Random distributed Rayleigh feedback fiber laser based on double-cladding weak ytterbium-doped fiber

Abstract

The invention discloses a random distributed Rayleigh feedback fiber laser based on double-cladding weak ytterbium-doped fiber, and relates to the field of fiber and fiber lasers. The random distributed Rayleigh feedback fiber laser comprises a pump laser source, a pump beam combiner and a cladding power stripper, and further comprises the double-cladding weak ytterbium-doped fiber used for simultaneously realizing distributed active gain and random distributed Rayleigh feedback; the output end of the pump beam combiner is connected with one end of the double-cladding weak ytterbium-doped fiber, and the other end of the double-cladding weak ytterbium-doped fiber is connected with the input end of the cladding power stripper; and the concentration value range of ytterbium ions in the double-cladding weak ytterbium-doped fiber is 0.5*10<23>-1*10<27> / m<3>. According to the random distributed Rayleigh feedback fiber laser, the problem that an existing random fiber laser cannot simultaneously provide distributed active gain and random distributed Rayleigh feedback is solved, and the effect of simultaneously providing distributed active gain and random distributed Rayleigh feedback through the single fiber is achieved.

Description

technical field

[0001] The invention relates to the field of optical fibers and optical fiber lasers, in particular to a randomly distributed Rayleigh feedback optical fiber laser based on a double-clad weakly doped ytterbium optical fiber. Background technique

[0002] Fiber lasers use fiber gratings as cavity mirrors to realize an all-fiber structure; the pump light is coupled into the gain fiber from the left cavity mirror, the pump light is reflected multiple times in the cladding and passes through the doped fiber core, and the light passes through the doped fiber core. During medium transmission, the doped particles in the ground state absorb light and transition to the metastable state. When the particle population inversion distribution is satisfied, stimulated emission occurs, and the Rayleigh reflection in the optical fiber with doped ions provides random distributed feedback. This results in random lasing; the fiber laser is actually a wavelength converter. [00...

Examples

Embodiment 1

[0058] A randomly distributed Rayleigh feedback fiber laser based on a double-clad weakly doped ytterbium fiber, including a pump laser source 1, a pump beam combiner 2 and a cladding power stripper 4, including for simultaneously realizing distributed active gain and The double-clad weakly doped ytterbium fiber 3 with randomly distributed Rayleigh feedback, the output end of the pump combiner 2 is connected to one end of the double-clad weakly doped ytterbium fiber 3, and the other end of the double-clad weakly doped ytterbium fiber 3 is connected to the cladding The input end of the layer power stripper 4 is connected, and the double-clad weakly doped ytterbium fiber 3 includes an outer cladding composed of pure silicate, an inner cladding of germanium silicate doped with a certain concentration of germanium ions, and the fiber Core, the core consists of germanosilicate doped with a low concentration of ytterbium ions, the concentration of ytterbium ions is 8x10 23 / m 3 , l...

Embodiment 2

[0060] Based on embodiment 1, it also includes FBG5 for enhancing laser feedback, and FBG5 is connected to the pump beam combiner 2 signal end; the structure is as figure 2 shown;

[0061] The concentration of ytterbium ions in double-clad weakly doped ytterbium fiber 3 is 8x10 23 / m 3 The pump laser source 1 is 976nm, the length of FBG5 is 1040nm, and the length of double-clad weakly doped ytterbium fiber 3 is 210m; FBG5 of 1040nm has high reflectivity and low transmittance to 1040nm light; the FBG is set to form a semi-open cavity structure, which enhances The feedback of the laser and the narrow line width of the FBG have a narrowing effect on the laser, thereby achieving a high-power random laser output with a lower threshold and narrower line width. Such as image 3 As shown, as the pump power increases, the laser power also increases continuously, such as Figure 4 The random fiber laser shown is the distribution of laser power along the longitudinal direction of th...

Embodiment 3

[0063] On the basis of Example 2, the pump laser source 1 is selected to be 976nm, the length of the double-clad weakly doped ytterbium fiber 3 is selected to be 170m, and the length of the FBG5 is selected to be 1060nm; the lasing efficiency of random fiber lasers in the 1060nm band can be greatly improved.

technical field

[0001] The invention relates to the field of optical fibers and optical fiber lasers, in particular to a randomly distributed Rayleigh feedback optical fiber laser based on a double-clad weakly doped ytterbium optical fiber. Background technique

[0002] Fiber lasers use fiber gratings as cavity mirrors to realize an all-fiber structure; the pump light is coupled into the gain fiber from the left cavity mirror, the pump light is reflected multiple times in the cladding and passes through the doped fiber core, and the light passes through the doped fiber core. During medium transmission, the doped particles in the ground state absorb light and transition to the metastable state. When the particle population inversion distribution is satisfied, stimulated emission occurs, and the Rayleigh reflection in the optical fiber with doped ions provides random distributed feedback. This results in random lasing; the fiber laser is actually a wavelength converter. [00...

Examples

Embodiment 1

[0058] A randomly distributed Rayleigh feedback fiber laser based on a double-clad weakly doped ytterbium fiber, including a pump laser source 1, a pump beam combiner 2 and a cladding power stripper 4, including for simultaneously realizing distributed active gain and The double-clad weakly doped ytterbium fiber 3 with randomly distributed Rayleigh feedback, the output end of the pump combiner 2 is connected to one end of the double-clad weakly doped ytterbium fiber 3, and the other end of the double-clad weakly doped ytterbium fiber 3 is connected to the cladding The input end of the layer power stripper 4 is connected, and the double-clad weakly doped ytterbium fiber 3 includes an outer cladding composed of pure silicate, an inner cladding of germanium silicate doped with a certain concentration of germanium ions, and the fiber Core, the core consists of germanosilicate doped with a low concentration of ytterbium ions, the concentration of ytterbium ions is 8x10 23 / m 3 , l...

Embodiment 2

[0060] Based on embodiment 1, it also includes FBG5 for enhancing laser feedback, and FBG5 is connected to the pump beam combiner 2 signal end; the structure is as figure 2 shown;

[0061] The concentration of ytterbium ions in double-clad weakly doped ytterbium fiber 3 is 8x10 23 / m 3 The pump laser source 1 is 976nm, the length of FBG5 is 1040nm, and the length of double-clad weakly doped ytterbium fiber 3 is 210m; FBG5 of 1040nm has high reflectivity and low transmittance to 1040nm light; the FBG is set to form a semi-open cavity structure, which enhances The feedback of the laser and the narrow line width of the FBG have a narrowing effect on the laser, thereby achieving a high-power random laser output with a lower threshold and narrower line width. Such as image 3 As shown, as the pump power increases, the laser power also increases continuously, such as Figure 4 The random fiber laser shown is the distribution of laser power along the longitudinal direction of th...

Embodiment 3

[0063] On the basis of Example 2, the pump laser source 1 is selected to be 976nm, the length of the double-clad weakly doped ytterbium fiber 3 is selected to be 170m, and the length of the FBG5 is selected to be 1060nm; the lasing efficiency of random fiber lasers in the 1060nm band can be greatly improved.

Images