CN115986539A - Fiber laser based on optical fiber coating resonant cavity - Google Patents

Abstract

The invention provides an optical fiber laser based on an optical fiber coating resonant cavity, which consists of a semiconductor laser LD, a Yb optical fiber and a quartz output head QBH, wherein the LD is additionally provided with a 1800nm high-reflection film at a coupling output end to be used as a high-reflection grating; the QBH is a customized QBH, the tail fiber is 20/400, a fiber cladding light stripper CPS in the original linear cavity light path is removed, and the QBH stripping capability is improved; the fiber end face of the fiber coupling part in the LD is plated with a film layer with the reflectivity of 99% in a film coating mode to replace the high-reflection grating, and the fiber end face of the QBH output fiber is plated with a film layer with the reflectivity of 10% in a film coating mode to replace the low-reflection grating. The invention provides an optical fiber coating resonant cavity structure, which is based on the existing linear cavity foundation, saves a half of optical fiber devices and greatly simplifies the original optical path.

Description

Fiber laser based on optical fiber coating resonant cavity

Technical Field

The invention relates to the technical field of laser, in particular to an optical fiber laser based on an optical fiber coating resonant cavity.

Background

The optical fiber laser is a novel solid laser taking doped optical fiber as a laser medium, and has the advantages of good heat dissipation, high beam quality and the like.

Like the traditional solid and gas laser, the optical fiber laser basically consists of three basic elements, namely a pumping source, a gain medium and a resonant cavity. The pumping source generally adopts a high-power semiconductor Laser (LD), the gain medium is a doped fiber or a common nonlinear fiber, the resonant cavity can be various linear resonant cavities formed by optical feedback elements such as fiber gratings, the pumping light enters the gain fiber through coupling of a proper optical coupling system, the gain fiber forms population inversion after absorbing the pumping light, and stable laser output is finally formed after stimulated amplification and mode selection of the resonant cavity.

The gain medium is an optical fiber core doped with rare earth ions, and the doped optical fiber is clamped between the 2 reflectors, so that an F-P resonant cavity is formed.

In the prior art, a plurality of linear cavity devices are arranged, the devices are connected in an optical fiber fusion mode, and the optical path is complex.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a simple linear cavity optical path which is only composed of an LD, an ytterbium-doped Yb optical fiber and an output head compared with the traditional linear cavity optical path and is used for solving the problems in the prior art.

The invention provides a fiber laser based on a fiber coating resonant cavity, which consists of a semiconductor laser LD, an ytterbium-doped Yb fiber and a quartz output head QBH,

the LD is added with a 1800nm high-reflection film at a coupling output end to be used as a high-reflection grating; the QBH is a customized QBH, the tail fiber is 20/400, a fiber cladding light stripper CPS in the original linear cavity light path is removed, and the QBH stripping capability is improved;

the fiber end face of the fiber coupling part in the LD is coated with a film layer with the reflectivity of 99% to replace the high reflecting grating, and the QBH output fiber end face is coated with a film layer with the reflectivity of 10% to replace the low reflecting grating.

Further, because the pump light and the laser can be transmitted in the same section of optical fiber, the beam combiner in the original linear cavity optical path can be removed.

The method of the invention has the following advantages:

the invention provides an optical fiber coating resonant cavity structure, which is based on the existing linear cavity foundation, saves a half of optical fiber devices and greatly simplifies the original optical path.

Drawings

FIG. 1 is a prior art linear cavity optical path diagram;

fig. 2 is a simplified linear cavity light path diagram of the present invention.

Detailed Description

The preferred embodiments of the present invention will be described in detail with reference to the following examples. It is to be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the present invention. Various modifications and substitutions may be made by those skilled in the art without departing from the spirit and scope of the invention, and all such modifications and substitutions are intended to be within the scope of the claims.

The high-low reflective gratings are used in pairs to form a resonant cavity so that output laser can be positively fed back in the cavity. The reflectivity of the output laser of the high reflecting grating is 99 percent, and the reflectivity of the low reflecting grating is 10 percent.

LD, laserdiode semiconductor laser;

the optical path structure of the optical resonant cavity is formed by a pair of gratings;

CPS, clasdingpower striper, fiber cladding Stripper;

QBH, quartz Block head, quartz output head.

The linear cavity light path is shown in fig. 1, an optical resonant cavity is formed by a high reflection grating, a ytterbium-doped Yb fiber and a low reflection grating, pumping light of an LD is made to have a wavelength of 976nm or 915nm by a beam combiner, ytterbium ions absorb energy to generate ion number inversion when the pumping light enters the resonant cavity and passes through a gain fiber, upper level ions spontaneously radiate to generate laser, the wavelength is selected by the resonant cavity, and 1080nm laser of stimulated radiation is finally generated.

To produce 150W of continuous light, 7 fiber devices were required. The device is many, and the light path is complicated.

The invention designs a fiber laser based on a fiber coating resonant cavity, the components of which are shown in figure 2,

and the LD is added with a 1800nm high-reflection film at the coupling output end to be used as a high-reflection grating.

QBH is a customized QBH, the tail fiber is 20/400, the original CPS is removed, and QBH stripping capacity is increased.

The end face of the fiber coupling part in the LD is coated with a film layer with the reflectivity of 99% to replace a high reflecting grating, and the end face of the QBH output fiber is coated with a film layer with the reflectivity of 10% to replace a low reflecting grating.

The simple linear cavity optical path provided by the invention has few components and simple optical path.

Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, it is intended that all such modifications and alterations be included within the scope of this invention as defined in the appended claims.

Claims (2)

1. A fiber laser based on fiber coating resonant cavity comprises a semiconductor laser LD, a Yb-doped fiber and a quartz output head QBH,

the LD is additionally provided with a 1800nm high-reflection film at the coupling output end to be used as a high-reflection grating; the QBH is a customized QBH, the tail fiber is 20/400, a fiber cladding light stripper CPS in the original linear cavity light path is removed, and the QBH stripping capability is improved;

the fiber end face of the fiber coupling part in the LD is coated with a film layer with the reflectivity of 99% to replace the high reflecting grating, and the QBH output fiber end face is coated with a film layer with the reflectivity of 10% to replace the low reflecting grating.

2. The fiber laser based on the fiber coating resonant cavity of claim 1, wherein the beam combiner in the original linear cavity optical path can be eliminated because both the pump light and the laser light can be transmitted in the same section of fiber.

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