A self-starting nine-cavity laser and device based on motor perturbation

Abstract

The present invention discloses a self-starting nine-cavity laser and device based on motor perturbation, relating to the technical field of lasers; the laser includes a non-linear amplification loop, a linear arm, a polarization-maintaining fiber coupler, and a motor perturbation module. The polarization-maintaining fiber coupler is respectively connected to the linear arm and the non-linear amplification loop. By applying high-frequency mechanical vibration to the polarization-maintaining passive fiber in the non-linear amplification loop through the motor perturbation module, a high-intensity initial noise signal is promoted to form in the cavity, promoting mode competition in the cavity and accelerating the entry of the noise into the positive feedback region of the resonant cavity. Self-starting of mode locking is realized under low pump power conditions, reducing waste of pump power and lowering the cost of the device.

Description

Technical Field

[0001] The present invention belongs to the technical field of lasers, and particularly relates to a self-starting nine-cavity laser and device based on motor perturbation. Background Art

[0002] Mode-locking technology is a key technology for ultrafast lasers to generate ultrashort pulses. Its basic principle is to introduce specific phase relationships or nonlinear effects in the laser cavity, so that randomly fluctuating optical signals oscillate back and forth in the cavity multiple times to form a stable ultrashort pulse sequence.

[0003] As a new mode-locking technology, the nine-cavity laser has gradually attracted attention in the fields of ultrafast laser processing, spectral detection, bio-optics, etc. due to its advantages of long life and high stability. To achieve fast self-starting in the existing nine-cavity laser mode-locking, generally a high pump current is required, and after startup, it is in a multi-pulse state. The fundamental frequency single-pulse state is obtained by gradually reducing the pump current, and this transition process from multi-pulses to single-pulse may fail under unreasonable designs; there will be a certain probability distribution for the startup time of the nine-cavity, and the startup time of individual cases may be relatively long; this leads to problems such as pump waste, probability distribution of startup time, cumbersome optimization adjustment, limited optical path parameter space and pulse parameter space in the existing nine-cavity mode-locking lasers. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems of pump waste, probability distribution of startup time, cumbersome optimization adjustment, limited optical path parameter space and pulse parameter space in the existing nine-cavity mode-locking lasers, and to propose a self-starting nine-cavity laser and device based on motor perturbation.

[0005] In the first aspect of the implementation of the present invention, first, a self-starting nine-cavity laser based on motor perturbation is proposed, which includes a nonlinear amplification loop, a linear arm, a polarization-maintaining fiber coupler, and a control module. The nonlinear amplification loop includes a motor perturbation module, a fiber fixing patch, and a polarization-maintaining passive fiber, where:

[0006] Two fiber fixing patches are used to fix both ends of the polarization-maintaining passive fiber respectively, and the fiber of the polarization-maintaining passive fiber between the fiber fixing patches is used as the perturbation fiber. A motor perturbation module is arranged on one side of the perturbation fiber in the horizontal direction.

[0007] The motor perturbation module is connected to the control module; the control module is used to receive the optical signal of the 2x2 polarization-maintaining fiber coupler and judge whether the optical signal is successfully mode-locked. If not mode-locked, a startup instruction is sent to the motor perturbation module; the startup instruction is used to control the motor perturbation module to beat the perturbation fiber, so that the perturbation fiber vibrates at high frequency mechanically.

[0008] Preferably, the output module includes an output jumper head, a polarization-maintaining fiber isolator, and a polarization-maintaining fiber grating;

[0009] One end of the output jumper head is sequentially connected to a polarization-maintaining fiber isolator and a polarization-maintaining fiber grating.

[0010] Preferably, the control module includes: a polarization-maintaining isolator, a photodetector, and a main control board and a drive module;

[0011] The control module is composed of a polarization-maintaining isolator, a photodetector, and a main control board and a drive module. The control module is respectively connected to a 2x2 polarization-maintaining fiber coupler, a motor perturbation module, and a polarization-maintaining wavelength division multiplexer;

[0012] The photodetector is used to convert the optical signal in the nine-word cavity laser into an electrical signal and send the electrical signal to the main control board and the drive module;

[0013] The main control board and the drive module are used to obtain the electrical signal and judge whether mode locking is successful. If mode locking fails, a start instruction is sent to the motor perturbation module;

[0014] The main control board and the drive module are also used to load a preset program and inject pump light into the polarization-maintaining wavelength division multiplexer, so that the polarization-maintaining wavelength division multiplexer couples the pump light into the polarization-maintaining active fiber.

[0015] Preferably, the nonlinear amplification loop further includes: a motor perturbation module, a fiber fixing patch, a polarization-maintaining passive fiber, a polarization-maintaining active fiber, a polarization-maintaining wavelength division multiplexer, and a phase shifter;

[0016] One end of the 2x2 polarization-maintaining fiber coupler away from the output module is respectively provided with a polarization-maintaining wavelength division multiplexer and a phase shifter. A polarization-maintaining active fiber is connected between the 2x2 polarization-maintaining fiber coupler and the polarization-maintaining wavelength division multiplexer. A polarization-maintaining passive fiber is connected between the 2x2 polarization-maintaining fiber coupler and the phase shifter. A fiber is connected between the polarization-maintaining wavelength division multiplexer and the phase shifter.

[0017] Preferably, the control module is respectively connected to the 2x2 polarization-maintaining fiber coupler and the polarization-maintaining wavelength division multiplexer.

[0018] Preferably, the motor perturbation module consists of a flapping handle and a motor. The output end of the motor is connected to the flapping handle. The motor perturbation module is used to receive the start instruction and load a preset motor voltage and motor working time according to the start instruction.

[0019] Preferably, the nine-word cavity laser further includes a pump source, and the pump source includes a 14-pin butterfly laser with a wavelength of 980 nm.

[0020] Preferably, the splitting ratio of the 2x2 polarization-maintaining fiber coupler is 40 / 60.

[0021] Advantages of the present invention:

[0022] 1) When the motor of the present invention is powered on and rotates, it drives the beating handle to continuously beat the polarization-maintaining passive optical fiber. Since the optical fiber is elastic and fixed by the optical fiber fixing sticker, the polarization-maintaining passive optical fiber is in a state of high-frequency tremor under the beating of the beating handle, and can introduce a noise signal with sufficient intensity when the laser is powered on, thereby accelerating mode locking.

[0023] 2) The present invention introduces a noise signal with a certain intensity through the beating of the beating handle, realizes self-starting of mode locking under a low pump current, reduces waste of pump power, and reduces device cost. Brief Description of the Drawings

[0024] The present invention will be further described below with reference to the drawings.

[0025] Figure 1 It is a schematic structural diagram of a self-starting nine-word cavity laser based on motor perturbation provided by an embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of a motor perturbation module of another self-starting nine-word cavity laser based on motor perturbation provided by an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of a beating handle of a self-starting nine-word cavity laser based on motor perturbation provided by an embodiment of the present invention;

[0028] Figure 4 It is a starting comparison diagram of a self-starting nine-word cavity laser based on motor perturbation provided by an embodiment of the present invention.

[0029] In the figure: 100, non-linear amplification loop; 101, linear arm; 102, motor perturbation module; 103, control module; 104, optical fiber fixing sticker; 105, polarization-maintaining passive optical fiber; 106, 2x2 polarization-maintaining optical fiber coupler; 107, polarization-maintaining active optical fiber; 108, polarization-maintaining wavelength division multiplexer; 109, optical fiber; 1010, phase shifter; 1011, output jump wire head; 1012, polarization-maintaining optical fiber isolator; 1013, polarization-maintaining fiber grating; 1021, beating handle; 1022, motor; 1031, polarization-maintaining isolator; 1032, photodetector; 1033, main control board and drive module. Detailed Embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0031] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0032] The embodiments of the present invention provide a self-starting nine-word cavity laser based on motor perturbation. Refer to Figures 1-3 , Figure 1 which is a schematic structural diagram of a self-starting nine-word cavity laser based on motor perturbation provided by the embodiments of the present invention. The nine-word cavity laser includes a nonlinear amplification loop 100, a linear arm 101, a polarization-maintaining fiber coupler 106, and a control module 103. The nonlinear amplification loop 100 includes a motor perturbation module 102, a fiber fixing sticker 104, and a polarization-maintaining passive fiber 105, where:

[0033] The two fiber fixing stickers 104 are used to fix the two ends of the polarization-maintaining passive fiber 105 respectively, and the fiber of the polarization-maintaining passive fiber 105 between the fiber fixing stickers 104 is used as the perturbation fiber. A motor perturbation module 102 is arranged on one side of the perturbation fiber in the horizontal direction;

[0034] The motor perturbation module 102 is connected to the control module 103; the control module 103 is used to receive the optical signal of the 2x2 polarization-maintaining fiber coupler 106 and judge whether the optical signal is successfully mode-locked. If not mode-locked, a start instruction is sent to the motor perturbation module; the start instruction is used to control the motor perturbation module 102 to beat the perturbation fiber to make the perturbation fiber vibrate at a high frequency.

[0035] In one implementation, the main control board and the drive module 1033 power on to drive the pump source and the motor perturbation module 102. The motor perturbation module 102 loads a preset motor voltage and motor operating time. The pump source injects pump light into the polarization-maintaining wavelength division multiplexer 108. The polarization-maintaining wavelength division multiplexer 108 receives the pump light and propagates it in the direction of the polarization-maintaining active fiber 107. The pump light propagates to the polarization-maintaining active fiber 107 and absorbs and emits continuous signal light through the polarization-maintaining active fiber 107. The signal light transmits clockwise and counterclockwise in the loop. Under the action of the asymmetry at the phase shifter 1010 and the polarization-maintaining active fiber 107, a nonlinear phase shift is generated. When the two optical signals reach the 2x2 polarization-maintaining fiber coupler 106, they interfere and propagate to the polarization-maintaining fiber grating 1013. The polarization-maintaining fiber grating 1013 reflects a part of the optical signal and propagates it back to the 2x2 polarization-maintaining fiber coupler 106. After passing through the 2x2 polarization-maintaining fiber coupler 106, it is divided into two optical signals again, and they respectively transmit clockwise and counterclockwise in the 2x2 polarization-maintaining fiber coupler 106 - polarization-maintaining wavelength division multiplexer 108 - phase shifter 1010 - 2x2 polarization-maintaining fiber coupler 106 and reach the 2x2 polarization-maintaining fiber coupler 106, where they are divided into two optical signals. One optical signal passes through the polarization-maintaining fiber grating 1013 - polarization-maintaining fiber isolator 1012 - output jump head 1011 and is output. The other optical signal passes through the polarization-maintaining isolator 1031 - photodetector 1032 - main control board and drive module 1033 for mode locking judgment. The photodetector 1032 converts the optical signal into an electrical signal. The main control board and drive module 1033 judge whether mode locking is successful according to the electrical signal. If it fails, the motor perturbation module 102 reloads the preset motor voltage and motor operating time, and the motor 1022 in the motor perturbation module drives the flapping handle 1021 to continuously flap the polarization-maintaining passive fiber 105 until mode locking is successful.

[0036] In one implementation, the 2x2 polarization-maintaining fiber coupler 106 and the polarization-maintaining wavelength division multiplexer 108 are connected through the polarization-maintaining active fiber 107. The 2x2 polarization-maintaining fiber coupler 106 and the phase shifter 1010 are connected through the polarization-maintaining passive fiber 105. The polarization-maintaining passive fiber 105 is fixed to the laser housing by two fiber fixing stickers 104. The polarization-maintaining passive fiber 105 between the two fiber fixing stickers 104 is 20 mm higher than the laser housing. The motor 1022 drives the flapping handle 1021 to continuously rotate and flap the polarization-maintaining passive fiber 105. The length of the flapping handle 1021 is 20 mm. The rotational speed of the motor 1022: DC = 3V, 15200 RPM; DC = 6V, 28000 RPM. That is, when the DC voltage is 3V, the rotational speed of the motor is 15200 RPM. When the DC voltage is 6V, the rotational speed of the motor is 28000 RPM.

[0037] In one implementation, the linear arm 101 is connected to the 2x2 polarization-maintaining fiber coupler 106, and the control module 103 is connected to the 2x2 polarization-maintaining fiber coupler 106 and the polarization-maintaining wavelength division multiplexer 108 through optical paths respectively, and the control module 103 is connected to the motor 1022 in the motor perturbation module 102 through an electric circuit.

[0038] In one implementation, the 2x2 polarization-maintaining fiber coupler 106 and the polarization-maintaining wavelength division multiplexer 108 are connected by a polarization-maintaining active fiber 107, the polarization-maintaining wavelength division multiplexer 108 and the phase shifter 1010 are connected by an optical fiber 109, the 2x2 polarization-maintaining fiber coupler 106 and the phase shifter 1010 are connected by a polarization-maintaining passive fiber 105, the polarization-maintaining passive fiber 105 is fixed by two fiber fixing stickers 104, and the motor perturbation module 102 is arranged on one side in the horizontal direction of the polarization-maintaining passive fiber 105 located between the two fiber fixing stickers 104.

[0039] In one implementation, for example: if there is no motor perturbation module 102 to perturb the optical fiber, a high pump current must be applied to achieve self-starting. At this time, the internal optical signal is in a multi-pulse state, and the pump current needs to be gradually reduced to obtain the fundamental frequency single-pulse state. The motor perturbation module 102 can introduce additional noise intensity to the laser at a low pump current, thereby accelerating the evolution of the fundamental frequency single pulse and achieving fast self-starting.

[0040] In one implementation, Figure 4 is a startup comparison diagram of a 9-word cavity laser with self-starting based on motor perturbation provided by an embodiment of the present invention; the finally achieved startup effect is as Figure 4 shown, avoiding the characteristic that a high pump current needs to be applied for the fast self-starting of the traditional 9-word cavity, realizing mode-locked self-starting at a low pump current, reducing the waste of pump power, lowering the device cost, and simplifying the optimization process of the 9-word cavity.

[0041] The above has described an embodiment of the present invention in detail, but the content is only a preferred embodiment of the present invention and cannot be considered as limiting the implementation scope of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A self-starting 9-shaped cavity laser based on motor disturbance, characterized in that: It comprises a nonlinear amplification loop (100), a linear arm (101), a 2x2 polarization-maintaining fiber coupler (106), and a control module (103); the nonlinear amplification loop (100) comprises a motor disturbance module (102), an optical fiber fixing patch (104), and a polarization-maintaining passive optical fiber (105), wherein: Two optical fiber fixing stickers (104) are used to fix two ends of a polarization-maintaining passive optical fiber (105) respectively, and the polarization-maintaining passive optical fiber (105) is used as a disturbance optical fiber, and a motor disturbance module (102) is provided on one side of the disturbance optical fiber in the horizontal direction; The motor disturbance module (102) is connected to a control module (103); the control module (103) is used to receive an optical signal from a 2x2 polarization-maintaining optical fiber coupler (106) and determine whether the optical signal is successfully mode-locked, and if not, to send a start instruction to the motor disturbance module; the start instruction is used to control the motor disturbance module (102) to strike the disturbance optical fiber, so as to cause the disturbance optical fiber to vibrate mechanically at a high frequency; The nonlinear amplification loop (100) further comprises: a polarization-maintaining active optical fiber (107), a polarization-maintaining wavelength division multiplexer (108), an optical fiber (109) and a phase shifter (1010); A polarization-maintaining wavelength division multiplexer (108) and a phase shifter (1010) are respectively arranged at one end of the 2x2 polarization-maintaining optical fiber coupler (106) away from the linear arm (101); a polarization-maintaining active optical fiber (107) is connected between the 2x2 polarization-maintaining optical fiber coupler (106) and the polarization-maintaining wavelength division multiplexer (108); a polarization-maintaining passive optical fiber (105) is connected between the 2x2 polarization-maintaining optical fiber coupler (106) and the phase shifter (1010); and an optical fiber (109) is connected between the polarization-maintaining wavelength division multiplexer (108) and the phase shifter (1010); The motor disturbance module (102) is composed of a slapping handle (1021) and a motor (1022); an output end of the motor (1022) is connected to the slapping handle (1021); and the motor disturbance module (102) is used to receive the start instruction and load a preset motor voltage and motor working time according to the start instruction.

2. A self-starting 9-shaped cavity laser based on motor disturbance according to claim 1, characterized in that: The linear arm (101) comprises an output jumper head (1011), a polarization-maintaining optical fiber isolator (1012) and a polarization-maintaining optical fiber grating (1013); One end of the output jumper head (1011) is connected in sequence to a polarization-maintaining optical fiber isolator (1012) and a polarization-maintaining optical fiber grating (1013).

3. A self-starting 9-shaped cavity laser based on motor disturbance according to claim 1, characterized in that: The control module (103) comprises: a polarization-maintaining isolator (1031), a photodetector (1032), and a main control board and a driving module (1033); The control module (103) is respectively connected to the 2x2 polarization-maintaining optical fiber coupler (106), the motor disturbance module (102) and the polarization-maintaining wavelength division multiplexer (108); The photoelectric detector (1032) is used to convert the optical signal in the 9-shaped cavity laser into an electrical signal, and send the electrical signal to the main control board and the driving module (1033); The main control board and the driving module (1033) are used to obtain the electrical signal and determine whether the mode is locked; The main control board and the driving module (1033) contain a 980nm band pump source, which injects pump light into the polarization-maintaining wavelength division multiplexer (108).

4. A self-starting 9-shaped cavity laser based on motor disturbance according to claim 1, characterized in that: The control module (103) is respectively connected to a 2x2 polarization-maintaining optical fiber coupler (106) and a polarization-maintaining wavelength division multiplexer (108).

5. The self-starting 9-shaped cavity laser based on motor disturbance according to claim 1 is characterized in that The 9-shaped cavity laser also includes a pump source, which includes a 14-pin butterfly laser with a wavelength of 980 nm.

6. A self-starting 9-shaped cavity laser based on motor disturbance according to claim 1, characterized in that The splitting ratio of the 2x2 polarization-maintaining fiber coupler (106) is 40 / 60.

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