Ultrafast fiber laser device capable of simultaneously outputting traditional solitons and dissipative solitons

Abstract

The utility model discloses an ultrafast fiber laser device capable of simultaneously outputting traditional solitons and dissipative solitons, and relates to the technical field of ultrafast laser. According to the utility model, through the innovative design of the laser, the dispersion regulation and control element pulse shaper is introduced into the cavity of the laser, and different dispersion curves are added at different wavelengths to accurately control the dispersion at different wavelengths, so that the simultaneous output of traditional solitons and dissipative solitons is realized; therefore, the stability, the efficiency and the multifunctionality of the laser system are obviously improved; the limitation of an existing ultrafast optical fiber laser on soliton output types is broken through, and the optical fiber laser capable of outputting multiple soliton types at the same time, especially traditional solitons and dissipative solitons at the same time, is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to superfast laser technology field, concretely relates to superfast fiber laser device that can output traditional soliton and dissipative soliton simultaneously. BACKGROUND

[0002] With the rapid development of laser technology, as an important light source, superfast fiber laser has been widely used in scientific research, industrial processing, medical treatment and many other fields. Superfast fiber laser can generate extremely short pulses (such as femtosecond pulses), and its advantages are concentrated pulse energy, high beam quality, flexible adjustment and other characteristics, especially in precision machining, spectroscopy and laser radar and other high-precision applications.

[0003] At present, the main way to obtain ultra-short pulses in fiber lasers depends on passive mode-locking technology. Because the stable transmission of ultra-short pulses in optical fibers requires the balance of self-phase / cross-phase modulation and fiber dispersion, the mode-locked pulses output by superfast fiber lasers can be generally referred to as optical solitons. Superfast fiber lasers have experienced decades of development, and behind almost every technological breakthrough, there is a shadow of soliton. In fact, soliton mode-locking is one of the important working states of superfast fiber lasers, and manipulating the dynamic characteristics of solitons with dispersion and nonlinear effects not only helps to improve the performance parameters of fiber soliton lasers, but also further promotes the application of superfast fiber lasers. For example, by adjusting the dispersion of the fiber resonant cavity, the mode-locked fiber laser can work in the traditional soliton and dissipative soliton mode. Correspondingly, the soliton pulse energy is also increased from the picojoule level of the traditional soliton to the nanojoule level of the dissipative soliton.

[0004] In the design and application of soliton lasers, although certain achievements have been made, there are still significant shortcomings in the simultaneous output of multiple soliton types, especially the dual output of traditional solitons and dissipative solitons. In superfast fiber lasers, the output of traditional solitons or dissipative solitons usually depends on the setting of the total dispersion in the cavity. In fact, once the total dispersion in the cavity is determined, the type of soliton output is also fixed, so traditional fiber lasers can only output a specific type of soliton, and cannot achieve parallel output of multiple solitons. This limitation makes the laser lack sufficient flexibility when facing diversified experimental demands, and it is difficult to meet the requirements in different application scenarios. Therefore, we propose a superfast fiber laser device that can output traditional solitons and dissipative solitons simultaneously. UTILITY MODEL CONTENTS

[0005] The utility model relates to superfast fiber laser device that can output traditional solitons and dissipative solitons simultaneously.

[0006] The utility model discloses in order to realize above-mentioned purpose specifically adopts following technical scheme:

[0007] The superfast optical fiber laser device capable of simultaneously outputting traditional solitons and dissipative solitons comprises:

[0008] A pump source is arranged for realizing import of pump light energy.

[0009] A wavelength division multiplexer is connected with the pump source.

[0010] A doped fiber gain optical fiber is arranged for providing gain amplification mechanism and converting pump light energy into laser energy.

[0011] A polarization controller is connected with the doped fiber gain optical fiber, and the polarization controller is used for regulating and controlling polarization state of in-cavity light.

[0012] An isolator is connected with the polarization controller, and the isolator is used for realizing unidirectional light transmission and unable to transmit light in reverse direction.

[0013] A pulse shaper is connected with the isolator, and the pulse shaper is used for adjusting phase of arbitrary frequency.

[0014] A coupler is connected with the input end of the pulse shaper.

[0015] A saturable absorber is connected with the output end of the coupler.

[0016] Further, the pump source selects 980nm pump light source.

[0017] Further, the wavelength division multiplexer selects 980 / 1550nm wavelength division multiplexer.

[0018] Further, the doped fiber gain optical fiber selects five-meter doped fiber.

[0019] Further, the isolator selects light coupler with splitting ratio 20:80.

[0020] Further, the pulse shaper selects pulse shaper with regulation range 1500nm-1600nm.

[0021] Further, the saturable absorber selects center wavelength 1550nm transmission saturable absorber.

[0022] The utility model discloses the beneficial effects are as follows:

[0023] 1. The utility model discloses a laser design through innovation, introduces dispersion control element pulse shaper in the laser cavity, adds different dispersion curves at different wavelengths, accurately controls the dispersion size at different wavelengths, and then realizes the simultaneous output of traditional soliton and dissipative soliton, thereby the stability, efficiency and multifunctionality of laser system are improved significantly.

[0024] 2. The utility model discloses the limitation of existing superfast fiber laser on soliton output type is broken through, realizes the fiber laser that can output multiple soliton types simultaneously, especially traditional soliton and dissipative soliton are output simultaneously. DRAWINGS

[0025] Figure 1 It is the schematic diagram of the utility model.

[0026] Signs: 1, pump source;2, wavelength division multiplexer;3, doped gain optical fiber;4, polarization controller;5, isolator;6, pulse shaper;7, coupler;8, saturable absorber. SPECIFIC IMPLEMENTATION

[0027] In order to make the purpose, technical scheme and advantage of the utility model embodiment more clear, below, the technical scheme in the utility model embodiment will be clearly and completely described with the drawings in the utility model embodiment.

[0028] Please refer to Figure 1 The utility model provides superfast fiber laser device that can output traditional soliton and dissipative soliton simultaneously, comprising:

[0029] Pump source 1, and pump source 1 realizes the introduction of pump light energy.

[0030] Wavelength division multiplexer 2, wavelength division multiplexer 2 is connected with pump source 1;Pump source 1 is acted on doped gain optical fiber 3 through wavelength division multiplexer 2, realizes the introduction of pump light energy.

[0031] Doped gain optical fiber 3, doped gain optical fiber 3 is used to provide gain amplification mechanism, converts pump light energy into laser energy.

[0032] Polarization controller 4, polarization controller 4 is connected with doped gain optical fiber 3, and polarization controller 4 is used to regulate the polarization state of cavity light.

[0033] Isolator 5, isolator 5 is connected with polarization controller 4, and isolator 5 is used to realize the unidirectional transmission of light, and the reverse cannot pass light.

[0034] Pulse shaper 6, pulse shaper 6 is connected with isolator 5, and pulse shaper 6 is used to adjust the phase of arbitrary frequency.

[0035] Coupler 7, the input end of coupler 7 is connected with pulse shaper 6.

[0036] Saturable absorber 8, saturable absorber 8 is connected with 80% output end of coupler 7.

[0037] Pump source 1 acts on doped gain optical fiber 3 through wavelength division multiplexer 2, realizes the introduction of pump light energy, doped gain optical fiber 3 provides gain amplification mechanism, converts pump light energy into laser energy, then doped gain optical fiber 3 is connected with polarization controller 4, polarization controller 4 can regulate the polarization state of the cavity light, then polarization controller 4 is connected with isolator 5, isolator 5 can ensure the unidirectional transmission characteristics of light, and the reverse cannot pass light, isolator 5 is connected with pulse shaper 6, pulse shaper 6 can adjust the phase of any frequency, which is equivalent to regulating the cavity dispersion, then pulse shaper 6 is connected with coupler 7 input end 7a, 20% output end 7c of coupler 7 is connected with output, 80% output end 7b is connected with saturable absorber 8, and the other parts of the cavity are connected with ordinary single-mode optical fiber.

[0038] In the embodiment, preferably, the pump source 1 selects a 980nm pump light source. The 980nm pump light source usually adopts a refrigeration package, has a built-in high-performance laser, and can ensure that the laser still provides stable output when the temperature, driving current and optical feedback change; can provide an output power of up to 600mW or more, meeting various high-power application requirements; has a low noise coefficient, which is conducive to obtaining a purer output light signal; has an excellent side mode suppression ratio, which can reduce the non-desired mode in the output light and improve the quality of the output light; is usually designed in a module form, which is convenient for integration into various fiber lasers and amplifier systems; through multiple back light damage protection measures such as back light isolation, back light filtering and back light warning, the 980nm pump light source can work reliably for a long time; the output optical power and wavelength stability are precisely controlled.

[0039] In the embodiment, preferably, the wavelength division multiplexer 2 selects a 980 / 1550nm wavelength division multiplexer. It can cover a wavelength range from 1520nm to 1600nm, adapt to different application requirements; the signal loss is small during transmission, which helps to maintain the signal quality; the passband characteristic is flat, which means that the signal attenuation in the passband is small; the isolation between different wavelengths is high, which reduces the interference between signals; the performance is stable in long-time operation, which is suitable for various environmental conditions; by transmitting multiple wavelength signals in the same optical fiber, the demand for optical fibers is reduced; it is transparent to signals of different rates and modulation modes, and can transmit various service signals; when the system is upgraded, the optical fiber line does not need to be modified, and it is easy to expand; the bandwidth of the optical fiber is effectively utilized, and the capacity of the communication system is improved; by increasing the number of wavelengths, the transmission capacity of the system can be greatly improved.

[0040] In this embodiment, preferably, the doped fiber gain fiber 3 is selected as a five-meter erbium-doped fiber. The Er3+ ions in the erbium-doped fiber can produce high energy transition under the action of pump laser, thereby realizing high optical amplification gain. The EDFA adopts distributed amplification, which can effectively reduce noise and has a lower noise coefficient than semiconductor amplifiers. The erbium-doped fiber has a wide emission spectrum and can realize wideband amplification, and the amplified spontaneous emission (ASE) spectrum bandwidth can reach 20-40nm. The EDFA is not sensitive to the polarization state of the input optical signal and has a wide range of applications. Compared with other traditional active devices, the EDFA has the advantages of high reliability, high beam quality, low loss, light weight, small size and anti-electromagnetic interference. Without photoelectric conversion, the optical signal can be directly amplified. The EDFA has low insertion loss, which is beneficial to maintaining signal quality. The operating wavelength range of the EDFA is usually between 1530nm and 1565nm, which is consistent with the low-loss window of the optical fiber, which is beneficial to long-distance communication

[0041] In this embodiment, preferably, the isolator 5 is selected as an optical coupler with a splitting ratio of 20:80.

[0042] In this embodiment, preferably, the pulse shaper 6 is selected as a pulse shaper with a control range of 1500nm-1600nm.

[0043] In this embodiment, preferably, the saturable absorber 8 is selected as a saturable absorber with a center wavelength of 1550nm. The 1550nm wavelength has a small attenuation of about 0.25dB / KM when transmitted in an optical fiber, which means that the signal can maintain high quality during long-distance transmission. The 1550nm wavelength is suitable for long-distance and large-bandwidth optical paths, and there are mature commercial optical amplifiers (such as EDFA) to compensate for the loss in line transmission, ensuring stable signal transmission. The use of a saturable absorber as a 1550nm femtosecond laser ensures the reliability and stability of the laser. Some 1550nm femtosecond lasers, such as the Mendocino series, have a simple and convenient operation panel and can be operated with one key. The output power can be easily adjusted. Some 1550nm femtosecond lasers, such as the Mendocino series, provide high cost performance and have low time jitter (60fs, no active stabilization)

[0044] The working principle and use process of the utility model: when the device is used, the dispersion values of the ordinary single-mode and the doped fiber gain fiber 3 are both negative dispersion, so that the output is a conventional soliton under the guidance of negative dispersion without introducing the pulse shaper 6.

[0045] The spatial light modulator in the pulse shaper 6 is placed in the Fourier plane, which modulates the phase of the incident light field, the incident light first passes through the grating diffraction, resulting in each frequency component forming a diffraction spot in the Fourier plane, the spatial light modulator precisely modulates the phase of the dispersed frequency, and then passes through the grating again, so that the modulated frequency components are re-converged, without the phase modulation of the spatial light modulator, the outgoing light is consistent with the incident light, then, by using a programmable liquid crystal spatial light modulator, the voltage on each pixel is adjusted to create a phase mask, realizing the flexible adjustment of the intra-cavity dispersion.

[0046] A very small positive dispersion is compensated by the pulse shaper 6 at the wavelength of 1530nm, which is not enough to offset the original negative dispersion in the cavity, therefore, the conventional soliton is generated at the wavelength of 1530nm, and a large positive dispersion is compensated by the pulse shaper 6 at the wavelength of 1570nm, so that the total dispersion is positive, therefore, the dissipative soliton is generated at the wavelength of 1570nm.

[0047] Under the mode-locked mechanism of the saturable absorber 8, the conventional soliton at 1530nm and the dissipative soliton at 1570nm can be generated simultaneously.

[0048] The above description of disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An ultrafast fiber laser device capable of simultaneously outputting a conventional soliton and a dissipative soliton, characterized in that, It comprises: a pump source (1) for introducing pump light energy; a wavelength division multiplexer (2) connected to the pump source (1); a doped gain fiber (3) for providing gain amplification mechanism to convert pump light energy into laser energy; a polarization controller (4) connected to the doped gain fiber (3) for regulating the polarization state of the intracavity light; an isolator (5) connected to the polarization controller (4) for realizing one-way light transmission and preventing light transmission in the reverse direction; a pulse shaper (6) connected to the isolator (5) for adjusting the phase of any frequency; a coupler (7) with its input end connected to the pulse shaper (6); a saturable absorber (8) connected to 80% of the output end of the coupler (7).

2. The ultrafast fiber laser device capable of simultaneously outputting a conventional soliton and a dissipative soliton according to claim 1, characterized in that: The pump source (1) is selected as a 980nm pump light source.

3. The ultrafast fiber laser device capable of simultaneously outputting a conventional soliton and a dissipative soliton of claim 1, wherein: The wavelength division multiplexer (2) is selected as a 980 / 1550nm wavelength division multiplexer.

4. The ultrafast fiber laser device capable of simultaneously outputting a conventional soliton and a dissipative soliton of claim 1, wherein: The doped gain fiber (3) is selected as a five-meter erbium-doped fiber.

5. The ultrafast fiber laser device capable of simultaneous output of a conventional soliton and a dissipative soliton according to claim 1, characterized in that: The isolator (5) is selected as an optical coupler with a splitting ratio of 20:

80.

6. The ultrafast fiber laser device capable of simultaneous output of a conventional soliton and a dissipative soliton according to claim 1, characterized in that: The pulse shaper (6) is selected as a pulse shaper with a regulation range of 1500nm-1600nm.

7. The ultrafast fiber laser device capable of simultaneous output of a conventional soliton and a dissipative soliton according to claim 1, characterized in that: The saturable absorber (8) is selected as a saturable absorber with a center wavelength of 1550nm.

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