JP4219499B2 - Grating-type optical component manufacturing apparatus and grating-type optical component manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a grating type optical component manufacturing apparatus and a method for manufacturing a grating type optical component that apply a grating to a grating forming region of an optical fiber.
[0002]
[Prior art]
In optical communication technology, grating-type optical components are widely used. For example, this grating-type optical component forms a stop band of transmitted light by a grating in a wavelength band different from the signal wavelength, transmits signal light from the input end to the output end, and inputs light having a wavelength in the stop band by the grating. It is reflected to the end side and taken out as monitoring light.
[0003]
As a method for forming the grating, a phase mask method using a mask (phase mask) is widely used. In this phase mask method, a grating forming region of an optical waveguide such as an optical fiber is irradiated with ultraviolet light through a mask (phase mask), and the optical waveguide such as an optical fiber is refracted by irradiation with ultraviolet light through the mask. Grating is performed by periodically arranging a portion with a high rate and a portion with a low refractive index due to ultraviolet light shielding in the longitudinal direction of the optical fiber.
[0004]
The core of the optical fiber is generally formed of germanium (Ge) -doped quartz (SiO ₂ ) glass. When this germanium-doped glass is irradiated with strong ultraviolet light, the refractive index of germanium increases, so that the phase on the optical fiber is increased. By projecting the interference fringes of ultraviolet light through the mask, it is possible to cause a periodic refractive index change in the core of the optical fiber and to form a diffraction grating. In addition to the phase mask method, a grating forming method includes a bolographic method that does not use a mask.
[0005]
By the way, when a grating is formed on an optical fiber by the phase mask method, for example, since interference fringes having a spacing of about 1 μm are projected onto the optical fiber, accurate posture accuracy (tilt and distance) between the optical fiber and the phase mask is ensured. Required. If an excimer laser is used to irradiate ultraviolet light, the excimer laser is less coherent than the argon laser and it is difficult to obtain clear interference fringes, so set the optical fiber close to the phase mask. It is desirable to do.
[0006]
Therefore, when manufacturing a grating-type optical component by the phase mask method, for example, using an apparatus as shown in FIGS. 4 and 5 , the optical fiber 2 is placed on the optical fiber 2 with the phase mask 8 in contact with the optical fiber 2. In addition, the phase mask 8 is directly mounted, and the grating is formed by irradiating UV light (ultraviolet light) from the upper side of the phase mask 8. That is, as shown in these drawings, two or more pairs of optical fibers 2 are arranged substantially in parallel on the planar upper surface of two optical fiber mounting bases 13 arranged with a gap between them. 2, the phase mask 8 is placed in contact with the optical fiber 2 in a well-balanced manner by its own weight, or the phase mask 8 is placed in contact with the optical fiber 2 by applying pressure to the phase mask 8 and, as described above, ultraviolet light. A grating was formed by irradiation.
[0007]
In general, the grating formation region 6 to remove the coating of the optical fiber 2 being adapted to the grating formation is performed, as shown in (b) of FIG. 5, the optical fiber mounting table 13, the optical fiber 2 The portions on both ends of the grating forming region 6 from which the coating is removed are mounted.
[0008]
[Problems to be solved by the invention]
However, the phase mask 8 is generally made of quartz and is very fragile despite being expensive. As described above, when the phase mask 8 and the optical fiber 2 are arranged in contact with each other, There is a problem that the expensive phase mask 8 is easily damaged.
[0009]
Further, when the phase mask 8 and the optical fiber 2 come into contact with each other, there is a problem in that foreign matter attached to the optical fiber 2 contaminates the phase mask 8 and becomes an obstacle to forming a grating.
[0010]
Furthermore, when forming the grating, tension is applied to the grating forming region 6 by fixing the covering portions of the both ends of the grating forming region 6 where the coating of the optical fiber 2 is not removed to the tension applying device side and applying tension. 5 and 6, in the apparatus as shown in FIGS. 5 and 6, the surface of the optical fiber mounting table 13 is formed in a planar shape, and the optical fiber 2 is mounted on the planar optical fiber. Since it is only sandwiched between the surface of the mounting table 13 and the phase mask 8, the fiber grating forming region 6 of the optical fiber 2 is bent or lifted depending on how the covering portion is installed (fixed) or how tension is applied. As a result, there is a problem that the installation accuracy of the phase mask 8 tends to be adversely affected.
[0011]
In addition, since the phase mask 8 is directly placed on the optical fiber 2 under pressure or under its own weight, the outer diameter accuracy of the optical fiber 2 itself and the optical fiber that is simultaneously processed (mounted on the optical fiber mounting table 13) are always processed. There is also a problem that the accuracy of the posture of the phase mask 8 and the optical fiber varies due to the outer diameter accuracy between the two.
[0012]
The present invention has been made in order to solve the above-described conventional problems, and its purpose is to prevent the phase mask from becoming dirty or scratched, and to provide an outer diameter accuracy of the optical fiber and an arrangement condition of the covering portion. It is an object of the present invention to provide a grating type optical component manufacturing apparatus and a grating type optical component manufacturing method capable of accurately forming a grating without being affected by the above.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration as means for solving the problems. That is, the grating-type optical component manufacturing apparatus of the present invention irradiates a grating forming region of an optical fiber with ultraviolet light through a mask, and a portion having a high refractive index due to ultraviolet light irradiation through the mask to the optical fiber. And a grating-type optical component manufacturing apparatus for performing grating by periodically arranging low refractive index portions due to ultraviolet light shielding in the longitudinal direction of the optical fiber, the manufacturing apparatus positioning the optical fiber and the mask The positioning device includes: an optical fiber array member having an optical fiber array groove formed on a surface side; an optical fiber upper surface arrayed in the optical fiber array groove of the optical fiber array member; and the mask. A positioning pin for mask positioning that secures a gap therebetween, and the surface side of the optical fiber array member is spaced from the optical fiber array groove. And an optical fiber arranged in the optical fiber array groove by inserting the positioning pin into the pin insertion groove and mounting a mask on the upper side of the positioning pin. A feature is that a gap is formed between the upper surface and the upper surface.
[0014]
Further, the depth of the optical fiber array groove and the depth of the pin insertion groove are substantially matched, and the diameter of the positioning pin is formed larger than the diameter of the optical fiber arrayed in the optical fiber array groove, and the depth of the pin insertion groove The thickness of the optical fiber array groove is smaller than the depth of the optical fiber array groove, which is a characteristic configuration of the grating type optical component manufacturing apparatus of the present invention.
[0015]
Furthermore, in the method for manufacturing a grating-type optical component of the present invention, the grating forming region of the optical fiber is irradiated with ultraviolet light through a mask, and the optical fiber is irradiated with ultraviolet light through the mask. And a method of manufacturing a grating-type optical component in which a portion having a low refractive index due to ultraviolet light shielding is periodically arranged in the longitudinal direction of the optical fiber to perform grating, the optical fiber array groove on the surface side and the optical fiber array groove Positioning for mask positioning that secures a gap between the optical fiber array member in which pin insertion grooves are formed at intervals and the optical fiber upper surface arrayed in the optical fiber array groove of the optical fiber array member and the mask. A pin is prepared, a positioning pin is inserted into the pin insertion groove, and a mask is mounted on the upper side of the positioning pin. And a means for solving the problems with the arrangement for irradiating ultraviolet light to the grating formation region of the optical fiber through the mask in a state in which a gap between the optical fiber upper surface that is arranged in the optical fiber array trenches.
[0016]
In the present invention configured as described above, by inserting a positioning pin into the pin insertion groove of the optical fiber array member and mounting the mask on the upper side of the positioning pin, the mask and the optical fiber array groove of the optical fiber array member are mounted. A space is provided between the upper surface of the optical fiber that is securely inserted and arranged.
[0017]
This gap is easily adjusted, for example, by adjusting the diameter of the positioning pin and the depth of the pin insertion groove, so that an optimum distance, that is, a very small gap is provided between the upper surface of the optical fiber and the mask. In this state, ultraviolet light is irradiated to the grating forming region of the optical fiber through the mask, so that the expensive mask is damaged or dust on the optical fiber adheres to the mask. In addition, it is possible to form a grating with a high attitude accuracy between the optical fiber and the mask without being affected by the outer diameter accuracy of the optical fiber and the arrangement of the covering portion. Since the formation can be performed, the above problem is solved.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the present embodiment, the same reference numerals are assigned to the same name portions as in the conventional example, and the duplicate description thereof is omitted. FIG. 1 shows a main configuration of a positioning device that constitutes an embodiment of a grating-type optical component manufacturing apparatus according to the present invention. 2A is a perspective view of the positioning device, FIG. 2B is a side view thereof, and FIG. 2 is a front view of the positioning device. It is shown.
[0019]
The manufacturing apparatus of this embodiment is an apparatus for forming a grating on an optical fiber by a phase mask method, and the manufacturing apparatus of this embodiment is an optical fiber 2 and a phase mask 8 as shown in these drawings. It has a positioning device. This positioning apparatus includes an optical fiber array member 3 having a V-groove 9 as an optical fiber array groove formed on the front surface side, an upper surface of the optical fiber 2 arrayed in the V-groove 9 of the optical fiber array member 3, and a phase mask 8. And positioning pins 1 for mask positioning for securing a gap between them.
[0020]
In the present embodiment, two optical fiber array members 3 are arranged with a gap therebetween, and on the surface side of the optical fiber array member 3 on both sides of the V groove 9 with a gap with the V groove 9. A V-shaped pin insertion groove 4 is formed, and the depth of the V groove 9 and the depth of the pin insertion groove 4 are substantially equal on the sub-micron level.
[0021]
The positioning pin 1 is made of cemented carbide, and the diameter of the positioning pin 1 is 127 μm, which is larger than the diameter of the optical fiber 2 arranged in the V-groove 9 (φ124 μm to 126 μm). The positioning pin 1 is made by centerless grinding, and the cylindricity per 10 mm length is 0.3 μm or less, and is formed with higher accuracy than the cylindricity of a general optical fiber. In the present embodiment example, four such positioning pins 1 are used. Each of these positioning pins 1 is inserted into the pin insertion groove 4 and a phase mask 8 is mounted on the upper side of the positioning pin 1. A gap is formed between the phase mask 8 and the upper surface of the optical fiber 2. The phase mask 8 is formed such that the length of the optical fiber 2 in the longitudinal direction is supported by the four positioning pins 1.
[0022]
The manufacturing apparatus of the grating type optical component of the present embodiment example has the positioning device formed as described above. Next, a manufacturing method of the grating type optical component using the manufacturing apparatus of the present embodiment example. explain.
[0023]
First, the positioning pin 1 is inserted into each of the pin insertion grooves 4, and then the optical fiber 2 is fixed along the V-groove 9 while applying tension to the optical fiber 2. It should be noted that the optical fiber 2 including the grating forming region 6 is previously removed from the coating, and after performing pressurized hydrogen treatment or the like for the purpose of improving the light-induced characteristics, the optical fiber 2 is inserted into the V groove 9. Fix it. Further, as shown in FIG. 2, the coating removal region of the optical fiber 2 has such a length that the coating portion does not cover the V groove 9 when the optical fiber 2 is inserted into the V groove 9.
[0024]
Thereafter, the phase mask 8 is placed on the positioning pins 1 inserted into the four pin insertion grooves 4 by its own weight. At this time, it arrange | positions so that the gravity center of the phase mask 8 may come to the approximate center of arrangement | positioning of the positioning pin 1. FIG.
[0025]
As described above, the grating formation of the optical fiber 2 is performed via the phase mask 8 with a slight gap of 2 μm, for example, between the upper surface of the optical fiber 2 arranged in the V-groove 9 and the phase mask 8. The region 6 is irradiated with ultraviolet light. Irradiation with ultraviolet light is performed using, for example, a KrF excimer laser.
[0026]
According to the present embodiment example, since the positioning device as shown in FIGS. 1 and 2 is provided, the phase mask 8 and the optical fiber 2 can be easily arranged through a very small gap as described above. it can.
[0027]
In order to prevent the phase mask 8 and the optical fiber 2 from coming into contact with each other by using the apparatus of the present embodiment, the expensive phase mask 8 can be damaged, or the optical fiber can be prevented. The phase mask 8 can be prevented from being soiled by foreign matters such as dust adhering to the optical fiber 2, and can be prevented from being adversely affected by the outer diameter accuracy of the optical fiber 2 itself and the outer diameter variation of the optical fibers 2 processed simultaneously. The posture accuracy between the phase mask 8 and the optical fiber 2 can be always accurately maintained with good reproducibility, and the grating can be formed very accurately.
[0028]
In particular, in this embodiment, the positioning pin 1 is a cemented carbide pin, is made by centerless grinding, and is formed with higher accuracy than the cylindricity of a general optical fiber. The attitude accuracy between the mask 8 and the optical fiber can be kept extremely accurately and with good reproducibility, and the grating can be formed more accurately and with good reproducibility.
[0029]
Further, since both sides of the grating forming region 6 of the optical fiber 2 are inserted and fixed in the V-groove 9 of the optical fiber arraying member 3, the optical fiber is placed on the surface of the optical fiber mounting table 13 formed in a flat shape as in the prior art. Unlike the case where the optical fiber 2 is mounted, it is possible to prevent the fiber grating forming region 6 of the optical fiber 2 from being bent or lifted depending on how the covering portion is fixed and how the tension is applied when the optical fiber 2 is tensioned. As a result, it is possible to prevent the installation accuracy of the phase mask 8 from being adversely affected, and to form a grating very accurately and with good reproducibility.
[0030]
Further, according to the present embodiment, the optical fiber 2 is inserted into the V-groove 9 with the positioning pin 1 inserted into the pin insertion groove 4 and the phase mask 8 is placed on the positioning pin 1 with its own weight. Since the phase mask 8 and the optical fiber 2 can be accurately positioned, the phase mask 8 and the optical fiber can be positioned very easily, and manufacturing of the grating type optical component can be performed very easily. it can.
[0031]
In addition, this invention is not limited to the said embodiment example, Various aspects can be taken. For example, in the above embodiment, the diameter of the positioning pin 1 is set to 127 μm, but the diameter of the positioning pin 1 is not particularly limited and is appropriately set and appropriately larger than the diameter of the optical fiber 2. By setting this value, the size of the gap between the optical fiber 2 and the phase mask 8 can be varied variously.
[0032]
In the above embodiment, the V-groove 9 and the pin insertion groove 4 formed in the optical fiber array member 3 have substantially the same depth. For example, as shown in FIG. It may be formed shallower than the depth of the V groove 9. In this case, for example, if the diameter of the positioning pin 1 is formed to be substantially equal to the diameter of the optical fiber 2, a gap is formed between the phase mask 8 and the optical fiber 2 by an amount that the pin insertion groove 4 is shallower than the V groove 9. Can be provided. Further, if the difference between the depth of the pin insertion groove 4 and the depth of the V groove 9 is increased, even if the positioning pin 1 having a diameter smaller than the diameter of the optical fiber 2 is inserted into the pin insertion groove 4, the phase mask 8 A gap can be provided between the optical fiber 2 and the optical fiber 2.
[0033]
Furthermore, in the above embodiment, the optical fiber array groove is the V-groove 9 and the pin insertion groove 4 is also a V-shaped groove. However, the shape of these grooves is not particularly limited and is set as appropriate. For example, one or both of these grooves may be U-shaped grooves.
[0036]
【The invention's effect】
According to the grating type optical component manufacturing apparatus and method of the present invention, the positioning pin is inserted into the pin insertion groove of the optical fiber array member, and the mask is mounted on the upper side of the positioning pin. A gap can be formed between the upper surface of the optical fiber arrayed in the optical fiber array groove of the fiber array member, and in this state, the grating forming region of the optical fiber is irradiated with ultraviolet light through the mask. By doing so, it is possible to prevent the expensive mask from being scratched and foreign matter such as dust of the optical fiber from adhering to the mask, and without being affected by the outer diameter accuracy of the optical fiber, etc. The grating can be formed with good reproducibility in a state where the posture accuracy between the optical fiber and the mask is high.
[0037]
Further, according to the manufacturing apparatus and the manufacturing method of the grating type optical component of the present invention, by arranging the optical fiber in the optical fiber array groove, for example, the optical fiber can be fixed in the optical fiber array groove when forming the grating. Therefore, even if tension is applied to the coated portion of the optical fiber at the time of forming the grating, it becomes possible to prevent the grating forming region of the optical fiber from being lifted or bent depending on how the tension is applied. The grating can be formed with high reproducibility while the posture accuracy with the mask is high.
[0038]
Furthermore, according to the grating type optical component manufacturing apparatus and method of the present invention, the gap can be easily adjusted, for example, by adjusting the diameter of the positioning pin and the depth of the pin insertion groove. An optimum distance, that is, a very small gap can be formed between the upper surface of the fiber and the mask, and a very good grating can be formed.
[0039]
Further, in the grating type optical component manufacturing apparatus, the depth of the optical fiber array groove and the depth of the pin insertion groove are substantially matched, and the diameter of the positioning pin is larger than the diameter of the optical fiber arrayed in the optical fiber array groove. Alternatively, by forming the depth of the pin insertion groove shallower than the depth of the optical fiber array groove, a gap can be generated between the mask and the optical fiber very easily and reliably.
[Brief description of the drawings]
FIG. 1 is a main part configuration diagram showing a positioning device provided in an embodiment of a grating type optical component manufacturing apparatus according to the present invention.
FIG. 2 is a front view of FIG.
FIG. 3 is a main part configuration diagram showing a positioning device provided in another embodiment of an apparatus for manufacturing a grating-type optical component according to the present invention.
FIG. 4 is an explanatory view showing a process in a conventional method of manufacturing a grating-type optical component .
FIG. 5 is a side view (a) and a front view (b) of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Positioning pin 2 Optical fiber 3 Optical fiber arrangement member 4 Pin insertion groove 6 Grating formation area 8 Phase mask 9 V groove 14 Protrusion part

Claims (4)

The optical fiber grating forming region is irradiated with ultraviolet light through a mask, and a portion having a high refractive index due to ultraviolet light irradiation through the mask and a portion having a low refractive index due to ultraviolet light shielding are applied to the optical fiber. An apparatus for manufacturing a grating-type optical component that performs grating by periodically arranging in the longitudinal direction, the manufacturing apparatus including a positioning device for the optical fiber and the mask, And an optical fiber array member having an optical fiber array groove formed therein, and a positioning pin for mask positioning that secures a gap between the upper surface of the optical fiber arrayed in the optical fiber array groove of the optical fiber array member and the mask. In addition, a pin insertion groove is formed on the surface side of the optical fiber arrangement member with a gap from the optical fiber arrangement groove. A gap is formed between the mask and the upper surface of the optical fiber arranged in the optical fiber arrangement groove by inserting a deciding pin and mounting the mask on the upper side of the positioning pin. Manufacturing equipment for grating-type optical components. 2. The grating according to claim 1, wherein the depth of the optical fiber array groove and the depth of the pin insertion groove are substantially matched, and the diameter of the positioning pin is formed larger than the diameter of the optical fiber arrayed in the optical fiber array groove. Type optical component manufacturing equipment. 2. The grating type optical component manufacturing apparatus according to claim 1, wherein the depth of the pin insertion groove is smaller than the depth of the optical fiber array groove. The optical fiber grating forming region is irradiated with ultraviolet light through a mask, and a portion having a high refractive index due to ultraviolet light irradiation through the mask and a portion having a low refractive index due to ultraviolet light shielding are applied to the optical fiber. A method of manufacturing a grating-type optical component in which gratings are periodically arranged in the longitudinal direction, and an optical fiber array in which an optical fiber array groove and a pin insertion groove are formed on the surface side through an interval between the optical fiber array groove And a positioning pin for mask positioning that secures a gap between the upper surface of the optical fiber arranged in the optical fiber arrangement groove of the optical fiber arrangement member and the mask, and the positioning pin is inserted into the pin insertion groove By mounting a mask on the upper side of the positioning pin, between the mask and the upper surface of the optical fiber arranged in the optical fiber arrangement groove Grating type optical component manufacturing method, which comprises irradiating ultraviolet light to the grating formation region of the optical fiber through the mask in a state in which through the gap.

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