CN203661069U - A gain spectrum flattening Raman optical fiber amplifier based on tellurite-based optical fibers - Google Patents

Abstract

The utility model discloses a gain spectrum flattening Raman optical fiber amplifier based on tellurite-based optical fibers. The gain spectrum flattening Raman optical fiber amplifier is connected to optical transmitters and optical receivers. The gain spectrum flattening Raman optical fiber amplifier comprises a first pump laser, a first combiner, an optical isolator, a band elimination filter, a second pump laser, a second combiner and a wave separator. Multiple optical transmitters and multiple optical receivers are arranged. The optical transmitters are connected with the first combiner through first optical fibers. The first pump laser is connected with the first combiner through a first-section second optical fiber. The output end of the first combiner is connected with the optical isolator through a first-section third optical fiber. The optical isolator is connected with the band elimination filter through a fourth optical fiber. The band elimination filter is connected with the second combiner through a fifth optical fiber. The second pump laser is connected with the second combiner through a second-section second optical fiber. The output end of the second combiner is connected with the wave separator through a second-section third optical fiber. The wave separator is connected with the optical receivers through sixth optical fibers. The gain spectrum flattening Raman optical fiber amplifier is simple in structure, can achieve gain flattening, is highly practical and is good in using effect.

Description

Gain Spectrum Flattened Raman Fiber Amplifier Based on Tellurium Fiber

technical field

The utility model relates to the technical field of optical communication, in particular to a Raman optical fiber amplifier with a flat gain spectrum based on a tellurium-based optical fiber. the

Background technique

As we all know, when light is transmitted over a long distance, due to the influence and limitation of factors such as transmit power, receiver sensitivity, fiber line attenuation, and dispersion, the amplitude of the light pulse output from the optical transmitter will be affected by the optical fiber after a certain distance. Attenuation, the waveform will also be distorted. Therefore, in order to carry out long-distance signal transmission, it is necessary to add an amplifier after the optical signal has been transmitted for a certain distance to amplify the attenuated signal and regenerate the optical pulse. the

Before the Erbium Doped Fiber Amplifier EDFA (Erbium Doped Fiber Amplifier) utility model, all optical fiber communication systems can only use the optical-electrical-optical relay mode because they cannot directly amplify optical signals. That is, the optical signal is first converted into an electrical signal, and information processing such as amplification and regeneration is performed in the electrical domain, and then it is converted into an optical signal for transmission in an optical fiber. This relay method has complex devices, high cost, and relatively low transmission quality. The erbium-doped fiber amplifier replaces the traditional optical-electrical-optical relay mode, and realizes the simultaneous amplification of multiple optical signals in one optical fiber, which greatly reduces the cost of optical relay; at the same time, it can achieve good coupling with the transmission optical fiber, which has the advantages of Advantages such as high gain and low noise. Therefore, it is successfully applied to the wavelength division multiplexing optical communication system, which greatly increases the information capacity and transmission distance that can be transmitted in the optical fiber. the

However, in the process of further developing the bandwidth resources in the low-loss area of the entire fiber, the bandwidth of about 30nm near 1550nm of the traditional erbium-doped fiber amplifier is far from enough; while the Raman amplifier based on tellurium-based fiber has a gain bandwidth of 50nm, as long as Selecting the appropriate pump light can amplify signals of any band, and its output gain is high, the gain flatness is good, the response time is fast, the saturated output power is large, the noise index is low, and it is easy to couple. Capacity expansion and upgrading, cost reduction and business increase have very important technical and economic value. the

Utility model content

The purpose of this utility model is to provide a gain-spectrum flat Raman fiber amplifier based on tellurium-based fiber, which has simple structure, reasonable design, convenient implementation and low cost, high output gain, good gain flatness, fast response time, and low saturation The output power is large, the noise index is low, the coupling is easy, the practicability is strong, the use effect is good, and it is convenient to popularize and use. the

In order to achieve the above object, the utility model is implemented according to the following technical solutions:

的取值范围为300cm^-1～ 500cm^-1，的取值范围为420cm^-1～620cm^-1，其中，i为信道数且i的取值为1～N，N为信号光总数且为整数。  A Gain Spectrum Flat Raman Fiber Amplifier Based on Tellurium Fiber, Connected to Optical Transmitter and Optical Receiver, Comprising First Pumping Laser, First Combiner, Optical Isolator, Band Stop Filter, Second Pumping A laser, a second multiplexer and a multiplexer, the optical transmitter and the optical receiver are arranged in multiples, and the output ends of the multiple optical transmitters are correspondingly connected to the input end of the first multiplexer through the first optical fiber, The output end of the first pump laser is connected to the input end of the first multiplexer through the first section of the second optical fiber, and the output end of the first multiplexer is optically isolated by connecting the first section of the third optical fiber The input end of the optical isolator, the output end of the optical isolator is connected to the input end of the band-stop filter through the fourth optical fiber, and the output end of the band-stop filter is connected to the input end of the second multiplexer through the fifth optical fiber, so The output end of the second pump laser is connected to the input end of the second wave combiner through the second section of the second optical fiber, and the output end of the second wave combiner is connected to the wave splitter through the second section of the third optical fiber The input end of the wave splitter is correspondingly connected to the input end of a plurality of optical receivers through a plurality of sixth optical fibers; the center wavelengths of the plurality of optical transmitters are different and a plurality of the optical transmitters The central wavelength λ _i of any one of the lasers is greater than the central wavelength λ _1P of the first pump laser and the central wavelength λ _2P of the second pump laser, and

The value range of is 300cm ^-1 ~ 500cm ^-1 , The value range of is from 420cm ^-1 to 620cm ^-1 , wherein, i is the number of channels and the value of i is 1 to N, and N is the total number of signal lights and is an integer.

As a further preferred solution of the present utility model, the central wavelength λ _i of any one of the plurality of optical transmitters and the central wavelength λ _1P of the first pump laser satisfy the frequency shift calculation formula Δv=(1/λ _1P ) —(1/λ _i ), where Δv is the frequency shift and the value range of Δv is 300cm ⁻¹ to 500cm ⁻¹ .

As a further preferred solution of the present utility model, the central wavelength λ _i of any one of the plurality of optical transmitters and the central wavelength λ _2P of the second pump laser satisfy the frequency shift calculation formula Δv=(1/λ _2P ) —(1/λ _i ), where Δv is the frequency shift and the value range of Δv is 420cm ⁻¹ to 620cm ⁻¹ .

As a further preferred solution of the present invention, the first section of the third optical fiber and the second section of the third optical fiber (6) are all tellurium-based high nonlinear fibers, and the Raman gain spectrum of the tellurium-based high nonlinear fibers is The normalized Raman gain coefficient ranges from 0.82×10 ^-12 m/W to 2.5×10 ^-12 m/W within the frequency shift range of 300cm ^-1 to 620cm ^-1 .

As a further preferred solution of the present invention, the center wavelength of the band-stop filter is the same as the center wavelength of the first pump laser. the

Compared with the prior art, the utility model has the advantages of simple structure, reasonable design, convenient implementation and low cost, high output gain, good gain flatness, fast response time, large saturated output power, low noise index, easy coupling, and strong practicability , the use effect is good, and it is convenient to popularize and use. the

Description of drawings

Fig. 1 is a block diagram of the utility model;

In the figure: 1—the first optical fiber; 2—the second optical fiber in the first section; 3—the third optical fiber in the first section; 4—the fourth optical fiber; 5—the fifth optical fiber; 6—the third optical fiber in the second section; 7— The sixth optical fiber; 8—optical transmitter; 9—the first pump laser; 10—the first multiplexer; 11—optical isolator; 12—band stop filter; 13—the second pump laser; 14—the first Two multiplexers; 15—demultiplexer; 16—optical receiver; 17—the second segment of the second optical fiber;

Fig. 2 is the Raman gain spectrum of the third optical fiber of the utility model;

Fig. 3 is the change law figure of signal light power with the length of optical fiber in the utility model;

Fig. 4 is an output gain diagram of each signal light of the optical fiber Raman amplifier of the present invention. the

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments thereof. The schematic embodiments and descriptions of the utility model are used to explain the utility model, but not as a limitation to the utility model. the

的取值范围为300cm^-1～500cm^-1，

的取值范围为420cm^-1～620cm^-1，其中，i为信道数且i的取值为1～N，N为信号光总数且为整数。  As shown in Figure 1, a kind of gain spectrum flat Raman fiber amplifier based on tellurium-based optical fiber of the present utility model is connected to optical transmitter 8 and optical receiver 16, including the first pumping laser 9, the first multiplexer 10 , an optical isolator 11, a band-stop filter 12, a second pump laser 13, a second multiplexer 14, and a multiplexer 15, the optical transmitter 8 and the optical receiver 16 are set to multiple, and the multiple The output end of the optical transmitter 8 is connected to the input end of the first multiplexer 10 through the first optical fiber 1, and the output end of the first pump laser 9 is connected to the first multiplexer through the first section of the second optical fiber 2. The input end of the first multiplexer 10 is connected, and the output end of the first multiplexer 10 is connected to the first section of the third optical fiber 3 for isolating the reverse transmission through the process of amplifying the signal light through the stimulated Raman scattering An optical isolator 11 of light, the output end of the optical isolator 11 is connected to the band-stop filter 12 for filtering out the continuous laser light produced by the first pump laser through the fourth optical fiber 4, and the band-stop filter 12 The output end of the second pump laser 13 is connected to the second multiplexer 14 for coupling the continuous laser light generated by the second pump laser 13 with the amplified signal light through the fifth optical fiber 5, and the output end of the second pump laser 13 Connect with the input end of the second multiplexer 14 through the second segment of the second optical fiber 17, the output end of the second multiplexer 14 is passed through the power used for the output of the second multiplexer 14 is not equal The second section of the third optical fiber 6 for which the signal is gain-compensated is connected to a wave splitter 15 for outputting a signal with equal power, and the output end of the wave splitter 15 is connected to a plurality of optical receivers 16 through a plurality of sixth optical fibers 7. The central wavelengths of each of the optical transmitters 8 are different, and the central wavelength λ _i of any one of the multiple optical transmitters 8 is greater than the central wavelength λ _1P of the first pump laser 9 and the second pump laser 9. the central wavelength λ _2P of the pump laser 13, and

The value range of is 300cm ^-1 ～500cm ^-1 ,

The value range of is from 420cm ^-1 to 620cm ^-1 , wherein, i is the number of channels and the value of i is 1 to N, and N is the total number of signal lights and is an integer.

In this embodiment, the central wavelength λ _i of any one of the plurality of optical transmitters 8 and the central wavelength λ _1P of the first pump laser 9 satisfy the frequency shift calculation formula Δv=(1/λ _1P )— (1/λ _i ), where Δv is the frequency shift and the value range of Δv is 300cm ⁻¹ to 500cm ⁻¹ .

The central wavelength λ _i of any one of the multiple optical transmitters 8 described in this embodiment and the central wavelength λ _2P of the second continuous pump laser 13 satisfy the frequency shift calculation formula Δv=(1/λ _2P )—(1/λ _i ), where Δv is the frequency shift and the value range of Δv is 420cm ⁻¹ ~620cm ⁻¹ .

The first section of the third optical fiber 3 and the second section of the third optical fiber 6 described in this embodiment are all tellurium-based high nonlinear fibers, and the Raman gain spectrum of the tellurium-based high nonlinear fibers is between 300cm ⁻¹ and 620cm The normalized Raman gain coefficient ranges from 0.82×10 ^-12 m/W to 2.5×10 ^-12 m/W in the frequency shift range of ^-1 .

The center wavelength of the band-stop filter 12 described in this embodiment is the same as the center wavelength of the first pump laser 9 . the

Adopt the utility model to carry out the method for optical signal amplification, comprise the following steps:

Step 1, select the first pump laser 9 whose central wavelength is λ _1P , the first pump laser 9 outputs the first continuous pump light and transmits it to the first multiplexer 10 through the first section of the second optical fiber 2; this implementation In the example, the first pump laser 9 with a central wavelength of λ _1P =1444.5nm and a power of 1W is selected;

Step 2. According to the frequency shift calculation formula Δv=(1/λ _1P )—(1/λ _i ), select a plurality of optical transmitters 8 with different center wavelengths, where λ _i is among the plurality of optical transmitters 8 any one of the center wavelengths, and a plurality of said optical transmitters 8 output a plurality of signal lights with different center wavelengths and transmit them to the first multiplexer 10 through a plurality of first optical fibers; as shown in Figure 2, where Δv is the frequency shift amount and the value range of Δv is 300cm ^-1 ~ 500cm ^-1 , the Raman gain coefficient first increases and then decreases with the frequency shift in the Raman gain spectrum in this value range; in this embodiment, each The wavelength range of the signal light sent by the optical transmitter 8 is 1510nm-1557nm and the interval between each wavelength is 1nm, and the optical power is 0.01mW;

Step 3: Coupling the first continuous pump light transmitted by the first section of the second optical fiber 2 and the multiple signal lights respectively transmitted by the plurality of first optical fibers 1 into the first section of the third optical fiber 1 through the first multiplexer 10 Fiber 3;

Step 4: The first continuous pump light and multiple signal lights input through the first multiplexer 10 are amplified by the stimulated Raman scattering effect in the first segment of the third optical fiber 3 and input to the multiple signal lights To the optical isolator 11, then through the fourth optical fiber 4 transmission input in the band-stop filter 12, the first continuous pumping light is filtered out through the band-stop filter 12;

Step 5. Select the center wavelength of the second pump laser 13 according to the frequency shift calculation formula Δv=(1/λ _2P )—(1/λ _i ), where λ _i is the center of any one of the multiple optical transmitters 8 wavelength, the second pump laser 13 outputs the second continuous pump light and passes it to the second multiplexer 14 through the second segment of the second optical fiber 17, and the wavelength output by the band-stop filter 12 passes through the second multiplexer 14 Input to the second section of the third optical fiber 6; as shown in Figure 2, Δv is the frequency shift and the value range of Δv is 420cm ^-1 ~ 620cm ^-1 , this value range in the Raman gain spectrum Raman gain coefficient varies with The frequency shift increases first decreases and then increases; in this embodiment, the center wavelength of the second pump laser 13 is 1419.9nm;

Step 6: The second continuous pump light and multiple signal lights coupled into the second segment of the third optical fiber 6 via the second multiplexer 14 undergo stimulated Raman scattering in the second segment of the third optical fiber 6 effect to gain compensation for multiple signal lights;

Step 7, a plurality of signal lights are amplified to different degrees with the first continuous pump light generated by the first pump laser 9 through the first section of the third optical fiber, and a plurality of signal lights are generated with the second pump laser 13 The second continuous pumping then passes through the second section of the third optical fiber for gain compensation, so that the optical power of a plurality of said signal lights is amplified by the same value and transmitted to the second multiplexer 14; in this embodiment, the The length of the first section of the third optical fiber 3 is 0.34km, and the length of the second section of the third optical fiber is 0.159km; due to the addition of the center in the second section of the third optical fiber 6 of the same type as the first section of the third optical fiber 3 The wavelength of the second continuous pump light is different from the wavelength of the first continuous pump light. The change of the wavelength of the second pump laser 13 changes the frequency shift range, so that the Raman signal in the second section of the third optical fiber 6 The gain coefficient and the Raman gain coefficient of the pair signal in the first section of the third optical fiber 3 are in a complementary trend, and the Raman gain coefficient of the first continuous pump light pair signal in the first section of the third optical fiber 3 increases with the frequency shift First increase and then decrease, the Raman gain coefficient of the second continuous pump light pair signal in the second section of the third optical fiber 6 first decreases and then increases with the increase of the frequency shift, so that in the first section of the third optical fiber 3 The first part of the frequency shift range is used to perform Raman amplification, and the second part of the frequency shift range is used in the second section of the third optical fiber 6 to compensate for the amplification power, and finally achieve the same effect. The change law of the optical power of multiple signal lights with the length of the third optical fiber is shown in Figure 3, the optical power of the signal light obviously converges to between 5.2×10 ^-4 W and 6.3×10 ^-4 W, and the abscissa indicates the length of the optical fiber, The unit is km; the ordinate indicates the optical power P, and the unit is W;

Step 8: The demultiplexer 15 separates the multiple mixed signal lights with equal optical power, and outputs the multiple signal lights with equal optical power after gain compensation. The final gain obtained by the signal light after gain compensation is shown in Figure 4. The abscissa represents the wavelength λ of the signal light, and the unit is nm; the ordinate represents the gain, and the unit is dB; it can be seen from Fig. The final gain obtained by the signal light tends to be equal. When the gain bandwidth is 48nm, the average gain is 17.72dB, and the gain flatness is 0.68dB. the

The technical solution of the utility model is not limited to the limitations of the above-mentioned specific embodiments, and any technical deformation made according to the technical solution of the utility model falls within the protection scope of the utility model. the

Claims (5)

1. the gain spectrum flattening Raman Fiber Amplifier based on telluro optical fiber, be connected in optical sender (8) and optical receiver (16), it is characterized in that, comprise the first pump laser (9), the first wave multiplexer (10), optical isolator (11), band stop filter (12), the second pump laser (13), the second wave multiplexer (14) and channel-splitting filter (15), described optical sender (8) and optical receiver (16) are set to multiple, the output of multiple optical senders (8) is connected with the input of the first wave multiplexer (10) by the first optical fiber (1) accordingly, the output of described the first pump laser (9) is connected with the input of the first wave multiplexer (10) by first paragraph the second optical fiber (2), the output of described the first wave multiplexer (10) is by connecting the input of optical isolator (11) for first paragraph the 3rd optical fiber (3), the output of described optical isolator (11) connects the input of band stop filter (12) by the 4th optical fiber (4), the output of described band stop filter (12) connects the input of the second wave multiplexer (14) by the 5th optical fiber (5), the output of described the second pump laser (13) is connected with the input of described the second wave multiplexer (14) by second segment the second optical fiber (17), the output of described the second wave multiplexer (14) connects the input of channel-splitting filter (15) by second segment the 3rd optical fiber (6), the corresponding many six fiberses (7) that pass through of output of described channel-splitting filter (15) are connected with the input of multiple optical receivers (16), the central wavelength lambda of any one in the different and multiple described optical senders (8) of the centre wavelength of described multiple optical sender (8) _iall be greater than the central wavelength lambda of described the first pump laser (9) _1Pcentral wavelength lambda with described the second pump laser (13) _2P, and span be 300cm ^-1～500cm ^-1,

span be 420cm ^-1～620cm ^-1, wherein, i is that the value of the number of channel and i is 1～N, N is flashlight sum and is integer.

2. the gain spectrum flattening Raman Fiber Amplifier based on telluro optical fiber according to claim 1, is characterized in that: the central wavelength lambda of any one in described multiple optical senders (8) _icentral wavelength lambda with described the first pump laser (9) _1Pmeet frequency displacement computing formula Δ v=(1/ λ _1P)-(1/ λ _i), wherein, Δ v is that the span of frequency shift amount and Δ v is 300cm ^-1～500cm ^-1.

3. the gain spectrum flattening Raman Fiber Amplifier based on telluro optical fiber according to claim 1, is characterized in that: the central wavelength lambda of any one in described multiple optical senders (8) _icentral wavelength lambda with described the second pump laser (13) _2Pmeet frequency displacement computing formula Δ v=(1/ λ _2P)-(1/ λ _i), wherein, Δ v is that the span of frequency shift amount and Δ v is 420cm ^-1～620cm ^-1.

4. the gain spectrum flattening Raman Fiber Amplifier based on telluro optical fiber according to claim 1, it is characterized in that: described first paragraph the 3rd optical fiber (3) and second segment the 3rd optical fiber (6) are telluro highly nonlinear optical fiber, and the raman gain spectrum of described telluro highly nonlinear optical fiber is at 300cm ^-1～620cm ^-1frequency swing in normalization Raman gain coefficienct scope be 0.82 × 10 ^-12m/W～2.5 × 10 ^-12m/W.

5. the gain spectrum flattening Raman Fiber Amplifier based on telluro optical fiber according to claim 1, is characterized in that: described band stop filter (12) centre wavelength is identical with the first pump laser (9) centre wavelength.

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