# US 2021/0239907 A1 · Ring resonator and manufacturing method thereof

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- Number: US 2021/0239907 A1
- Document ID: US20210239907A1
- Status: Published application
- Kind: A1
- Application number: 17/172,416
- Filed: 2021-02-10
- Published: 2021-08-05
- Earliest claimed: 2019-12-12
- Assignees: Korea Advanced Institute of Science and Technology
- Applicants: Korea Advanced Institute of Science and Technology
- Inventors: Kyoungsik Yu; Gyeongho Son; Mohamad Syahadi
- Web page: https://patentgrep.com/patent/US20210239907A1

## CPC

- G02B 6/2934: {Fibre ring resonators, e.g. fibre coils}
- G02B 6/10: of the optical waveguide type (G02B6/02, G02B6/24 take precedence; devices or arrangements for the control of light by electric, magnetic, electro-magnetic or acoustic means G02F1/00; transferring the modulation of modulated light G02F2/00; optical logic elements G02F3/00; optical analogue/digital converters G02F7/00)
- G02B 6/245: Removing protective coverings of light guides before coupling
- G02B 6/255: Splicing of light guides, e.g. by fusion or bonding
- H01P 7/082: {Microstripline resonators (H01P7/088 takes precedence)}
- H01S 3/1062: {using a controlled passive interferometer, e.g. a Fabry-Perot etalon}
- H01S 3/06791: {Fibre ring lasers (fibre laser gyrometers G01C19/72)}
- H01S 3/1608: {erbium}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B)
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL

## Abstract

A ring resonator includes a core. Both ends of the core in a lengthwise direction are connected to have a circular shape. The ring resonator further includes a cladding surrounding the core, a jacket surrounding the cladding and a sleeve surrounding a portion of the jacket. A portion of the core is exposed from the cladding and the jacket.

## Claims

### Claim 1

A ring resonator, comprising:
a core having two ends, wherein both ends of the core in a lengthwise direction are connected to have a circular shape;
a cladding surrounding the core; and
a jacket surrounding the cladding,
wherein a portion of the core is exposed from the cladding and the jacket.

### Claim 2 (depends on 1)

The ring resonator of claim 1, further comprising:
a sleeve surrounding a portion of the jacket.

### Claim 3 (depends on 1)

The ring resonator of claim 1, further comprising:
a shrinking sleeve that is arranged to surround a portion where the both ends of the core are connected to each other.

### Claim 4 (depends on 3)

The ring resonator of claim 3, wherein the shrinking sleeve is fitted to the jacket.

### Claim 5

A method of manufacturing a ring resonator, comprising:
removing portions of a jacket which are arranged on both ends and a central portion of an optical fiber, wherein the optical fiber includes a core having a predetermined length, a cladding surrounding the core, and the jacket surrounding the cladding;
connecting both ends of the optical fiber; and
etching the cladding arranged in the central portion of the optical fiber from which the portion of the jacket is removed.

### Claim 6 (depends on 5)

The method of claim 5, further comprising:
inserting a sleeve to surround a remaining portion of the jacket, before the connecting of both ends of the optical fiber.

### Claim 7 (depends on 5)

The method of claim 5 further comprising:
providing a shrinking sleeve to surround a portion where both ends of the optical fiber are connected.

### Claim 8 (depends on 5)

The method of claim 5, wherein the etching of the cladding includes etching the cladding using an aqueous solution of hydrofluoric acid.

### Claim 9 (depends on 8)

The method of claim 8, wherein the aqueous solution of hydrofluoric acid has a concentration of 49%.

### Claim 10 (depends on 8)

The method of claim 8, wherein in the etching of the cladding, the cladding is etched so that the etched cladding has a diameter of 10 μm or less.

### Claim 11 (depends on 5)

The method of claim 5, wherein the optical fiber has a length of about 80 mm, each of the portions of the jacket that are removed at the both ends of the optical fiber has a length of about 5 mm, and the portions of the jacket, which is removed at the central portion of the optical fiber, has a length of about 20 mm.

### Claim 12 (depends on 6)

The method of claim 6, wherein the sleeve has a length of about 11 mm.