CN211789975U - A high-stability multi-wavelength fiber laser with adjustable wavelength interval - Google Patents

Abstract

A high-stability multi-wavelength fiber laser with adjustable wavelength interval belongs to the fields of optical fiber communication and instrumentation. This laser is connected to the polarization controller two (09), the polarization maintaining fiber one (10), the polarization controller three (11) and the polarization maintaining fiber two in sequence between the interfaces 081 and 082 of the fiber coupler one (08). (12) constitute a double-order Sagnac filter; pump (01), wavelength division multiplexer (02), doped fiber (03), fiber coupler one (04), high nonlinear fiber (05), polarization control The first (06) and the second fiber coupler (07) form a NALM-NOLM structure, which suppresses mode competition and greatly improves the stability of the laser output. The wavelength separation can be varied by adjusting the two polarization controllers in the filter. The laser has the advantages of simple structure and flexible output wavelength, and is suitable for wavelength division multiplexing system.

Description

A high-stability multi-wavelength fiber laser with adjustable wavelength interval

technical field

The utility model relates to a high-stability multi-wavelength fiber laser with adjustable wavelength interval, belonging to the fields of optical fiber communication and instrumentation.

Background technique

With the rapid rise of the information technology industry in modern society, the number of Internet users in the world is increasing exponentially, and the communication capacity is continuously increasing. The dense wavelength division multiplexing system can effectively improve the communication capacity by increasing the number of channels in the system. The working principle of the system is to multiplex multiple wavelength optical signals into optical fibers for transmission. Usually, the laser light source signal used in the system is a DFB semiconductor laser array. Each laser in the array lasing outputs a light source signal. Although the idea and idea Simple, but will greatly increase the cost and complexity of the communication system. Due to its simple structure, low cost, and stable output of multiple wavelengths at the same time, multi-wavelength fiber lasers have a wide range of applications in the field of fiber optic communications, optical signal processing, optical sensing, and microwave photonic technology. The basic components of a multi-wavelength fiber laser are: a gain fiber and a pump source doped with rare earth elements, a mechanism to suppress mode competition, and a filter containing multiple optical channels. With the deepening of research, many types of multi-wavelength lasers have been designed, such as narrow linewidth multi-wavelength lasers, tunable wavelength range multi-wavelength lasers, and wavelength interval tunable multi-wavelength lasers. The introduction of these lasers has greatly promoted the development of optical communication systems.

Among them, the proposal of multi-wavelength lasers with variable wavelength interval can meet the needs of communication networks with different channel intervals, which is beneficial to the improvement of the flexibility of communication networks, and reduces the cost and complexity, which is very important for the development of future communication networks. meaning. In addition, the output stability of multi-wavelength lasers has also received widespread attention, and researchers have proposed various structures to improve multi-wavelength stability, such as the use of nonlinear polarization rotation, nonlinear optical ring mirrors, and so on. The utility model uses an all-fiber structure, cascading the comb filter and the NALM-NOLM structure, and by adjusting the polarization controller, the stability of the multi-wavelength output can be improved, and the wavelength interval of the output wavelength can be flexibly changed at the same time, which is beneficial to the applications in optical communication systems.

Utility model content

The main technical problem solved by the utility model is to solve the problem that many fiber lasers can not maintain long-term stability while realizing multi-wavelength laser output. A high-stability multi-wavelength fiber laser with adjustable wavelength interval is proposed.

The technical solutions adopted are as follows:

Including pump light source, wavelength division multiplexer, doped fiber, fiber coupler 1, fiber coupler 2, fiber coupler 3, polarization maintaining fiber 1 and polarization maintaining fiber 2 with different lengths, polarization controller 1, polarization control Device two, polarization controller three.

The pump light source is connected to the input end of the wavelength division multiplexer, the first port of the wavelength division multiplexer is connected to one end of the doped fiber, and the second port of the wavelength division multiplexer is connected to the third port of the second fiber coupler. The port four of the doped fiber is connected to the fiber coupler one, and the right port five of the fiber coupler one is connected to the right port six of the fiber coupler two. A highly nonlinear optical fiber and a polarization controller one are connected in sequence between the other port on the right side of the fiber coupler one and the left port seven of the fiber coupler two. The right port 8 of the fiber coupler 2 is connected to the left port 9 of the fiber coupler 3. The right port 10 and the port 9 of the fiber optic coupler 3 are connected to the polarization-related controller 2, the polarization maintaining fiber 1, and the polarization maintaining fiber 1 in turn. Controller three and PM fiber two.

The doped fibers are doped fibers, ytterbium-doped fibers and thulium-doped fibers.

The effect that the utility model has is as follows:

A highly stable multi-wavelength laser with variable wavelength interval is proposed. The laser uses a double-order Sagnac filter cascaded with a NALM-NOLM structure. The double-order Sagnac filter is used as a wavelength selection element. By adjusting the polarization controller two and the polarization controller three in the filter, the interval of the output wavelength will change. The NALM-NOLM structure is used to suppress the wavelength competition in the laser cavity and improve the stability of the output structure. In addition, by adjusting the polarization controller one in the NALM-NOLM structure, the position of the output wavelength can be changed to a certain extent, that is, the tuning of the wavelength is realized.

Description of drawings

Figure 1 shows a highly stable multi-wavelength fiber laser with adjustable wavelength interval.

Fig. 2 is a schematic diagram of the wavelength interval change of a high-stability multi-wavelength fiber laser with adjustable wavelength interval, the wavelength interval in Fig. (a) is Δλ ₁ , and the wavelength interval in Fig. (b) is Δλ ₂ (Δλ ₁ ≠Δλ ₂ ) .

FIG. 3 is a schematic diagram of wavelength tuning of a highly stable multi-wavelength fiber laser with adjustable wavelength interval.

Detailed ways

The utility model is further described below in conjunction with the accompanying drawings.

Embodiment 1

A high-stability multi-wavelength fiber laser with adjustable wavelength interval, as shown in Figure 1, includes a pump light source 01, a wavelength division multiplexer 02, a doped fiber 03, a fiber coupler 04, a high nonlinear fiber 05. Polarization controller one 06, fiber coupler two 07, fiber coupler three 08, polarization controller two 09, polarization maintaining fiber one 10, polarization controller three 11, polarization maintaining fiber two 12.

The pump light source 01 is connected to the input end of the wavelength division multiplexer 02 , and the port one 021 of the wavelength division multiplexer 02 is connected to one end of the doped fiber 03 . The other port of the input end of the wavelength division multiplexer 02 is connected to the left port 071 of the second fiber coupler 07 . The right port 031 of the doped fiber 03 is connected to the fiber coupler one 04 , and the port 041 of the fiber coupler one 04 is connected to the fiber coupler two 07 . The other port 042 of the first fiber coupler 04 and the port 072 of the second fiber coupler 07 are connected to the high nonlinear fiber 05 and the polarization controller one 06 at one time to form a NALM-NOLM structure. The right port 073 of the optical fiber coupler 07 is connected to the left side of the optical fiber coupler 3 08, and the left port 081 and the right port 082 of the optical fiber coupler 08 are connected to the polarization controller two 09 and the polarization maintaining fiber one in turn. 10. The third polarization controller 11 and the second polarization maintaining fiber 12 form a double-order Sagnac filter. The second port 083 on the left side of the third fiber coupler 08 is used as the output port of the laser. The lengths of the polarization-maintaining fiber one 10 and the polarization-maintaining fiber two 12 are different.

The difference between the second embodiment and the first embodiment is that

The doped fiber 03 is a ytterbium-doped fiber, the length of the highly nonlinear fiber 05 is greater than 100 meters, and the length difference between the first polarization maintaining fiber (10) and the second polarization maintaining fiber (12) is greater than or equal to 0.5 meters.

The difference between Embodiment 3 and Embodiment 1 and Embodiment 2 is that

The doped fiber 03 is a thulium-doped fiber, the length of the high nonlinear fiber 05 is greater than 120 meters, and the length difference between the first polarization maintaining fiber (10) and the second polarization maintaining fiber (12) is greater than or equal to 0.8 meters.

Claims (6)

1. A wavelength interval adjustable high stability multi-wavelength fiber laser is characterized in that:

the polarization maintaining fiber coupler comprises a pump light source (01), a wavelength division multiplexer (02), a doped fiber (03), a fiber coupler I (04), a high nonlinear fiber (05), a polarization controller I (06), a fiber coupler II (07), a fiber coupler III (08), a polarization controller II (09), a polarization maintaining fiber I (10), a polarization controller III (11) and a polarization maintaining fiber II (12), wherein the pump light source (01) is connected with the input end of the wavelength division multiplexer (02), a port I021 of the wavelength division multiplexer (02) is connected with one end of the doped fiber (03), the other port of the input end of the wavelength division multiplexer (02) is connected with a left port 071 of the fiber coupler II (07), a right port 031 of the doped fiber (03) is connected with the fiber coupler I (04), a port 041 of the fiber coupler I (04) is connected with the fiber coupler II (07), and the other port 042 of the fiber coupler I (04) and the port 072 of the fiber coupler II (07) are connected at one time The polarization maintaining fiber laser comprises a nonlinear fiber (05) and a first polarization controller (06), a right port 073 of a second fiber coupler (07) is connected with the left side of a third fiber coupler (08), a second polarization controller (09), a first polarization maintaining fiber (10), a third polarization controller (11) and a second polarization maintaining fiber (12) are sequentially connected between a left port 081 and a right port 082 of the third fiber coupler (08), and a left second port 083 of the third fiber coupler (08) serves as an output port of the laser.

2. A wavelength interval tunable high stability multi-wavelength fiber laser according to claim 1, wherein the doped fiber (03) comprises an erbium doped fiber, a ytterbium doped fiber or a thulium doped fiber.

3. A wavelength interval tunable high stability multi-wavelength fiber laser according to claim 1, wherein the lengths of the first polarization maintaining fiber (10) and the second polarization maintaining fiber (12) are different.

4. The fiber laser of claim 1, wherein the splitting ratio of the first fiber coupler (04), the second fiber coupler (07) and the third fiber coupler (08) is 50:50, 70:30, 80:20, or 90: 10.

5. The fiber laser of claim 1, wherein when the doped fiber (03) is ytterbium doped, the length of the highly nonlinear fiber (05) is greater than 100 meters, and the difference between the lengths of the first polarization maintaining fiber (10) and the second polarization maintaining fiber (12) is greater than or equal to 0.5 meter.

6. The high-stability multi-wavelength fiber laser with adjustable wavelength interval according to claim 1, wherein when the doped fiber (03) is a thulium-doped fiber, the length of the high-nonlinearity fiber (05) is greater than 120 m, and the difference between the lengths of the polarization maintaining fiber I (10) and the polarization maintaining fiber II (12) is greater than or equal to 0.8 m.

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