CN111900601B - A high-power tunable chaotic laser light source device - Google Patents

Abstract

The invention belongs to the technical field of chaotic lasers, and discloses a high-power tunable chaotic laser light source device, comprising a tunable DBR laser, an optical attenuator, a tunable laser, a first optical coupler, a single-mode fiber, a fiber Bragg grating, a Two optical couplers and broadband dielectric film mirrors; the tunable DBR laser is connected to one end of the optical attenuator, the other end of the optical attenuator is connected to the first port of the first optical coupler, and the tunable laser is connected to the first optical attenuator. The second port of the coupler is connected, the common port of the first optical coupler is connected to the single-mode fiber and the fiber Bragg grating in sequence, and then connected to the common port of the second optical coupler, and the first port of the second optical coupler is reflected by the broadband dielectric film mirror connection, and the second port is used for outputting the amplified chaotic laser; the invention can realize the output of 100-watt high-power tunable chaotic laser, with large tunable range, good time domain stability and good beam quality.

Description

A high-power tunable chaotic laser light source device

technical field

The invention belongs to the field of chaotic laser, in particular to a high-power tunable chaotic laser light source device.

Background technique

The chaotic laser has the characteristics of noise-like broad spectrum and high concealment. It is widely used in the fields of secure communication, high-speed random number generation, laser ranging, and optical fiber network fault detection. However, its output power is generally very small, only in the order of milliwatts, which limits its application development to a large extent. At present, erbium-doped fiber amplifier (EDFA) is the most common chaotic laser amplifying device, which can amplify signal light with a bandwidth of 30nm, and the output power is 10mW~20W. However, due to the influence of erbium ion gain saturation, it is difficult to further amplify the chaotic optical signal (patent number CN201720578585.4), and the amplified spontaneous emission of EDFA will affect the signal-to-noise ratio of the output signal light. In addition, in the chaotic secure communication, it is hoped that the center wavelength of the chaotic carrier can be tunable in a wide range. However, the center wavelength of the chaotic laser can only be adjusted in a small range due to the limitation of gain and bandwidth.

The random fiber laser has high output power, high signal-to-noise ratio and simple structure, and can be widely used in optical fiber sensing, earth and environmental science, medical and life science and other fields. Research based on high-power random fiber lasers shows that the output power of random fiber lasers has reached the order of one hundred watts.

Based on this, if random lasers can be applied to the field of chaotic lasers to achieve high-power chaotic laser output in the order of 100 watts, the application range of chaotic lasers can be greatly expanded.

SUMMARY OF THE INVENTION

The invention overcomes the shortcomings of the prior art, and the technical problem to be solved is: providing a high-power tunable chaotic laser light source device.

In order to solve the above technical problems, the technical solution adopted in the present invention is: a high-power tunable chaotic laser light source device, comprising a tunable DBR laser, an optical attenuator, a tunable laser, a first optical coupler, a single-mode optical fiber, an optical fiber Bragg grating, second optical coupler, broadband dielectric film mirror;

The tunable DBR laser is connected to one end of the optical attenuator, the other end of the optical attenuator is connected to the first port of the first optical coupler, the tunable laser is connected to the second port of the first optical coupler, and the first optical coupling The common port of the optical coupler is connected to the single-mode fiber and fiber Bragg grating in sequence, and then connected to the common port of the second optical coupler. The first port of the second optical coupler is connected to the broadband dielectric film mirror, and the second port is used for output amplification. chaotic laser;

The laser light output by the tunable DBR laser enters the single-mode fiber through the optical attenuator and the first optical coupler; the pump light of the order of 100 watts output by the tunable laser enters the single-mode fiber after passing through the first optical coupler, The tunable laser, the first optical coupler, the single-mode fiber, the fiber Bragg grating, and the broadband dielectric film reflector form a random fiber laser; the broadband dielectric film reflector is used to reflect the laser output from the tunable DBR laser back to the tunable DBR laser to generate chaotic laser output; random fiber laser is used to randomly amplify the chaotic laser output by the tunable DBR laser, and is also used to output random laser. perturbation; the fiber Bragg grating is used to reflect the remaining pump light, so that it returns to the single-mode fiber to participate in the chaotic laser amplification process.

The optical attenuator is a unidirectional attenuator for attenuating the light returning to the tunable DBR laser.

The central optical frequency of the tunable laser is 13 THz larger than that of the tunable DBR laser, and the tuning ranges of the tunable laser and the tunable DBR laser are both 40 nm.

The central wavelength of the fiber Bragg grating is the same as the wavelength of the pump light output by the tunable laser.

The reflectivity of one side of the fiber Bragg grating close to the single-mode fiber is 95%.

The length of the single-mode fiber is 15 km.

The second optical coupler is a 1×2 optical coupler, and the splitting ratio between the first port and the second port is 20:80.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention adopts a semi-open cavity tunable random fiber laser structure, injects the chaotic laser output from the tunable DBR laser into the random laser that the tunable laser provides the pump light source, and utilizes the high output power of the random laser. The chaotic laser is effectively amplified to obtain a 100-watt tunable chaotic light source.

2. Compared with EDFA, the present invention is not affected by erbium ion gain saturation, can greatly improve the signal-to-noise ratio, and at the same time can improve the conversion efficiency of pump light.

3. The present invention uses a broadband dielectric film mirror to form a semi-open cavity tunable random fiber laser structure. By setting a broadband dielectric film mirror at the output end of the random laser, the threshold value can not only be significantly reduced, the utilization rate of light can be improved, and at the same time, it can be used as a chaotic generator. The feedback cavity further increases the wavelength tuning range of the chaotic laser, and finally the structural gain bandwidth of the present invention satisfies the tunable range of the chaotic laser of 40 nm.

In summary, the present invention provides a high-power tunable chaotic laser light source device, which can achieve high power in the order of hundreds of watts, has a large tunable range, good time-domain stability, and good beam quality.

Description of drawings

FIG. 1 is a schematic structural diagram of a high-power tunable chaotic laser light source device according to an embodiment of the present invention.

In the figure: 1-tunable DBR laser, 2-optical attenuator, 3-tunable laser, 4-first optical coupler, 5-single-mode fiber, 6-fiber Bragg grating, 7-second optical coupler, 8- Broadband dielectric film mirror.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not All the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work, all belong to the protection scope of the present invention.

As shown in FIG. 1, an embodiment of the present invention provides a high-power tunable chaotic laser light source device, including a tunable DBR laser 1, an optical attenuator 2, a tunable laser 3, a first optical coupler 4, a single-mode fiber 5. Fiber Bragg grating 6, second optical coupler 7, broadband dielectric film mirror 8; the tunable DBR laser 1 is connected to one end of the optical attenuator 2, and the other end of the optical attenuator 2 is connected to the first optical coupler The first port of 4 is connected, the tunable laser 3 is connected to the second port of the first optical coupler 4, and the common port of the first optical coupler 4 is sequentially connected to the single-mode fiber 5, the fiber Bragg grating 6 and the second optical coupler. 7 is connected to the common port, the first port of the second optical coupler 7 is connected to the broadband dielectric film mirror 8, and the second port is used to output the amplified chaotic laser.

In this embodiment, the laser output from the tunable DBR laser 1 enters the single-mode fiber 5 through the optical attenuator 2 and the first optical coupler 4, and the pump light of the order of 100 watts output from the tunable laser 3 passes through the first optical coupler 4. After an optical coupler 4 enters the single-mode fiber 5, the tunable laser 3, the first optical coupler 4, the single-mode fiber 5, the fiber Bragg grating 6, and the broadband dielectric film mirror 8 form a random fiber laser; the broadband dielectric film The mirror 8 is used to reflect the laser output from the tunable DBR laser 1 back to the tunable DBR laser 1, so that it produces a tunable chaotic laser output. In addition, the random laser generated in the random fiber laser also passes through the first optical coupler 4, The optical attenuator 2 returns to the tunable DBR laser 1 to generate chaotic disturbance; the fiber Bragg grating 6 is used to reflect the remaining pump light, so that it returns to the single-mode fiber 5 to participate in the chaotic laser amplification process.

Specifically, in this embodiment, the optical attenuator 2 is a unidirectional attenuator, which is used to attenuate the light returning to the tunable DBR laser 1 .

Specifically, in this embodiment, the central optical frequency of the tunable laser 3 is 13 THz greater than that of the tunable DBR laser 1 , and the tuning ranges of the tunable laser 3 and the tunable DBR laser 1 are both 40 nm.

Specifically, in this embodiment, the center wavelength of the fiber Bragg grating 6 is the same as the wavelength of the pump light output by the tunable laser 3 . The reflectivity of the fiber Bragg grating 6 is 95%. The length of the single-mode fiber 5 is 15 km.

Specifically, in this embodiment, the first optical coupler 4 and the second optical coupler 7 are 1×2 optical couplers, and the splitting ratio between the first port and the second port of the second optical coupler 7 is 20 :80.

Specifically, in this embodiment, the center wavelength of the tunable DBR laser 1 is 1550nm, and the output power is in the order of milliwatts; the center wavelength of the tunable laser 3 is 1450nm, and the output power is in the order of hundreds of watts; The wavelength tuning range of the DBR laser 1 is all 40 nm, and the center wavelength of the fiber Bragg grating (6) is 1450 nm. Finally, the power of the chaotic laser output from the second port of the second optical coupler 7 is one hundred watts, and the center wavelength is 1550 nm. , the wavelength tuning range is from 1526 nm to 1566 nm.

According to the stimulated Raman scattering theory, there is the following relation:

表示介电常数：c表示光速；

表示光波的频率宽度；

表示光的频率；

表示光波的波长宽度。联立计算式（1）~（5），得到：拉曼激光器3中心波长比种子光中心波长小100 nm为最优解。Among them, E ( ω _p , z ), E ( ω _s , z ) represent the intensity of the output light (pump light intensity) of the Raman laser 3 and the intensity between the pump light and the seed light output by the Raman laser 3, respectively The difference (ie the Stokes light intensity); ω _p , ω _s represent the pump light frequency and Stokes light frequency, respectively; n _p , ns _represent the corresponding refractive index and Stokes light of the pump light, respectively z represents the fiber length; χ ( ω _s ) represents the polarizability; λ represents the wavelength; g represents the gain; i represents the imaginary number; the real part of the formula reflects the phase change, and the imaginary part reflects the intensity change.

Represents the dielectric constant: c represents the speed of light;

Represents the frequency width of the light wave;

represents the frequency of light;

Indicates the wavelength width of a light wave. Simultaneously calculate equations (1) to (5), and obtain: the optimal solution is that the central wavelength of Raman laser 3 is 100 nm smaller than the central wavelength of the seed light.

According to the theory of light propagation in optical fibers, there are:

Among them, P ( z ) represents the change of optical power along the fiber _; P0 represents the power of the input fiber; α _p represents the attenuation of the optical power of the input fiber; z represents the length of the fiber ; α represents the attenuation caused by the entire fiber. By combining (4), (6), and (7), combined with the final realization of chaotic light output with high power (100 watts), the length of the single-mode fiber in the random laser can be calculated: the optimal solution for the length of the single-mode fiber 5 is z=15 km.

In the embodiment of the present invention, a tunable laser 3, a 2×1 optical coupler 4, a single-mode fiber 5, a fiber Bragg grating 6, and a broadband dielectric film mirror 8 form a semi-open cavity tunable random fiber laser, as shown in the dotted box in Figure 1 shown. A semi-open cavity tunable random fiber laser participates in the dynamics of chaotic laser generation. Specifically, on the one hand, the light output from the tunable DBR laser 1 reaches the half-open cavity tunable random fiber laser part through the optical attenuator 2, and is reflected back to the tunable DBR laser 1 by the broadband dielectric film mirror 8; The partially random laser generated by the tunable random fiber laser is injected into the tunable DBR laser 1 from the left output. Therefore, the optical mixing of these two processes perturbs the tunable DBR laser 1 to generate a more complex tunable chaotic laser. When the tunable chaotic laser generated by the tunable DBR laser 1 reaches the half-open cavity tunable random fiber laser through the optical attenuator 2, the tunable chaotic laser is amplified by the random fiber laser to the order of 100 watts, and the output of the 100-watt level through the optical coupler 7 Tunable chaotic lasers. In the present invention, the pump optical power output by the tunable laser 3 is in the order of 100 watts. Therefore, after the chaotic laser is amplified by the random laser, the second port of the second optical coupler 7 can output the order of 100 watts. Tunable chaotic laser in the range of 1526 nm ~1566 nm.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (6)

1. A high-power tunable chaotic laser source device is characterized by comprising a tunable DBR laser (1), an optical attenuator (2), a tunable laser (3), a first optical coupler (4), a single-mode optical fiber (5), a fiber Bragg grating (6), a second optical coupler (7) and a broadband dielectric film reflecting mirror (8);

the tunable DBR laser (1) is connected with one end of an optical attenuator (2), the other end of the optical attenuator (2) is connected with a first port of a first optical coupler (4), a tunable laser (3) is connected with a second port of the first optical coupler (4), a common port of the first optical coupler (4) is connected with a common port of a second optical coupler (7) after being sequentially connected with a single-mode optical fiber (5) and a fiber Bragg grating (6), a first port of the second optical coupler (7) is connected with a broadband dielectric film reflecting mirror (8), and the second port is used for outputting amplified chaotic laser;

laser output by the tunable DBR laser (1) enters a single mode fiber (5) through an optical attenuator (2) and a first optical coupler (4); the pump light of hundred watt level output by the tunable laser (3) enters the single-mode fiber (5) through the first optical coupler (4), and the tunable laser (3), the first optical coupler (4), the single-mode fiber (5), the fiber Bragg grating (6) and the broadband dielectric film reflecting mirror (8) form a random fiber laser; the broadband dielectric film reflecting mirror (8) is used for reflecting the laser output by the tunable DBR laser (1) back to the tunable DBR laser (1) to enable the laser to generate chaotic laser output; the random fiber laser is used for randomly amplifying chaotic laser output by the tunable DBR laser (1) and outputting random laser, and the random laser part returns to the tunable DBR laser (1) and then further disturbs the output laser; the fiber Bragg grating (6) is used for reflecting the residual pump light to enable the residual pump light to return to the single-mode fiber (5) to participate in the chaotic laser amplification process, and the central wavelength of the fiber Bragg grating (6) is the same as the wavelength of the pump light output by the tunable laser (3).

2. The high-power tunable chaotic laser source device according to claim 1, wherein the optical attenuator (2) is a one-way attenuator for attenuating the light returning to the tunable DBR laser (1).

3. The high-power tunable chaotic laser source device as claimed in claim 1, wherein the tunable laser (3) has a central optical frequency 13THz higher than that of the tunable DBR laser (1), and the tuning ranges of the tunable laser (3) and the tunable DBR laser (1) are both 40 nm.

4. The high-power tunable chaotic laser light source device according to claim 1, wherein the reflectivity of the fiber bragg grating (6) on the side close to the single-mode fiber (5) is 95%.

5. A high power tunable chaotic laser source device according to claim 1, wherein the length of the single mode fiber (5) is 15 km.

6. The high-power tunable chaotic laser light source device according to claim 1, wherein the second optical coupler (7) is a 1 x 2 optical coupler, and the splitting ratio of the first port to the second port is 20: 80.

Images