deteriorates and the fixing force may be reduced. Therefore, the optical fiber inserted through the ferrule is likely to be misaligned, and there is a possibility that the light coupling efficiency may be greatly reduced, which is a problem.

In the above configuration, a cylindrical member that holds the optical fiber holding member in the inner hole may be provided.

In this way, since the optical fiber holding member can be easily positioned, the accuracy of adjusting the optical axis of light can be improved and the light coupling efficiency can be increased.

In the above configuration, in the case where the optical fiber holding member is provided with a plate glass that is in contact with the end face closest to the optical element and hermetically seals the opening of the cylindrical member on the optical element side, The glass part provided with the light attenuation function may be the plate glass.

It is preferable to manufacture an optical module by incorporating optical components for an optical module having the above-described configuration as appropriate.

In this way, the operational effects of the corresponding configuration already described can be enjoyed in the same manner.

As described above, according to the present invention, since the function of attenuating light is given to the existing glass parts arranged on the optical path, the number of parts does not increase excessively to attenuate the light. . Therefore, it is possible to provide an optical module that can reliably attenuate light while preventing an increase in the number of components.

1 is a schematic longitudinal sectional view showing a main part of an optical module according to a first embodiment of the present invention. The schematic longitudinal cross-sectional view which shows the principal part of the optical module which concerns on the 2nd Embodiment of this invention. The schematic longitudinal cross-sectional view which shows the principal part of the optical module which concerns on the 3rd Embodiment of this invention. The schematic longitudinal cross-sectional view which shows the principal part of the optical module which concerns on the 4th Embodiment of this invention. The schematic longitudinal cross-sectional view which shows the principal part of the optical module which concerns on the 5th Embodiment of this invention.

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

FIG. 1 is a diagram showing an optical module according to the first embodiment of the present invention. The optical module includes an optical module optical component 1 as a main configuration. In the figure, the range in which the optical path of light is formed is indicated by a chain line.

The optical component 1 for an optical module is housed in a cylindrical sleeve folder 2 having a flange portion 2a on one end side (on the optical element 10 side disposed when incorporated in an optical module), and an inner hole of the sleeve folder 2. And a glass stub 4 fixed to the inner surface of one end of the guide sleeve 3.

As shown in the drawing, in a state in which the optical module optical component 1 is incorporated in the optical module, the ferrule 6 with the optical fiber 5 inserted and fixed is inserted into the inner hole of the guide sleeve 3 from the other end side (network side). The end surfaces of the ferrule 6 and the glass stub 4 are abutted with each other. The butted portions of the glass stub 4 and the ferrule 6 are each processed into a convex spherical surface in order to suppress a decrease in light coupling efficiency. On the other hand, the end surface of the glass stub 4 on the side opposite to the convex spherical surface (the optical element 10 side to be described later) may be a plane parallel to a plane orthogonal to the optical axis. In order to reduce, the inclined surface is inclined with respect to a plane orthogonal to the optical axis. In this embodiment, the ferrule 6 serves as an optical fiber holding member, and no other optical fiber exists on the optical path on the optical element 10 side than the end of the ferrule 6 on the optical element 10 side. Yes.

Although not shown, the glass stub 4 is manufactured by heat-treating a glass rod disposed on one end side of the inner hole of the guide sleeve 3. More specifically, first, the glass rod is softened by heat treatment so that both end surfaces of the glass rod are convex spherical surfaces by surface tension, and the periphery of the guide sleeve 3 is thermally fixed to the inner surface of the guide sleeve 3. Thereafter, the above-described glass stub 4 is manufactured by processing the convex spherical surface on one side of the glass rod on the optical element 10 side into an inclined surface that is inclined with respect to a plane orthogonal to the optical axis. Therefore, the glass stub 4 is a product composed of a single type of glass component in which no other member such as an optical fiber exists.

The optical component 1 for an optical module further includes a cylindrical stem folder 7 fixed to the end face of the flange 2a of the sleeve folder 2, and a lens folder 8 fitted and fixed in the inner hole of the stem folder 7. The lens holder 8 is provided with a spherical lens 9 fixed with a low melting point glass G. Here, the shape of the lens is not limited to the spherical lens 9, and the shape may be other than a spherical shape as long as the lens has a light condensing function.

As shown in the figure, in a state where the optical component 1 for an optical module is incorporated in the optical module, the stem 11 in which the optical element 10 is arranged is fixed to the lens folder 8, and the optical element 10 is connected to the lens folder 8 and the stem 11. It is accommodated in the enclosed space. The optical element 10 has at least one of a function of emitting light and a function of receiving light. For example, a light emitting element such as a semiconductor laser or a light receiving element such as a photodiode is used depending on the use of the optical module. Elements are used. In this embodiment, the optical element 10 is composed of a light receiving element, and receives the light transmitted from the network side while being condensed by the ball lens 9.

In the above configuration, the optical component 1 for the optical module includes the sleeve folder 2, the guide sleeve 3, the glass stub 4, the stem folder 7, the lens folder 8, and the ball lens 9. That is, the optical module optical component 1 is a portion excluding the ferrule 6 that holds the optical fiber 5 continuous on the network side and the stem 11 on which the optical element 10 is mounted from the configuration of the optical module.

And as a characteristic configuration of the present embodiment, the glass stub 4 which is a glass part has a function of attenuating light. The function of attenuating light is imparted to the glass stub 4 by containing a dopant that attenuates light. As the dopant, metal ions such as Co, Mn, Ni, Cr, V, Fe, and Cu are used. When the glass stub 4 is manufactured as described above, the dopant can be contained in the glass stub 4 if the dopant is preliminarily contained in the glass rod before the heat treatment that is the base material of the glass stub 4. . In addition, content of a dopant is suitably adjusted according to a light attenuation amount.

In this way, even if the light used in the optical module has a high output, the glass stub 4 can attenuate the light to a predetermined level. Therefore, it is possible to reliably prevent the optical element 10 from being damaged by receiving light of a light amount that is greater than or equal to the light receivable level by the optical element 10.

In addition, since the function of attenuating light is given to the glass stub 4 previously arranged on the optical path, it is not necessary to separately arrange a new member on the optical path in order to attenuate the light. Therefore, since the number of parts does not increase excessively in order to attenuate the light, the number of assembling steps does not increase, and the manufacturing cost can be reduced.

Furthermore, since the glass stub 4 is directly fixed to the inner surface of the guide sleeve 3 by heat treatment, the glass stub 4 is fixed to the guide sleeve 3 with glass. Therefore, when the glass stub 4 attenuates light, even if the glass stub 4 generates heat due to absorption of light, the fixing portion of the glass stub 4 has high heat resistance derived from the glass, so that the fixing portion deteriorates due to heat. As a result, it is possible to reliably prevent a situation in which the fixing force is reduced. As a result, even when high-power light is used, the positional deviation of the glass stub 4 does not occur due to heat, so that light can be stably attenuated.

Although various composition systems can be used as the glass composition system that can be used for the glass stub 4 described above, it is preferably made of borosilicate glass. In particular, the glass stub 4 is SiO ₂ 65 to 85%, B ₂ O ₃ 8 to 25%, LiO ₂ + Na ₂ O + K ₂ O 1.5 to 10%, Al ₂ O ₃ 0 to 10% by mass%. It is preferably made of borosilicate glass containing MgO + CaO + SrO + BaO + ZnO 0-5% and CoO 0.1-10%. This is because the weather resistance is excellent and the refractive index difference from the core portion of the optical fiber 5 can be reduced. In the above composition, CoO is a component that functions as a dopant that attenuates light.

FIG. 2 is a diagram showing an optical module according to the second embodiment of the present invention. The optical module according to the second embodiment is different from the optical module according to the first embodiment described above at the end of the guide sleeve 3 included in the optical component 1 for optical module on the optical element 10 side. Instead of the glass stub 4, a fiber stub 13 in which the optical fiber 12 is inserted and fixed is arranged. The fiber stub 13 is inserted into the inner hole of the guide sleeve 3 and is abutted with the ferrule 6 inside the guide sleeve 3. Then, similarly to the glass stub 4 described above, the butted portion of the fiber stub 13 is a convex spherical surface, and the end surface opposite to the butted portion, that is, the end surface on the optical element 10 side is with respect to a plane orthogonal to the optical axis. The surface is inclined. In this embodiment, the optical fiber holding member is composed of the ferrule 6 and the fiber stub 13, and other optical fibers are disposed on the optical path on the optical element 10 side than the end surface on the optical element 10 side of the fiber stub 13. Is in a state that does not exist.

In the optical module according to the second embodiment, the spherical lens 9 is provided with the above-described dopant, thereby providing a light attenuation function.

As a glass composition system that can be used for the spherical lens 9, various glass compositions such as borosilicate glass and B ₂ O ₃ —La ₂ O ₃ —ZnO—Ta ₂ O ₅ glass are used depending on the refractive index. be able to. When it is necessary to increase the refractive index in order to shorten the focal length of light, the spherical lens 9 is in mass%, SiO ₂ 0 to 10%, Al ₂ O ₃ 0 to 15%, B ₂ O ₃ 5 to 25%, Li ₂ O + Na ₂ O + K ₂ O 0-10%, MgO 0-10%, CaO 0-7%, SrO 0-5%, BaO 0-12%, ZnO 10-30%, La ₂ O ₃ 15 B ₂ containing ~ 35%, Ta ₂ O ₅ 15.5-25%, ZrO ₂ 0-10%, Gd ₂ O ₃ 0-20%, WO ₃ 0-10%, CoO 0.1-10% It is preferably made of O ₃ —La ₂ O ₃ —ZnO—Ta ₂ O ₅ glass. Of the above composition, CoO is a component that functions as a dopant.

FIG. 3 is a diagram showing an optical module according to the third embodiment of the present invention. The optical module according to the third embodiment is largely different from the optical modules according to the first and second embodiments in two ways. First, the guide sleeve 3 is omitted, and the ferrule 6 is directly held in the inner hole of the sleeve folder 2. Secondly, the opening on the optical element 10 side of the sleeve folder 2 included in the optical component 1 for an optical module is hermetically sealed with a plate glass 14 in order to prevent entry of foreign matters such as dust from the outside, The end face of the ferrule 6 on the optical element 10 side is abutted against and brought into contact with the plate glass 14. The plate glass 14 is indirectly fixed to the inner surface of the sleeve folder 2 with a low melting point glass or fixed with an adhesive. In this embodiment, the plate glass 14 is fixed in a state of being in contact with the stopper 2b extending to the inner diameter side at the end of the sleeve folder 2 on the optical element 10 side.

In the optical module according to the third embodiment, the light attenuation function is imparted by containing the above-mentioned dopant in the plate glass 14.

As a glass composition that can be used for the plate glass 14, various glass compositions such as soda lime glass and borosilicate glass can be used. When it is necessary to reduce the influence of the reflected light on the optical fiber 5 and the plate glass 14, the plate glass 14 is 50% by mass, SiO ₂ 50-80%, Al ₂ O ₃ 0-20%, B ₂ O _3. 5-20%, MgO 0-10%, CaO 0-10%, SrO 0-10%, BaO 0-10%, Na ₂ O 0-10%, K ₂ O 0-10%, ZnO 0-10% , TiO ₂ 0 to 10%, ZrO ₂ 0 to 10%, and CoO 0.1 to 10%. In the above composition, CoO is a component that functions as a dopant.

In addition, since this plate glass 14 is also abutted against the ferrule 6, it is preferable that it is the glass composition similar to the glass stub 4 demonstrated in said 1st Embodiment. Moreover, you may make it incline the end surface by the side of the optical element 10 of the plate glass 14 with respect to the plane orthogonal to an optical axis.

FIG. 4 is a diagram showing an optical module according to the fourth embodiment of the present invention. The optical module according to the fourth embodiment is different from the optical module according to the third embodiment in that the plate glass 14 is omitted and the tip of the ferrule 6 is directly abutted against the stopper 2b of the sleeve folder 2. At the point where it was positioned.

In the optical module according to the fourth embodiment, since the glass component on the optical path between the optical element 10 and the end surface of the ferrule 6 on the optical element 10 side is only the spherical lens 9, By containing the above-mentioned dopant, the light attenuation function is imparted.

FIG. 5 shows an optical module according to the fifth embodiment of the present invention. The optical module according to the fifth embodiment is different from the optical modules according to the first to fourth embodiments in that a receptacle in which a ferrule 6 that holds an optical fiber 5 that propagates light is detachably held is held. The fiber pigtail 15 in which the optical fiber 5 is inserted and fixed is not a type, but is a pigtail type optical module fixed to the stem folder 7 via the pigtail support 16.

The end face of the fiber pigtail 15 on the optical element 10 side may be a plane parallel to a plane orthogonal to the optical axis. In this embodiment, in order to reduce the influence of reflected light, the end surface on the plane orthogonal to the optical axis is used. It has an inclined surface. In this embodiment, the optical fiber holding member becomes the fiber pigtail 15 and there is no other optical fiber on the optical path on the optical element 10 side than the end face on the optical element 10 side of the fiber pigtail 15. It has become.

In the optical module according to the fifth embodiment, since the glass component on the optical path between the optical element 10 and the end face on the optical element 10 side of the fiber pigtail 16 is only the spherical lens 9, the lens 9 has a light attenuation function by containing the above-mentioned dopant.

As described above, according to the optical modules according to the first to fifth embodiments of the present invention, light is attenuated to the existing glass parts (glass stub 4, spherical lens 9, plate glass 14) arranged on the optical path. Therefore, the number of parts does not increase excessively in order to attenuate light. Therefore, it is possible to provide an optical module that can reliably attenuate light while preventing an increase in the number of components. Moreover, since the function which attenuates light is provided by making a glass component contain a metal ion as a dopant, the advantage that an attenuation characteristic cannot change easily with heat can also be enjoyed. Further, since the glass component is directly fixed to the holding member (the guide sleeve 3 or the lens folder 8) or indirectly fixed by the low melting point glass, the glass component is not lighted when the light is attenuated. Even if a part of the heat is absorbed and heat is generated, it is difficult to cause a situation in which the fixed portion is deteriorated by heat. Therefore, it is possible to prevent the positional deviation of the glass parts as much as possible.

Here, in the third embodiment, even if the plate glass 14 is fixed to the opening of the guide sleeve 3 with an adhesive, the plate glass 14 is placed in the opening of the guide sleeve 3 when the ferrule 6 is abutted against the plate glass 14. Since it is pressed against the provided stopper 2b, it is possible to prevent displacement of the plate glass 14. Moreover, even if a positional deviation occurs in the plate glass 14, the plate glass 14 does not have a function of condensing light and only allows light to pass therethrough.

In addition, this invention is not limited to said embodiment, It can implement with a various form. For example, in the above embodiment, the glass components (glass stub 4, ball lens 9, plate glass 14) disposed on the optical path between the optical element 10 and the end of the optical fiber 5 (12) on the optical element 10 side. ), The case where a light attenuating function is given to only one is explained, but when a plurality of glass parts are arranged on the optical path of the section, the light attenuating function is provided to two or more glass parts. You may make it provide. Specifically, in the optical module according to the first embodiment, both the glass stub 4 and the spherical lens 9 may be provided with an optical attenuation function. In the optical module according to the third embodiment, A light attenuation function may be imparted to both the plate glass 14 and the spherical lens 9. In this way, the amount of light attenuation can be easily and reliably increased as compared with the case where only one of the glass parts is provided with the light attenuation function. In other words, the amount of light attenuation as a whole can be easily adjusted by combining these glass components. Also, in this case, when realizing a predetermined amount of light attenuation, it is only necessary to absorb light step by step with each glass component, so that the amount of light absorption with one glass component can be kept small. it can. Therefore, the calorific value of the individual glass parts is relaxed, and the heat resistance can be further improved. Therefore, there is an advantage that it is possible to suitably cope with a request for further increasing the output of light.

Also, in the optical modules according to the first embodiment and the third embodiment, as in the optical module according to the second embodiment, the light attenuation function may be given only to the spherical lens 9. The spherical lens 9 is often desired to have a high refractive index in order to improve the light coupling efficiency and shorten the focal length to make the device compact. When the spherical lens 9 contains a metal ion dopant, it is often possible to improve the refractive index as well as the light attenuation function. Therefore, it can be said that providing the light attenuation function to the spherical lens 9 as described above is preferable in that a high refractive index can be achieved simultaneously with the provision of the attenuation function.

In addition, in the optical modules according to the first to fifth embodiments described above, the optical attenuation function is imparted to the glass component by containing the dopant. Instead of containing the dopant, the glass module is formed by, for example, vapor deposition or sputtering. A light attenuation function may be imparted to the glass component by forming a metal film such as Cu on the surface of the component.

A confirmation test was conducted to demonstrate the usefulness of the present invention. The results are described below.

First, in the optical module according to the first embodiment, the attenuation factor of light was confirmed when the glass stub 4 containing the glass composition shown in Table 1 below was used.

As can be seen from Table 1 above, it can be confirmed that the light is reliably attenuated when any of the glass stubs 4 of Examples 1 to 3 is used. Specifically, in Example 1, an attenuation factor of 3.0 dB or more is realized for each of light of 1310 nm and 1550 nm. Similarly, the attenuation rate of 5.7 dB or more is achieved in Example 2 and the attenuation rate of 15.0 dB or more is achieved in Example 3 with respect to both lights of these two wavelengths.

Next, in the optical module according to the second embodiment, the light attenuation rate was confirmed when the spherical lens 9 containing the glass composition shown in Table 2 below was used.

As can be seen from Table 2 above, it can be confirmed that the light is reliably attenuated even when any of the spherical lenses 9 of Examples 4 to 6 is used. Specifically, with respect to each of light of 1310 nm and 1550 nm, the attenuation rate of 2.9 dB or more in Example 4, 5.7 dB or more in Example 5, and 15.0 dB or more in Example 6 The rate is realized.

Further, in the optical module according to the third embodiment, the attenuation factor of light was confirmed when the plate glass 14 containing the glass composition shown in Table 3 below was used.

As can be seen from Table 3 above, it can be confirmed that the light is reliably attenuated when any of the glass plates 14 of Examples 7 to 9 is used. Specifically, with respect to each of light at 1310 nm and 1550 nm, the attenuation rate of 1.5 dB or more in Example 7, the attenuation rate of 2.9 dB or more in Example 8, and the attenuation of 7.5 dB or more in Example 9 The rate is realized.

In any of the above Examples 1 to 9, since the same attenuation factor is shown for each of the light of 1310 nm and 1550 nm, the wavelength dependency of the attenuation factor is in the wavelength band of 1310 to 1550 nm. It can be recognized that there are few. Since this wavelength band is a band used in long-distance optical communication, if these optical modules are used for the application, highly reliable communication can be realized.

Further, the light attenuation factor can be adjusted by appropriately combining the glass stub 4, the spherical lens 9, and the plate glass 14 according to these embodiments. Specifically, for example, in the optical module according to the first embodiment, when the glass stub 4 of Example 1 and the spherical lens 9 of Example 5 are incorporated, light in the wavelength band of 1310 to 1550 nm On the other hand, an attenuation factor of about 9.0 dB can be realized. Further, when the glass stub 4 of Example 2 and the spherical lens 9 of Example 5 are incorporated in this optical module, an attenuation factor of about 12.0 dB with respect to light having a wavelength band of 1310 to 1550 nm. Can be realized.

DESCRIPTION OF SYMBOLS 1 Optical component for optical modules 2 Sleeve folder 3 Guide sleeve 4 Glass stub 5 Optical fiber 6 Ferrule 7 Stem folder 8 Lens folder 9 Ball lens 10 Optical element 11 Stem 12 Optical fiber 13 Fiber stub 14 Plate glass 15 Fiber pigtail 16 Pigtail support G Low melting point glass

Claims

One or more glass parts are provided on an optical path between an optical element that emits and / or receives light and an end face closest to the optical element of an optical fiber that is inserted and fixed in an optical fiber holding member. In optical components for optical modules,
An optical component for an optical module, wherein an optical attenuation function is provided to at least one of the one or more glass components.
2. The optical component for an optical module according to claim 1, wherein the glass component having the light attenuation function contains a dopant that attenuates light.
3. The optical component for an optical module according to claim 2, wherein the dopant is at least one ion selected from Co, Mn, Ni, Cr, V, Fe, and Cu.
The glass component containing the said dopant is arrange | positioned two or more on the optical path between the said optical element and the end surface nearest to the said optical element of the said optical fiber, The Claim 2 or 3 characterized by the above-mentioned. Optical parts for optical modules.
The glass component having the light attenuation function is a lens that collects light passing through an optical path between the optical element and an end face of the optical fiber closest to the optical element. 5. The optical component for an optical module according to any one of 1 to 4.
6. The glass stub according to claim 1, wherein the glass component having the light attenuating function is a glass stub having a convex spherical surface that comes into contact with an end surface of the optical fiber holding member closest to the optical element. An optical component for an optical module as described in 1.
Whether the glass component imparted with the light attenuation function is directly fixed to the holding member that holds the glass component on the optical path between the optical element and the end face closest to the optical element of the optical fiber by heat treatment, The optical component for an optical module according to any one of claims 1 to 6, wherein the optical component is fixed indirectly by low-melting glass.
The optical component for an optical module according to any one of claims 1 to 7, further comprising a cylindrical member that holds the optical fiber holding member in an inner hole.
The glass component imparted with the light attenuation function is a plate glass that comes into contact with an end surface of the optical fiber holding member closest to the optical element and hermetically seals the opening of the cylindrical member on the optical element side. The optical component for an optical module according to claim 8.
10. An optical module comprising the optical module for an optical module according to claim 1 incorporated therein.