JP5415683B2 - Polarizing glass, optical isolator using the same, and manufacturing method thereof - Google Patents

Description

  The present invention relates to a high-performance polarizing glass incorporated in an optical device used in combination with a semiconductor laser, an optical isolator using the same, and a manufacturing method thereof.

In an optical device such as an optical isolator used in combination with a semiconductor laser, polarizing glass is used as a component.
As the polarizing glass, metal-dispersed polarizing glass is mainly used.
Here, the metal-dispersed polarizing glass is obtained by orientation-dispersing shape anisotropic metal particles on both surface layers of the light transmission surface, and the wavelength for optical communication is 1.31 μm or 1.55 μm. The extinction ratio is about 30 dB in the entire wavelength region.

  On the other hand, the extinction ratio of the Faraday rotator, which is a component of the optical isolator, is about 30 dB over the entire operating wavelength range, and the extinction ratio in the operating wavelength band required for the polarizing glass used in the single-stage optical isolator is the central wavelength. 35 dB or more, and 30 dB or more at the wavelength used end.

  As a structure of the optical isolator, two polarizing glasses of 10 mm square or more and a Faraday rotator are bonded together in a direction in which the extinction ratio is maximized in the vicinity of 45 degrees of the polarization direction of the polarizing glass. In some cases, a 0.5 mm × 0.6 mm rectangular parallelepiped chip-like element (cutting element) is cut out and combined with a magnet, and this combination is increasing in recent years.

  An optical isolator having a structure using a chip element cut out from such a bonding element has an advantage that the cost can be reduced as compared with a configuration in which the polarizing glass and the Faraday rotator are separately fixed. However, even in this configuration, the proportion of the cost of the polarizer is high, which is an obstacle to the cost reduction of the optical isolator.

Therefore, Patent Document 1 discloses a processing method for dividing a metal-dispersed polarizing glass base material in order to reduce costs.
However, in this processing method, the extinction ratio of the obtained divided polarizing glass is 40 dB at the central wavelength, but the extinction ratio at the use wavelength end that is ± 10 nm away from the central wavelength is 27 dB or less than the required extinction ratio. End up.
Furthermore, the polarizing glass produced by the above-described processing method of Patent Document 1 shows a large warp when AR coating is performed after cutting and polishing. For this reason, when bonding with an adhesive agent, the thickness variation of an adhesive agent will arise. In order to suppress this thickness variation, it is necessary to press the polarizing glass from both sides when fixing the adhesive. However, since the chip element thus prepared has poor moisture resistance and heat resistance, 85 ° C. × 85% RH, 2000 When a dump heat test is performed under the condition of time, a defect occurs.

JP 2003-156623 A

  The present invention has a small performance deterioration as a polarizing glass, and particularly when bonded to a Faraday rotator, the thickness variation of the adhesive is small, and a metal-dispersed polarizing glass that realizes an inexpensive manufacturing cost and a manufacturing method thereof, And it aims at providing the optical isolator using this metal dispersion type | mold polarizing glass, and its manufacturing method.

In order to solve the above problems, the present invention provides a metal-dispersed polarizing glass manufactured by processing a metal-dispersed polarizing glass plate produced by dividing a metal-dispersed polarizing glass base material, The type polarizing glass base material is obtained by orientation-dispersing shape anisotropic metal particles on both side surface layers, and the metal dispersion type polarizing glass plate has the metal dispersion type polarizing glass base material on the light transmission surface. The metal-dispersed polarizing glass is obtained by polishing and heat-treating the metal-dispersed polarizing glass plate, and the warp size is 2 μm / mm. Provided is a metal-dispersed polarizing glass characterized by the following.

In the metal-dispersed polarizing glass of the present invention, a metal-dispersed polarizing glass base material in which shape-anisotropic metal particles are dispersed on both surface layers is divided into a plurality of pieces on a plane perpendicular to the light transmission surface, and then divided. The resulting metal dispersion type polarizing glass base material is polished and heat-treated, and the warp of the glass is 2 μm / mm or less.
Thus, since one metal dispersion-type polarizing glass base material is a metal dispersion-type polarization glass divided into a plurality of pieces, for example, when manufacturing an optical isolator, conventionally, two pieces of metal dispersion-type polarization glass are used. Although the base material was necessary, since the metal-dispersed polarizing glass of the present invention can be manufactured from one metal-dispersed polarizing glass base material, the cost for the polarizer can be reduced.

In addition, since the metal dispersion type polarizing glass has a small warp due to the polishing process and the heat treatment, it is a glass in which the distortion of the glass surface is greatly reduced. Can be prevented.
And since the warp of the glass is 2 μm / mm or less, for example, when bonding with a Faraday rotator or the like, it is possible to prevent variation in the thickness of the adhesive within the bonding surface. Adhesive strength can be increased, and distortion can be prevented from occurring. Thereby, moisture resistance and heat resistance can be improved, and a chip element (cutting element) that does not deteriorate optical characteristics can be obtained.
Therefore, the performance deterioration as a polarizing glass is very small, and particularly when bonded to a Faraday rotator, the thickness variation of the adhesive is small and an inexpensive metal-dispersed polarizing glass can be obtained.

The metal-dispersed polarizing glass was heat-treated on the metal-dispersed polarizing glass plate at a temperature of 350 to 400 ° C. and a processing time of 50 to 100 hours in an atmosphere containing hydrogen as the heat treatment. it is good preferable to things.

  In this way, silver halide dispersed on the dividing surface is obtained by using a metal-dispersed polarizing glass that has been subjected to heat treatment at a temperature of 350 to 400 ° C. and a treatment time of 50 to 100 hours in an atmosphere containing hydrogen. As a result, metal particles having anisotropy can be deposited on the dividing surface. For this reason, the extinction ratio at the center wavelength of the polarizing glass can be made very high performance of 44 dB or more, and a metal-dispersed polarizing glass with further improved optical characteristics can be obtained.

The metal dispersion type polarizing glass, the metal dispersion polarizing glass plate, as the polishing process, it is good preferable to those grinding allowance, polishing was carried out for more than 10 [mu] m.

  As described above, by setting the polishing allowance to 10 μm or more, it becomes a metal dispersion type polarizing glass from which distortion in the cutting process for division is removed, so that the metal dispersion type polarizing glass with a smaller warp is obtained. ing. Moreover, since the load of removing the processing strain in the heat treatment can be reduced, a metal-dispersed polarizing glass with a smaller warp can be obtained.

An optical isolator manufactured using the above-described metal-dispersed polarizing glass, wherein the optical isolator has a chip-shaped bonding element in which the metal-dispersed polarizing glass and the Faraday element are bonded together with an adhesive. it is good preferable to those made using a cutting and cutting element.

As described above, the metal-dispersed polarizing glass of the present invention has an extinction ratio of 44 dB or more at the central wavelength even when the area is as large as 10 mm square or more, and the size of the warp considered to be strain is 2 μm / mm or less. ing.
For this reason, the optical isolator having a bonded structure obtained by bonding the metal-dispersed polarizing glass of the present invention and the Faraday rotator through an adhesive is a very high-performance and low-cost optical isolator. be able to.

Further, the present invention is a method for producing a metal-dispersed polarizing glass, wherein a metal-dispersed polarizing glass base material in which shape-anisotropic metal particles are oriented and dispersed on both surface layers is formed on a surface perpendicular to the light transmission surface. A metal-dispersed polarizing glass plate is divided into a plurality of sheets, and then the metal-dispersed polarizing glass plate is subjected to polishing and heat treatment, whereby the warp size of the metal-dispersed polarizing glass is obtained. Is 2 μm / mm or less, and a method for producing a metal-dispersed polarizing glass is provided .

In the metal-dispersed polarizing glass of the present invention, a metal-dispersed polarizing glass base material in which shape-anisotropic metal particles are dispersed on both surface layers is divided into a plurality of pieces on a plane perpendicular to the light transmission surface, and then divided. Polishing processing and heat treatment are performed on the metal-dispersed polarizing glass base material, and the warp of the glass is 2 μm / mm or less.
As described above, by dividing one metal dispersion-type polarizing glass base material into a plurality of pieces, for example, when manufacturing an optical isolator, conventionally, two metal dispersion-type polarizing glass base materials were required. However, in the present invention, since a plurality of metal-dispersed polarizing glasses can be obtained from one metal-dispersed polarizing glass base material, an optical isolator can be manufactured from a single metal-dispersed polarizing glass base material. The cost occupied by the polarizer can be reduced.

Moreover, since the warp of the metal-dispersed polarizing glass can be reduced to 2 μm / mm or less by performing polishing and heat treatment, the distortion in the glass can be greatly reduced, and the glass base material was cut. Therefore, it is possible to prevent the deterioration of optical characteristics.
And since the warp of the metal-dispersed polarizing glass can be reduced, for example, when bonding with a Faraday rotator or the like, it is possible to prevent variation in the thickness of the adhesive within the bonding surface, Adhesive strength can be increased, and distortion can be prevented from occurring. As a result, it is possible to improve the moisture resistance and heat resistance, and it is possible to manufacture a chip element that does not deteriorate optical characteristics.
Therefore, there is no performance deterioration as a polarizing glass, and particularly when bonded to a Faraday rotator, it is possible to manufacture a metal-dispersed polarizing glass that has a small thickness variation of the adhesive and realizes an inexpensive manufacturing cost.

Further, the heat treatment is in an atmosphere containing hydrogen, the temperature was 350 to 400 ° C., and it is good preferable that the treatment time to be 50 to 100 hours.

  Thus, in an atmosphere containing hydrogen, by performing a heat treatment at a temperature of 350 to 400 ° C. and a treatment time of 50 to 100 hours, a metal halide such as silver halide dispersed on the dividing surface can be reduced, As a result, anisotropic metal particles can be deposited on the dividing surface. Therefore, the extinction ratio at the center wavelength of the polarizing glass can be made extremely high performance of 44 dB or more, and a metal-dispersed polarizing glass with further improved optical characteristics can be manufactured.

Further, the polishing process, it is good preferable to be a grinding allowance than 10 [mu] m.

In this way, by setting the polishing allowance to 10 μm or more, the distortion in the cutting process can be removed more strongly, and therefore the warp can be reduced to a smaller value.
In addition, since the load for removing the processing strain in the heat treatment can be reduced, the strain can be further removed. Therefore, a metal-dispersed polarizing glass having a smaller warp can be produced.

In addition, a metal dispersion type polarizing glass manufactured by the above-described method for manufacturing a metal dispersion type polarizing glass and a Faraday element are bonded together using an adhesive to produce a bonding element, and then the bonding element is formed into a chip shape. cutting to prepare a cut element, it is good preferable to produce by using the cutting elements.

According to the present invention, it is possible to produce a metal-dispersed polarizing glass having an extinction ratio of 42 dB or more at the center wavelength even when the area is a large size of 10 mm square or more and a warp due to strain of 2 μm / mm or less.
For this reason, a very high-performance optical isolator can be produced at low cost by bonding the metal-dispersed polarizing glass of the present invention, a Faraday rotator, and an adhesive. As for the characteristics, the extinction ratio is 44 dB or more at the center wavelength, 32 dB or more in the wavelength band used, and the adhesive thickness variation in the adhesive layer is so small that it can be substantially ignored. An optical isolator that does not occur can be manufactured.

  As described above, since the metal-dispersed polarizing glass of the present invention is obtained by dividing one metal-dispersed polarizing glass base material into a plurality of sheets, for example, when manufacturing an optical isolator, Since it can manufacture from a metal dispersion-type polarizing glass base material, the cost which a polarizer occupies can be reduced. Moreover, since the metal dispersion type polarizing glass with a small warp is obtained by performing the polishing process and the heat treatment, the distortion in the glass can be greatly reduced, thereby preventing the deterioration of the optical characteristics. Can do. And since the warp is small, it can prevent the adhesive thickness from varying in the bonding surface when bonded to a Faraday rotator, etc., so that the bonding strength can be increased and distortion is generated. Can be prevented. Thereby, the moisture resistance and heat resistance can be improved, and further, it can be used for producing an optical device in which optical characteristics are not deteriorated.

Hereinafter, the present invention will be described more specifically.
As described above, the performance degradation as a polarizing glass is very small, especially when bonded to a Faraday rotator, the thickness variation of the adhesive is small, and the metal-dispersed polarizing glass that realizes an inexpensive manufacturing cost and its Development of a manufacturing method was awaited.

Then, the present inventors investigated from the manufacturing method of a metal dispersion type polarizing glass base material, and investigated the cause of the warp generated when the metal dispersion type polarizing glass base material was cut.
As a result, the metal-dispersed polarizing glass base material gives anisotropy to the metal particles by applying a directional tension to the glass, and this anisotropy appears by cutting, It was found that warping occurred. For this reason, it has been discovered that the glass warp reaches a maximum of about 100 μm (6.7 μm / mm) in the case of a 15 mm square polarizing glass after cutting. This warping can be suppressed only to about 60 μm (4 μm / mm) by polishing. Accordingly, the present inventors have made extensive studies on a glass processing method for further suppressing this warpage. As a result of performing heat treatment in addition to polishing, the warp of the polarizing glass is reduced to 30 μm (2 μm / mm). ) It was found that the following can be suppressed, and the present invention was completed.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.
In the metal-dispersed polarizing glass of the present invention, a metal-dispersed polarizing glass base material in which shape-anisotropic metal particles are dispersed on both surface layers is divided into a plurality of pieces on a plane perpendicular to the light transmission surface, and then divided. The resulting metal dispersion type polarizing glass base material is polished and heat-treated, the warp of the glass is 2 μm / mm or less, and the processing strain generated on the divided surface is removed.

Thus, since one metal dispersion-type polarizing glass base material is a metal dispersion-type polarization glass divided into a plurality of pieces, for example, when manufacturing an optical isolator, conventionally, two pieces of metal dispersion-type polarization glass are used. Although the base material was necessary, since the metal-dispersed polarizing glass of the present invention can produce two or more sheets from a single metal-dispersed polarizing glass base material, an optical isolator is formed from a single polarizing glass substrate. And the cost occupied by the polarizer can be reduced.
In addition, since the metal dispersion type polarizing glass with a small warp is obtained by the polishing process and the heat treatment, the distortion in the glass can be greatly reduced, so that the deterioration of the optical characteristics can be prevented. it can.
And since the warp of the glass is 2 μm / mm or less, for example, when bonding with a Faraday rotator or the like, it is possible to prevent variation in the thickness of the adhesive within the bonding surface. Adhesive strength can be increased, and distortion can be prevented from occurring. As a result, it is possible to obtain a chip element that has improved moisture resistance and heat resistance and that does not deteriorate optical characteristics.
Therefore, the performance degradation as a polarizing glass is very small, especially when bonded to a Faraday rotator, the thickness variation of the adhesive is small, and a metal-dispersed polarizing glass realizing an inexpensive manufacturing cost can be obtained. .

  In the present invention, the metal-dispersed polarizing glass is obtained by subjecting a metal-dispersed polarizing glass plate to a heat treatment at a temperature of 350 to 400 ° C. and a processing time of 50 to 100 hours in an atmosphere containing hydrogen. can do.

  Thus, the halogen dispersed on the split surface of the metal-dispersed polarizing glass plate is obtained by performing heat treatment at a temperature of 350 to 400 ° C. and a treatment time of 50 to 100 hours in an atmosphere containing hydrogen. By reducing a metal halide such as silver halide, anisotropic metal particles can be deposited on the dividing surface. For this reason, the extinction ratio at the center wavelength of the polarizing glass can be made extremely high as 44 dB or more, and a metal-dispersed polarizing glass with further improved optical characteristics can be obtained.

  Further, the metal-dispersed polarizing glass can be obtained by polishing a metal-dispersed polarizing glass plate with a polishing allowance of 10 μm or more.

  As described above, by setting the polishing allowance to 10 μm or more, the metal-dispersed polarizing glass is free from distortion in the cutting process, so that the metal-dispersed polarizing glass having a smaller warp can be obtained. Moreover, since the load of removing the processing strain in the heat treatment can be reduced, a metal-dispersed polarizing glass with a smaller warp can be obtained.

  The manufacturing method of the metal-dispersed polarizing glass of the present invention can be made as the following steps, and an example thereof will be described below, but the present invention is not limited to these.

Two quartz substrates on which a metal-dispersed polarizing glass base material is pasted are set on a hot plate, and a wax for fixing the metal-dispersed polarizing glass is placed on the upper surface of the substrate, and the temperature at which the wax melts Heat to above.
After heating, a 15 mm square, 480 μm thick metal dispersion type polarizing glass base material and a dummy glass having substantially the same thickness are placed on the melted wax so as to surround the metal dispersion type polarizing glass base material. Then, another quartz base material that has been heated in advance is placed on the metal-dispersed polarizing glass and the dummy glass to form a sandwich structure of base material-metal-dispersed polarizing glass base material-base material, and the entrained air Place a weight so as to escape and cool.
The thickness of the metal-dispersed polarizing glass base material indicates the width of the space between the surface through which light is transmitted.

  Note that the metal-dispersed polarizing glass base material used in the present invention has a large number of chip-like cutting elements (for example, about 0.5 mm × 0.6 mm square) after being bonded to a Faraday rotator. A size of about 10 mm square or more, for example, a size of 15 mm square is used. Regarding the thickness, a thickness obtained by adding a cutting allowance and a polishing allowance to the thickness of the metal-dispersed polarizing glass after the division is necessary so as to become a plurality of pieces after being divided into the metal-dispersed polarizing glass plates. When two metal-dispersed polarizing glasses are obtained from one metal-dispersed polarizing glass base material, although it depends on the cutting allowance, a thickness of 400 μm or more is required, and considering the workability, 450 μm It is preferable to set it as the above thickness.

Further, the substrate is not limited to quartz, and can be made of a material generally used for polishing, such as stainless steel, alumina, and blue plate glass.
As the dummy glass, general glass can be used, for example, blue plate glass or the like.

  Using a cutting device with as little cutting allowance as possible, for example, a multi-blade cutting device, or a wire saw, the metal sandwich type polarizing glass base material is cut along a plane perpendicular to the light transmission surface of the cooled sandwich structure, Two sets of metal-dispersed polarizing glass plates bonded to the substrate can be obtained from one sandwich structure.

In addition, when the thickness of the metal-dispersed polarizing glass base material to be used is thick, for example, 600 μm or more, two sets of metal-dispersed polarizing glass plates adhered to the base material are separated from the base material. One polarizing glass plate can also be used.
Even when the thickness of the metal-dispersed polarizing glass is even thicker, it can be similarly divided into metal-dispersed polarizing glass plates having a desired thickness.
Thus, there is no restriction | limiting in particular in the thickness of a metal dispersion type | mold polarizing glass base material.

  Since the divided surface of the metal-dispersed polarizing glass plate after the above steps is in a frosted glass state, it cannot be used as it is for optical use. For this reason, it is necessary to mirror-polish the dividing surface with a polishing device, set it to the polishing device in a state of being attached to the base material, and using a polishing agent such as colloidal silica, the thickness can be reduced to a certain extent. Polish to the thickness. In addition, about what the metal dispersion glass becomes single, it can adhere | attach with an above-described base material with a wax, and can grind | polish.

In this polishing process, the polishing allowance can be 10 μm or more.
In this way, by setting the polishing allowance to 10 μm or more, distortion in the cutting process can be removed more strongly, and therefore the size of the warp can be made smaller.
In addition, since it is possible to reduce the processing strain removal load in the heat treatment, it is possible to further remove the strain, and thus it is possible to manufacture a metal-dispersed polarizing glass with a smaller warp.

After the above steps, the metal-dispersed polarizing glass plate is heated on the hot plate together with the base material, the wax is dissolved and taken out, washed, and an anti-reflective coating is applied.
However, the metal-dispersed polarizing glass plate after the above process has poor extinction performance and a large warp, so it is still unsuitable for use in an optical isolator that takes the form of a bonded element. Heat treatment is essential.

  In the present invention, the metal-dispersed polarizing glass plate obtained in the above-described step is set in a heating furnace, and the warp is reduced by removing the processing strain by annealing to obtain a metal-dispersed polarizing glass.

Conditions for this heating can be a temperature of 350 to 400 ° C., a time of about 50 to 100 hours, and an atmosphere containing hydrogen.
Thereby, the metal halide such as silver halide dispersed on the dividing surface can be reduced, and as a result, anisotropic metal particles can be deposited on the dividing surface. Therefore, the extinction ratio at the center wavelength of the polarizing glass can be made extremely high, 44 dB or more. Thus, a metal-dispersed polarizing glass with further improved optical characteristics can be produced.

  Here, the heat treatment may be performed before or after polishing. When performing before polishing, heat the quartz plate on the hot plate, take out the metal-dispersed polarizing glass plate and perform the heat treatment, and then paste it again on the quartz plate heated on the hot plate, and put the weight It is possible to perform polishing by cooling to room temperature while suppressing warping.

  Thus, according to the manufacturing method of the present invention, for example, when manufacturing an optical isolator, conventionally, two metal-dispersed polarizing glass base materials were required. Since a plurality of metal-dispersed polarizing glass can be obtained from a metal-dispersed polarizing glass base material, an optical isolator can be manufactured from a single metal-dispersed polarizing glass base material, thereby reducing the cost of the polarizer. be able to.

Moreover, since the warp of the metal-dispersed polarizing glass can be set to 2 μm / mm or less, distortion in the glass can be greatly reduced, and deterioration of optical characteristics due to cutting of the glass base material can be prevented. . Then, when the metal-dispersed polarizing glass of the present invention is bonded to a Faraday rotator or the like, it is possible to prevent variations in the thickness of the adhesive within the bonding surface, to increase the adhesive strength, and to prevent distortion. Occurrence can be prevented. As a result, it is possible to improve the moisture resistance and heat resistance, and it is possible to manufacture a chip element that does not deteriorate optical characteristics.
Therefore, there is no performance deterioration as a polarizing glass, and particularly when bonded to a Faraday rotator, it is possible to manufacture a metal-dispersed polarizing glass that has a small thickness variation of the adhesive and realizes an inexpensive manufacturing cost.

  Thereafter, an optical isolator can be produced using the produced metal-dispersed polarizing glass. As described above, according to the present invention, it is possible to produce a metal-dispersed polarizing glass with reduced cost without deterioration of optical characteristics. Therefore, by using the polarizing glass, there is no deterioration of optical characteristics. In addition, an optical isolator capable of reducing the cost can be manufactured.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these.
(Example)
25 metal dispersion type polarizing glass base materials were prepared. The optical insertion loss, quenching performance, and warpage of this metal-dispersed polarizing glass base material were evaluated. As a result, the value of the optical insertion loss was 0.03 dB to 0.06 dB, the extinction performance was 44 dB to 52 dB at the center wavelength, the warp averaged 15 μm (1 μm / mm), and the maximum was 20 μm (1.3 μm / mm). .
Two quartz plates with a diameter of 100 mm are heated on a hot plate heated to 100 ° C., wax is melted on the quartz plate, a metal dispersion type polarizing glass base material having a thickness of 480 μm and four blue plate glasses having a thickness of about 480 μm. And then put another quartz plate on it and cool it to room temperature while expelling bubbles with heavy stones, and make a sandwich structure of quartz glass-blue plate glass surrounded by metal dispersion type polarizing glass-quartz glass did.

This sandwich structure is cut (sliced) perpendicularly to the light transmission surface of the metal-dispersed polarizing glass base material using a 0.010 mm-thick wire. Two metal-dispersed polarizing glass plates attached to a 165 μm quartz plate were obtained.
Thereafter, the metal-dispersed polarizing glass plate was polished by 10 μm using colloidal silica with a polishing apparatus.
After polishing, heating on a hot plate, taking out the metal-dispersed polarizing glass plate from the quartz plate, putting the metal-dispersed polarizing glass plate with both sides into a mirror surface into a quartz core tube, and heating at 350 ° C. for 50 hours After heating, optical insertion loss, quenching performance, and warpage were evaluated.

The warpage was measured by using the focusing mechanism of the microscope as follows.
Place a metal piece with a known thickness on the silicon wafer to be the reference surface, calibrate the dial associated with the microscope, set the metal-dispersed polarizing glass on the silicon wafer, and a1: position of the upper surface of the silicon wafer, a2: The position of the upper surface of the polarizing glass is measured, and a2-a1 = A is obtained.
Next, the metal-dispersed polarizing glass is turned over, and similarly, b1: position of the upper surface of the silicon wafer and b2: position of the upper surface of the polarizing glass are measured, and b2−b1 = B is obtained.
And the value of AB was calculated. This value is the sled value. Further, in order to compare samples of different sizes, the warp per unit length of the sample was obtained.

Thereafter, AR coating was applied to both surfaces of the metal-dispersed polarizing glass, bonded with a Faraday rotator and silicone resin, and then cut into a 0.5 mm × 0.6 mm square chip shape.
After this chip-shaped cutting element was bonded to an alumina substrate with an adhesive and an optical isolator configured to be sandwiched between two rectangular magnets was created, the optical insertion loss and the quenching performance were evaluated.

(Comparative Examples 1 and 2)
In the examples, a metal-dispersed polarizing glass was produced in the same manner as in the examples except that polishing and heat treatment were not performed (Comparative Example 1). And evaluation similar to the Example was performed.
Further, in the examples, a metal-dispersed polarizing glass was produced in the same manner as in the examples except that the heat treatment was not performed (Comparative Example 2). And evaluation similar to the Example was performed.

As a result of evaluating the metal-dispersed polarizing glass produced in the examples, the optical insertion loss was 0.03 dB to 0.05 dB, which was almost the same as that of the metal-dispersed polarizing glass base material. The extinction performance was 44 dB to 50 dB at the central wavelength, the average of the warp was 15 μm (1 μm / mm), and the maximum was 30 μm (2 μm / mm). These physical properties were almost the same as those of the metal-dispersed polarizing glass base material.
Further, as a result of evaluating the characteristics of the optical isolators manufactured in the examples, the optical insertion loss at the central wavelength of 1.55 μm is 0.12 to 0.25 dB, the extinction performance is 36 dB to 42 dB at the central wavelength, the wavelength 1. It was found that at 54 μm and 1.56 μm, 32 dB to 36 dB, sufficiently high performance as an optical isolator.
Moreover, when the dump heat test of 85 degreeC * 85% RH and 2000 hours was done, the defect did not generate | occur | produce.

On the other hand, as a result of evaluating 50 metal-dispersed polarizing glasses of Comparative Example 1, the average value of the warp was 55 μm (3.7 μm / mm) and the maximum value was 100 μm (6.7 μm / mm). The thickness of the metal-dispersed polarizing glass of Comparative Example 1 was about 165 μm.
Moreover, as a result of evaluating 50 metal-dispersed polarizing glasses of Comparative Example 2, the optical insertion loss is improved from 0.02 dB to 0.04 dB compared to the metal-dispersed polarizing glass base material, but the quenching performance is 30 dB to It was deteriorated to 40 dB. Further, the warp had an average value of 35 μm (2.3 μm / mm) and a maximum value of 60 μm (4 μm / mm). In addition, the thickness of the metal dispersion type | mold polarizing glass of the comparative example 2 was 150 micrometers-155 micrometers.

  As described above, by performing the polishing process and the heat treatment, the warp generated by dividing the metal dispersion-type polarizing glass base material can be greatly reduced, and the optical insertion loss and quenching performance can be reduced. It was found that the level could be almost the same as the material.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Claims (7)

A metal-dispersed polarizing glass produced by processing a metal-dispersed polarizing glass plate produced by dividing a metal-dispersed polarizing glass base material,
The metal-dispersed polarizing glass base material is obtained by orientation-dispersing shape anisotropic metal particles on both surface layers,
The metal-dispersed polarizing glass plate is obtained by dividing the metal-dispersed polarizing glass base material into a plurality of sheets on a plane perpendicular to the light transmission surface,
The metal-dispersed polarizing glass is obtained by polishing and heat-treating the metal-dispersed polarizing glass plate, and having a warp size of 2 μm / mm or less. Glass. The metal dispersion polarizing glass, the metal dispersion polarizing glass plate, wherein a polishing process, the polishing allowance metal distributed polarization according to claim 1, characterized in that the polishing is carried out more than 10μm Glass. An optical isolator manufactured using the metal-dispersed polarizing glass according to claim 1 or 2 , wherein the optically isolator is formed by bonding the metal-dispersed polarizing glass and the Faraday element with an adhesive. An optical isolator manufactured using a cutting element obtained by cutting a bonded element into a chip shape. A method for producing a metal-dispersed polarizing glass,
A metal-dispersed polarizing glass base material in which shape-anisotropic metal particles are oriented and dispersed on both side surface layers is divided into a plurality of pieces on a plane perpendicular to the light transmission surface to produce a metal-dispersed polarizing glass plate,
Next, the metal dispersion type polarization glass plate is subjected to polishing and heat treatment so that the warp size of the metal dispersion type polarization glass is 2 μm / mm or less. Glass manufacturing method. 5. The method for producing a metal-dispersed polarizing glass according to claim 4 , wherein the heat treatment is performed in an atmosphere containing hydrogen at a temperature of 350 to 400 ° C. and a treatment time of 50 to 100 hours. The polishing method of manufacturing a metal dispersion polarizing glass according to claim 4 or claim 5, characterized in that the grinding allowance or more 10 [mu] m. A metal-dispersed polarizing glass manufactured by the method for manufacturing a metal-dispersed polarizing glass according to any one of claims 4 to 6 and a Faraday element are bonded together using an adhesive, and a bonded element is obtained. A method for manufacturing an optical isolator, comprising: manufacturing a cut element by cutting the bonded element into a chip shape, and using the cut element.