JP2005165105A - Optical coupling element, method for manufacturing the same and utilization of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical coupling element such as an optical fiber array which can be inexpensively and easily manufactured, a method for manufacturing the optical coupling element and the use of the optical coupling element. <P>SOLUTION: In the method for manufacturing the optical coupling element, optical fibers 3 are fixed in optical fiber fixing grooves 4 by using a manufacturing tool 1 comprising a recessed part 2 for storing the base part of the optical coupling element, the optical fiber fixing grooves 4 and erection parts 5 arranged on both the sides of the recessed part 2, the base part 6 of the optical coupling element is stored in the recessed part to bring the optical fibers in to contact with the surface of the base part 6 of the optical coupling element, then the optical fibers are stuck and fixed to the surface of the base part 6 of the optical coupling element. Then end face processing allowing light incidence is applied to one end side of the stuck and fixed optical fibers to obtain the optical coupling element. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical coupling element for high-power laser light, and in particular, an optical coupling element that can be easily manufactured at low cost for connecting a semiconductor laser array and an optical fiber array, a manufacturing method thereof, and use of the optical coupling element About.

  A semiconductor laser array is provided as one of high-power light sources. An optical fiber array is used as an optical coupling element for coupling output light from the semiconductor laser array with an optical fiber. In the general coupling method, the incident end of the optical fiber array is arranged as close as possible to the light emitting surface of the semiconductor laser array, and the two are abutted to achieve optical coupling. In such an optical coupling structure, in order to perform optical coupling more efficiently, the optical fibers arranged on the optical fiber array must be arranged as accurately as possible according to the period of the light emitting point of the semiconductor laser array.

In a conventional general optical fiber array, an optical fiber fixing groove is provided, and an optical fiber is arranged using the groove. In order to arrange the optical fibers with high accuracy, it is necessary to manufacture the optical fiber fixing grooves on the optical fiber array with extremely small mechanical tolerances. For this reason, the optical fiber fixing groove is generally manufactured by a processing method by etching or grinding. Various types of optical fiber array structures have been proposed so far (see, for example, Patent Documents 1 to 3).
US Pat. No. 5,734,766 Japanese Utility Model Publication No. 5-11110 JP-A-5-93828

  However, it is not easy to manufacture an optical fiber array having an optical fiber fixing groove manufactured with extremely small mechanical tolerances, resulting in an increase in manufacturing cost. Moreover, since it is necessary to produce by etching or grinding, the material is also limited.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an optical coupling element such as an optical fiber array that can be easily manufactured at low cost, a manufacturing method thereof, and use thereof.

In order to achieve the above object, the present invention uses a manufacturing jig having a concave portion in which an optical coupling element base is accommodated, and an optic fiber fixing groove and a bridge portion disposed on both sides of the concave portion. An optical fiber is fixed in the fiber fixing groove, the optical coupling element base is accommodated in the recess, the optical fiber is brought into contact with the surface of the optical coupling element base, and then the optical fiber is bonded and fixed to the surface of the optical coupling element base. Next, an optical coupling element manufacturing method is provided, wherein an optical coupling element is obtained by performing an end face treatment that allows light incidence on one end side of an optical fiber that is bonded and fixed.
Moreover, this invention provides the optical coupling element which does not have the groove | channel for optical fiber fixation manufactured by the said manufacturing method.
In the optical coupling element of the present invention, the optical coupling element is preferably an optical fiber array in which a plurality of optical fibers are fixed in parallel.
The present invention also provides a high-power light source comprising the optical coupling element and the semiconductor laser array, and optically coupling the optical coupling element and the semiconductor laser array to guide high-power laser light through an optical fiber.
Furthermore, the present invention provides a solid-state laser system that uses the high-power light source as an excitation light source.

According to the method for manufacturing an optical coupling element of the present invention, an optical fiber fixing groove having a high positional accuracy for laying an optical fiber is provided in a manufacturing jig having a concave portion for accommodating the optical coupling element base. Without providing an optical fiber fixing groove in the element base, an optical fiber installed on a manufacturing jig is bonded and fixed to the surface of the optical coupling element base, so that an optical coupling element such as an optical fiber array can be easily formed at low cost. Can be manufactured.
In addition, since it is no longer necessary to provide an optical fiber fixing groove in the optical coupling element base, the degree of freedom of selection of the material of the optical coupling element base is increased. For example, stainless steel having high workability is used as the optical coupling element base material. It can be used. Thereby, an inexpensive and highly accurate optical coupling element can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view for explaining an example of the manufacturing method of the optical coupling element of the present invention, FIG. 2 is a perspective view showing an example of the optical coupling element of the present invention, and FIG. 3 is preferably used in the manufacturing method of the present invention. It is a perspective view of a manufacturing jig. In these drawings, reference numeral 1 is a manufacturing jig, 2 is a recess, 3 is an optical fiber, 4 is an optical fiber fixing groove, 5 is an installation part, 6 is an optical coupling element base, 7 is a base, and 8 is an optical coupling element ( Optical fiber array).

  In the manufacturing method of the present invention, a manufacturing jig 1 as shown in FIG. 3 is used. This manufacturing jig 1 has a U-shape in plan view having a recess 2 for accommodating the optical coupling element base 6 in the center, and a plurality of optical fiber fixing grooves 4 are formed on both sides of the recess 2. The erection part 5 having the projection is provided. These erected parts 5 have a protruding height, a groove depth, and a depth at which the optical fiber 3 erected on the upper surface of the optical coupling element base 6 can be brought into contact with the optical coupling element base 6 in the recess 2. It is provided at the arrangement position.

  The optical fiber fixing groove 4 provided in each of the erection parts 5 is suitable for the upper surface of the optical coupling element base 6 in a state where the optical fiber 3 is fixed to the optical fiber fixing grooves 4 of the plurality of erection parts 5. The position is precisely adjusted so as to obtain a proper position and arrangement interval. The groove shape of the optical fiber fixing groove 4 is suitable for the shape of the optical fiber 3 to be used. For example, a V-shaped groove is used when a round optical fiber having a circular cross-sectional shape is used, and a rectangular groove is formed when a rectangular optical fiber having a square cross-sectional shape is used.

  In this example, a plurality of optical fiber fixing grooves 4 are installed in each installation part 5 in a state in which a large number of optical fibers 3 are accurately arranged in parallel, and a large number of optical fibers 3 are bonded and fixed. Although the case where (optical fiber array) is manufactured is shown, the number of optical fibers 3 is not particularly limited, and can be one or more depending on the type of optical coupling element 8 to be manufactured. .

  The optical coupling element base 6 accommodated in the recess 2 of the manufacturing jig 1 includes a plurality of bases 7 protruding on the upper surface side. These pedestals 7 may have a constant protruding height, or when the optical fiber 3 from which a part of the coating is removed is bonded and fixed on the pedestal 7 as shown in FIG. The protrusion height of the pedestal portion for bonding and fixing the coating portion 3b of the optical fiber 3 can be appropriately adjusted and formed as compared with the pedestal portion for bonding and fixing 3a (the coating removal portion).

  In the present invention, since there is no need to provide an optical fiber fixing groove in the optical coupling element base 6, the degree of freedom in selecting the material of the optical coupling element base 6 is widened, and silicon, ceramics, In addition to quartz glass and the like, stainless steel having high workability can be used as the optical coupling element base material.

A procedure for manufacturing an optical coupling element according to the manufacturing method of the present invention using the manufacturing jig 1 and the optical coupling element base 6 will be described.
First, a plurality of optical fibers 3 are fixed in parallel to the installation part 5 of the manufacturing jig 1. The optical fiber 3 can be selected from various optical fibers according to the type of the optical coupling element 8, and for example, a single mode optical fiber, a multimode optical fiber, a large diameter optical fiber for a high output laser, or the like can be used. it can. In addition, the installed optical fiber 3 has a part of the coating on the end surface treated side removed.

  Next, as shown in FIG. 1, the optical coupling element base 6 is accommodated in the recess 2 of the manufacturing jig 1. When the optical coupling element base 6 is accommodated and the optical fiber is pressed downward by a pressing means (not shown) as required, the laid optical fiber 3 contacts the upper surface of the base 7 of the optical coupling element base 6.

  Next, the optical fiber 3 in contact with the upper surface of the base 7 of the optical coupling element base 6 is bonded and fixed to the base 7. This adhesive fixing can be performed using various conventionally known adhesives used for bonding optical fibers and various optical components. Examples of the adhesive include epoxy adhesives and cyanoacrylate adhesives. Agents, urethane adhesives, hot melt adhesives, and the like.

Next, one side of the optical fiber 3 bonded and fixed to the upper surface of the base 7 of the optical coupling element base 6 is cut at an appropriate position, and the other side of the optical fiber 3 is removed from the optical fiber fixing groove 4 of the erection unit 5 to manufacture the optical fiber. The optical coupling element 8 is removed from the tool 1.
Next, an end face treatment capable of entering light is applied to one end side of the optical fiber 3 bonded and fixed to the optical coupling element 8, thereby obtaining the optical coupling element 8 shown in FIG. 2. This end surface treatment can be performed by a method such as polishing one end side of the optical coupling element base 6 together with the end surface of the optical fiber 3.

  The optical coupling element 8 shown in FIG. 2 manufactured as described above has a large number of optical fibers 3 bonded and fixed in parallel to the upper surface of the base 7 of the optical coupling element base 6. Is characterized by not having an optical fiber fixing groove. The optical fiber 3 fixed to the optical coupling element 8 is accurately arranged according to the period of the light emitting point of the semiconductor laser array. The end face of each optical fiber 3 can be subjected to an end face treatment for antireflection such as an antireflection film or oblique polishing so that laser light emitted from the light emitting point of the semiconductor laser array is efficiently incident. The optical coupling element 8 of the present invention can be applied to the optical communication field and the optical application field that use an optical coupling element such as an optical fiber array, and can also be used when, for example, an optical waveguide and an optical fiber are coupled. .

Since the optical coupling element 8 does not have the optical fiber fixing groove in the optical coupling element base 6, the optical coupling element 8 can be manufactured inexpensively and easily.
In addition, since it is not necessary to form an optical fiber fixing groove in the optical coupling element base 6, the degree of freedom in selecting the material of the optical coupling element base 6 is increased. For example, stainless steel having high workability is used as the optical coupling element base material. It becomes possible. Thereby, the inexpensive and highly accurate optical coupling element 8 can be provided.

According to the manufacturing method of the present invention shown in FIG. 1, an optical fiber array having the structure shown in FIG. 2 was manufactured as an optical coupling element.
The used manufacturing jig is U-shaped as shown in FIG. 3, and has a length of 132 mm, a width of 50 mm, a height to the upper end of the erection part of 6.5 mm, a recess of 30 mm × 17 mm, and a erection part width of 0.5 mm. Nineteen V-grooves having a depth of 500 μm were formed at intervals of 500 μm on three erected portions. The mechanical tolerance of the V groove was within 20 μm.
Nineteen single-mode optical fibers (cladding outer diameter 125 μm, coating outer diameter 0.25 mm) were installed in parallel in the installation part of the manufacturing jig.
Next, a stainless steel optical coupling element base (length 10 mm, width 25 mm, height 6 mm) is accommodated in the recess of the manufacturing jig, and the optical fiber contacting the upper surface is bonded onto the pedestal with an acrylic adhesive. Fixed.
Next, the optical fiber was cut at the position of one end of the optical coupling element base 6, and further, one end side of the optical coupling element base 6 was mirror-polished to perform an end surface treatment of the optical fiber, thereby manufacturing an optical fiber array.

FIG. 4 shows a histogram of the amount of deviation from the design center position for the optical fiber position on the end face of the optical fiber array manufactured according to this embodiment. FIG. 4A shows the frequency distribution of deviation in the horizontal direction, and FIG. 4B shows the frequency distribution of deviation in the vertical direction.
It can be seen that the optical fiber can be arranged with an accuracy of ± 3 μm or less in the horizontal and vertical directions by this manufacturing method.

It is a top view explaining an example of the manufacturing method of the optical coupling element of this invention. It is a perspective view which shows an example of the optical coupling element of this invention. It is a perspective view which illustrates a suitable manufacturing jig in the manufacturing method of the present invention. It is a histogram of the deviation | shift amount of the optical fiber in the produced optical coupling element which shows the result of the Example which concerns on this invention, and was manufactured.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Manufacturing jig, 2 ... Recessed part, 3 ... Optical fiber, 4 ... Optical fiber fixing groove, 5 ... Construction part, 6 ... Optical coupling element base, 7 ... Base, 8 ... Optical coupling element.

Claims (5)

  Using a manufacturing jig having a recess in which the optical coupling element base is accommodated and an erected portion having an optical fiber fixing groove and disposed on both sides of the recess, the optical fiber is fixed in the optical fiber fixing groove, and The optical coupling element base is accommodated in the recess, the optical fiber is brought into contact with the surface of the optical coupling element base, the optical fiber is then bonded and fixed to the surface of the optical coupling element base, and then the optical fiber is bonded to one end side of the bonded optical fiber. A method of manufacturing an optical coupling element, wherein an optical coupling element is obtained by performing an incident end surface treatment.   An optical coupling element which is manufactured by the manufacturing method according to claim 1 and does not have an optical fiber fixing groove.   The optical coupling element according to claim 2, which is an optical fiber array in which a plurality of optical fibers are fixed in parallel.   A high-output light source comprising the optical coupling element according to claim 2 and a semiconductor laser array, and optically coupling the optical coupling element and the semiconductor laser array to guide high-power laser light through an optical fiber. A solid-state laser system using the high-power light source according to claim 4 as an excitation light source.

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