CN111834879A - A Multiwavelength Brillouin Fiber Laser - Google Patents

Abstract

The invention discloses a multi-wavelength Brillouin optical fiber laser, which comprises a narrow linewidth adjustable laser (1), a first optical fiber coupler (2), a first optical amplifier (3), a four-port optical circulator (4), a first Brillouin optical fiber (5), a three-port optical circulator (6), a second Brillouin optical fiber (7), a second optical amplifier (8) and a second optical fiber coupler (9), wherein laser output by the narrow linewidth adjustable laser (1) is used as a Brillouin Pump (BP), the BP generates stimulated Brillouin scattering in the first Brillouin optical fiber to generate a first-order Stokes (BS1), the BS1 generates cascade stimulated Brillouin scattering in the second Brillouin optical fiber to generate a second-order Stokes (BS2) and a third-order Stokes (BS3), and by means of power gain effects of the first optical amplifier and the second optical amplifier, thus, a multi-wavelength fiber laser with a wavelength interval of three times the Brillouin frequency shift value can be obtained. The multi-wavelength fiber laser has a simple structure and low cost, and has application potential in optical communication, wavelength division multiplexing systems, microwave photons and fiber sensing networks.

Description

A Multiwavelength Brillouin Fiber Laser

technical field

The invention relates to the fields of optical fiber communication technology, optical fiber laser technology and microwave photonic technology, in particular to a multi-wavelength Brillouin fiber laser with triple Brillouin frequency shift wavelength interval.

Background technique

With the rapid development of Internet technology and various communication technologies, the development trend of all-optical communication networks is bound to move towards ultra-high-speed, ultra-large capacity, and long-distance transmission. Multi-wavelength fiber lasers are an effective way to generate a large number of multi-wavelengths by combining the nonlinear gain in Brillouin gain fibers with the linear gain of erbium-doped fiber amplifiers. Multiwavelength fiber lasers have potential applications in high-capacity dense wavelength-division multiplexing systems, microwave photonics, fiber-optic sensor networks, and optical component testing.

Multi-wavelength Brillouin fiber lasers have the following advantages: stable multi-wavelength output at room temperature, wide tunable range, low threshold power, low noise intensity, etc. Most of the research is still stuck on the multi-wavelength output with single or double Brillouin frequency shift, where the single Brillouin frequency shift interval of standard single mode fiber is about 0.08nm. Such a wavelength interval makes it difficult to adjust the signal, and also causes crosstalk between channels to increase the bit error rate, which is far from meeting the needs of modern technology. Therefore, research on multi-wavelength Brillouin fiber lasers with simple and practical three times or more times has become an urgent need for various technologies.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a multi-wavelength Brillouin fiber laser, through which cascade stimulated Brillouin scattering occurs in two ordinary single-mode quartz fibers with the same Brillouin frequency shift through Brillouin pump light. The power gain of the amplifier can realize the cyclic cascade Brillouin frequency shift, so as to realize the multi-wavelength Brillouin laser output whose wavelength interval is three times the Brillouin frequency shift (about 30GHz). The proposed new multi-wavelength distribution The Liaoyuan laser has a simple optical path structure and low optical path loss, and can be used in multi-wavelength optical communication, optical generation of microwave signals, etc.

The present invention adopts the following technical solutions for solving the above-mentioned technical problems:

A multi-wavelength Brillouin fiber laser, characterized by comprising a narrow linewidth tunable laser (1), a first fiber coupler (2), a first optical amplifier (3), and a four-port optical circulator (4) , a first Brillouin fiber (5), a three-port optical circulator (6), a second Brillouin fiber (7), a second optical amplifier (8), and a second fiber coupler (9).

The described multi-wavelength Brillouin fiber laser is characterized in that the output end of the narrow linewidth tunable laser (1) is connected to the A1 port of the A end of the four-port fiber coupler (2), and the four-port fiber coupler B is The B1 port of the end is connected to the input end of the first optical amplifier (3), the 41 port of the four-port optical circulator (4) is connected to the output end of the first optical amplifier, and the 42 port of the four-port optical circulator (4) is connected to the first optical amplifier. One end of a Brillouin fiber (5) is connected, the 62 ports of the three-port optical circulator (6) are connected to the other end of the first Brillouin fiber (5), and the 61 ports of the three-port optical circulator (6) and The 63 ports are connected, the 43 ports of the four-port optical circulator (4) are connected with one end of the second Brillouin fiber (7), and the other end of the second Brillouin fiber (7) is connected with the second optical amplifier (8). One end is connected, the 44 port of the four-port optical circulator (4) is connected with the D1 port of the D end of the second fiber coupler (9), the C1 port of the C end of the second fiber coupler is connected with the other end of the second optical amplifier, the first The D2 port of the D end of the second fiber coupler is connected to the A2 port of the A end of the first fiber coupler. The B2 port of the B end of the first fiber coupler is the laser output port of the multi-wavelength Brillouin fiber laser. The laser output port can be connected to the spectrum analyzer instrument.

The multi-wavelength Brillouin fiber laser is characterized in that the laser output from the narrow linewidth tunable laser is used as Brillouin pump light (BP), and the BP passes through the B1 port of the first fiber coupler (2). Enter the first optical amplifier (3) for amplification, and the amplified BP is injected into one end of the first Brillouin gain fiber (5) through the 42 ports of the four-port fiber circulator (4), and Brillouin scattering occurs with it, when When the power of the BP exceeds the stimulated Brillouin threshold of the first Brillouin fiber, it will generate a first-order Stokes light (BS1) with a Brillian shift value of the reverse transmission frequency and the three-port optical ring. The optical fiber mirror (6) will reflect the residual forward BP back to the first Brillouin fiber to enhance the power of BS1, and BS1 is injected into the second Brillouin fiber through port 43 of the four-port optical circulator (4). Brillouin scattering occurs at one end of (7), and when the power of BS1 is sufficient, it will excite the second-order Stokes light (BS2) in the second Brillouin fiber with the frequency downshifted by the Brillouin frequency shift value. , BS2 is output from the 44 ports of the four-port fiber circulator (4), enters the second optical amplifier (8) through the second fiber coupler (9) for amplification, and the amplified BS2 is injected into the second Brillouin fiber (7) When the power of BS2 exceeds the stimulated Brillouin threshold of the second Brillouin fiber, it will generate third-order Stokes light whose frequency is down-shifted by the Brillouin frequency shift value. (BS3), after BS3 is amplified by the second optical amplifier, a part of BS3 enters the first optical amplifier through the optical path C1-D2-A2-B1 for amplification, as the subsequent generation of higher-order Stokes light BS6, BS9, BS12, etc. The other part of BS3 is output by the B2 port of the first fiber coupler. Due to the power gain function of the first optical amplifier and the second optical amplifier, on the one hand, the power loss in the optical path is compensated, and on the other hand Amplify the Stokes light so that the stimulated Brillouin scattering process in the first Brillouin fiber and the second Brillouin fiber can be cascaded, so that the B2 port of the first fiber coupler can be analyzed by spectroscopy The instrument can observe multi-wavelength Brillouin lasers with three times the Brillouin frequency shift wavelength interval.

The multi-wavelength Brillouin fiber laser is characterized in that the first Brillouin fiber and the second Brillouin fiber are single-mode silica fibers with the same Brillouin frequency shift value.

The multi-wavelength Brillouin fiber laser is characterized in that the first optical amplifier and the second optical amplifier are both self-made erbium-doped fiber amplifiers, and the second optical amplifier also needs to be designed for bidirectional amplification.

Description of drawings

FIG. 1 is a schematic diagram of a multi-wavelength Brillouin fiber laser device.

The reference numerals in Fig. 1 are explained as: 1- narrow linewidth tunable laser, 2- first fiber coupler, 3- first optical amplifier, 4- four-port optical circulator, 5- first Brillouin fiber , 6-three-port optical circulator, 7-second Brillouin fiber, 8-second optical amplifier, 9-second fiber coupler, A1-first port of the first fiber coupler A end, A2-first The second port of the A-end of the fiber coupler, B1- the first port of the B-end of the first fiber-optic coupler, B2- the second port of the B-end of the first fiber-optic coupler, C1- the first port of the C-end of the second fiber-optic coupler, D1- The first port of the D end of the second fiber coupler, D2- the second port of the D end of the second fiber coupler, 41- the first port of the four-port optical circulator, 42- the second port of the four-port optical circulator, 43- The third port of the four-port optical circulator, 44- the fourth port of the four-port optical circulator, 61- the first port of the three-port optical circulator, 62- the second port of the three-port optical circulator, 63- the third port of the three-port optical circulator The third port of the optical circulator.

Figure 2 is an output spectrum of a multi-wavelength Brillouin fiber laser.

Detailed ways

The technical solutions of the present invention will be further described below with reference to the accompanying drawings.

A multi-wavelength Brillouin fiber laser, characterized by comprising a narrow linewidth tunable laser (1), a first fiber coupler (2), a first optical amplifier (3), and a four-port optical circulator (4) , a first Brillouin fiber (5), a three-port optical circulator (6), a second Brillouin fiber (7), a second optical amplifier (8), and a second fiber coupler (9).

It is characterized in that the output end of the narrow linewidth tunable laser (1) is connected to the A1 port of the A end of the four-port optical fiber coupler (2), and the B1 port of the B end of the four-port optical fiber coupler is connected to the input of the first optical amplifier (3). port 41 of the four-port optical circulator (4) is connected to the output end of the first optical amplifier, port 42 of the four-port optical circulator (4) is connected to one end of the first Brillouin fiber (5), three Port 62 of the port optical circulator (6) is connected to the other end of the first Brillouin fiber (5), ports 61 and 63 of the three-port optical circulator (6) are connected, and the four-port optical circulator (4) Port 43 is connected to one end of the second Brillouin fiber (7), the other end of the second Brillouin fiber (7) is connected to one end of the second optical amplifier (8), and 44 of the four-port optical circulator (4) The port is connected to the D1 port of the D end of the second fiber coupler (9), the C1 port of the C end of the second fiber coupler is connected to the other end of the second optical amplifier, and the D2 port of the D end of the second fiber coupler is coupled to the first fiber The A2 port at the end A of the first fiber coupler is connected to the A2 port at the B end of the first fiber coupler, and the B2 port at the B end of the first fiber coupler is the laser output port of the multi-wavelength Brillouin fiber laser, and the laser output port can be connected to the spectrum analyzer.

The multi-wavelength Brillouin fiber laser is characterized in that the laser output from the narrow linewidth tunable laser is used as Brillouin pump light (BP), and the BP passes through the B1 port of the first fiber coupler (2). Enter the first optical amplifier (3) for amplification, and the amplified BP is injected into one end of the first Brillouin gain fiber (5) through the 42 ports of the four-port fiber circulator (4), and Brillouin scattering occurs with it, when When the power of the BP exceeds the stimulated Brillouin threshold of the first Brillouin fiber, it will generate a first-order Stokes light (BS1) with a Brillian shift value of the reverse transmission frequency and the three-port optical ring. The optical fiber mirror (6) will reflect the residual forward BP back to the first Brillouin fiber to enhance the power of BS1, and BS1 is injected into the second Brillouin fiber through port 43 of the four-port optical circulator (4). Brillouin scattering occurs at one end of (7), and when the power of BS1 is sufficient, it will excite the second-order Stokes light (BS2) in the second Brillouin fiber with the frequency downshifted by the Brillouin frequency shift value. , BS2 is output from the 44 ports of the four-port fiber circulator (4), enters the second optical amplifier (8) through the second fiber coupler (9) for amplification, and the amplified BS2 is injected into the second Brillouin fiber (7) When the power of BS2 exceeds the stimulated Brillouin threshold of the second Brillouin fiber, it will generate third-order Stokes light whose frequency is down-shifted by the Brillouin frequency shift value. (BS3), after BS3 is amplified by the second optical amplifier, a part of BS3 enters the first optical amplifier through the optical path C1-D2-A2-B1 for amplification, as the subsequent generation of higher-order Stokes light BS6, BS9, BS12, etc. The other part of BS3 is output by the B2 port of the first fiber coupler. Due to the power gain function of the first optical amplifier and the second optical amplifier, on the one hand, the power loss in the optical path is compensated, and on the other hand Amplify the Stokes light so that the stimulated Brillouin scattering process in the first Brillouin fiber and the second Brillouin fiber can be cascaded, so that the B2 port of the first fiber coupler can be analyzed by spectroscopy The instrument can observe multi-wavelength Brillouin lasers with three times the Brillouin frequency shift wavelength interval.

The technical characteristics of the narrow linewidth tunable laser: the linewidth is less than 1MHz, the output wavelength and power can be continuously tuned, the wavelength range is C+L band, and the power is 15mW.

The first optical amplifier and the second optical amplifier are self-made erbium-doped fiber amplifiers, and the second optical amplifier is a bidirectional amplification design. Both optical amplifiers have a 980nm pump laser and a 1550nm/980nm wavelength division multiplexer. It is connected with a 6m long erbium-doped fiber, and the maximum output power of the 980nm pump laser is 400mW.

Figure 2 is the output of the multi-wavelength Brillouin fiber laser. The output result is that the output power of the narrow linewidth tunable laser is 2.5mw, the wavelength is 1530.33nm, the output power of the 980nm in the first optical amplifier is 284mw, the second The 980nm output power in the optical amplifier is 380mw, the length of the first Brillouin fiber and the second Brillouin fiber are both 20km, and the Brillouin frequency shift value is both 10.85GHz, four-port optical circulator and three-port optical circulator All are single-mode silica fiber optical circulators, and the first fiber coupler and the second fiber coupler are both measured under the condition of 3dB single-mode silica fiber coupler.

The working process of the present invention is described in detail above. For those of ordinary skill in the art, according to the idea provided by the present invention, there may be changes in the specific implementation manner, such as the type of fiber amplifier, the position of the fiber amplifier, and the three Other schemes with the same effect of the port optical fiber circulator, etc., these changes should also be regarded as the protection scope of the present invention.

Claims (5)

1. A multi-wavelength Brillouin fiber laser, characterized in that it comprises a narrow linewidth tunable laser (1), a first fiber coupler (2), a first optical amplifier (3), a four-port optical circulator ( 4), a first Brillouin fiber (5), a three-port optical circulator (6), a second Brillouin fiber (7), a second optical amplifier (8), and a second fiber coupler (9). 2. described a kind of multi-wavelength Brillouin fiber laser, is characterized in that, the output end of narrow linewidth tunable laser (1) is connected with the A1 port of four-port fiber coupler (2) A end, and four-port fiber coupling The B1 port of the B end of the optical amplifier is connected to the input end of the first optical amplifier (3), the 41 port of the four-port optical circulator (4) is connected to the output end of the first optical amplifier, and the 42 port of the four-port optical circulator (4) is connected to one end of the first Brillouin fiber (5), the port 62 of the three-port optical circulator (6) is connected to the other end of the first Brillouin fiber (5), and the port 61 of the three-port optical circulator (6) The port is connected to port 63, the port 43 of the four-port optical circulator (4) is connected to one end of the second Brillouin fiber (7), and the other end of the second Brillouin fiber (7) is connected to the second optical amplifier (8 ) is connected to one end of the 4-port optical circulator (4), the port 44 of the four-port optical circulator (4) is connected to the D1 port of the D end of the second fiber coupler (9), and the C1 port of the C end of the second fiber coupler is connected to the other end of the second optical amplifier. , the D2 port of the D end of the second fiber coupler is connected to the A2 port of the A end of the first fiber coupler, the B2 port of the B end of the first fiber coupler is the laser output port of the multi-wavelength Brillouin fiber laser, and the laser output port can be connected to spectrum analyzer. 3. described a kind of multi-wavelength Brillouin fiber laser, it is characterized in that, the laser output of the narrow linewidth tunable laser is used as Brillouin pump light (BP), and BP passes through the first fiber coupler (2). The B1 port enters the first optical amplifier (3) for amplification, and the amplified BP is injected into one end of the first Brillouin gain fiber (5) through the 42 port of the four-port fiber circulator (4), and Brillouin scattering occurs therewith , when the power of the BP exceeds the stimulated Brillouin threshold of the first Brillouin fiber, it will generate a first-order Stokes light (BS1) with a Brillian shift value of the reverse transmission frequency of the reverse transmission, three-port The optical circulator (6) acts as a fiber mirror and will reflect the residual forward BP back to the first Brillouin fiber to enhance the power of BS1. BS1 is injected into the second Brillouin fiber through port 43 of the four-port optical circulator (4). One end of the Brillouin fiber (7) and Brillouin scattering occurs with it. When the power of BS1 is sufficient, it will excite the second Brillouin fiber in the second Brillouin fiber to generate the second-order Stokes light whose frequency is down-shifted by the Brillouin frequency shift value ( BS2), BS2 is output by the 44 ports of the four-port fiber circulator (4), enters the second optical amplifier (8) through the second fiber coupler (9) for amplification, and the amplified BS2 is injected into the second Brillouin fiber ( 7) and Brillouin scattering occurs with it. When the power of BS2 exceeds the stimulated Brillouin threshold of the second Brillouin fiber, it will generate a third-order Stoke with a frequency downshift of the Brillouin frequency shift value. Stokes light (BS3), after BS3 is amplified by the second optical amplifier, a part of BS3 enters the first optical amplifier through the optical path C1-D2-A2-B1 for amplification, as the subsequent generation of higher-order Stokes light BS6, BS9, The Brillouin pump light of BS12, etc., and the other part of BS3 is output from the B2 port of the first fiber coupler. Due to the power gain function of the first optical amplifier and the second optical amplifier, on the one hand, the power loss in the optical path is compensated, and the other is On the one hand, the Stokes light is amplified, so that the stimulated Brillouin scattering process in the first Brillouin fiber and the second Brillouin fiber can be cascaded, so that the B2 port of the first fiber coupler is used The spectrum analyzer can observe multi-wavelength Brillouin lasers with three times the Brillouin frequency shift wavelength interval. 4. The multi-wavelength Brillouin fiber laser, characterized in that the first Brillouin fiber and the second Brillouin fiber are single-mode silica fibers with the same Brillouin frequency shift value. 5. The multi-wavelength Brillouin fiber laser, characterized in that the first optical amplifier and the second optical amplifier are both self-made erbium-doped fiber amplifiers, wherein the second optical amplifier can amplify bidirectionally.

Images