Multi-wavelength tunable pulse laser

Abstract

The utility model provides a multi-wavelength tunable pulse laser, and the laser comprises a first laser light source which is configured to generate first laser; a second laser light source configured to: generate a second laser light; a third laser light source configured to: generate a third laser; a fourth laser light source configured to: generate a fourth laser light; the input end of the light beam adjusting assembly is respectively connected with the first laser light source, the second laser light source, the third laser light source and the fourth laser light source; the output end of the light beam adjusting assembly is connected with the first collimator and the second collimator respectively; the first collimator is configured to collimate the first sub-laser; the second collimator is configured to collimate the second sub-laser, the second laser, the third laser, and the fourth laser. The multi-wavelength tunable pulse laser can output laser of various different wavelengths, multi-wavelength integration is achieved, the application range is wide, and different laser requirements of multiple fields can be met.

Description

Technical Field

[0001] This application relates to the field of laser technology, and more particularly to a multi-wavelength tunable pulsed laser. Background Technology

[0002] Short-pulse lasers have wide applications in precision machining, laser ranging, and lidar. Various techniques are commonly used for generating and modulating laser pulses, including gain switching, Q-switching (loss switching), cavity emptying, and mode-locking. For nanosecond-level pulse technology, there are currently many reported single-wavelength pulse laser technologies and systems. For multi-wavelength switching lasers, solid-state lasers are the primary method, employing Q-switching schemes. While these can generate significant energy, the overall structure is complex, resulting in a large system size, which is not conducive to practical applications. For example, commercially available three-wavelength lasers have separate laser heads and power supply modules, making integrated design impossible and failing to meet the needs of lasers with wavelengths greater than three.

[0003] Therefore, there is an urgent need for a multi-wavelength laser with integrated functions. Utility Model Content

[0004] This application provides a multi-wavelength tunable pulsed laser that can achieve multi-wavelength integration and meet different laser needs in multiple fields.

[0005] This application provides a multi-wavelength tunable pulsed laser, comprising: a first laser source configured to generate a first laser; a second laser source configured to generate a second laser, wherein the wavelength of the first laser is greater than the wavelength of the second laser; a third laser source configured to generate a third laser, wherein the wavelength of the second laser is greater than the wavelength of the third laser; a fourth laser source configured to generate a fourth laser, wherein the wavelength of the third laser is greater than the wavelength of the fourth laser; a beam adjustment assembly, wherein the input end of the beam adjustment assembly is connected to the first laser source, the second laser source, the third laser source, and the fourth laser source respectively; a first collimator and a second collimator, wherein the output end of the beam adjustment assembly is respectively connected to the first laser source, the second laser source, the third laser source, and the fourth laser source; and a first collimator and a second collimator, wherein the output end of the beam adjustment assembly is respectively connected to the first laser source and the second laser source; and a second collimator. The system is connected to a first collimator and a second collimator; wherein, the beam adjustment component is configured to: split a first laser beam into a first sub-laser and a second sub-laser, and transmit the first sub-laser to the first collimator; the first laser has a first power, the second sub-laser has a second power, and the wavelengths of the first sub-laser and the second sub-laser are both the same as the wavelength of the first laser; the beam adjustment component is further configured to: combine the second sub-laser, the second laser, the third laser, and the fourth laser, and transmit them to the second collimator; the first power and the second power are different; the first collimator is configured to: collimate the first sub-laser; the second collimator is configured to: collimate the second sub-laser, as well as the second laser, the third laser, and the fourth laser.

[0006] Optionally, the beam conditioning assembly includes a coupler and a beam conditioner; the input of the coupler is connected to a first laser source, and the output of the coupler is connected to the beam conditioner and a first collimator, respectively; the coupler is configured to split the first laser beam into a first sub-laser and a second sub-laser; the input of the beam conditioner is connected to the output of the coupler, a second laser source, a third laser source, and a fourth laser source, respectively, and the output of the beam conditioner is connected to a second collimator; the beam conditioner is configured to transmit the second sub-laser, the second laser, the third laser, and the fourth laser to the second collimator.

[0007] Optionally, the multi-wavelength tunable pulsed laser also includes a drive control board, on which the first laser source, the second laser source, the third laser source, the fourth laser source, and the beam adjustment assembly are all mounted.

[0008] Optionally, the multi-wavelength tunable pulsed laser also includes: a housing, a drive control board disposed inside the housing, and a first collimator and a second collimator disposed outside the housing; wherein the dimensions of the housing are 95mm × 95mm × 19mm; and the weight of the multi-wavelength tunable pulsed laser is less than 180g.

[0009] Optionally, the housing includes a top plate, two first side plates, two second side plates, and a bottom plate; the drive control board is disposed on the bottom plate; the top plate and the first side plates are detachably connected to the second side plates; the second side plates are provided with a first through hole and a second through hole, the first through hole being used to pass through an optical fiber, and the second through hole being used to pass through an electrical wire; wherein, the two first through holes are located on both sides of the two second through holes.

[0010] Optionally, the first laser source, the second laser source, the third laser source, and the fourth laser source are all multimode semiconductor lasers; the wavelength of the first laser is 1550nm; the wavelength of the second laser is 1060nm; the wavelength of the third laser is 980nm; and the wavelength of the fourth laser is 650nm.

[0011] Optionally, the drive control board includes a continuous constant current control module and a pulse constant current control module; the continuous constant current control module is configured to provide a continuous constant current to the fourth laser source; the pulse constant current control module is configured to provide nanosecond pulse current to the first laser source, the second laser source, and the third laser source.

[0012] Optionally, the drive control board includes a laser switch chip, which includes six switch channels; one of the six switch channels is configured to output a continuous constant current to the fourth laser source; two of the six switch channels are configured to output nanosecond pulse currents to the second and third laser sources respectively; and three of the six switch channels are configured to output nanosecond pulse currents to the first laser source after being connected in parallel and superimposed.

[0013] Optionally, the first collimator includes a first lens, a second lens, and a first window sheet arranged sequentially along the light emission direction; both sides of the first lens, the second lens, and the first window sheet are provided with anti-reflection coatings in the wavelength range of 1550±3nm; the second collimator includes a third lens, a fourth lens, and a second window sheet arranged sequentially along the light emission direction; both sides of the third lens, the fourth lens, and the second window sheet are provided with anti-reflection coatings in the wavelength range of 600 to 2000nm.

[0014] Optionally, the multi-wavelength tunable pulsed laser further includes: a first connecting fiber and a second connecting fiber, wherein the first connecting fiber is connected between the beam conditioner and the second collimator; the second connecting fiber is connected between the first laser source and the coupler, between the second laser source and the beam conditioner, between the third laser source and the beam conditioner, between the fourth laser source and the beam conditioner, and between the coupler and the first collimator; wherein the core of the first connecting fiber is 200 μm and the core of the second connecting fiber is 105 μm.

[0015] The multi-wavelength tunable pulsed laser provided in this application can combine the output wavelengths of both invisible and visible light bands. The visible light band can be used for indication, serving as a positioning indicator. The position of the laser in the invisible light band can be determined by the indicator light for ease of use. Furthermore, the integration of four different laser bands in this multi-wavelength tunable laser improves overall integration, facilitating miniaturization, portability, and ease of use, thus meeting the needs of various fields. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a multi-wavelength coordinated laser provided in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of a conventional wavelength division multiplexer.

[0019] Figure 3 This is a schematic diagram of the structure of a beam adjustment component provided in an embodiment of this application;

[0020] Figure 4 This is a schematic diagram of the structure of a drive control board provided in an embodiment of this application;

[0021] Figure 5This is a schematic diagram of a pulse constant current test for a drive control board provided in an embodiment of this application;

[0022] Figure 6 This is a schematic diagram of the structure of an optical fiber head and collimator provided in an embodiment of this application;

[0023] Figure 7 This is a schematic diagram of the structure of a first collimator and a second collimator provided in an embodiment of this application;

[0024] Figure 8 This is a schematic diagram of the structure of a shell provided in an embodiment of this application;

[0025] Figure 9 This is a schematic diagram of tests at different wavelengths provided in the embodiments of this application;

[0026] Figure 10 This application provides a method for testing the continuous optical power and laser voltage at a wavelength of 655nm.

[0027] Figure 11 This application provides a method for testing the continuous optical power and laser voltage at a wavelength of 980nm.

[0028] Figure 12 This application provides a method for testing the continuous optical power and laser voltage at a wavelength of 1060nm.

[0029] Figure 13 This application provides a method for testing the continuous optical power and laser voltage at a wavelength of 1550nm.

[0030] Illustration markings:

[0031] 11-First laser source; 12-Second laser source; 13-Third laser source; 14-Fourth laser source; 15-Beam adjustment assembly; 151-Coupled; 152-Beam adjuster; 16-First collimator; 161-First lens; 162-Second lens; 163-First window; 17-Second collimator; 171-Third lens; 172-Fourth lens; 173-Second window; 18-Drive control board; 181-FPGA; 182-Power and communication interface; 183 -485 communication chip; 184-beam adjustment component mounting position; 185-laser switch chip; 186-laser source empty space; 187-external trigger signal interface; 188-amplifier; 189-PD photodetector interface; 19-housing; 191-top plate; 192-first side plate; 193-second side plate; 1931-first through hole; 1932-second through hole; 194-bottom plate; 20-first connecting optical fiber; 21-second connecting optical fiber; 22-first optical fiber head; 23-second optical fiber head. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the protection scope of this application.

[0033] In the following description, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0034] Furthermore, in this application, directional terms such as "upper," "lower," "inner," and "outer" are defined relative to the indicated placement of the components in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the placement of the components in the accompanying drawings.

[0035] Figure 1 This is a schematic diagram of the structure of a multi-wavelength tunable pulsed laser provided in an embodiment of this application.

[0036] See Figure 1 The multi-wavelength tunable pulsed laser provided in this application embodiment includes a first laser source 11, a second laser source 12, a third laser source 13, a fourth laser source 14, a beam adjustment component 15, a first collimator 16, and a second collimator 17.

[0037] The first laser source 11 is used to generate the first laser.

[0038] The second laser source 12 is used to generate the second laser; the wavelength of the first laser is greater than the wavelength of the second laser.

[0039] The third laser source 13 is used to generate the third laser; the wavelength of the second laser is greater than the wavelength of the third laser.

[0040] The fourth laser source 14 is used to generate the fourth laser; the wavelength of the third laser is greater than the wavelength of the fourth laser.

[0041] The input end of the beam adjustment component 15 can be connected to the first laser source 11, the second laser source 12, the third laser source 13, and the fourth laser source 14 via optical fibers, respectively. The output end of the beam adjustment component 15 can be connected to the first collimator 16 and the second collimator 17 via optical fibers, respectively.

[0042] The beam adjustment component 15 is used to split the first laser beam into a first sub-laser and a second sub-laser. The first sub-laser has a first power, and the second sub-laser has a second power. The wavelengths of both the first and second sub-lasers are the same as the wavelength of the first laser. The first sub-laser is then transmitted to the first collimator 16. The beam adjustment component 15 is also used to transmit the second sub-laser, as well as the second, third, and fourth lasers, to the second collimator 17. The first and second powers are different. In other words, the beam adjustment component 15 can split the first laser beam into first and second sub-lasers of different powers to meet different power requirements of the first laser. The beam adjustment component 15 can also combine the first, second, third, and fourth lasers and output them to meet the switching output requirements of lasers with different wavelengths. After beam combining, the lasers are used sequentially by the beam adjustment component 15 according to usage requirements.

[0043] The first collimator 16 is used to collimate the first sub-laser.

[0044] The second collimator 17 is used to collimate the second sub-laser, as well as the second, third, and fourth lasers. The use of the first collimator 16 and the second collimator 17 avoids laser loss.

[0045] Thus, the multi-wavelength tunable pulsed laser provided in this application embodiment can output four different wavelengths of laser light. Moreover, for the first laser, it can also output a first sub-laser and a second sub-laser with different powers. The first power can be greater than the second power, or it can be less than the second power; the specific relationship between the first power and the second power can be adjusted according to actual needs.

[0046] In other specific implementations, the multi-wavelength tunable pulsed laser provided in this application embodiment may also include a fifth laser source, which may be connected to the beam adjustment component 15.

[0047] Alternatively, it may include multiple lasers of different wavelengths, such as a fifth laser source, a sixth laser source, and a seventh laser source. The fifth laser source, the sixth laser source, and the seventh laser source are respectively connected to the beam adjustment component 15, thereby meeting the output requirements of multi-wavelength lasers.

[0048] In some feasible implementations, the wavelength of the first laser can be 1550nm; the wavelength of the second laser can be 1060nm; the wavelength of the third laser can be 980nm; and the wavelength of the fourth laser can be 650nm.

[0049] Specifically, the aforementioned different wavelengths have excellent applications in various fields. For example, in optical communication, 1550nm lasers, as signal sources or optical amplifiers, possess high power and high efficiency output characteristics, ensuring sufficient intensity of optical signals during long-distance transmission, thereby improving transmission efficiency and reliability. In fiber optic sensing, 1550nm lasers provide stable and high-quality laser signals for fiber optic sensors, enabling high-sensitivity and high-resolution measurements, and are widely used for the precise measurement of physical quantities such as temperature, pressure, and strain. 1060nm lasers are commonly used in skin repair and cosmetic treatments; their wavelength can effectively penetrate tissue and interact with various biological tissues, exhibiting excellent cutting and coagulation effects. Furthermore, 1060nm lasers are also widely used in industrial manufacturing, such as micro-nano fabrication, precision drilling, and cutting.

[0050] Thus, the output wavelength of the multi-wavelength tunable pulsed laser provided in this application embodiment can be 1550nm, 1060nm, and 980nm in the invisible light band, and 650nm in the visible light band. The visible light band can be used for indication, serving as a positioning indicator. The position of the laser at 1550nm, 1060nm, and 980nm in the invisible light band can be determined by the indicator light, facilitating use. Simultaneously, the integration of four different wavelength bands in this multi-wavelength tunable laser improves overall integration, facilitating miniaturization and portability.

[0051] It should be emphasized that the wavelengths of the first, second, third, and fourth lasers mentioned above are merely examples. In other different implementations, the wavelengths of the first, second, third, and fourth lasers can also be other values, such as 514nm, 633nm, 800-1000nm, etc.

[0052] Figure 2 This is a schematic diagram of a conventional wavelength division multiplexer.

[0053] To transmit four wavelengths through a single optical fiber, the conventional approach is to utilize multiple wavelength division multiplexing (WDM) devices. WDM is a passive optical device that uses single-mode fiber to combine or separate two beams of light with different wavelengths. By combining multiple WDMs, multiple wavelengths of light can be coupled into the same fiber for transmission, or multiple wavelengths of light from the same fiber can be separated and transmitted into different fibers. To transmit four wavelengths through a single fiber, three WDM devices are required, such as... Figure 2As shown, the 980nm wavelength enters the tapered WDM1-1 through PM980 fiber or Hi1060 fiber 2-1 (single-mode fiber), and the 1060nm wavelength enters the tapered WDM1-1 through PM980 fiber or Hi1060 fiber 2-2 (single-mode fiber). The 980nm and 1060nm wavelengths enter the filter-type WDM1-2 through PM980 fiber or Hi1060 fiber 2-3 (single-mode fiber). The filter-type WDM has a built-in filter (which can reflect wavelengths of 900-1100nm and transmit laser light in the 1520-1580nm and 620-680nm bands). The 980nm and 1060nm wavelengths enter the filter-type WDM1-2 through the filter-type WDM1-2. 2 is reflected and output from Hi1060 fiber 2-4 (single-mode fiber); 1550nm and 650nm wavelength lasers are injected into tapered WDM1-3 from Hi1060 fibers 2-6 and 2-7 (single-mode fibers) respectively. These two wavelengths of laser are then transmitted to filter-type WDM1-2 through Hi1060 fiber 2-5 (single-mode fiber), and the two wavelengths are then output from Hi1060 fiber 2-4 (single-mode fiber). Finally, 980nm, 1060nm, 1550nm, and 650nm lasers are input from ports 2-1, 2-2, 2-6, and 2-7 respectively, and output from port 2-4.

[0054] In the conventional implementation methods described above, all optical fibers involved are single-mode fibers. This means that lasers in the four wavelength bands of 980nm, 1060nm, 1550nm, and 650nm must be single-mode semiconductor lasers (i.e., the laser uses a single-mode chip internally to generate single-mode laser light, which is then coupled out through a single-mode fiber, allowing the single-mode fiber to be fused with the WDM devices used in the conventional method). However, when selecting semiconductor lasers, factors such as cost and output power must be considered, especially since the output power of a 1550nm semiconductor laser needs to exceed 1W (high output power is required to meet application requirements; therefore, a laser with an output power exceeding 1W must be selected). Single-mode semiconductor lasers cannot achieve such high output power and are also very expensive.

[0055] In this embodiment, multimode semiconductor lasers are more suitable. The output fibers of the multimode semiconductor lasers with wavelengths of 1550nm, 1060nm, 980nm, and 650nm are all 105 / 125 / 250μm multimode fibers (that is, the connecting fibers between the first laser source 11, the second laser source 12, the third laser source 13, and the fourth laser source and the beam adjustment component 15, respectively, with a fiber core of 105μm, a cladding of 125μm, a coating of 250μm, and a numerical aperture NA of 0.22).

[0056] In other words, the output pigtail of the multi-wavelength tunable pulsed laser provided in this application embodiment is a multimode fiber. In conventional beam adjustment methods, single-mode fiber cannot be matched. Therefore, considering that it can have fiber adjustment function to match the requirements of multimode fiber, and at the same time meet the output power of the laser, this application designs a beam adjustment component 15 with coupling-adjustment two-in-one function.

[0057] Figure 3 This is a schematic diagram of the structure of a beam adjustment component provided in an embodiment of this application.

[0058] In some feasible implementation methods, combined Figure 1 and Figure 3 The beam adjustment assembly 15 may include a coupler 151 and a beam adjuster 152.

[0059] The input end of the coupler 151 is connected to the first laser source 11, and the output end of the coupler 151 is connected to the beam adjuster 152 and the first collimator 16 respectively. The coupler 151 is used to split the first laser into two beams, one of which is the first sub-laser and the other is the second sub-laser.

[0060] The input end of the beam modulator 152 is connected to the output end of the coupler 151, the second laser source 12, the third laser source 13 and the fourth laser source 14 respectively, and the output end of the beam modulator 152 is connected to the second collimator 17. The beam modulator 152 is used to transmit the second sub-laser, the second laser, the third laser and the fourth laser to the second collimator 17.

[0061] The beam adjustment assembly 15 can achieve the effect of outputting four different wavelengths from the same optical fiber, which is one of the features of the laser. This avoids the need to constantly change optical fibers to obtain different laser wavelengths during use. The beam adjustment assembly 15 can use a lightweight aluminum housing, which reduces the space occupied by optical components inside the whole machine, reduces weight, and also provides better heat dissipation. Both the coupler 151 and the beam modulator 152 contained within can be manufactured using advanced fused tapered technology. One type is a 1×2 coupler, where coupler 151 is the fused tapered region of the 1×2 coupler. Laser light in the 1550nm band enters coupler 151 through the transmission fiber and is split into two beams. By using couplers 151 with different ratios, arbitrary power ratios can be achieved. One beam is output to the first collimator 16 through the output fiber, and the other beam enters beam modulator 152 through the fiber. The other type is a 4×1 beam modulator 152, using a multimode fiber with a core diameter of 200μm, a cladding diameter of 220μm, a coating diameter of 250μm, and a numerical aperture (NA) of 0.22 as the output fiber. The larger core diameter provides better coupling tolerance, reduces optical power loss, and ensures efficient optical signal transmission. The beams output from the multimode semiconductor laser enter the fused taper region of the 4×1 beam conditioner 152 through multimode optical fibers, and are then combined into the output fiber of the beam conditioner 152. The coupling efficiency at 650nm and 1550nm is greater than 85%, and the coupling efficiency at 980nm and 1060nm wavelengths is greater than 95%.

[0062] Figure 4 This is a schematic diagram of the structure of a drive control board provided in an embodiment of this application. Figure 5 This is a pulse constant current test diagram of the drive control board provided in the embodiments of this application.

[0063] In some implementations, see Figure 4 and Figure 5 The multi-wavelength tunable pulsed laser also includes a drive control board 18. The first laser source 11, the second laser source 12, the third laser source 13, the fourth laser source 14, and the beam adjustment assembly 15 are all located on the drive control board 18.

[0064] Specifically, a Field Programmable Gate Array (FPGA) 181 can be set in the central area of ​​the drive control board 18, which can effectively solve the problem of the small number of gate circuits in the device.

[0065] The right side of the drive control board 18 may be equipped with a power supply and communication interface 182 for easy electrical and communication connections. The drive control board 18 may also be equipped with a 485 communication chip 183 for communication connections. A laser switch chip 185 may also be provided for controlling the laser's on / off state. Laser source slots 186 may be provided on the left side, sequentially for mounting the first laser source 11, the second laser source 12, the third laser source 13, and the fourth laser source 14. On the bottom side of the drive control board 18, an external trigger signal interface 187, an amplifier 188, and a PD photodetector interface 189 are sequentially provided.

[0066] Specifically, the first laser source 11, the second laser source 12, the third laser source 13, and the fourth laser source 14 provided in this application embodiment can all be multimode semiconductor laser emitters. The packaging shells of these four multimode semiconductor lasers can all adopt rectangular metal shells with solder sealing process. This packaging form can be 7.6mm thick and 17.05mm wide, which not only reduces the volume occupied, but also reduces the height of the whole machine. The bottom of the metal shell is tightly attached to the bottom plate of the machine through thermal grease, which is more conducive to heat dissipation of multimode semiconductor lasers. At the same time, this packaging form can withstand higher laser power. The pins of the multimode semiconductor lasers can be tightly attached to the circuit board of the drive control board 18, reducing the load generated, thereby reducing the rise time of the light pulse, and thus reducing the output laser pulse width. This makes the actual output pulse width more closely match the set pulse width.

[0067] The drive control board 18 can use an FPGA181 as the main control chip for communication with the host computer, main logic control, analog output, PWM signal output, etc., to realize functions such as 485 communication protocol parsing, system protection, laser power control, frequency pulse width modulation signal, and average optical power calculation. In addition, the drive control board 18 also has an external trigger function. The optical pulse width is configured by software, and the frequency is consistent with the external trigger input, which can realize single trigger or BURST function.

[0068] In some feasible implementations, the laser switch chip 185 constitutes a power control circuit. The laser switch chip 185 can include six switching channels, each with two main functions: rapid channel closing and cutting off, and voltage-to-current conversion. These channels can output drive current independently or in parallel. This drive current can be directly applied to a pulsed laser to generate a pulsed laser signal. The drive control board 18 can output one continuous current and three pulsed currents to drive four multimode semiconductor lasers respectively. Specifically, one of the six switching channels outputs a continuous constant current to drive the fourth laser source (e.g., a multimode semiconductor laser with a wavelength of 650nm), two of the six switching channels output nanosecond pulse currents to drive the second and third laser sources (e.g., multimode semiconductor lasers with wavelengths of 980nm and 1060nm respectively), and the remaining three switching channels are connected in parallel and superimposed to output a larger amplitude nanosecond pulse current to drive the first laser source (e.g., a multimode semiconductor laser with a wavelength of 1550nm). Each channel can control the amplitude of the output current by adjusting the input analog voltage, and control the frequency and pulse width of the output current by inputting an enable signal. The analog input to the laser switch chip can be generated by the FPGA181, and the digital enable signal can be generated by the FPGA181 and the pulse signal reconstruction circuit.

[0069] An additional PD photodetector interface 189 is added to monitor the average power of the output light. The signal is amplified by the transimpedance amplifier 188 and fed back to the FPGA 181. The FPGA 181 compares the set value with the returned value to complete the PID adjustment and improve the stability of the laser output power.

[0070] The drive control board 18 can be connected to a host computer (PC) via an RS485 communication interface. Users can set the output power, frequency and pulse width of each multimode semiconductor laser, start / stop the laser, select the output laser wavelength, adjust the power, frequency and pulse width parameters of the laser, and monitor the laser parameters and alarm information in real time.

[0071] In one feasible implementation, by setting a drive control board 18 to control the on / off of lasers of different wavelengths, wavelength accuracies of 980±2nm, 1060±2nm, and 1550±2nm can be achieved. After the laser is started, the three wavelengths of 980nm, 1060nm, and 1550nm can be switched arbitrarily. The repetition frequency of each wavelength can be adjusted from 1 to 100Hz, the pulse width of the 980nm and 1060nm wavelengths is continuously adjustable from 8 to 60ns, and the pulse width of the 1550nm wavelength is continuously adjustable from 10 to 60ns. The output power of each wavelength is continuously and linearly adjustable. The output power of the 980nm and 1060nm wavelengths can be continuously adjusted from 0 to 100mW, and the 1550nm wavelength laser is split into two beams, one with adjustable power from 0 to 60mW and the other with adjustable power from 0 to 540mW. Each of the three laser wavelengths has a specific divergence angle. For the 980nm and 1060nm bands, the divergence angle is 1 mrad. For the 1550nm band, the higher-power output laser has a divergence angle of 35 mrad, while the lower-power output laser has a divergence angle of 1 mrad. The output spot diameter for all three wavelengths is 3 mm.

[0072] Thus, the multi-wavelength tunable pulsed laser provided in this application embodiment highly integrates four different wavelengths of multimode semiconductor lasers and an independently designed and developed embedded integrated circuit board, which can realize the functions of positioning indication, low repetition rate continuous adjustment, nanometer-level pulse width continuous adjustment, and three wavelengths switchable in the invisible light band. It is suitable for aerospace and other application fields with extremely high requirements for device miniaturization, integration, and lightweighting.

[0073] Figure 6 This is a schematic diagram of the structure of an optical fiber head and collimator provided in an embodiment of this application.

[0074] See also Figure 1 and Figure 6 The multi-wavelength tunable pulsed laser also includes a housing 19, a first fiber optic connector 22, and a second fiber optic connector 23. A drive control board 18 is disposed inside the housing 19, and a first collimator 16 and a second collimator 17 are disposed outside the housing 19. A beam adjustment assembly 15 is connected to the first collimator 16 via the first fiber optic connector 22, and the beam adjustment assembly 15 is also connected to the second collimator 17 via the second fiber optic connector 23. Figure 6 Figure (a) shows a schematic diagram of the structure of the first fiber optic head 22 and the first collimator 16. Figure 6 Figure (b) shows a schematic diagram of the structure of the second fiber optic connector 23 and the second collimator 17. In this implementation, the structures of the first fiber optic connector 22 and the second fiber optic connector 23 can be the same; in other feasible implementations, the structures of the first fiber optic connector 22 and the second fiber optic connector 23 can be different.

[0075] Specifically, the coupler 151 can be connected to the first collimator 16 via the first fiber optic connector 22, and the beam adjuster 152 can be connected to the second collimator 17 via the second fiber optic connector 23.

[0076] The first fiber optic connector 22 and the second fiber optic connector 23 can both be FC / PC fiber optic connectors. The FC / PC fiber optic connectors are connected to the first collimator 16 and the second collimator 17 through a simple alignment-insertion-tightening method.

[0077] In this way, on the one hand, the optical fibers located outside the housing 19 and connected to the first optical fiber head 22 and the second optical fiber head 23 can have a certain length, and the fixed positions of the first collimator 16 and the second collimator 17 can be adjusted arbitrarily, making operation simple and application convenient; on the other hand, the FC / PC optical fiber head is easy to disassemble from the first collimator 16 and the second collimator 17, and it is more convenient to test by directly using the optical fiber head output.

[0078] Figure 7 This is a schematic diagram of the structure of the first collimator 16 and the second collimator 17 provided in the embodiments of this application.

[0079] Figure 7 Image (a) shows a schematic diagram of the structure of the first collimator 16. Figure 7 Figure (b) shows a schematic diagram of the structure of the second collimator 17. In this implementation, the structures of the first collimator 16 and the second collimator 17 can be the same. In other feasible implementations, the structures of the first collimator 16 and the second collimator 17 can be different.

[0080] See Figure 7 As shown, the first collimator 16 includes a first lens 161, a second lens 162, and a first window 163 arranged sequentially along the optical path.

[0081] The first lens 161 has a focal length of 1.0 mm and a diameter of 1.2 mm, and both sides are coated with an anti-reflection coating covering a wavelength range of 1550 ± 3 nm. The second lens 162 has a focal length of 0.8 mm and a diameter of 1.2 mm, and both sides are coated with an anti-reflection coating covering a wavelength range of 1550 ± 3 nm. The first window 163 has high transmittance, and both sides of the first window 163 are coated with an anti-reflection coating covering a wavelength range of 1550 ± 3 nm.

[0082] The second collimator 17 includes a third lens 171, a fourth lens 172, and a second window 173 arranged sequentially along the optical path.

[0083] The third lens 171 has a focal length of 1.0 mm and a diameter of 1.2 mm, and both sides are coated with an anti-reflection coating covering a wavelength range of 600-2000 nm. The fourth lens 172 has a focal length of 0.8 mm and a diameter of 1.2 mm, and both sides are coated with an anti-reflection coating covering a wavelength range of 600-2000 nm. The second window 173 has high transmittance, and both sides of the second window 173 are coated with an anti-reflection coating covering a wavelength range of 600-2000 nm.

[0084] The purpose of the first window 163 and the second window 173 is to reduce power loss and prevent dust and moisture, thereby extending the service life of the device.

[0085] In this multi-wavelength tunable pulsed laser, the first collimator 16 and the second collimator 17 can not only achieve collimated laser output, but also set different divergence angles according to actual needs to meet more practical applications. The divergence angle of the second collimator 17 can be 36 mrad, and the divergence angle of the first collimator 16 can be 2-4 mrad. Collimators with different divergence angles can be replaced as needed.

[0086] In some feasible implementations, the dimensions of the housing 19 can be 95mm × 95mm × 19mm; the weight of the multi-wavelength tunable pulsed laser is less than 180g. This achieves miniaturization and lightweight design of the multi-wavelength tunable pulsed laser.

[0087] Figure 8 This is a schematic diagram of the structure of a shell provided in an embodiment of this application.

[0088] Figure 8 Image (a) shows a top view of housing 19. Figure 8 Figure (b) shows a schematic diagram of the structure of the shell 19.

[0089] like Figure 8 As shown, the housing 19 may include a detachable top plate 191, two first side plates 192, two second side plates 193, and a bottom plate 194. The top plate 191 and the first side plates 192 can be detachably connected to the second side plates 193. The second side plates 193 have two first through holes 1931 for optical fibers and two second through holes 1932 for electrical wires. The first through holes 1931 and the second through holes 1932 are located on the same second side plate 193, facilitating wiring. The cross-sectional shape of the first through holes 1931 is partially elliptical, and the cross-sectional shape of the second through holes 1932 is circular. The first through holes 1931 can be located at the top of the second side plates 193, and the second through holes 1932 can be located at the center of the second side plates 193, with the two first through holes 1931 located on either side of the two second through holes 1932.

[0090] The modular housing 19 design facilitates weight reduction and allows the multi-wavelength tunable pulsed laser to be integrated as a subsystem into the desired system. During use, the top plate 191 and the first side plate 192 can be removed for installation, simplifying installation and reducing overall weight. Furthermore, it facilitates assembly, disassembly, and maintenance. During assembly, maintenance personnel can secure all optical and electrical components to the base plate 194 of the housing 19, making routine maintenance and troubleshooting easier.

[0091] See also the following for some feasible implementation methods. Figure 3 The optical fiber may include a first connecting fiber 20 and a second connecting fiber 21. The first connecting fiber 20 is connected between the beam conditioner 152 and the second collimator 17, and the other devices are connected by the second connecting fiber 21 (between the first laser source 11 and the coupler 151, between the second laser source 12 and the beam conditioner 152, between the third laser source 13 and the beam conditioner 152, between the fourth laser source 14 and the beam conditioner 152, between the coupler 151 and the beam conditioner 152, and between the coupler 151 and the first collimator 16). The core of the first connecting fiber 20 is 200 μm, the cladding is 220 μm, and the coating is 250 μm. The first connecting fiber 20 is a multimode fiber with a numerical aperture (NA) of 0.22. The core of the second connecting fiber 21 is 105 μm, the cladding is 125 μm, and the coating is 250 μm. The second connecting fiber 21 is also a multimode fiber with a numerical aperture (NA) of 0.22. All optical fibers inside the housing 19 are bare fibers, which reduces weight and makes them easier to coil within the limited space of the housing. The first connecting fiber 20 and the second connecting fiber 21 located on the outside can both be covered with 900μm loose tubes for protection.

[0092] In some feasible implementations, the first laser source 11, the second laser source 12, the third laser source 13, and the fourth laser source 14 can be arranged sequentially in the left-side region inside the housing 19. The second connecting optical fiber 21 connecting the third laser source 13 and the fourth laser source 14 to the beam adjustment assembly 15 can be wound counterclockwise 3 / 4 turn along the inner sidewall of the housing 19, and then wound in a figure-eight shape to connect to the beam adjustment assembly 15. The bending radius of the second connecting optical fiber 21 inside the housing 19 can be guaranteed to be greater than the minimum bending radius of the optical fiber (30mm) to ensure that a suitable bending radius will not affect the output optical power.

[0093] In one specific implementation, the drive control board 18 operates in both continuous constant current and pulsed constant current modes. The drive control board 18 includes a continuous constant current control module (not shown in the figure) and a pulsed constant current control module (not shown in the figure). The continuous constant current control module controls the continuous constant current mode of the drive control board 18, and the pulsed constant current control module controls the pulsed constant current mode of the drive control board 18. Specifically, the continuous constant current control module can provide a continuous constant current to the fourth laser source; the pulsed constant current control module can provide nanosecond pulsed currents to the first, second, and third laser sources.

[0094] In this way, the drive control board 18 can provide a continuously adjustable indicator light with a continuous current output for a 650nm red semiconductor laser, and can also provide nanosecond pulsed currents for multimode semiconductor lasers with wavelengths of 980nm, 1060nm, and 1550nm, enabling the laser to output nanosecond-level pulsed light to meet the needs of various applications. The operator can generate continuous or pulsed currents on the drive board as needed via host computer software or external trigger signals. The magnitude of the drive current, pulse width, and frequency can all be adjusted to achieve modulation of the multimode semiconductor laser.

[0095] Thus, the multi-wavelength tunable pulsed laser provided in this application embodiment is based on nanosecond-level gain-switching pulse modulation technology of fiber laser optical path structure. Compared with most commonly used solid-state laser solutions, it can more easily achieve modulation of laser pulse width and repetition frequency. Simultaneously, an indicator light band is added, realizing the integrated optical path structure and electronic control module of three signal lasers and indicator light sources. Structurally, this electronic control module can embed four multimode semiconductor lasers and a two-in-one device; functionally, it integrates the driving functions of four wavelength lasers: 650nm, 980nm, 1060nm, and 1550nm. Specifically, it provides continuous constant current drive for the 650nm multimode semiconductor laser and nanosecond-level pulse drive for the other three wavelengths. The advantages of multimode semiconductor lasers—identifiable, compact, and lightweight—enhance practical application applicability. This multi-wavelength tunable pulsed laser features low output noise, good constant current characteristics, and strong anti-interference capability. It also incorporates surge protection and overshoot suppression mechanisms, enabling efficient and precise adjustment of laser operating parameters and stable output of three specific wavelengths of laser light.

[0096] In some feasible implementations, the main interface of the host computer includes a core parameter configuration operation function area, an operation information display function area, and a software supplementary function area.

[0097] (1) Core parameter configuration operation function area

[0098] The core parameter configuration operation function area mainly includes the control of the parameter output corresponding to three wavelengths, and the parameter range corresponding to each wavelength, as shown in Table 1.

[0099] Table 1. Parameter ranges for each wavelength

[0100] Wavelength (nm) Power (mW) Pulse width (ns) Frequency (Hz) 655 0-200 (continuous light) / / 980 0-400 8-60 1-100 1060 0-500 20-60 1-100 1550 0-1300 20-60 1-100

[0101] During operation, first drag the parameter control or enter the corresponding parameters in the numeric input box to the right of the control, and then click the corresponding output control. The operation information of the control can be viewed in the information display area below. Parameter configuration is not allowed during laser output; it is only possible when the output is off. After entering parameters, you need to click "Confirm Parameter" to configure them to the lower-level machine. The output controls for each wavelength are mutually exclusive; when one wavelength is selected, the interfaces for the other two wavelengths will be locked and cannot be operated.

[0102] (2) Operation information display function area

[0103] The operation information display area mainly shows current and historical operation information, making it convenient for operators to view the historical information of equipment operation.

[0104] (3) Software Additional Function Area

[0105] The software's additional function area mainly includes serial port selection, device connection, device disconnection, connection status display, wavelength selection, device emergency stop, parameter saving, and software exit functions. The serial port selection control contains the serial port numbers of all devices searched during software startup, allowing the operator to switch between different devices. Device connection, device disconnection, and connection status displays primarily manage the device communication ports. Wavelength selection allows switching waveform parameter settings. The device emergency stop function allows the operator to quickly stop the output. Parameter saving stores the current, pulse width, and repetition frequency corresponding to multiple wavelengths, updating these parameters upon software restart. Software exit functions to shut down laser output and close the interface.

[0106] Figure 9 This is a schematic diagram of different wavelength tests provided in the embodiments of this application.

[0107] See Figure 9 The image shows the test results of controlling a multi-wavelength tunable pulsed laser using host computer software. The wavelength test (detection equipment: YOKOGAWA spectrometer AQ6373B, AQ6375B; AOP ATP8000-17) is also shown. Figure 9 In the middle (a), the test results are at a wavelength of 655 nm. Figure 9 (b) shows the test results at a wavelength of 980nm. Figure 9 (c) shows the test results at a wavelength of 1060nm. Figure 9 (d) shows the test results at a wavelength of 1550nm.

[0108] Figure 10 This application provides a method for testing the continuous optical power and laser voltage at a wavelength of 655nm. Figure 11 This application provides a method for testing the continuous optical power and laser voltage at a wavelength of 980nm. Figure 12 This application provides a method for testing the continuous optical power and laser voltage at a wavelength of 1060nm. Figure 13 This application provides a method for testing the continuous optical power and laser voltage at a wavelength of 1550nm.

[0109] See Figures 10 to 13 As shown, the laser output power is obtained from the test results of continuous optical power and voltage variation with current in four wavelength bands: 980nm, 1060nm, 1550nm, and 650nm (test equipment: Thorlabs probes S121C and S401C; meter PM100D).

[0110] (4) Divergence angle test (testing equipment: DUMA BeamOn WSR spot analyzer; Thorlabs laser observation card)

[0111] ① The divergence angle of the first collimator that outputs a 1550nm laser wavelength (80% optical power) is 36mrad, as shown in Table 2 below.

[0112] Table 2. Size of the first light spot

[0113]

[0114] ② The divergence angle of the second collimator that outputs 1550 (20% optical power) / 1060 / 980 / 655nm laser wavelength is 2mrad, as shown in Table 3 below.

[0115] Table 3. Second Spot Size Table

[0116]

[0117]

[0118] The multi-wavelength tunable pulsed laser provided in this application can output lasers of various wavelengths. One of the wavelengths, a 650nm visible light beam, can be used as an indicator light in conjunction with the other invisible wavelength lasers to facilitate observation of the position of the invisible light. Furthermore, the three invisible light beams can meet the needs of different fields, improving applicability. Moreover, the four different wavelength lasers are integrated into a single housing, enhancing overall integration and facilitating miniaturization, portability, and ease of use.

[0119] It should be noted that, upon considering the specification and practicing the application disclosed herein, those skilled in the art will readily conceive of other embodiments of this application. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0120] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The true scope is indicated by this application.

Claims

1. A multi-wavelength tunable pulsed laser, characterized in that, include: The first laser source is configured to generate a first laser. A second laser source is configured to generate a second laser; the wavelength of the first laser is greater than the wavelength of the second laser. A third laser source is configured to generate a third laser; the wavelength of the second laser is greater than the wavelength of the third laser. A fourth laser source is configured to generate a fourth laser; the wavelength of the third laser is greater than the wavelength of the fourth laser. A beam adjustment assembly, the input end of which is connected to the first laser source, the second laser source, the third laser source, and the fourth laser source, respectively; The output of the beam adjustment assembly is connected to the first collimator and the second collimator, respectively; The beam adjustment component is configured to split the first laser beam into a first sub-laser and a second sub-laser, and transmit the first sub-laser to the first collimator; the first laser has a first power, the second sub-laser has a second power, and the wavelengths of the first sub-laser and the second sub-laser are the same as the wavelength of the first laser; the first power and the second power are different. The beam adjustment assembly is further configured to combine the second sub-laser, the second laser, the third laser, and the fourth laser into a single beam and transmit it to the second collimator; The first collimator is configured to collimate the first sub-laser; The second collimator is configured to collimate the second sub-laser, as well as the second laser, the third laser, and the fourth laser.

2. The multi-wavelength tunable pulsed laser according to claim 1, characterized in that, The beam adjustment assembly includes a coupler and a beam adjuster; The input end of the coupler is connected to the first laser source, and the output end of the coupler is connected to the beam adjuster and the first collimator, respectively; the coupler is configured to split the first laser beam into a first sub-laser and a second sub-laser. The input end of the beam modulator is connected to the output end of the coupler, the second laser source, the third laser source, and the fourth laser source, respectively, and the output end of the beam modulator is connected to the second collimator; the beam modulator is configured to transmit the second sub-laser, the second laser, the third laser, and the fourth laser to the second collimator.

3. The multi-wavelength tunable pulsed laser according to claim 2, characterized in that, Also includes: The drive control board is equipped with the first laser source, the second laser source, the third laser source, the fourth laser source, and the beam adjustment component.

4. The multi-wavelength tunable pulsed laser according to claim 3, characterized in that, Also includes: The housing has a drive control board disposed inside it, and the first collimator and the second collimator are disposed outside it. The dimensions of the housing are 95mm × 95mm × 19mm; the weight of the multi-wavelength tunable pulse laser is less than 180g.

5. The multi-wavelength tunable pulsed laser according to claim 4, characterized in that, The housing includes a top plate, two first side plates, two second side plates, and a bottom plate; The drive control board is mounted on the base plate; Both the top plate and the first side plate are detachably connected to the second side plate; The second side plate is provided with a first through hole and a second through hole. The first through hole is used to pass through an optical fiber, and the second through hole is used to pass through an electrical wire. The two first through holes are located on both sides of the two second through holes.

6. The multi-wavelength tunable pulsed laser according to claim 5, characterized in that, The first laser source, the second laser source, the third laser source, and the fourth laser source are all multimode semiconductor lasers; The wavelength of the first laser is 1550nm; the wavelength of the second laser is 1060nm; the wavelength of the third laser is 980nm; and the wavelength of the fourth laser is 650nm.

7. The multi-wavelength tunable pulsed laser according to claim 6, characterized in that, The drive control board includes a continuous constant current control module and a pulse constant current control module; The continuous constant current control module is configured to provide a continuous constant current to the fourth laser source; The pulse constant current control module is configured to provide nanosecond pulse current to the first laser source, the second laser source, and the third laser source.

8. The multi-wavelength tunable pulsed laser according to claim 6, characterized in that, The drive control board includes a laser switch chip, and the laser switch chip includes six switch channels; Among them, one of the six switching channels is configured to output a continuous constant current to the fourth laser source; two of the six switching channels are configured to output nanosecond pulse currents to the second laser source and the third laser source, respectively; and three of the six switching channels are configured to output nanosecond pulse currents to the first laser source after being connected in parallel and superimposed.

9. The multi-wavelength tunable pulsed laser according to claim 8, characterized in that, The first collimator includes a first lens, a second lens, and a first window plate arranged sequentially along the light emission direction; both sides of the first lens, the second lens, and the first window plate are provided with anti-reflection coatings in the wavelength range of 1550±3nm; The second collimator includes a third lens, a fourth lens, and a second window arranged sequentially along the light output direction; both sides of the third lens, the fourth lens, and the second window are provided with an anti-reflection coating in the wavelength range of 600 to 2000 nm.

10. The multi-wavelength tunable pulsed laser according to claim 9, characterized in that, Also includes: First connecting optical fiber and second connecting optical fiber; The first connecting optical fiber is connected between the beam modulator and the second collimator; The second connecting optical fiber is connected between the first laser source and the coupler, between the second laser source and the beam modulator, between the third laser source and the beam modulator, between the fourth laser source and the beam modulator, between the coupler and the beam modulator, and between the coupler and the first collimator; The core of the first connecting optical fiber is 200 μm, and the core of the second connecting optical fiber is 105 μm.

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