FIBER LASER APPARATUS AND METHOD OF MANUFACTURING AMPLIFYING COIL

• US 20170170622A1
• Filed: 02/28/2017
• Published: 06/15/2017
• Est. Priority Date: 02/12/2015
• Status: Active Grant

• Current Assignee: Fujikura Limited
• Original Assignee: Fujikura Limited
• Inventors: Kashiwagi, Masahiro
• Granted Patent: US 10,530,113 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 6/02 Optical fibres with cladding with or without a coating
• CPC Class Codes: G02B 6/4457 Bobbins; Reels
• CPC Class Codes: G02B 6/449 Twisting
• CPC Class Codes: G02B 6/46 Processes or apparatus adapted for installing or repairing optical fibres or optical cables installation of cables containing electric conductors and optical fibres H02G
• CPC Class Codes: H01S 3/04 Arrangements for thermal management
• CPC Class Codes: H01S 3/042 for solid state lasers H01S3/0401 takes precedence
• CPC Class Codes: H01S 3/06704 Housings; Packages
• CPC Class Codes: H01S 3/06729 Peculiar transverse fibre profile
• CPC Class Codes: H01S 3/06733 Fibre having more than one cladding
• CPC Class Codes: H01S 3/0675 Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers
• CPC Class Codes: H01S 3/094003 the pumped medium being a fibre
• CPC Class Codes: H01S 3/094007 Cladding pumping, i.e. pump light propagating in a clad surrounding the active core
• CPC Class Codes: H01S 3/09415 the pumping beam being parallel to the lasing mode of the pumped medium, e.g. end-pumping

Abstract

A fiber laser apparatus includes a pumping light source which launches pumping light, an amplifying optical fiber which includes a core and a noncircular cladding, and absorbs the pumping light to launch laser light, an amplifying coil which has a configuration around which the amplifying optical fiber is wound, a first reflector which is provided on an input side of the amplifying coil and is configured to reflect the laser light toward the amplifying coil, and a second reflector which is provided on a launching side of the amplifying coil, has a lower reflectance than a reflectance of the first reflector, and is configured to reflect the laser light toward the amplifying coil.

Claims

1. A fiber laser apparatus, comprising:

a pumping light source which launches pumping light;

an amplifying optical fiber which includes a core and a noncircular cladding, and absorbs the pumping light to launch laser light;

an amplifying coil which has a configuration around which the amplifying optical fiber is wound;

a first reflector which is provided on an input side of the amplifying coil and is configured to reflect the laser light toward the amplifying coil; and

a second reflector which is provided on a launching side of the amplifying coil, has a lower reflectance than a reflectance of the first reflector, and is configured to reflect the laser light toward the amplifying coil;

wherein in the amplifying coil, the amplifying optical fiber is wound with a center axis of the amplifying optical fiber as a center in a state of being twisted in a peripheral direction of the amplifying optical fiber, and the wound amplifying optical fiber is fixed and integrated.

2. The fiber laser apparatus according to claim 1,

wherein in the amplifying coil, a portion between adjacent amplifying optical fibers is filled with a resin.

3. The fiber laser apparatus according to claim 1, further comprising:

a cooling member which cools the amplifying coil.

4. The fiber laser apparatus according to claim 1,

wherein a twist amount of the amplifying optical fiber gradually increases in a direction from the first reflector side toward the second reflector side.

5. The fiber laser apparatus according to claim 1, wherein the twist amount of the amplifying optical fiber is 3 turns/m or less.

6. A method of manufacturing an amplifying coil, comprising:

winding an amplifying optical fiber in a coil shape while lowering a portion of the amplifying optical fiber onto one surface of a base; and

filling a portion between adjacent amplifying optical fibers with a resin to fix the amplifying optical fibers to each other.

7. A method of manufacturing an amplifying coil, comprising:

winding an amplifying optical fiber drawn out from a bobbin around a rotary jig to wind the amplifying optical fiber in a coil shape; and

filling a portion between adjacent amplifying optical fibers with a resin to fix the amplifying optical fibers to each other,

wherein when the amplifying optical fiber is wound in a coil shape, a rotation axis of the bobbin and a rotation axis of the rotary jig are disposed to be non-parallel to each other.