CN202405608U - Multi-wavelength optical fiber laser based on fusible cone gratings of optical fiber coupler - Google Patents

Abstract

A multi-wavelength fiber laser based on a fiber coupler fusion cone grating relates to a fiber laser and is suitable for the field of fiber communication. The problem of poor stability of the laser structure and difficulty in controlling the number of output laser wavelengths in current multi-wavelength fiber lasers is solved. The first pump source (51) in this laser is connected to the first port (411) of the first wavelength division multiplexer, and the second port (412) of the first wavelength division multiplexer is connected to the first port (412) of the coupler 21), the third port (413) of the first wavelength division multiplexer is connected to one end of the first active single-mode optical fiber (11), and the other end of the first active single-mode optical fiber (11) is connected to the third port of the coupler. port (23); the first to N fiber gratings (31, 32, ..., 3M, 3(M+1), 3(M+2), ..., 3N) have inconsistent central wavelengths, are all fiber Bragg gratings, and have no overlapping reflection bandwidths. N=2-50, 0≤M≤N, M and N are both positive integers.

Description

Multi-wavelength fiber laser based on fiber coupler fused cone grating

technical field

The utility model relates to an optical fiber laser, which is suitable for the field of optical fiber communication.

Background technique

The discovery and use of light sources by humans can be traced back to the primitive tribes who used fire for lighting. All light sources before the generation of lasers could not improve the directionality and brightness qualitatively. No matter how many devices are added to adjust the output light, the divergence angle is large, The problem of energy inconcentration cannot be effectively solved all the time. The reason for this is that all light sources before laser generation are not coherent light sources, and their inherent disadvantages are large divergence angle and low brightness. It was not until the early 1960s that the advent of the first ruby laser completely solved this problem. With the continuous maturity of laser technology, the application field of laser has been further expanded. At present, lasers have been developed to include semiconductor lasers, optical fibers Lasers, _CO2 lasers, free electron lasers and other huge laser systems with different fundamentals. Considering the advantages and disadvantages of various lasers, fiber lasers are favored by the majority of scientific researchers for their good beam quality, compact structure, low thermal efficiency, and high light-to-light conversion efficiency, and they have shown huge economic benefits in basic applications. and social benefits.

At present, fiber lasers based on cladding pumping technology have attracted widespread attention due to their good beam quality, high conversion efficiency, and compact structure. In 2004, the single-fiber output power of fiber lasers reached the kilowatt level. In 2009, IPG reported that it had achieved a single-fiber 10,000-watt single-mode laser output. However, as the power increases, various nonlinear effects such as SBS, SRS, and FWM seriously degrade the beam quality and become a huge obstacle to further increase the laser power. The proposal of large mode area LMA fiber has become a feasible method. In the case of keeping the optical power density constant, increasing the fiber radius can effectively increase the optical power that the fiber can carry, which provides a great opportunity for the preparation of high-power fiber lasers. necessary prerequisite. However, due to the limited increase in fiber radius, too large fiber radius makes the mode field complex and the beam quality cannot be guaranteed. Therefore, the problem that this method can solve is limited by the size of the fiber. Another method is the power amplifier MOPA of the main control oscillator. This method can effectively increase the laser power, and the quality of the output laser is very high, but it is also limited by the optical power carrying capacity of a single fiber.

Fiber lasers play an irreplaceable role in the field of communication. Fiber lasers with multiple wavelengths and narrow linewidths have always been the goal pursued in the field of communications. At present, fiber lasers can achieve multi-wavelength, narrow linewidth laser output and high conversion efficiency. High, played a very important role in promoting the progress of optical communication. However, most of the existing multi-wavelength lasers use a comb filter structure, specifically a sampling grating, an M-Z interferometer composed of two 3dB couplers, an F-P etalon, etc., and the stability is poor. And it is difficult to effectively control the number of wavelengths.

Therefore, the current problems faced by multi-wavelength fiber lasers are: the stability of the laser structure is poor, and the number of wavelengths of the output laser is difficult to control.

Utility model content

The technical problem to be solved by the utility model is that the stability of the laser structure is poor, and it is difficult to control the number of wavelengths of the output laser.

The technical scheme of the utility model is:

A multi-wavelength fiber laser based on a fiber coupler fusion taper grating, the laser includes a first active single-mode fiber, a coupler, the first to Nth fiber gratings written in the fusion taper region of the coupler, a first pump source, and a first pumping source. A wavelength division multiplexer, the connection mode of each device is:

The first pump source is connected to the first port of the first wavelength division multiplexer, the second port of the first wavelength division multiplexer is connected to the first port of the coupler, and the third port of the first wavelength division multiplexer is connected to the second port of the first wavelength division multiplexer. One end of an active single-mode fiber, the other end of the first active single-mode fiber is connected to the third port of the coupler;

The laser signal is output from the second port or/and the fourth port of the coupler;

The central wavelengths of the first to Nth fiber gratings written in the fusion cone of the coupler are all inconsistent, they are all fiber Bragg gratings, and the reflection bandwidths have no overlapping parts;

The first to Mth fiber gratings are written on one of the optical fibers in the fusing zone of the coupler, and the M+1 to Nth fiber gratings are written on the other optical fiber in the fusing zone of the coupler;

N=2-50, 0≤M≤N, both M and N are non-negative integers.

Compared with the prior art, the utility model has the following beneficial effects:

The comb filter in the traditional multi-wavelength fiber laser relies on the frequency selection function of the sampling grating to select the optical signal, but the production of the sampling grating is difficult, and the accuracy is difficult to meet the requirements, and the selection and theory of the optical signal cannot be achieved. Calculating the same requirements, in the multi-wavelength laser structure described in the utility model, each grating corresponds to a laser signal of a wavelength, which has low manufacturing difficulty and high precision; traditional multi-wavelength lasers are difficult to control the number of wavelengths, and too many wavelengths will cause The laser signal power of each output wavelength is reduced, and the output wavelength is too small to meet the requirements. The utility model adopts the method of connecting multiple gratings in series in the fusion cone area of the coupler, and the number of gratings is the number of output wavelengths. Strong control.

Description of drawings

Figure 1 is a multi-wavelength fiber laser based on a fiber coupler fused cone grating that outputs N wavelengths.

Figure 2 is a multi-wavelength fiber laser based on a fiber coupler fused cone grating outputting fifty wavelengths.

Figure 3 is a multi-wavelength fiber laser based on a fiber coupler fused cone grating that outputs U wavelengths.

Figure 4 is a multi-wavelength fiber laser based on a fiber coupler fused cone grating outputting two wavelengths.

Figure 5 is a multi-wavelength fiber laser based on a fiber coupler fused cone grating outputting five wavelengths.

Figure 6 is a multi-wavelength fiber laser based on a fiber coupler fused cone grating with a 3×3 coupler.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

Implementation Mode 1

A multi-wavelength fiber laser based on a fiber coupler fusion cone grating, as shown in Figure 1, the laser includes a first active single-mode fiber 11, a coupler, the first to Nth fiber gratings 31 written in the coupler fusion cone region 2, 32, ..., 3M, 3(M+1), 3(M+2), ..., 3N, the first pumping source 51, the first wavelength division multiplexer, the connection mode of each device is:

The first pump source 51 is connected to the first port 411 of the first wavelength division multiplexer, the second port 412 of the first wavelength division multiplexer is connected to the first port 21 of the coupler, and the second port 412 of the first wavelength division multiplexer is connected to the first port 21 of the coupler. The three ports 413 are connected to one end of the first active single-mode optical fiber 11, and the other end of the first active single-mode optical fiber 11 is connected to the third port 23 of the coupler.

The laser signal is output from the second port 22 and/or the fourth port 24 of the coupler.

The central wavelengths of the first to Nth fiber gratings 31, 32, ..., 3M, 3(M+1), 3(M+2), ..., 3N written in the fusion cone region 2 of the coupler are all inconsistent, and all For fiber Bragg gratings, the reflection bandwidths do not overlap.

The first to Mth fiber gratings 31, 32, ..., 3M are written on one of the optical fibers in the coupler fusion tapered region 2, and the M+1 to Nth fiber gratings 3(M+1), 3(M +2), ..., 3N are written on the other fiber in the coupler fusing zone 2.

N=2-50, 0≤M≤N, both M and N are non-negative integers.

Implementation mode two

The multi-wavelength fiber laser based on the fiber coupler fusion taper grating, as shown in Figure 2, the laser includes the first active single-mode fiber 11, the coupler, and the first to fiftieth fiber gratings 31 written in the coupler fusion taper region 2 , 32, ..., 350, the first pumping source 51, the first wavelength division multiplexer, the connection mode of each device is:

The first pump source 51 is connected to the first port 411 of the first wavelength division multiplexer, the second port 412 of the first wavelength division multiplexer is connected to the first port 21 of the coupler, and the second port 412 of the first wavelength division multiplexer is connected to the first port 21 of the coupler. The three ports 413 are connected to one end of the first active single-mode optical fiber 11, and the other end of the first active single-mode optical fiber 11 is connected to the third port 23 of the coupler.

The laser signal is output from the second port 22 and/or the fourth port 24 of the coupler.

The center wavelengths of the first to fiftieth fiber gratings 31 , 32 , .

The first to fiftieth fiber gratings 31 , 32 , .

Implementation Mode Three

A multi-wavelength fiber laser based on a fiber coupler fusion cone grating, as shown in Figure 3, the laser includes first and second active single-mode fibers 11, 12, 3×3 couplers, written in the 3×3 coupler fusion cone region 2's first to Uth fiber gratings 31, 32, ..., 3M, 3(M+1), 3(M+2), ..., 3N, 3(N+1), 3(N+2) , ..., 3U, the first and second pump sources 51, 52, the first and second wavelength division multiplexers, the connection methods of each device are:

The first port 21 of the 3×3 coupler is connected to the second port 412 of the first wavelength division multiplexer, the first port 411 of the first wavelength division multiplexer is connected to the first pump source 51, and the first wavelength division multiplexer The third port 413 of the coupler is connected to one end of the first active single-mode optical fiber 11, and the other end of the first active single-mode optical fiber 11 is connected to the third port 23 of the 3×3 coupler.

The second port 22 of the 3×3 coupler is connected to the second port 422 of the second wavelength division multiplexer, the first port 421 of the second wavelength division multiplexer is connected to the second pump source 52, and the second wavelength division multiplexer The third port 423 of the coupler is connected to one end of the second active single-mode optical fiber 12, and the other end of the second active single-mode optical fiber 12 is connected to the fourth port 24 of the 3×3 coupler.

The first to Uth fiber gratings 31, 32, ..., 3M, 3(M+1), 3(M+2), ..., 3N, 3(N The central wavelengths of +1), 3(N+2), ..., 3U are all inconsistent, they are all fiber Bragg gratings, and the reflection bandwidths do not overlap.

The laser signal is output from the fifth port 25 or/and the sixth port 26 of the 3×3 coupler.

The first to the Mth fiber gratings 31, 32, ..., 3M, the M+1 to the Nth fiber gratings 3(M+1), 3(M+2), ..., 3N and the N+1 to the Nth fiber gratings U fiber gratings 3(N+1), 3(N+2), .

U=2～50, 0≤M≤N≤U, M, N and U are all non-negative integers.

Implementation Mode Four

Based on the multi-wavelength fiber laser of the fiber coupler fusion cone grating, as shown in Figure 4, the laser includes the first active single-mode fiber 11, the coupler, the first and second fiber gratings 31 written in the coupler fusion cone region 2, 32. The first pumping source 51, the first wavelength division multiplexer, the connection mode of each device is as follows:

The first pump source 51 is connected to the first port 411 of the first wavelength division multiplexer, the second port 412 of the first wavelength division multiplexer is connected to the first port 21 of the coupler, and the second port 412 of the first wavelength division multiplexer is connected to the first port 21 of the coupler. The three ports 413 are connected to one end of the first active single-mode optical fiber 11, and the other end of the first active single-mode optical fiber 11 is connected to the third port 23 of the coupler.

The laser signal is output from the second port 22 and/or the fourth port 24 of the coupler.

The center wavelengths of the first and second fiber gratings 31 and 32 written on the fusing region 2 of the coupler are inconsistent, they are all fiber Bragg gratings, and the reflection bandwidths have no overlap.

The first and second fiber gratings 31 and 32 are written on one of the optical fibers in the fusing zone 2 of the coupler.

Implementation Mode Five

A multi-wavelength fiber laser based on a fiber coupler fusion taper grating, as shown in Figure 5, the laser includes a first active single-mode optical fiber 11, a coupler, the first to fifth fiber gratings 31 written in the coupler fusion taper region 2, 32, 33, 34, 35, the first pumping source 51, the first wavelength division multiplexer, the connection mode of each device is:

The first pump source 51 is connected to the first port 411 of the first wavelength division multiplexer, the second port 412 of the first wavelength division multiplexer is connected to the first port 21 of the coupler, and the second port 412 of the first wavelength division multiplexer is connected to the first port 21 of the coupler. The three ports 413 are connected to one end of the first active single-mode optical fiber 11, and the other end of the first active single-mode optical fiber 11 is connected to the third port 23 of the coupler.

The laser signal is output from the second port 22 and/or the fourth port 24 of the coupler.

The central wavelengths of the first to fifth fiber gratings 31 , 32 , 33 , 34 , and 35 written on the fusing region 2 of the coupler are all inconsistent, and they are all fiber Bragg gratings, and the reflection bandwidths do not overlap.

The first and second fiber gratings 31, 32 are written on one of the fibers in the coupler fusing zone 2, and the third to fifth fiber gratings 33, 34, 35 are written on the other of the coupler fusing zone 2. on the root fiber.

Embodiment six

A multi-wavelength fiber laser based on a fiber coupler fusion cone grating, as shown in Figure 6, the laser includes first and second active single-mode fibers 11, 12, 3×3 couplers, written in the 3×3 coupler fusion cone region 2's first to fiftieth fiber gratings 31, 32, ..., 35, 36, 37, ..., 312, 313, 314, ..., 350, the first and second pumping sources 51, 52, the first 1. The second wavelength division multiplexer, the connection mode of each device is:

The first port 21 of the 3×3 coupler is connected to the second port 412 of the first wavelength division multiplexer, the first port 411 of the first wavelength division multiplexer is connected to the first pump source 51, and the first wavelength division multiplexer The third port 413 of the coupler is connected to one end of the first active single-mode optical fiber 11, and the other end of the first active single-mode optical fiber 11 is connected to the third port 23 of the 3×3 coupler.

The second port 22 of the 3×3 coupler is connected to the second port 422 of the second wavelength division multiplexer, the first port 421 of the second wavelength division multiplexer is connected to the second pump source 52, and the second wavelength division multiplexer The third port 423 of the coupler is connected to one end of the second active single-mode optical fiber 12, and the other end of the second active single-mode optical fiber 12 is connected to the fourth port 24 of the 3×3 coupler.

The central wavelengths of the first to fiftieth fiber gratings 31, 32, ..., 35, 36, 37, ..., 312, 313, 314, ..., 350 written in the fusion cone region 2 of the 3*3 coupler are all Inconsistent, both are fiber Bragg gratings, and the reflection bandwidths do not overlap.

The laser signal is output from the fifth port 25 or/and the sixth port 26 of the 3×3 coupler.

First to fifth fiber gratings 31, 32, ..., 35, sixth to twelfth fiber gratings 36, 37, ..., 312 and thirteenth to fiftieth fiber gratings 313, 314, ..., 350 are respectively written on three different optical fibers in the fusing zone 2 of the 3×3 coupler.

Claims (1)

1. The multi-wavelength fiber laser based on the fiber coupler fusion cone grating is characterized in that: the laser comprises the first active single-mode optical fiber (11), the coupler, and is written in the first to The Nth fiber grating (31, 32, ..., 3M, 3(M+1), 3(M+2), ..., 3N), the first pumping source (51), the first wavelength division multiplexer , the connection mode of each device is: The first pumping source (51) is connected to the first port (411) of the first wavelength division multiplexer, and the second port (412) of the first wavelength division multiplexer is connected to the first port (21) of the coupler. The third port (413) of a wavelength division multiplexer is connected to one end of the first active single-mode optical fiber (11), and the other end of the first active single-mode optical fiber (11) is connected to the third port (23) of the coupler ; The laser signal is output from the second port (22) or/and the fourth port (24) of the coupler; The central wavelengths of the first to Nth fiber gratings (31, 32, ..., 3M, 3(M+1), 3(M+2), ..., 3N) written in the coupler's fusing region (2) They are all inconsistent, they are all fiber Bragg gratings, and there is no overlap in the reflection bandwidth; The first to Mth fiber gratings (31, 32, ..., 3M) are written on one of the optical fibers in the coupler fusion tapered region (2), and the M+1th to Nth fiber gratings (3(M+1 ), 3(M+2),..., 3N) are written on another optical fiber in the coupler's fusing zone (2); N=2-50, 0≤M≤N, both M and N are non-negative integers. 2. The multi-wavelength fiber laser based on fiber coupler fused cone grating according to claim 1, characterized in that: The coupler is a 3×3 coupler; The first port (21) of the 3×3 coupler is connected to the second port (412) of the first wavelength division multiplexer, and the first port (411) of the first wavelength division multiplexer is connected to the first pumping source (51 ), the third port (413) of the first wavelength division multiplexer is connected to one end of the first active single-mode optical fiber (11), and the other end of the first active single-mode optical fiber (11) is connected to the 3 × 3 coupler third port (23); The second port (22) of the 3×3 coupler is connected to the second port (422) of the second wavelength division multiplexer, and the first port (421) of the second wavelength division multiplexer is connected to the second pumping source (52 ), the third port (423) of the second wavelength division multiplexer is connected to one end of the second active single-mode optical fiber (12), and the other end of the second active single-mode optical fiber (12) is connected to the 3 × 3 coupler fourth port (24); Write the first to Uth fiber gratings (31, 32, ..., 3M, 3(M+1), 3(M+2), ..., 3N, The central wavelengths of 3(N+1), 3(N+2),...,3U) are all inconsistent, they are all fiber Bragg gratings, and the reflection bandwidths have no overlapping parts; The laser signal is output from the fifth port (25) or/and the sixth port (26) of the 3×3 coupler; The first to the Mth fiber gratings (31, 32, ..., 3M), the M+1th to the Nth fiber gratings (3(M+1), 3(M+2), ..., 3N) and the Nth +1 to U-th fiber gratings (3(N+1), 3(N+2), ..., 3U) are respectively written on three different optical fibers in the fusion cone region (2) of the 3×3 coupler; U=2～50, 0≤M≤N≤U, M, N and U are all non-negative integers.

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