Manufacturing device and manufacturing method of optical fiber grating

Patent metadata

Field	Value
Publication number	US-10976487-B2
Application number	US-201616078211-A
Country	US
Kind code	B2
Filing date	Dec 15, 2016
Priority date	Mar 25, 2016
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A manufacturing device of an optical fiber grating to write a grating in a core of an optical fiber by irradiating the optical fiber with laser light includes: a fixing device that fixes the optical fiber to at least one of a first position located more on an upstream side and a second position located more on a downstream side in a conveyance direction of the optical fiber than a laser light irradiating position of the optical fiber in a case of writing the grating; and a feeder having a structure capable of linearly reciprocating in the conveyance direction and adapted to feed a predetermined length of the optical fiber in the conveyance direction in a case where a fixed state of the optical fiber by the fixing device is released.

First claim

The invention claimed is:

1. A manufacturing device of an optical fiber grating writing a grating in a core of an optical fiber by irradiating the optical fiber with laser light, the device comprising:
a fixing device configured to fix the optical fiber to at least one of a first position located more on an upstream side and a second position located more on a downstream side in a conveyance direction of the optical fiber than a laser light irradiating position of the optical fiber in a case of writing the grating;
a feeder configured to be capable of linearly reciprocating in the conveyance direction and configured to feed a predetermined length of the optical fiber in the conveyance direction in a case where a fixed state of the optical fiber by the fixing device is released, the feeder comprising:
a fixed portion having a guide extending in the conveyance direction, and
a movable portion capable of reciprocating along the guide; and

a holder attached to a position right above the movable portion and configured to hold the optical fiber when the movable portion is moved in the conveyance direction.

2. The manufacturing device of an optical fiber grating according to claim 1 , wherein the feeder comprises an irradiator attached to the movable portion and configured to emit laser light.

3. The manufacturing device of an optical fiber grating according to claim 2 , wherein
the movable portion is moved in a direction along a longitudinal direction of the optical fiber in a state where the holder does not hold the optical fiber, and
the irradiator is configured to emit laser light to a phase mask arranged at the irradiating position.

4. The manufacturing device of an optical fiber grating according to claim 1 , further comprising:
an infeed device configured to feed the optical fiber; and
a winder configured to wind up the optical fiber in which the grating has been written.

5. The manufacturing device of an optical fiber grating according to claim 1 , further comprising:
a first tension applicator arranged more on an upstream side than the first position and configured to apply tension to be applied to the optical fiber; and
a second tension applicator arranged more on a downstream side than the second position and configured to apply tension to be applied to the optical fiber.

6. The manufacturing device of an optical fiber grating according to claim 5 , wherein each of the first tension applicator and the second tension applicator comprises:
a pair of fixed pulleys where the optical fiber is passed around in a rotatably supported manner; and
a movable pulley where the optical fiber is passed halfway around at a lower position between the pair of fixed pulleys.

7. The manufacturing device of an optical fiber grating according to claim 6 , wherein each of the first tension applicator and the second tension applicator comprises a load variable mechanism connected to the movable pulley and capable of adjusting a load applied to the optical fiber.

8. The manufacturing device of an optical fiber grating according to claim 7 , wherein
the load variable mechanism comprises:
a load measuring mechanism configured to measure a load applied to the optical fiber; and
a load applying mechanism configured to apply a load to the optical fiber, and
the load variable mechanism adjusts a load applied to the optical fiber by controlling the load applying mechanism in accordance with a measurement result of the load measuring mechanism.

9. A manufacturing method of an optical fiber grating, comprising:
fixing an optical fiber to at least one of a first position located more on an upstream side and a second position located more on a downstream side in a conveyance direction of the optical fiber than a laser light irradiating position of the optical fiber in order to write a grating in a core of the optical fiber;
irradiating the irradiating position with the laser light;
releasing a fixed state of the optical fiber at the first position and the second position;
feeding a predetermined length of the optical fiber in the conveyance direction by using a feeder having a structure capable of linearly reciprocating in the conveyance direction and comprising,
a fixed portion having a guide extending in the conveyance direction,
a movable portion capable of reciprocating along the guide, and
a holder attached to a position right above the movable portion and configured to hold the optical fiber when the movable portion is moved in the conveyance direction; and

holding the optical fiber when the movable portion is moved in the conveyance direction.

10. The manufacturing method of an optical fiber grating according to claim 9 , in which the feeder is provided with an irradiator configured to emit laser light, the method comprising, in the step of irradiating the laser light:
moving the feeder in a direction along a longitudinal direction of the optical fiber, and emitting the laser light from the irradiator to a phase mask arranged at the irradiating position.

11. The manufacturing method of an optical fiber grating according to claim 9 , further comprising: feeding an optical fiber having a length corresponding to the predetermined length from an infeed device to the first tension applicator arranged more on an upstream side than the first position and configured to apply tension to the optical fiber before fixing the optical fiber; and also winding up the optical fiber by a winder from the second tension applicator arranged more on a downstream side than the second position and configured to apply tension to the optical fiber.

12. The manufacturing method of an optical fiber grating according to claim 9 , further comprising: adjusting a load applied to the optical fiber during a period from when emission of the laser light is terminated until the optical fiber is started to be fixed again.

13. The manufacturing method of an optical fiber grating according to claim 12 , further comprising, in the step of adjusting a load:
measuring a load applied to the optical fiber; and
controlling a load applied to the optical fiber in accordance with a measurement result of the load.

Assignees

• Fujikura Ltd

Inventors

• Hata Keiichiro
• Ohmori Kenichi

Classifications

• G02B6/02152 Primary

  involving moving the fibre or a manufacturing element, stretching of the fibre (G02B6/02147 takes precedence) · CPC title

• G02B6/02123 Primary

  characterised by the method of manufacture of the grating (photolithography G03F7/0005) · CPC title

• G02B6/02

  Optical fibres with cladding {with or without a coating} · CPC title

• G02B6/02147

  Point by point fabrication, i.e. grating elements induced one step at a time along the fibre, e.g. by scanning a laser beam, arc discharge scanning (G02B6/02133 and G02B6/02142 take precedence) · CPC title

• G02B6/02138

  based on illuminating a phase mask · CPC title