JPH0293506A - Incident/exit unit exchange type optical circuit parts - Google Patents

Abstract

PURPOSE:To allow connection of various kinds of optical fibers to the optical circuit parts by providing lens units having junctures for lenses and optical fibers for collimation freely attachably and detachably to the optical parts. CONSTITUTION:An attenuating plate 5 is fixed to a case 1 and the inside of the case 1 is collimated by the lens unit 2. Respectively the same kind of the optical fibers 9a, 9b are connected to the incident side and exist side of the plate 5 and the fibers 9a, 9b are freely attachable and detachable to the from the lens units 2, 2 via connectors 10a, 10b. The juncture 2c which is connected with a fitting part 2a of a prescribed diameter at one end, a collar part 2b at the center and the connector 10 of the optical fiber 9 at the other end is formed to the unit 2. The plate has internally the lens 3 and is opened and formed with an insertion part 2d into which the end part of the connector 10 is inserted. Correspondence to many kinds of the fibers is possible simply by exchanging the lens unit if one unit of the optical circuit parts is prepd.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an optical circuit component used mainly in optical communication systems, and is an optical circuit component that can be used with a variety of optical fibers by unitizing input and output parts. It is related to.

[Conventional technology]

An optical attenuator will be described below as a typical example of an optical circuit component. Conventional optical attenuators are broadly classified into two types. One type is an optical attenuator 30, whose plan view is shown in FIG. 6, which is mainly used for multimode applications. The light emitted from the fiber 33 of the plug 32 connected to the input side receptacle 31 is converted into parallel light by the collimating lens 34, and after being attenuated to a predetermined value by the attenuation plates 35a and 35b, the light is transmitted to the output side receptacle by the condenser lens 36. The light is focused on the fiber 39 of the plug 38 connected to the plug 37. The second type is an optical attenuator 40, whose plan view is shown in FIG. 7, which is mainly used for single mode. This type also has a collimating lens 34 similar to the above-mentioned one.
．． Damping plates 35a, 35b. Although the condenser lens 36 is used, the fitting precision of the receptacle is such that the core diameter is as small as 10pm in the case of single mode, so the coupling loss will be large. are used on the incident side and the output side, respectively. Furthermore, in each of the above-mentioned types, the core diameter of the fiber used is determined in order to optimize the coupling efficiency. Figure 6 is for multi-mode with a core diameter of 50 μm;
The figure is for a single mode with a core diameter of 10 pm. [Problem to be Solved by the Invention] As described in the prior art, the receptacle 31, 37 or adapter 4, which is an interface point with an external signal,
1. Furthermore, lenses 34, 36, and internal transmission optical fiber 4
2 is fixed to the main body. Generally, when the core diameter and numerical aperture of an optical fiber are limited, the positions of the input and output fibers and the positional relationship between the collimating lens and the condensing lens are determined in order to bring the coupling loss close to the minimum value. Therefore, the number of optical attenuators that can be used is limited to one type depending on the core diameter and numerical aperture, that is, depending on the type of optical fiber. This necessitates the use of separate optical attenuators for each type of optical fiber. The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an optical circuit component such as an optical attenuator that can connect various types of optical fibers without being limited to the types of optical fibers. [Means for Solving the Problems] The input/output unit replaceable optical circuit component of the present invention is shown in FIG.
As shown in FIG. 2, in order to be compatible with many types of optical fibers 9, a connector 2c that is connected to the optical fiber 9 and a lens 3 that collimates light on the optical circuit component A side are integrated. The lens unit 2 is configured to be detachable from the optical circuit component A, and the lens unit 2 and the optical circuit component A are positioned by a positioning mechanism, so that the optical fiber 9 can be adjusted according to the type of the optical fiber 9. The lens unit 2 can be replaced on both the input and output sides. Furthermore, by configuring the lens unit 2 to have a lens configuration that corresponds to each optical fiber 9, it is possible to connect many types of optical fibers 9 with a single optical circuit component A. [Embodiment] FIG. 1 is a plan view illustrating an embodiment of the input/emission unit/) exchangeable optical circuit component of the present invention, in which an optical attenuator is shown as the optical circuit component A. In the figure, l is a case constituting the outer casing of optical circuit component A, and 2
Reference numeral 5 indicates a lens unit that is detachable from the case l, and 5 indicates an attenuation plate as an optical component. The attenuation plate 5 is fixed to the case 1, and the light inside the case 1 is collimated by the lens unit 2. The attenuator 5 has optical fibers 9a and 9b of the same type connected to the incident side and the output side, respectively, and these optical fibers 9a and 9b are connected to the lens unit 2 through connectors 10a and lOb, respectively.
2. It is detachable. FIG. 2 is an enlarged sectional view showing part of the lens unit 2 and the case l. The lens unit 2 has a fitting part 2a of a predetermined diameter at one end, a collar part 2b at the center, and a connecting part 2c to which a connector 10 of an optical fiber 9 is connected at the other end. The insertion portion 2d into which the end portion of the connector 10 is inserted is formed as an opening. As the lens 3, a rod lens 3a with an outer diameter of 2 mm, which is commonly used in optical communications, shown in FIG. 2 is provided. This is a single mode with a core diameter of 10#Lm or a core diameter of 501L.
Used for multi-mode of m. Also, if you try to use this unit with a plastic fiber with a core diameter of 1 mm, the incident light will protrude from the lens and the coupling loss will be as large as 10 dB, making it unusable.In this case, as the lens 3, for example, By using a large convex lens 3b, a practical coupling loss of about 3 dB can be used. Also, the core diameter is 200 mm, which is usually manufactured using multi-component glass.
Optimal coupling can be obtained by using lens units compatible with fibers such as gm and 400 gm. On the other hand, in the case 1, a fitting hole 1aa corresponding to the fitting part 2a of the lens unit 2 and an optical path 1ab of a predetermined diameter are formed in the side wall 1a, which is the part on the entrance side and the exit side. These fitting parts and fitting holes constitute a positioning mechanism, and the case l of the optical circuit component A and the lens unit 2
The positioning between the As shown in FIG. 4(a), these fitting portions 2a and fitting holes 1
aa is sufficient accuracy for optical axis alignment, for example, gap A is lIL
Fit with accuracy of m or less. This precision can be easily produced by machining. Alternatively, it can be realized even more easily by using positioning pins or the like in the manufacturing process. The positioning of the case l and the lens unit 2 is performed by using the fitting portion 2aa and the fitting hole 1a as shown in FIG. 4(b).
c may be formed into a tapered shape. In order to securely hold the lens unit 2 to the case 1, a screw 6a shown in FIG. 2 is used. A pin 6b shown in FIG. 5 may also be used. The operation of the above-mentioned configuration will be explained with reference to FIGS. 1 and 2. The lens unit 2 is detachable from the case 1 of the optical circuit component A, and the lens unit 2 is detachable for each lens 3 corresponding to various optical fibers. 2 can be provided. When this lens unit 2 is attached to the case 1, it is automatically positioned using the fitting portion 2a and the fitting hole 1aa that constitute a positioning mechanism. Then, the lens units 2.2 are attached to the incident side and the output side of the optical circuit component A, respectively, and the connectors 10a and 10b of the optical fibers 9a and 9b are respectively connected to the connecting portions 2 of the lens units 2.2.
Connect to C. As a result, the light in the optical fiber 9a on the input side is collimated by the lens 3 of the one lens unit 2, passes through the attenuation plate 5, is attenuated by a predetermined amount, and is attenuated by the lens 3 of the other lens unit 2 on the output side. is transmitted to the optical fiber 9b. To use another optical fiber 9 with a different core diameter or NA, simply replace the lens unit 2 having the lens 3 corresponding to this optical fiber 9 and use the same optical circuit component A.
A similar effect can be obtained by connecting another optical fiber <9 to. In the above-described embodiment, a fixed attenuator having a fixed attenuation plate was used as the optical component 5, but the same effect can be obtained by using a variable attenuator whose attenuation amount can be varied. Further, by changing the type of optical connector 9 of the lens unit 2, various types of optical connectors 9 can be used. A similar idea is used between lens units 2 and 2. The optical component (portion 5 in FIG. 3) can be changed to, for example, a wavelength selection filter, a half mirror, or the like. [Effects of the Invention] As explained above, according to the input/output unit replaceable optical circuit component of the present invention, if one optical circuit component is prepared, the core diameter and HA can be adjusted by simply replacing the lens unit. It can accommodate many different types of fibers. In addition, in order to support many types of fibers, lens uni-/
) only need to be prepared, which has a great advantage in terms of cost.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the input/emission unit replaceable optical circuit component of the present invention, Fig. 2 is a partially enlarged sectional view of the lens unit and case, and Fig. 3 is a plan view showing an example of the optical circuit component of the present invention. 4(a) is a sectional view illustrating one positioning mechanism, FIG. 4(b) is a sectional view showing another positioning mechanism, and FIG. 5 is a sectional view showing how the lens unit and case are fixedly held FIGS. 6 and 7 are cross-sectional views showing other examples of optical attenuators, which are conventional optical circuit components. A... Optical circuit component, l... Case, laa... Fitting part, 2... Lens unit), 2a... Fitting hole, 3
...Lens (3a...rod lens, 3b...convex lens). 5... Optical components, 9 (9a, 9b)... Optical fiber 10 (lOob)... Lens unit. Patent applicant Anritsu Corporation

Claims (1)

[Claims] A collimated light beam is coupled between the optical fiber (9a) connected to the input side and the optical fiber (9b) connected to the output side, and optical attenuation occurs in the middle of the collimated light beam. In an optical circuit component (A) in which an optical component (5) such as a plate is arranged, a lens for collimation is provided on an incident side and an output side of the optical circuit component, respectively positioned by a positioning mechanism and removably provided. (3) An input/output unit exchangeable optical circuit component that can freely connect optical fibers with different core diameters or NAs by providing a lens unit (2) equipped with an optical fiber connection part (2c).