JP2016035529A - Polarizer substrate, magnetooptical element substrate for optical isolator, manufacturing method for the polarizer substrate, and manufacturing method for magnetooptical element for optical isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of easily and reliably manufacturing a magnetooptical element for an optical isolator including polarizers having small angular changes of polarizer axes.SOLUTION: A polarizer substrate 1 is formed, by arraying a plurality of polarizers 2 made of rectangular small glass pieces in a sheet form and integrating them. Individual polarizer axes 2a hereof are provided so as to be arrayed in the same direction. Further, the polarizers 2 are formed rectangular, and the polarizer axis 2a for each of the polarizers is provided so as to be arrayed in a direction where it is inclined against the side of the polarizer at 45°.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polarizer substrate, a magneto-optical element substrate for an optical isolator, a method for manufacturing a polarizer substrate, and a method for manufacturing a magneto-optical element for an optical isolator.

  In a laser module used for optical communication or the like, when the reflected return light returns to the laser oscillator, the laser oscillation becomes unstable. Therefore, in order to prevent the reflected return light from returning to the laser oscillator, an optical isolator is usually disposed on the optical path of the laser oscillator.

  As shown in FIG. 12, the optical isolator 100 includes two polarizers 101 and 102 whose polarization axes are 45 °, a Faraday rotator 103 disposed therebetween, a magnet 104, and these members. And a holder 105 for holding. Here, the magnet 104 applies a magnetic field in order to rotate the polarization plane of incident light by the Faraday rotator 103. The magnet 104 can be omitted when a self-biased Faraday rotator is used.

  Next, the principle of preventing the reflected return light by the optical isolator will be described based on FIG. Here, when viewed from the forward direction (the direction in which the light emitted from the laser oscillator 106 travels), the polarization axis 102 a of the second polarizer 102 is clockwise from the polarization axis 101 a of the first polarizer 101. It shall be inclined 45 °.

  First, in the forward direction, as shown in FIG. 13A, the forward direction light L1 emitted from the laser oscillator 106 has a polarization plane P1 perpendicular to the polarization axis 101a of the first polarizer 101. Only light passes through the first polarizer 101. The light that has passed through the first polarizer 101 passes through the Faraday rotator 103, so that the polarization plane P1 rotates 45 ° clockwise. Thereby, the polarization plane P1 of the light that has passed through the Faraday rotator 103 becomes perpendicular to the polarization axis 102a of the second polarizer 102, and the light that has passed through the Faraday rotator 103 passes through the second polarizer 102.

  On the other hand, in the reverse direction (the direction in which the light emitted from the laser oscillator 106 is reflected and returned), the polarization plane P2 of the reflected return light L2 is that of the second polarizer 102 as shown in FIG. Since it remains perpendicular to the polarization axis 102a, it passes through the second polarizer 102. The light L2 that has passed through the second polarizer 102 passes through the Faraday rotator 103, whereby the polarization plane P2 further rotates 45 ° in the same direction (clockwise when viewed from the forward direction). Thereby, the polarization plane P2 of the light L2 that has passed through the Faraday rotator 103 is parallel to the polarization axis 101a of the first polarizer 101, and the light L2 that has passed through the Faraday rotator 103 passes through the first polarizer 101. Cannot pass. As a result, the optical isolator configured in this manner can prevent the reflected return light L2 from returning to the laser oscillator 106.

  Here, the optical isolator shown in FIG. 12 and FIG. 13 is called a single type, but the optical isolator has three polarizers and a total of one polarizer provided between the three polarizers. There is also a so-called semi-double type equipped with two Faraday rotators. Semi-double type optical isolators are often used as broadband optical isolators. Note that the principle of blocking the reflected return light by the semi-double type optical isolator is substantially the same as that of the above-mentioned sill-glue type, and therefore detailed description is omitted.

  A polarizer used for an optical isolator is generally manufactured by cutting a large polarizer substrate into small pieces. A polarizer substrate is usually formed by heating a glass preform in which metal halide particles are dispersed and then stretching the glass preform, and then reducing the glass obtained by stretching so that a part of the elongated metal halide particles. Or it manufactures by changing all into a metal particle (for example, refer patent document 1 and 2). That is, the polarizing action of light is imparted by orienting the elongated metal particles having shape anisotropy in the reduction layer formed on the surface layer portion of the glass.

JP-A-8-231241 Japanese translation of PCT publication No. 2006-511834

  By the way, in Patent Document 2, as a method of manufacturing a magneto-optical element for an optical isolator, a large Faraday rotator substrate is laminated so as to be sandwiched between two large polarizer substrates (polarizing glass sheets), thereby producing a large magnetic field. It is disclosed that an optical element substrate (isolator sheet) is manufactured and a small magneto-optical element (isolator) is cut out from the magneto-optical element substrate (isolator sheet). In this way, since many magneto-optical elements can be manufactured at once, the manufacturing efficiency of the magneto-optical element is improved.

  However, when the stretched molded product is used as it is as a polarizer substrate, the orientation direction of the metal particles of the polarizer substrate may not be uniform in the plane, and the angle change of the polarization axis may occur. When a magneto-optical element is manufactured by this method, there is a possibility that performance may be deteriorated.

  In Patent Document 2, as a measure for suppressing the change in the angle of the polarization axis of the polarizer substrate, the in-plane temperature profile during stretching of the glass serving as the polarizer substrate until the change in the angle of the polarization axis is below an allowable value. Although it is disclosed that adjustment of manufacturing parameters such as tension and acting tension is repeated, it is not a practical measure. If an attempt is made to reduce the change in the angle of the polarization axis of the entire polarizer substrate during stretch molding, the manufacturing conditions during stretching will become severer, and the manufacturing efficiency of the polarizer substrate will deteriorate. Such a problem becomes more prominent as the polarizer substrate becomes larger.

  In view of the above circumstances, an object of the present invention is to easily and surely manufacture a magneto-optical element for an optical isolator having a polarizer with a small change in the angle of the polarization axis.

  The polarizer substrate according to the present invention, which was created to solve the above-described problems, is characterized in that a plurality of polarizers made of glass pieces are integrated in a state of being arranged in a sheet form.

  According to such a configuration, one polarizer substrate is configured by an assembly of a plurality of polarizers made of glass pieces. By using such an assembly of small polarizers, it is possible to selectively collect those having a small change in the angle of the polarization axis. Therefore, it is possible to easily and reliably manufacture a substrate having a small change in the angle of the polarization axis as compared with the case where one polarizer substrate is formed with a large single polarizer. Therefore, if a magneto-optical element substrate is manufactured using the thus configured polarizer substrate and then the magneto-optical element substrate is cut to manufacture a magneto-optical element for an optical isolator, the angle change of the polarization axis A magneto-optical element having a small polarizer can be manufactured easily and reliably.

  In the above configuration, the polarization axes of the plurality of polarizers may be provided along the same direction. Here, “along the same direction” means not only when the polarization axes of any two polarizers are geometrically parallel to each other but also when they can be regarded as substantially parallel. Specifically, for example, when the respective polarization axes at two arbitrary positions of the two polarizers are compared, the deviation of the angle between the two polarization axes is in the range of −0.1 ° to + 0.1 °. In that case, it is considered substantially parallel.

  In this way, since the directions of the polarization axes are substantially uniform throughout the polarizer substrate, the orientation of the polarization axes can be easily managed when the polarizer substrate is cut.

  In this case, the plurality of polarizers may be rectangular, and for each of the plurality of polarizers, the polarization axis may be provided along a direction parallel to the side of the polarizer. You may provide so that it may follow the direction which inclines at 45 degrees with respect to the edge | side of a child. Here, “along a direction parallel to the side” means not only when the polarization axis of the polarizer is geometrically parallel to the side of the corresponding polarizer, but also when it can be regarded as substantially parallel. “To be along a direction inclined at 45 ° to the side” means not only when the polarization axis of the polarizer is geometrically inclined at 45 ° with respect to the side of the corresponding polarizer. This also includes the case where it can be regarded as substantially inclined by 45 ° (hereinafter the same). Specifically, for example, when the polarization axis at an arbitrary position of one polarizer is in a range of −0.1 ° to + 0.1 ° with respect to the side, substantially with respect to the side. Consider parallel. Further, for example, when the polarization axis at an arbitrary position of one polarizer is in the range of 44.9 ° to 45.1 ° with respect to the side, it is inclined substantially 45 ° with respect to the side. It is considered.

  In the above configuration, at least two of the plurality of polarizers may be provided along directions in which the polarization axes are different from each other.

  In this way, polarizers with different polarization axes are included in the polarizer substrate. That is, by configuring the polarizer substrate with an assembly of a plurality of polarizers, the orientation of the polarization axis in the polarizer substrate can be freely designed.

  In this case, the plurality of polarizers have a rectangular shape, and the plurality of polarizers include a polarizer provided such that the polarization axis is along a direction parallel to the side of the polarizer, and the polarization axis is the side of the polarizer. And a polarizer provided so as to be along a direction inclined at 45 ° with respect to.

  Said structure WHEREIN: It is preferable that the some polarizer is adhere | attached on the base material.

  If it does in this way, it will become possible to mutually integrate by the simple operation | work of adhere | attaching each polarizer to a base material.

  In this case, a gap may be formed between adjacent polarizers.

  In this way, the polarizer substrate can be easily cut using the gap between the adjacent polarizers.

  In the above configuration, it is preferable that the polarizer is bonded to the substrate with an adhesive having ultraviolet releasability. Here, the “adhesive having ultraviolet releasability” means an adhesive whose adhesive strength is reduced by irradiation with ultraviolet rays (hereinafter the same).

  This is convenient because the substrate can be peeled off from each polarizer by irradiating ultraviolet rays when necessary.

  In the above configuration, each of the plurality of polarizers preferably exhibits an angle change of the polarization axis of 0.0175 ° / mm or less.

  In this way, a highly accurate magneto-optical element can be manufactured.

  In the above configuration, the width and length of each of the plurality of polarizers are preferably 15 mm or less, and the width and length of the polarizer substrate are preferably 10 mm or more.

  In this way, since the polarizer substrate can be sufficiently enlarged using a small polarizer, the manufacturing efficiency of the magneto-optical element for the optical isolator is further improved.

  In the above configuration, it is preferable that an identification unit for identifying at least one of the front and back sides and the orientation is provided. Here, “orientation” means the top, bottom, left and right directions of the polarizer substrate in plan view.

  That is, when producing a magneto-optical element substrate for an optical isolator, it is necessary to identify the front and back of the polarizer substrate or the direction thereof. Therefore, as described above, it is preferable to provide identification means on the polarizer substrate so that the front and back of the polarizer substrate or the direction thereof can be easily confirmed.

  A magneto-optical element substrate for an optical isolator according to the present invention, which has been created to solve the above problems, includes a polarizer substrate having the above-described configuration as appropriate, and a Faraday rotator substrate, and the polarizer substrate is a Faraday substrate. It is provided integrally on each of the front and back surfaces of the rotor substrate.

  According to such a configuration, as already described, a magneto-optical element for an optical isolator having a polarizer with a small angle change of the polarization axis can be easily and reliably manufactured.

  In the above configuration, three or more polarizer substrates may be provided, and a Faraday rotator may be provided between adjacent polarizer substrates.

  In this way, a magneto-optical element for a broadband optical isolator such as a semi-dal type can be manufactured.

  A method for producing a polarizer substrate according to the present invention, which has been created to solve the above-mentioned problems, is characterized in that a plurality of polarizers made of glass pieces are adhered on a substrate in a state of being arranged in a sheet form.

  According to said structure, the polarizer board | substrate which has an effect mentioned already can be manufactured.

  In the above configuration, it is preferable to obtain a plurality of polarizers by cutting them out from a plurality of stretched polarizer base materials.

  In this way, it is possible to manufacture a polarizer substrate by selecting a polarizer having good characteristics with a small change in the angle of the polarization axis.

  Said structure WHEREIN: It is preferable that a polarizer is cut out only from the center part of the width direction orthogonal to the extending | stretching direction of a polarizer base material.

  In other words, the stretched polarizer base material generally has a greater change in the angle of the polarization axis toward both ends in the width direction. In other words, the central part in the width direction of the polarizer base material exhibits good characteristics with a small change in the angle of the polarization axis. Therefore, if it is set as said structure, the polarizer board | substrate consisting of a polarizer with a small angle change of a polarization axis can be manufactured easily.

  The method for manufacturing a magneto-optical element for an optical isolator according to the present invention, which has been created to solve the above-described problems, includes a step of manufacturing a polarizer substrate by any one of the above-described methods, and a method for manufacturing the polarizer substrate with a Faraday. It includes a step of manufacturing a magneto-optical element substrate for an isolator by bonding to each of the front and back surfaces of the rotor substrate, and a step of manufacturing a plurality of magneto-optical elements by cutting the magneto-optical element substrate. And

  In this way, as already described, a magneto-optical element having a polarizer with a small change in the angle of the polarization axis can be easily and reliably manufactured.

  In the configuration described above, in the step of manufacturing the polarizer substrate, the gap is formed between the adjacent polarizers and bonded to the base material, and in the step of manufacturing the magneto-optical element, a cutting blade is inserted into the gap. The magneto-optic element substrate is preferably cut.

  In this way, since the amount of the polarizer cut and removed by the cutting blade can be reduced, the polarizer can be effectively used.

  In the above configuration, in the step of manufacturing the polarizer substrate, the polarizer is bonded to the base material with an adhesive having ultraviolet releasability, and in the step of manufacturing the magneto-optical element substrate, the adhesive having ultraviolet adhesive property is used. The polarizer substrate may be bonded to the Faraday rotator substrate, and the base material may be peeled off by ultraviolet rays that are irradiated when the polarizer substrate is bonded to the Faraday rotator substrate. Here, the “adhesive having ultraviolet adhesiveness” means an adhesive that generates an adhesive force when irradiated with ultraviolet rays.

  In this case, the polarizer of the polarizer substrate can be bonded to the Faraday rotator substrate, and at the same time, the base material of the polarizer substrate can be peeled off from the polarizer, which is very efficient.

  As described above, according to the present invention, it is possible to simply and reliably provide a magneto-optical element for an optical isolator having a polarizer whose angle change of the polarization axis is small.

It is a top view which shows the polarizer board | substrate which concerns on embodiment of this invention. It is XX sectional drawing of FIG. FIG. 2 is an enlarged view of a Y region shown in FIG. 1 and is a diagram for explaining an angle change of a polarization axis. (A)-(g) is a top view which shows the modification of the polarizer board | substrate which concerns on embodiment of this invention. It is a top view which shows the modification of the polarizer board | substrate which concerns on embodiment of this invention. It is a perspective view for demonstrating the process of extending | stretching a glass preform included in the manufacturing method of the magneto-optical element for optical isolators which concerns on embodiment of this invention. (A)-(c) is a top view for demonstrating the process of manufacturing a polarizer board | substrate from a polarizer base material included in the manufacturing method of the magneto-optical element for optical isolators which concerns on embodiment of this invention. is there. It is sectional drawing for demonstrating the condition of the beginning of the process of manufacturing a magneto-optical element board | substrate from a polarizer board | substrate and a Faraday rotator board | substrate included in the manufacturing method of the magneto-optical element for optical isolators which concerns on embodiment of this invention. is there. It is sectional drawing for demonstrating the condition of the middle stage of the process of manufacturing a magneto-optical element board | substrate from a polarizer board | substrate and a Faraday rotator board | substrate included in the manufacturing method of the magneto-optical element for optical isolators which concerns on embodiment of this invention. is there. It is sectional drawing for demonstrating the condition of the final stage of the process of manufacturing a magneto-optical element board | substrate from a polarizer board | substrate and a Faraday rotator board | substrate included in the manufacturing method of the magneto-optical element for optical isolators which concerns on embodiment of this invention. is there. (A)-(b) is a perspective view for demonstrating the process of manufacturing a magneto-optical element from the magneto-optical element board | substrate included in the manufacturing method of the magneto-optical element for optical isolators which concerns on embodiment of this invention. is there. It is sectional drawing of an optical isolator. It is a figure for demonstrating the principle of an optical isolator, Comprising: (a) shows the case where light advances to a forward direction, (b) shows the case where light advances to a reverse direction, respectively.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 1, the polarizer board | substrate 1 which concerns on embodiment of this invention integrates the several polarizer 2 which consists of a glass piece in the state arranged in the sheet form.

  Each polarizer 2 has a rectangular shape (in the illustrated example, a square), and the polarizer substrate 1 also has a rectangular shape (in the illustrated example, a square) as a whole. Each side of the polarizer 2 and each side of the corresponding polarizer substrate 1 facing each side of the polarizer 2 are parallel to each other.

  Each of the polarization axes 2a of each polarizer 2 is provided along the same direction. Specifically, in the illustrated example, the polarization axis 2 a of each polarizer 2 is provided along a direction parallel to one side of the polarizer substrate 1.

  The width and length of each polarizer 2 are, for example, 15 mm or less, preferably 5 to 10 mm, and more preferably 5 to 7 mm. The width and length of the polarizer substrate 1 are, for example, 10 mm or more, preferably 10 -20 mm, more preferably 10-14 mm mm. The thickness of each polarizer 2 is, for example, 0.1 to 0.5 mm, preferably 0.15 to 0.25 mm.

  A gap 3 is formed between adjacent polarizers 2. The width W1 of the gap 3 is, for example, 500 μm or less, preferably 30 to 250 μm, and more preferably 30 to 150 μm. In this embodiment, the gap 3 extends linearly so as to straddle two opposite sides of the polarizer substrate 1. Note that another member such as an adhesive may be disposed in the gap 3. Further, the sides of the adjacent polarizers 2 may be brought into contact with each other so that no gap is provided between the adjacent polarizers 2.

  As shown in FIG. 2, the polarizer substrate 1 includes a single sheet-like base material 4, and each polarizer 2 is bonded onto the base material 4 via an adhesive layer 5. That is, each polarizer 2 is integrated by the base material 4. The base material 4 is formed from a flexible material such as a resin. The adhesive layer 5 is formed of an adhesive having ultraviolet peelability. As the base material 4 and the adhesive layer 5, for example, an adhesive tape such as ELEP HOLDER (registered trademark) ELP DU-2187G manufactured by Nitto Denko Corporation can be used. In addition, the adhesive layer 5 should just be peelable by giving some peeling energy, and is not limited to what peels with an ultraviolet-ray. Further, when the sides of the adjacent polarizers 2 are joined together with an adhesive or the like and integrated into a sheet shape, the base material 4 and the adhesive layer 5 may be omitted.

  Each polarizer 2 exhibits an angle change of the polarization axis 2a of 0.0175 ° / mm or less, preferably 0.0120 ° / mm or less, more preferably 0.0065 ° / mm. Here, the angle change of the polarization axis 2a is obtained as follows. That is, as shown in FIG. 3, a straight line L perpendicular to the stretch molding direction of each polarizer 2 is set, and at two points P1 and P2 provided in an arbitrary section on the straight line L, the light intensity is minimum. The obtained angle is defined as the polarization axis angle at each position (stretched metal particle angles θ1, θ2), and the value obtained by dividing the difference between the respective polarization axis angles by the length M of the P1 to P2 section is defined as the angle change of the polarization axis 2a. . In this embodiment, the length M of the P1 to P2 section is set to a value of “width−2 mm” of each polarizer 2.

  The polarizer substrate 1 is not limited to the embodiment shown in FIG. 1. For example, when the polarization axes 2 a of all the polarizers 2 are arranged so as to be substantially in the same direction, 4 (a) to 4 (c), and in the case where the polarization axes 2a of at least two polarizers 2 are arranged so as to face substantially different directions, FIG. Modifications as shown in d) to (g) are mentioned.

  Specifically, as shown in FIG. 4A, the polarizer substrate 1 is composed of polarizers 2 of the same size, and the polarization axis 2 a of each polarizer 2 is relative to one side of the polarizer substrate 1. It may be provided along the direction inclined at 45 °. 4B, the polarizer substrate 1 includes polarizers 2 having different sizes, and the polarization axis 2a of each polarizer 2 is along a direction parallel to one side of the polarizer substrate 1. It may be provided as follows. Further, as shown in FIG. 4C, the polarizer substrate 1 includes polarizers 2 of different sizes, and the polarization axis 2 a of each polarizer 2 is 45 ° with respect to one side of the polarizer substrate 1. It may be provided along the direction of inclination.

  On the other hand, as shown in FIGS. 4D and 4E, the polarizer substrate 1 is composed of a polarizer 2 having the same size, and the polarization axis 2 a of the polarizer 2 is parallel to one side of the polarizer substrate 1. Those provided so as to be along the direction and those provided so that the polarization axis 2 a is inclined at 45 ° with respect to one side of the polarizer substrate 1 may be included. 4 (f) and 4 (g), the polarizer substrate 1 includes polarizers 2 of different sizes, and the polarization axis 2a is along a direction parallel to one side of the polarizer substrate 1. What was provided and what was provided so that the polarization axis 2a may be along the direction which inclines at 45 degrees with respect to one side of the polarizer board | substrate 1 may be contained.

  Further, as shown in FIG. 5, in order to identify the front and back and / or orientation, the polarizer substrate 1 may be provided with a notch z as an identification means. In this way, when producing a magneto-optical element substrate for an optical isolator, the front and back of the polarizer substrate 1 or the direction thereof can be easily confirmed based on the notch z. Attaching mistakes can be reduced. The identification means may be marking or the like.

  Next, a method for manufacturing a magneto-optical element for an optical isolator will be described. In addition, in this manufacturing method, the manufacturing method of the polarizer board | substrate 1 comprised as mentioned above and the manufacturing method of the magneto-optical element board | substrate for optical isolators containing this polarizer board | substrate 1 are also demonstrated.

  First, as shown in FIG. 6, a glass preform 6 in which metal halide particles are dispersed is prepared. Examples of the halogen of the metal halide include chlorine, bromine, iodine and the like. Examples of the metal halide include silver, copper, gold, or platinum that is chloride, bromide, or iodide. The glass preform 6 in which the metal halide particles are dispersed can be manufactured by a known method.

  Next, as shown in the figure, the glass preform 6 is heated in a heating region H constituted by a furnace (not shown) and is pulled downward while being sandwiched between rollers 7 disposed below the heating region H. The glass preform 6 is stretched (redrawn). Thereby, the metal halide particles in the glass preform 6 are elongated and oriented in the stretching direction.

At this time, the glass preform 6 is stretched in a state where the viscosity of the glass preform 6 in the heating region H is 10 ^7.5 to 10 ^10.5 dPa · s, preferably 10 ⁸ to 10 ¹⁰ dPa · s. . This prevents re-spheronization after the metal halide particles are elongated by stretching. In addition, the extending | stretching speed by the roller 7 of the glass preform 6 shall be 50-500 mm / min, for example.

  The width W3 of the stretched glass 8 is, for example, 1/7 to 1/15, preferably about 1/10 of the width W2 of the glass preform 6 before heating.

  The aspect ratio of the metal halide particles contained in the stretch-formed glass is, for example, in the range of 2: 1 to 200: 1.

  Next, the stretched glass is subjected to a reduction treatment, and the elongated metal halide particles are reduced to metal particles. Thereby, a polarizer base material having a polarization function derived from the elongated metal particles is manufactured. In addition, the extinction ratio of the optical isolator finally manufactured can be adjusted with reduction process time.

  The aspect ratio of the metal particles contained in the polarizer base material is, for example, in the range of 2: 1 to 50: 1.

  In addition, it is preferable to polish at least two opposing surfaces (light incident surface and light exit surface) of the glass preform 6 or to polish at least two opposing surfaces of the glass 8 stretched before the reduction treatment. .

  Next, as shown in FIG. 7A, the rectangular polarizer 2 is cut out from the plurality of polarizer base materials 9 manufactured as described above, as indicated by broken lines in the figure. At this time, the polarizer 2 is cut out from a region in the polarizer base material 9 where the change in the angle of the polarization axis is 0.0175 ° / mm or less. That is, the entire polarizer base material 9 does not have to have an angle change of the polarization axis of 0.0175 ° / mm or less, and the region of the polarizer base material 9 where the polarizer 2 is cut out is the angle of the polarization axis. It only has to satisfy the change. Therefore, as compared with the case where the change in the angle of the polarization axis of the entire polarizer base material 9 is made as small as possible, the manufacturing conditions for stretching the polarizer base material 9 can be relaxed. Here, since the central portion 9a in the width direction orthogonal to the extending direction of the polarizer base material 9 often exhibits good characteristics in which the change in the angle of the polarization axis is smaller than both end portions 9b in the width direction, the polarizer It is preferable that the polarizer 2 is cut out only from the central portion 9 a in the width direction of the base material 9.

  Then, as shown in FIG. 7B, the plurality of polarizers 2 cut out from the polarizer base material 9 are arranged in a sheet shape as shown in FIG. It is bonded to the base material to be bonded through an adhesive layer having ultraviolet peelability. Thereby, the polarizer substrate 1 is manufactured.

  Although the case where one polarizer 2 is cut out from one polarizer base material 9 has been illustrated and described, a plurality of polarizers 2 may be cut out from one polarizer base material 9. When the polarization axis 2 a of the polarizer 2 is inclined by about 45 ° with respect to the side, when the polarizer 2 is cut out from the polarizer substrate 1, the side of the polarizer 2 that is cut out is approximately about the side of the polarizer substrate 1. Adjust the cut-out direction so that it is inclined 45 °.

  Next, as shown in FIG. 8, the two polarizer substrates 1 are arranged on the front and back surfaces of the Faraday rotator substrate 10 via adhesive layers 11 having ultraviolet adhesiveness. At this time, the polarization axes of the polarizers 2 of the two polarizer substrates 1 facing each other with the Faraday rotator substrate 10 in between must be shifted from each other by about 45 °. Therefore, as the two polarizer substrates 1, for example, the polarizer substrates 1 shown in FIGS. 1 and 4A are used in pairs. Of course, the polarizer substrate 1 shown in FIGS. 4B and 4C may be used as a pair, or the polarizer substrate 1 shown in FIGS. 4D and 4E may be used as a pair. Alternatively, the polarizer substrate 1 shown in FIG. 4F and FIG. 4G may be used as a pair.

  After the polarizer substrate 1 and the Faraday rotator substrate 10 are laminated, as shown in FIG. 9, the laminate 12 is irradiated with ultraviolet rays using an ultraviolet irradiation device 13. Thereby, as shown in FIG. 10, the adhesive layer 5 having ultraviolet peelability peels from the polarizer 2 together with the base material 4, and the adhesive layer 11 having ultraviolet adhesive properties is formed between each polarizer 2 and the Faraday rotator substrate. 10 is bonded. Thereby, the magneto-optical element substrate 14 for an optical isolator is manufactured.

  Note that the adhesive layer 11 for bonding the polarizer substrate 1 and the Faraday rotator substrate 10 is not limited to an adhesive having ultraviolet adhesive properties, and various adhesives having optical transparency (transparency) are used. can do.

  In the magneto-optical element substrate 14, the base material 4 may remain attached to the polarizer 2. In this way, the substrate 4 can be used as a protective film for the polarizer 2. In this case, it is preferable to peel off the base material 4 after cutting the magneto-optical element substrate 14 (see FIG. 11).

  Furthermore, the Faraday rotator substrate 10 may be larger or smaller than the polarizer substrate 1, but preferably has the same size. The width and length of the Faraday rotator substrate 10 are, for example, 20 mm or less, preferably 10 mm to 15 mm. The thickness of the Faraday rotator substrate 10 is, for example, 0.1 mm to 10 mm, preferably 0.3 mm to 0.7 mm.

  Finally, as shown in FIG. 11A, the magneto-optical element substrate 14 is cut into an arbitrary size with a cutting blade 15 to obtain a magnetic material for a plurality of optical isolators as shown in FIG. The optical element 16 is manufactured.

  Specifically, in this embodiment, the magneto-optical element substrate 14, specifically, the Faraday rotator substrate 10 is cut by inserting the cutting blade 15 into the gap 3 provided in advance between the adjacent polarizers 2. doing. In this way, the amount of the polarizer 2 cut and removed by the cutting blade 15 can be suppressed. Moreover, since the joint of the adjacent polarizer 2 corresponding to the gap 3 is cut, the joint of the polarizer 2 does not remain in the plane after cutting. If there is a seam in the plane of the polarizer 2, the polarization function deteriorates, and is usually handled as a defective product. Therefore, as described above, by cutting the magneto-optical element substrate 14 at a position including the gap 3, it is possible to reduce the portion discarded as a defective product. Note that a portion other than the gap 3 may be cut, and the magneto-optical element substrate 14 may be cut smaller than the size of the original polarizer 2. Further, without inserting the cutting blade 15 into the gap 3 of the polarizer 2, a portion including the gap 3 may be discarded after the cutting is completed.

  As the cutting blade 15, for example, a wire saw, a water cutter, a laser cutter, or the like can be used in addition to the wheel cutter as illustrated. Such a cutting means can be similarly applied when the polarizer 2 is first cut out from the polarizer base material 9 as shown in FIG.

  The width and length of the magneto-optical element 16 are, for example, 0.3 to 2.5 mm, preferably 0.5 to 1.5 mm.

The inventors of the present application have realized the following characteristics by the optical isolator using the magneto-optical element 16 manufactured by the above method.
(1) Extinction ratio to light of 1310 nm: 40 dB or more (2) Extinction ratio to light of 1550 nm: 40 dB or more (3) Insertion loss: 0.2 dB or less

  In addition, this invention is not limited to said embodiment, It can implement with a various form.

  In the above-described embodiment, the single-type magneto-optical element 16 is manufactured by cutting the laminated magneto-optical element substrate 14 with one Faraday rotator substrate 10 sandwiched between two polarizer substrates 1. As explained, the semi-double type magneto-optic element is manufactured by cutting the laminated magneto-optic element substrate in the order of polarizer substrate, Faraday rotator substrate, polarizer substrate, Faraday rotator substrate, and polarizer substrate. You may make it do. Of course, the Faraday rotator substrate may be disposed between each of the four or more polarizer substrates, and the laminated magneto-optical element substrate may be cut to manufacture the magneto-optical element.

  In the above-described embodiment, the magneto-optical element substrate 14 in which the polarizer substrate 1 is integrally provided on each of the front and back surfaces of one Faraday rotator substrate 10 has been described. A magneto-optical element substrate in which a polarizer substrate is laminated and integrated only on one of the surfaces may be manufactured. That is, after the magneto-optical element substrate is cut to manufacture a magneto-optical element in which the polarizer is integrally provided only on one surface of the Faraday rotator, the magneto-optical element polarizer is not provided. Another polarizer may be disposed opposite to the surface to function as an optical isolator.

  In the above-described embodiment, the case where the magneto-optical element substrate 14 is manufactured using the single large Faraday rotator substrate 10 has been described. A plurality of Faraday rotators arranged in a sheet shape and integrated may be used. This makes it easy to increase the size of the magneto-optical element substrate.

  In the above embodiment, the case where the polarizer substrate 1 is formed from the rectangular polarizer 2 has been described. However, the shape of the polarizer is not particularly limited. For example, the polarizer is not less than a circle, a triangle, or a pentagon. It may be a polygon.

DESCRIPTION OF SYMBOLS 1 Polarizer substrate 2 Polarizer 2a Polarization axis 3 Gap 4 Base material 5 Adhesive layer 6 Glass preform 7 Roller 8 Glass 9 Polarizer base material 9a Center part 9b Both ends 10 Faraday rotator substrate 11 Adhesive layer 12 Laminate 13 Ultraviolet Irradiation device 14 Magneto-optical element substrate 15 Cutting blade 16 Magneto-optical element z Notch H Heating area

Claims (20)

  A polarizer substrate, wherein a plurality of polarizers made of small glass pieces are integrated in a sheet-like arrangement.   The polarizer substrate according to claim 1, wherein the polarization axes of the plurality of polarizers are provided so as to be along the same direction. The plurality of polarizers have a rectangular shape,
The polarizer substrate according to claim 2, wherein a polarization axis of each of the plurality of polarizers is provided along a direction parallel to a side of the polarizer. The plurality of polarizers have a rectangular shape,
The polarizer substrate according to claim 2, wherein a polarization axis of each of the plurality of polarizers is provided so as to be along a direction inclined at 45 ° with respect to a side of the polarizer.   2. The polarizer substrate according to claim 1, wherein at least two of the plurality of polarizers are provided along directions in which polarization axes are different from each other. The plurality of polarizers have a rectangular shape,
The plurality of polarizers are provided such that a polarization axis is provided along a direction parallel to the side of the polarizer, and a direction in which the polarization axis is inclined at 45 ° with respect to the side of the polarizer. The polarizer substrate according to claim 5, wherein the polarizer substrate is provided with a polarizer provided on the polarizer.   The polarizer substrate according to claim 1, wherein the plurality of polarizers are bonded on a base material.   The polarizer substrate according to claim 7, wherein a gap is formed between the adjacent polarizers.   The polarizer substrate according to claim 7 or 8, wherein the polarizer is bonded to the base material with an adhesive having ultraviolet releasability.   10. The polarizer substrate according to claim 1, wherein each of the plurality of polarizers exhibits an angle change of a polarization axis of 0.0175 ° / mm or less.   11. The width and length of each of the plurality of polarizers is 15 mm or less, and the width and length of the polarizer substrate is 10 mm or more. 11. Polarizer substrate.   12. The polarizer substrate according to claim 1, further comprising an identification unit configured to identify at least one of the front and back sides and the orientation. A polarizer substrate according to any one of claims 1 to 12 and a Faraday rotator substrate.
A magneto-optical element substrate for an optical isolator, wherein the polarizer substrate is integrally provided on each of the front and back surfaces of the Faraday rotator substrate.   The magneto-optical element substrate for an optical isolator according to claim 13, wherein three or more polarizer substrates are provided, and the Faraday rotator is provided between adjacent polarizer substrates. .   A method for producing a polarizer substrate, comprising: adhering a plurality of polarizers made of glass pieces on a substrate in a state of being arranged in a sheet form.   The method of manufacturing a polarizer substrate according to claim 15, wherein the plurality of polarizers are obtained by cutting out from a plurality of stretched polarizer base materials.   The method for producing a polarizer substrate according to claim 16, wherein the polarizer is cut out only from a central portion in a width direction orthogonal to the extending direction of the polarizer base material. A step of manufacturing a polarizer substrate by the method according to any one of claims 15 to 17,
Bonding the polarizer substrate to each of the front and back surfaces of the Faraday rotator substrate to manufacture a magneto-optical element substrate for an optical isolator;
And a step of manufacturing a plurality of magneto-optical elements by cutting the magneto-optical element substrate. A method of manufacturing a magneto-optical element for an optical isolator. In the step of manufacturing the polarizer substrate, while adhering to the base material in a state where a gap is formed between the adjacent polarizers,
19. The method of manufacturing a magneto-optical element for an optical isolator according to claim 18, wherein in the step of manufacturing the magneto-optical element, a cutting blade is inserted into the gap to cut the magneto-optical element substrate. In the step of manufacturing the polarizer substrate, the polarizer is bonded to the base material with an adhesive having ultraviolet releasability,
In the step of manufacturing the magneto-optical element substrate, the polarizer substrate is bonded to the Faraday rotator substrate with an adhesive having ultraviolet adhesiveness, and irradiation is performed when the polarizer substrate is bonded to the Faraday rotator substrate. The method for producing a magneto-optical element for an optical isolator according to claim 18 or 19, wherein the substrate is peeled off by ultraviolet rays.

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