# US 8,570,653 B2 · Polarizing glass and optical isolator

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,570,653 B2
- Document ID: US8570653B2
- Status: Granted
- Kind: B2
- Application number: 13/431,119
- Filed: 2012-03-27
- Published: 2012-07-19
- Granted: 2013-10-29
- Earliest claimed: 2008-10-16
- Assignees: Hoya Candeo Optronics Corporation
- Applicants: Yoshitaka Yoneda
- Inventors: Yoshitaka Yoneda
- Web page: https://patentgrep.com/patent/US8570653B2

## CPC

- G02F 1/093: {used as non-reciprocal devices, e.g. optical isolators, circulators (G02F1/0955 takes precedence)}
- C03C 3/118: containing aluminium
- C03C 14/006: {the non-glass component being in the form of microcrystallites, e.g. of optically or electrically active material}
- G02B 5/3058: {comprising electrically conductive elements, e.g. wire grids, conductive particles}
- G02B 27/288: {Filters employing polarising elements, e.g. Lyot or Solc filters (G02B5/3016 takes precedence)}
- C03C 2214/16: Microcrystallites, e.g. of optically or electrically active material
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

The near-field extinction ratio of a polarizing glass is increased. A polarizing glass contains anisotropically shaped metal particles oriented and dispersed in a glass substrate, which contains 0.40-0.85 wt % Cl relative to the entire glass substrate. The Vickers hardness ranges from 360 to 420, the Knoop hardness number ranges from 400 to 495, or the glass substrate contains at least one component selected from the group consisting of Y2O3, La2O3, V2O3, Ta2O3, WO3, and Nb2O5. The content of each of the selected components ranges from 0.05-4 mole percent, and if a plurality of the components are selected, the total content of the components is 6 mole percent or less.

## Claims

### Claim 1

A polarizing glass comprising:
a glass substrate; and
anisotropically shaped metal particles oriented and dispersed in the glass substrate;
wherein the glass substrate comprises a silicate glass, a borate glass, or a borosilicate glass;
wherein the glass substrate comprises a first component comprising at least one of Y2O3, La2O3, V2O5, Ta2O5, WO3, and Nb2O5, and a content of each species comprised in the first component ranges from 0.05 to 4 mole percent, or a total content of the first component is 6 mole percent or less if more than one of the species are comprised in the first component;
wherein a Cl content in the glass substrate ranges from 0.47 to 0.58 wt % based on a total weight of the glass substrate;
wherein the anisotropically shaped metal particles comprise anisotropically shaped copper particles; and
wherein the glass substrate comprises, in terms of wt % relative to the entire glass substrate:
SiO2: 55-63
B2O3: 16-22,
Al2O3: 7-10,
alkali metal oxide: 8-12,
alkali earth metal oxide: 0-3,
copper oxide: 0.3-1.0,
SnO: 0-0.3,
As2O3: 0-3, and
F: 0.5-1.0.

### Claim 2 (depends on 1)

The polarizing glass of claim 1,
wherein raw materials of the glass substrate comprise, in terms of wt %:
SiO2: 48-65,
B2O3: 13-33,
Al2O3: 6-13,
AlF3: 0-5,
alkali metal oxide: 7-17,
alkali metal chloride: 0-5,
alkali earth metal oxide: 0-5,
copper oxide and copper halide: 0.3-2.5,
SnO: 0-0.6, and
As2O3: 0-5.

### Claim 3 (depends on 1)

The polarizing glass of claim 1, wherein an extinction ratio at a measurement distance of 15 mm is 45.2 dB or more in response to at least one of light in a wavelength band with a center wavelength of 1.31 μm and light in a wavelength band with a center wavelength of 1.55 μm.

### Claim 4 (depends on 1)

An optical isolator, comprising the polarizing glass of claim 1.

### Claim 5 (depends on 1)

An optical isolator, comprising:
a Faraday rotating element; and
at least one polarizer,
wherein the polarizer comprises the polarizing glass of claim 1.

### Claim 6 (depends on 1)

The polarizing glass of claim 1, wherein the anisotropically shaped metal particles consist essentially of anisotropically shaped copper particles.

### Claim 7 (depends on 6)

The polarizing glass of claim 6, wherein raw materials of the glass substrate comprise, in terms of wt %:
SiO2: 48-65,
B2O3: 13-33,
Al2O3: 6-13,
AlF3: 0-5,
alkali metal oxide: 7-17,
alkali metal chloride: 0-5,
alkali earth metal oxide: 0-5,
copper oxide and copper halide: 0.3-2.5,
SnO: 0-0.6, and
As2O3: 0-5.

### Claim 8 (depends on 1)

The polarizing glass of claim 1, wherein the first component comprises Y2O3.

### Claim 9 (depends on 1)

The polarizing glass of claim 1, wherein the first component comprises La2O3.

### Claim 10 (depends on 1)

The polarizing glass of claim 1, wherein the first component comprises V2O5.

### Claim 11 (depends on 1)

The polarizing glass of claim 1, wherein the first component comprises Ta2O5.

### Claim 12 (depends on 1)

The polarizing glass of claim 1, wherein the first component comprises WO3.

### Claim 13 (depends on 1)

The polarizing glass of claim 1, wherein the first component comprises Nb2O5.

### Claim 14

A polarizing glass comprising:
a glass substrate; and
anisotropically shaped metal particles oriented and dispersed in the glass substrate;
wherein the glass substrate comprises a silicate glass, a borate glass, or a borosilicate glass;
wherein the glass substrate comprises a first component comprising at least one of Y7O3, La7O3, V2O5, Ta2O5, WO3, and Nb2O5, and a content of each species comprised in the first component ranges from 0.05 to 4 mole percent, or a total content of the first component is 6 mole percent or less if more than one of the species are comprised in the first component;
wherein a Cl content in the glass substrate ranges from 0.47 to 0.58 wt % based on a total weight of the glass substrate; and
wherein a maximum of absolute values of amounts of shift in polarization axis at sites 5 mm away from a center point on a principle surface is 0.137° or less.

### Claim 15

A process of producing a polarizing glass comprising anisotropically shaped metal particles oriented and dispersed in a glass substrate by stretching a glass preform, the process comprising:
melting raw materials of the glass substrate in an airtight melting furnace; and
replacing at least one alkali oxide component in raw materials of the glass substrate with an alkali chloride component,
wherein the glass substrate comprises a silicate glass, a borate glass, or a borosilicate glass;
wherein the glass substrate comprises a first component comprising at least one of Y2O3, La2O3, V2O5, Ta2O5, WO3, and Nb2O5, and a content of each species comprised in the first component ranges from 0.05 to 4 mole percent, or a total content of the first component is 6 mole percent or less if more than one of the species are comprised in the first component, and
wherein a Cl content in the glass substrate ranges from 0.47 to 0.58 wt % based on a total weight of the glass substrate.

### Claim 16 (depends on 15)

The process of claim 15, wherein the anisotropically shaped metal particles comprise anisotropically shaped copper particles, and
wherein raw materials of the glass substrate are melted, the raw materials comprising, in terms of wt %:
SiO2: 48-65,
B2O3: 13-33,
Al2O3: 6-13,
AlF3: 0-5,
alkali metal oxide: 7-17,
alkali metal chloride: 0-5,
alkali earth metal oxide: 0-5,
copper oxide and copper halide: 0.3-2.5,
SnO: 0-0.6, and
As2O3: 0-5.