CN211182779U - An all-fiber tunable multi-wavelength fiber laser with variable wavelength interval - Google Patents

Abstract

An all-fiber tunable multi-wavelength fiber laser with variable wavelength interval belongs to the fields of optical fiber communication and instrumentation, and can realize the tuning of the wavelength range and the change of the wavelength interval at the same time. In this laser, polarization controller 1, polarization-maintaining fiber 1, polarization controller 2, and polarization-maintaining fiber 2 are connected in sequence between the two ports of fiber coupler 1 to form a double-order Sagnac fiber filter with variable wavelength interval. . The polarization dependent isolator, the polarization controller three and the polarization maintaining fiber three constitute the Lyot filter. The above two filters are cascaded, and the third polarization controller is adjusted to realize the tuning of the wavelength range, and the adjustment of the two polarization controllers in the double-order Sagnac fiber filter can realize the change of the wavelength interval. The highly nonlinear optical fiber can form a four-wave mixing effect, which is beneficial to the output of stable wavelength, and at the same time realizes the change of the number of wavelengths. The laser has a simple structure and flexible output wavelength, which is beneficial to the application in optical communication and optical wavelength division multiplexing systems.

Description

An all-fiber tunable multi-wavelength fiber laser with variable wavelength interval

technical field

The utility model relates to a tunable multi-wavelength optical fiber laser with variable wavelength interval of all optical fibers, belonging to the fields of optical fiber communication and instrumentation.

Background technique

Since the 21st century, human society has undergone earth-shaking changes, the field of science and technology has developed rapidly, and people's lives have changed with each passing day. The advent of the information age has greatly increased people's requirements for communication speed and communication capacity, and optical fiber communication has emerged as the times require and has played an important role. At present, the 100G optical fiber transmission network has been commercialized. With the exponential growth of network data volume, the related technologies of 400G optical fiber transmission network are becoming mature day by day, and the standardization work is also progressing steadily. In the optical network, the wavelength division multiplexing technology is a commonly used technology, which uses multiple channels of different wavelengths to transmit information. Generally speaking, multiple laser light sources are required to generate multiple wavelengths, and the use of a single-wavelength laser will greatly increase the cost of the system. Multi-wavelength fiber lasers have the advantages of high performance, compact structure, low cost and low insertion loss, and can provide multiple wavelengths at the same time to meet the needs of the system. It is an effective solution to reduce the number of lasers and reduce system costs. In recent years, researchers have designed various types of multi-wavelength fiber lasers, such as fiber grating-based multi-wavelength single-longitudinal-mode fiber lasers, few-mode multi-wavelength lasers, and Brillouin erbium-doped fiber lasers.

In addition, multi-wavelength lasers with tunable wavelength range and variable wavelength interval have also received great attention, and their proposals have improved the flexibility of the system. Combining the two to form a tunable multi-wavelength fiber laser with variable wavelength interval will be better applicable to the system, meet the different needs in the optical communication system, and reduce the cost and complexity of the system at the same time. The development of communication network is of great significance.

The utility model uses an all-fiber structure, realizes the wavelength output of different ranges by adjusting the three polarization controllers, and can flexibly change the wavelength interval of multiple wavelengths at the same time, and can also realize the change of the number of wavelengths to a certain extent.

Utility model content

The main technical problem solved by the utility model is to solve the problem that the wavelength interval cannot be changed while realizing the tunable range of the output wavelength of many fiber lasers. wavelength fiber lasers.

The specific scheme adopted is as follows:

Including pump light source, wavelength division multiplexer, doped fiber, high nonlinear fiber, fiber coupler 1, fiber coupler 2, polarization maintaining fiber 1, polarization maintaining fiber 2, polarization maintaining fiber 3, polarization controller 1, Polarization Controller II, Polarization Controller III, Optical Fiber Circulator, Polarization Dependent Isolator.

The pump light source is connected to the input end on the right side of the wavelength division multiplexer, the port one on the left side of the wavelength division multiplexer is connected to one end of the doped fiber, and the port two on the right side of the wavelength division multiplexer is connected to the fiber coupler two The port three of the doped fiber is connected to the left port four of the doped fiber and the fiber circulator is connected. Port 5 of the optical fiber circulator is connected to the right port of the optical fiber coupler 1. Between the port 6 and port 7 of the optical fiber coupler 1, the polarization controller 1, the polarization maintaining fiber 1, the polarization controller 2, and the maintaining fiber are connected in sequence. Polarized fiber two. The other port of the optical fiber circulator, port eight, is connected to the polarization dependent isolator, the right port nine of the polarization dependent isolator is connected to the polarization controller three, and the second port on the right side of the polarization controller three is connected to the polarization maintaining fiber three. . Next, the polarization-maintaining fiber three is connected with the high nonlinear fiber, and finally the port ten of the high nonlinear fiber is connected with the right port of the fiber coupler three. The second port on the left side of fiber coupler two is used as the output end of the laser.

The doped fibers include erbium-doped fibers, ytterbium-doped fibers and thulium-doped fibers.

The effect that the utility model has is as follows:

A tunable multi-wavelength fiber laser with variable wavelength interval is proposed. The laser first uses a combination of two polarization-maintaining fibers with different lengths and two polarization controllers to form a double-order Sagnac fiber filter with variable wavelength interval, and then uses a polarization-dependent isolator, polarization controller and polarization-maintaining fiber to form a Lyot filter. Finally, the above two fiber filters are cascaded. Adjustment of the two polarization controllers in the two-order Sagnac filter with variable wavelength spacing enables the change of wavelength spacing. Tuning the polarization controller in the Lyot enables a wide range of wavelength tuning. The polarization dependent isolator also ensures that light travels in the forward direction in the loop. Accessing a highly nonlinear optical fiber can form a four-wave mixing effect, suppress wavelength competition, and obtain stable laser output while greatly increasing the number of output wavelengths.

Description of drawings

FIG. 1 is a schematic structural diagram of an all-fiber tunable multi-wavelength fiber laser with variable wavelength interval.

FIG. 2 is a schematic diagram of wavelength tuning of an all-fiber tunable multi-wavelength fiber laser with variable wavelength interval.

Fig. 3 is a schematic diagram of the wavelength interval change of a tunable multi-wavelength fiber laser with variable wavelength interval of all-fiber, the wavelength interval of Fig. (a) is Δλ, and the wavelength interval of Fig. (b) is Δλ` (Δλ≠Δλ`).

Figure 4 is a schematic diagram of the change in the number of wavelengths of an all-fiber tunable multi-wavelength fiber laser with variable wavelength interval, the number of wavelengths in Figure (a) is m (m>0), and the number of wavelengths in Figure (b) is n (n> 0) (m≠n).

Detailed ways

The invention is further described below with reference to the accompanying drawings.

Embodiment 1

A tunable multi-wavelength fiber laser with variable wavelength interval, as shown in Figure 1, includes a pump light source 01, a wavelength division multiplexer 02, a doped fiber 03, a fiber circulator 04, a fiber coupler 05, Polarization Controller One 06, Polarization Maintaining Fiber One 07, Polarization Controller Two 08, Polarization Maintaining Fiber Two 09, Polarization Dependent Isolator 10, Polarization Controller Three 11, Polarization Maintaining Fiber Three 12, High Nonlinear Fiber 13, Fiber Coupling Device II 14.

The pump light source 01 is connected to the input end 021 of the wavelength division multiplexer 02, the left port 023 of the wavelength division multiplexer is connected to one end of the doped fiber 03, and the right port 022 of the wavelength division multiplexer is connected to the fiber The port three 142 of the coupler two is connected, and the left port four 041 of the doped fiber 03 is connected to the fiber circulator. The port five 042 of the optical fiber circulator is connected to the right port of the optical fiber coupler one 05 . Between port six 052 and port seven 051 of fiber coupler one 05, polarization controller one 06, polarization maintaining fiber one 07, polarization controller two 08, polarization maintaining fiber two 09 are connected in sequence. The other port 043 of the optical fiber circulator 04 is connected to the left side of the polarization dependent isolator 10, the right port nine 101 of the polarization dependent isolator is connected to the polarization controller three 11, and the second port 111 on the right side of the polarization controller three 11 Connected to the polarization-maintaining fiber three 12. The third polarization maintaining fiber 12 is connected to the high nonlinear fiber 13 , and the tenth port 131 of the high nonlinear fiber 13 is connected to the right port of the second fiber coupler 14 . The second port 141 on the left side of the second fiber coupler 14 is used as the output end of the laser. The doped fiber 03 is an erbium-doped fiber, the length of the polarization maintaining fiber 1 07 and the polarization maintaining fiber 2 09 are different, the length of the polarization maintaining fiber 3 12 is less than 0.2 meters, and the length of the high nonlinearity fiber 13 is greater than 200 meters.

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 polarization-maintaining fiber 3 12 is less than 0.15 meters, and the length of the high nonlinear fiber 13 is greater than 100 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 polarization-maintaining fiber 12 is less than 2 meters, and the length of the high nonlinear fiber 13 is greater than 150 meters.

Claims (6)

1. A tunable multi-wavelength fiber laser with a variable all-fiber wavelength interval, characterized in that: Including pump light source (01), wavelength division multiplexer (02), doped fiber (03), fiber circulator (04), fiber coupler one (05), polarization controller one (06), polarization maintaining fiber One (07), polarization controller two (08), polarization maintaining fiber two (09), polarization dependent isolator (10), polarization controller three (11), polarization maintaining fiber three (12), high nonlinear fiber ( 13), the second fiber coupler (14), the pump light source (01) is connected to the input end (021) of the wavelength division multiplexer (02), and the left port one (023) of the wavelength division multiplexer is connected to the doping One end of the fiber (03) is connected, the port two (022) on the right side of the wavelength division multiplexer is connected with the port three (142) of the fiber coupler two, and the left port four (041) of the doped fiber (03) is connected with the fiber The circulator is connected, the port five (042) of the optical fiber circulator is connected to the right port of the optical fiber coupler one (05), between the port six (052) and the port seven (051) of the optical fiber coupler one (05), press Connect to polarization controller one (06), polarization maintaining fiber one (07), polarization controller two (08), polarization maintaining fiber two (09), and the other port (043) of the fiber circulator (04) and polarization The left side of the correlation isolator (10) is connected, the right port nine (101) of the polarization correlation isolator is connected to the polarization controller three (11), and the second port (111) on the right side of the polarization controller three (11) is connected to the polarization controller three (11). Polarization-maintaining fiber three (12) is connected, polarization-maintaining fiber three (12) is connected to high nonlinear fiber (13), and port ten (131) of high nonlinear fiber (13) is connected to the right side of fiber coupler two (14) The ports are connected, and the second port (141) on the left side of the fiber coupler two (14) is used as the output end of the laser, wherein the lengths of the polarization maintaining fiber one (07) and the polarization maintaining fiber two (09) are different. 2. An all-fiber tunable multi-wavelength fiber laser with variable wavelength interval 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 kind of tunable multi-wavelength fiber laser with variable all-fiber wavelength interval according to claim 1, is characterized in that, when using erbium-doped fiber as gain fiber, the length of three (12) polarization-maintaining fibers is less than 0.2 meters , the length of the high nonlinear optical fiber (13) is greater than 200 meters. 4. The tunable multi-wavelength fiber laser with a variable all-fiber wavelength interval according to claim 1, characterized in that, when using ytterbium-doped fiber as the gain fiber, the length of three (12) polarization-maintaining fibers is less than 0.15 meters , the length of the high nonlinear optical fiber (13) is greater than 100 meters. 5. a kind of tunable multi-wavelength fiber laser with variable all-fiber wavelength interval according to claim 1, is characterized in that, when using thulium-doped fiber as gain fiber, the length of three (12) polarization-maintaining fibers is less than 2 meters , the length of the high nonlinear optical fiber (13) is greater than 150 meters. 6. The all-fiber tunable multi-wavelength fiber laser with variable wavelength interval according to claim 1, wherein the splitting ratio of the second fiber coupler (14) can be 50:50, 70:30, 80 :20, 90:10.

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