A coaxial output of different characteristic lasers

Abstract

The application discloses a coaxial output different characteristic laser beam combiner, and belongs to the technical field of lasers, which comprises at least two laser oscillators, the laser oscillator comprises a full reflection mirror and a laser output mirror, a laser medium, a laser pulse generator and a polarization controller are sequentially arranged in an oscillation cavity formed by the full reflection mirror and the laser output mirror; the laser oscillators share one laser output mirror, and a coaxial combiner is arranged at the front end of the laser output mirror, so that coaxial combination of multiple lasers in the cavity is realized. The coaxial output different characteristic laser beam combiner can realize combination of multiple lasers in the cavity, the combination light path is not disturbed by external environmental factors, the output combined laser can contain sub-lasers with different characteristics, each sub-laser can be controlled, and the composition of the pulse sequence in the combined laser and the working time sequence of each sub-laser can be adjusted and controlled.

Description

Technical Field

[0001] This invention relates to a laser, specifically a beam combining laser capable of coaxially outputting lasers with different characteristics, belonging to the field of laser technology. Background Technology

[0002] Currently, lasers have gradually penetrated into various application fields, especially in the processing and manufacturing field. Based on the differences in the interaction between lasers with different properties and matter, in order to obtain ideal material processing and treatment effects, increasingly higher requirements are placed on the performance and use of laser light sources in practical applications. One crucial application is to use two or more lasers with different properties to make the laser beams act on the same position of the object being processed simultaneously or in a certain time sequence. The traditional solution for this laser application is to use a spatial or spectral beam combining optical path with multiple optical elements outside the laser cavity to combine the laser beams and point them into a coaxial and unidirectional laser beam.

[0003] Existing laser extracavity beam combining devices are shown in the attached figure. Figure 1 As shown, the synchronous controller 8 sends trigger signals to the two pump light drive controllers 7 respectively. The pump light drive controllers 7 control the pump light source 6 to generate pump pulses to pump the laser medium 2. Lasers with wavelengths λ1 and λ2 are generated in the laser resonant cavity composed of the total reflection mirror 1 and the laser output mirror 3. The lasers with wavelengths λ1 and λ2 are output from the laser output mirror 3 respectively. After being reflected by the 45° total reflection mirror 5, the laser with wavelength λ2 is converged with the laser with wavelength λ1 outside the laser and converged into the coaxial beam combiner 4. The combined laser beam can act on the same position of the object being processed.

[0004] It can be seen that traditional extracavity laser beam combining devices use a spatial or spectral beam combining optical path with multiple optical elements outside the laser cavity to combine individual laser beams into a coaxial and unidirectional beam. However, in actual laser application environments, due to the increased complexity of the external optical path and optical components, changes in environmental vibration, temperature, airflow, and component stress will cause changes in the optical elements and their supporting structures, leading to changes in the beam combining optical path and causing the combined laser beam to separate. This results in the laser beam not being able to converge at the same position on the workpiece, affecting processing results and work efficiency. Furthermore, the sub-laser pulse sequences contained in the output combined laser beam have the same characteristics, and its output form is singular and inflexible, greatly limiting laser applications, especially in the fields of laser precision manufacturing, laser cleaning, and laser processing.

[0005] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides a beam combiner capable of coaxially outputting lasers with different characteristics. It can combine multiple lasers within the cavity, and the beam combining optical path is not affected by external environmental factors. The output beam combiner can contain sub-lasers with different characteristics, each sub-laser can be controlled independently, and the composition of the pulse sequence in the beam combiner and the working timing of each sub-laser can be adjusted.

[0007] To solve the above technical problems, the present invention adopts the following technical solution:

[0008] A beam combiner capable of coaxially outputting lasers with different characteristics is characterized by comprising at least two laser oscillators, each laser oscillator including a total reflection mirror and a laser output mirror, wherein a laser medium, a laser pulse generator, and a polarization controller are sequentially installed in the oscillation cavity formed by the total reflection mirror and the laser output mirror.

[0009] The laser oscillator uses a single laser output mirror, and a coaxial beam combiner is provided at the front end of the laser output mirror. By using a single laser output mirror, coaxial beam combining of multiple lasers can be achieved within the cavity.

[0010] Furthermore, the laser output mirror is a dual-color or multi-color output mirror.

[0011] Furthermore, the laser medium is pumped by a pump source, which is connected to the output port of the pump light drive controller. The input port of the pump light drive controller is connected to the output port of the synchronization controller.

[0012] Furthermore, the pump source is a pulse pump, and the pump source can be multiple pump sources with different wavelengths or multiple pump sources with the same wavelength.

[0013] Furthermore, the laser pulse generator is connected to the output port of the pulse drive controller, and the input port of the pulse drive controller is connected to the output port of the synchronization controller.

[0014] Furthermore, the synchronization controller is equipped with a time base signal source as a time reference point, which periodically outputs synchronization trigger signals to the pump light drive controller and the pulse drive controller. The synchronization trigger signal has adjustable pulse width and adjustable frequency, which allows each drive controller to have an adjustable time delay. The synchronization controller is also equipped with a temperature control device for monitoring and controlling the temperature of the pump light source.

[0015] Furthermore, the pulse drive controller controls the laser pulse generator to control the characteristics of the oscillating laser pulse. The laser output by the laser pulse generator operates with a certain pulse repetition frequency and pulse width, which depend on the electrical pulses emitted by the pulse drive controller.

[0016] A polarization controller is used to change the polarization state of a laser, select a beam that meets the output requirements, and match the polarization states of each laser path.

[0017] Furthermore, the coaxial combiner can be a dispersive element, an optical fiber combiner, a polarization beam splitter, or a 45° dichroic mirror, with the front and rear surfaces of the 45° dichroic mirror coated with high-transmittance and high-reflection films corresponding to the laser wavelength, respectively.

[0018] Furthermore, the laser medium includes, but is not limited to, crystalline materials.

[0019] Compared with the prior art, the present invention, by adopting the above technical solution, has the following advantages:

[0020] 1. This invention features high stability, adjustability, and scalability, and can coaxially output lasers with different characteristics (pulse frequency, pulse width, wavelength).

[0021] 2. This invention can achieve beam combining of multiple lasers within the cavity by sharing a single laser output mirror. Unlike the traditional method of combining multiple lasers after they output their lasers, this invention can overcome the problem that the traditional external laser beam combining optical path is easily affected by external environmental factors.

[0022] 3. This invention can control the pump source and laser pulse generator by adjusting the time delay of the drive controller, so that the laser oscillator can generate a variety of laser pulses. After beaming, lasers with different characteristics (pulse frequency, pulse width, wavelength) can be output coaxially, which can overcome the problem that the output laser pulse train of traditional lasers has a single and uncontrollable characteristic.

[0023] 4. This invention effectively expands the application fields of lasers. It can combine multiple laser beams before output, and the pulse operating frequency composition, wavelength, and working time sequence between each frequency pulse train of the output laser are adjustable. This results in a highly efficient, stable, and precise coaxial output laser. It can be used in research and applications with more complex environments and high requirements for laser characteristics. For example, in the industrial field, it can be used for precise positioning, processing, cleaning, and measurement control in factories with mechanical vibration and unstable temperatures; in the field of laser imaging, it can be used for real-time dynamic imaging and complex environment detection imaging; in the life sciences, it can be used for biological tissue imaging, photodynamic therapy, and resection; and in fields such as laser spectroscopy, ultrafast dynamics, and long-distance free-space optical communication.

[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of two laser beam combining devices that realize two laser beam combining devices outside the laser cavity in the prior art;

[0026] Figure 2 Example 1 shows a beam combiner that coaxially outputs two lasers with different characteristics (pulse frequency, pulse width, wavelength);

[0027] Figure 3 Example 2 is a beam combiner that coaxially outputs multiple lasers with different characteristics;

[0028] Figure 4 Example 3 describes a laser combining two lasers with different characteristics that achieves coaxial output based on an optical fiber combiner.

[0029] Figure 5 Example 4 is a laser that combines two laser beams with different characteristics to achieve coaxial output based on a dispersive element.

[0030] In the figure, 1-total reflection mirror, 2-laser medium, 3-laser output mirror, 4-coaxial beam combiner, 5-45° total reflection mirror, 6-pump source, 7-pump light drive controller, 8-synchronization controller, 9-laser pulse generator, 10-polarization controller, 11-pulse drive controller, 12-fiber beam combiner, 13-dispersion element. Detailed Implementation

[0031] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0032] Example 1

[0033] like Figure 2 As shown, the present invention provides a beam combiner laser capable of coaxially outputting lasers with different characteristics, comprising two laser oscillators, each comprising a total reflection mirror 1 and a laser output mirror 3. A laser medium 2, a laser pulse generator 9, and a polarization controller 10 are sequentially installed in the oscillation cavity formed by the total reflection mirror 1 and the laser output mirror 3. The two laser oscillators share a single laser output mirror 3.

[0034] Two laser oscillators share a single laser output mirror 3, and complete laser oscillation and obtain optimal output power at the same position on the laser output mirror 3, thereby achieving coaxial beam combining laser, which has the characteristics of high stability, controllability, and scalability.

[0035] The laser medium 2 is pumped by the pump source 6, which is connected to the output port of the pump light drive controller 7. The input port of the pump light drive controller 7 is connected to the output port of the synchronization controller 8.

[0036] The laser pulse generator 9 is connected to the output port of the pulse drive controller 11, and the input port of the pulse drive controller 11 is connected to the output port of the synchronization controller 8.

[0037] A coaxial beam combiner 4 is provided at the front end of the laser output mirror 3, and a 45° total reflection mirror 5 is provided on the side of the coaxial beam combiner 4 to change the direction of laser transmission.

[0038] The two laser oscillators include a first laser oscillator and a second laser oscillator. The first laser oscillator is used to generate a laser with wavelength λ1, pulse frequency f1, and pulse width t1, and the second laser oscillator is used to generate a laser with wavelength λ2, pulse frequency f2, and pulse width t2. λ1 and λ2, f1 and f2, and t1 and t2 can be the same or different.

[0039] The total reflection mirror 1 is the end mirror of the laser oscillation cavity, used to generate oscillations of the laser within the cavity.

[0040] The laser medium 2, under the irradiation of the pump light source 6, provides inverted particles that generate laser oscillations. The laser medium 2 includes, but is not limited to, crystalline materials, and may also be laser media doped with, bonded with, or cemented with rare earth ions, glass, ceramics, optical fibers, dyes, titanium sapphire, etc.

[0041] The laser output mirror 3 is a partially transmittance dual-color output mirror, which has a certain transmittance for beams with wavelengths λ1 and λ2.

[0042] The coaxial beam combiner 4 is used to combine the beams of wavelengths λ1 and λ2 into a single laser beam, converting it into a laser beam with a single direction.

[0043] The 45° total reflection mirror 5 is used to change the transmission direction of the wavelength λ2 laser and reflect the wavelength λ2 laser to the coaxial beam combiner 4.

[0044] The pump source 6 is pulse pumped. The laser medium 2 usually has multiple gain absorption bands of different wavelengths. Therefore, the pump source 6 can be multiple pump sources of different wavelengths or multiple pump sources of the same wavelength.

[0045] The synchronization controller 8 is equipped with a time base signal source as a time reference point, and periodically outputs a synchronization trigger signal to the pump light drive controller 7 and the pulse drive controller 11. The synchronization trigger signal has adjustable pulse width and adjustable frequency, which allows each drive controller to have an adjustable time delay. The synchronization controller 8 is also designed with a temperature control device to monitor and control the temperature of the pump light source 6.

[0046] The synchronization controller 8 has multiple output ports and can generate multiple trigger signals simultaneously, sending each trigger signal to the corresponding pump light drive controller 7 and pulse drive controller 11. The pump light drive controller 7 drives the pump light source 6 to pump the laser medium 2. The operating frequency, pulse width, duty cycle, and synchronization timing of the pump pulses output by the pump light source 6 are controlled by the pump light drive controller 7.

[0047] The pulse drive controller 11 controls the laser pulse generator 9, thereby controlling the characteristics of the oscillating laser pulse. The laser output by the laser pulse generator 9 operates with a certain pulse repetition frequency and pulse width, which depends on the electrical pulses emitted by the pulse drive controller 11.

[0048] The polarization controller 10 selects the beam that meets the output requirements by changing the laser polarization state, so that the polarization states of each laser are matched, thereby enabling beam merging.

[0049] The specific working principle of this embodiment is as follows:

[0050] The synchronization controller 8 uses its built-in time base signal as a time reference point to adjust and control the pump light drive controller 7 and the pulse drive controller 11 respectively. The pump light drive controller 7 drives the pump light source 6 to pump the laser medium 2. The pulse drive controller 11 controls the laser pulse generator 9 to control the characteristics of the oscillating laser pulse. Under the illumination of the pump light source 6, the laser medium 2 in the laser oscillator generates the inverted particles required for laser oscillation. The laser pulse generator 9 executes the control command of the pulse drive controller 11 to regulate the oscillating laser in the laser oscillator. The polarization controller 10 changes the laser polarization state to select the beam that meets the output requirements, so that the polarization states of each laser are matched, thereby enabling beam merging. The 45° total reflection mirror 5 is used to change the transmission direction of the wavelength λ2 laser, reflecting the wavelength λ2 laser to the coaxial beam combiner 4. Wavelengths λ1 and λ2 are combined into one laser by the coaxial beam combiner 4, and output through the partially transmittance dual-color laser output mirror 3, while reflecting light of other wavelengths.

[0051] Example 2

[0052] like Figure 3 As shown, Embodiment 2 discloses a beam combiner that coaxially outputs multiple lasers with different characteristics. The difference between Embodiment 2 and Embodiment 1 is that:

[0053] Example 2 includes three laser oscillators, which share a single laser output mirror 3; in Example 2, there are two coaxial beam combiners 4 and two 45° total reflection mirrors 5.

[0054] The laser output mirror 3 in Example 2 is a partially transmittance multicolor output mirror.

[0055] The three laser oscillators include a first, a second, and a third laser oscillator, which generate lasers with wavelengths λ1, λ2, and λ3, respectively.

[0056] The laser with wavelength λ2 is reflected by the 45° total reflection mirror 5 to the coaxial beam combiner 4, and wavelengths λ1 and λ2 are combined into a single laser beam. The laser with wavelength λ3 is reflected by the 45° total reflection mirror 5 to the coaxial beam combiner 4, and wavelengths λ3, λ1, and λ2 are combined into a single laser beam. The laser beam is then output through a multicolor output mirror with partial transmittance and reflects light of other wavelengths.

[0057] Example 3

[0058] like Figure 4 As shown, Embodiment 3 discloses a beam-combining laser that achieves coaxial output of two lasers with different characteristics based on an optical fiber beam combiner. The difference between Embodiment 3 and Embodiment 1 is that:

[0059] The front end of the laser output mirror 3 is provided with an optical fiber combiner 12. The optical fiber combiner 12 combines the laser transmission fibers of wavelength λ1 and wavelength λ2 into a single optical fiber for output. Finally, the combined laser beam is output through the laser output mirror 3. The laser output mirror 3 is a partially transmittance dual-color output mirror, which has a certain transmittance for the beams of wavelengths λ1 and λ2.

[0060] Example 4

[0061] like Figure 5 As shown, Embodiment 4 discloses a beam combiner that achieves coaxial output of two lasers with different characteristics based on a dispersive element. The difference between Embodiment 4 and Embodiment 1 is that:

[0062] The laser output mirror 3 has a dispersive element 13 at its front end. The dispersive element 13 combines laser beams of different wavelengths λ1 and λ2 from different directions into a single beam path, which is then output through the laser output mirror 3. The laser output mirror 3 is a partially transmittance bicolor output mirror, which has a certain transmittance for beams of wavelengths λ1 and λ2.

[0063] The coaxial beam combiner 4 in this invention can combine two or more lasers into a single laser, converting it into a laser with a single direction. The type of coaxial beam combiner 4 is selected based on the characteristics of the generated laser.

[0064] When the coaxial beam combiner 4 is a dispersive element 13, the dispersive element 13 can be an optical element with dispersive capabilities, such as a prism, Brewster prism, diffraction grating, reflection grating, or a medium with an asymmetric structure. It combines lasers of different wavelengths from different directions into a single light path. In practical applications, it can be combined as needed, depending on the laser wavelength range, refractive index, reflectivity, diffraction efficiency, and accuracy that need to be separated.

[0065] When the coaxial combiner 4 is an optical fiber combiner 12, the refraction and total reflection of the optical fiber are used to couple lasers from different directions together and transmit them through the tail of the optical fiber.

[0066] When the coaxial beam combiner 4 is a polarization beam splitter, it can be a polarization beam splitter prism, fiber-coupled output polarization beam splitter (combiner), etc., which can combine lasers of different polarization states in different directions into one optical channel for output.

[0067] When the coaxial beam combiner 4 is a 45° dichroic mirror with high-transmittance and high-reflection films corresponding to the laser wavelength on its front and rear surfaces respectively, lasers of different wavelengths in different directions can be combined and output in the same optical path.

[0068] The above description provides examples of the preferred embodiments of the present invention. Parts not detailed herein are common knowledge to those skilled in the art. The scope of protection of the present invention is determined by the claims. Any equivalent modifications based on the technical teachings of the present invention are also within the scope of protection of the present invention.

Claims

1. A beam combiner capable of coaxially outputting lasers with different characteristics, characterized in that: It includes at least two laser oscillators, each comprising a total reflection mirror (1) and a laser output mirror (3). A laser medium (2), a laser pulse generator (9), and a polarization controller (10) are sequentially installed in the oscillation cavity formed by the total reflection mirror (1) and the laser output mirror (3). The laser oscillator uses a single laser output mirror (3), and a coaxial beam combiner (4) is provided at the front end of the laser output mirror (3). By using a single laser output mirror (3), coaxial beam combining of multiple lasers can be achieved in the cavity. The laser medium (2) is pumped by the pump light source (6), which is connected to the output port of the pump light drive controller (7), and the input port of the pump light drive controller (7) is connected to the output port of the synchronization controller (8). The laser pulse generator (9) is connected to the output port of the pulse drive controller (11), and the input port of the pulse drive controller (11) is connected to the output port of the synchronization controller (8). The synchronization controller (8) is equipped with a time base signal source as a time reference point, and periodically outputs a synchronization trigger signal to the pump light drive controller (7) and the pulse drive controller (11). The synchronization trigger signal has the characteristics of adjustable pulse width and adjustable frequency, which makes each drive controller have an adjustable time delay. The synchronization controller (8) is also equipped with a temperature control device for monitoring and controlling the temperature of the pump light source (6).

2. A beam combiner capable of coaxially outputting lasers with different characteristics as described in claim 1, characterized in that: The laser output mirror (3) is a dual-color or multi-color output mirror.

3. A beam combiner capable of coaxially outputting lasers with different characteristics as described in claim 1, characterized in that: The pump source (6) is a pulse pump, and the pump source (6) can be multiple pump sources with different wavelengths or multiple pump sources with the same wavelength.

4. A beam combiner capable of coaxially outputting lasers with different characteristics as described in claim 1, characterized in that: The pulse drive controller (11) controls the laser pulse generator (9) to control the characteristics of the oscillating laser pulse. The laser output by the laser pulse generator (9) operates with a certain pulse repetition frequency and pulse width. The frequency and pulse width depend on the electrical pulses emitted by the pulse drive controller (11). The polarization controller (10) is used to change the polarization state of the laser, select the beam that meets the output requirements, and match the polarization states of each laser.

5. A beam combiner capable of coaxially outputting lasers with different characteristics as described in claim 1, characterized in that: The coaxial combiner (4) is a dispersive element (13), an optical fiber combiner (12), a polarization beam splitter, or a 45° dichroic mirror. The front and back surfaces of the 45° dichroic mirror are coated with high-transmittance and high-reflection films corresponding to the laser wavelength, respectively.

6. A beam combiner capable of coaxially outputting lasers with different characteristics as described in claim 1, characterized in that: Laser media (2) include, but are not limited to, crystalline materials.

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