A fiber hybrid solid-state laser amplification system

Abstract

This invention provides a fiber-optic hybrid solid-state laser amplification system, comprising a fiber seed source, a pulse selector, a continuous laser seed source, a fiber combiner, a fiber collimator, a solid-state amplifier, a pump source, and a control circuit for receiving external trigger signals. The control circuit processes the signals and controls the switching of the pulse selector and the continuous laser seed source. The continuous laser seed source is connected to the fiber combiner, and the fiber seed source is connected to the fiber combiner via the pulse selector. The fiber combiner allows the continuous laser from the continuous laser seed source and the pulsed laser from the fiber seed source to enter the fiber collimator together. The output light of the fiber collimator enters the solid-state amplifier. The pump light emitted from the pump source is coupled into the gain medium of the solid-state amplifier. The output light of the solid-state amplifier separates the continuous laser and the pulsed laser through a beam splitter.

Description

Technical Field

[0001] This invention relates to a control system, and more particularly to a fiber hybrid solid-state laser amplification system. Background Technology

[0002] As the throughput requirements for each processing step in the manufacturing of electronic products, PCBs, and consumer electronics continue to increase, laser precision machining, which involves moving the laser beam across the workpiece surface, requires two methods: moving the beam or moving the workpiece itself. To maximize the throughput of laser processing steps, this movement speed should be as fast as possible. However, beam positioning accuracy limits the movement speed. In linear scribing, scanning speeds can reach 10 m / s or faster, but in scribing complex patterns, the scanning speed is limited, with a maximum speed of only 0.3 m / s or even slower. Therefore, the scanning speed in current micromachining processes is a parameter with a wide range of variations. To achieve excellent processing results, the laser must meet the following requirements.

[0003] Each pulse (or burst of pulses) emitted by the laser has a consistent pulse energy. This ensures that the amount of material removed and ablated remains consistent.

[0004] Each laser pulse is delivered to the workpiece surface at uniform intervals. This ensures that the heat-affected zone on the workpiece surface is minimized and consistent process quality is guaranteed.

[0005] Because the scanning speed varies significantly during processing, the spatial pulse spacing can only remain constant if the laser pulse repetition frequency changes with the scanning speed. From an application perspective, an ideal ultrafast laser can be approximated as a black box. This means that the laser can completely satisfy any output signal provided by the external motion control system and emit laser pulses, while the pulses emitted by the laser are consistent on the energy scale and ensure minimal jitter on the time scale.

[0006] The current mainstream solution is to use an optical fiber seed pulse selector and a spatial acousto-optic modulator. During the interval of frequency conversion processing, the first pulse selector releases an adjustable seed source pulse to balance the excess energy in the amplifier. At this time, the spatial acousto-optic modulator must be used to control the whole machine to be in a state of no light emission. However, the spatial acousto-optic modulator will cause at least 15% energy loss, and the diffracted output light spot will often be deformed. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art and provide a fiber hybrid solid-state laser amplification system. This invention solves at least some of the problems in the prior art.

[0008] This invention is implemented as follows:

[0009] This invention provides a fiber-optic hybrid solid-state laser amplification system, comprising a fiber seed source, a pulse selector, a continuous laser seed source, a fiber combiner, a fiber collimator, a solid-state amplifier, a pump source, and a control circuit for receiving external trigger signals. The control circuit processes the signals and controls the switching of the pulse selector and the continuous laser seed source. The continuous laser seed source is connected to the fiber combiner, which is connected via the pulse selector. The fiber combiner allows both the continuous laser and the pulsed laser from the continuous laser seed source to enter the fiber collimator. The output light from the fiber collimator enters the solid-state amplifier. The pump light emitted from the pump source is coupled into the gain medium of the solid-state amplifier. The output light of the solid-state amplifier separates the continuous laser and the pulsed laser through a beam splitter. The pulse output of the fiber seed source is controlled by the pulse selector. When the fiber seed source is not outputting pulses, the pulse selector is in a closed state. At this time, the continuous laser seed source is turned on to enter the solid-state amplifier to maintain the energy conservation of the solid-state amplifier, so that giant pulses will not occur during the next pulse amplification from the fiber seed source.

[0010] Furthermore, the optical fiber seed source is a ytterbium-doped optical fiber seed source.

[0011] Furthermore, the continuous laser seed source is a semiconductor laser.

[0012] Furthermore, the solid-state amplifier uses Nd:YVO4 gain dielectric.

[0013] Furthermore, the pump source is a fiber-coupled semiconductor laser.

[0014] Furthermore, the beam splitter uses a double-coated lens, which is coated with an anti-reflection coating and a total reflection coating.

[0015] Furthermore, the continuous laser output from the beam splitter is absorbed by the laser absorber.

[0016] Furthermore, when a random trigger signal is given from the outside, the control circuit will cause the pulse selector to release a pulsed laser of the same frequency. The control circuit will also cause a continuous laser to fill the pulse interval of the pulsed laser. After the pulsed laser and the continuous laser enter the solid-state amplifier, the continuous laser consumes more of the energy stored in the gain medium, so that when the pulse of the pulsed laser enters the solid-state amplifier, the energy storage time of the gain medium is the same, and the amplified pulse energy is consistent.

[0017] The present invention has the following beneficial effects:

[0018] This invention provides a fiber-optic hybrid solid-state laser amplification system. The system involves coupling two seed sources of different wavelengths (pulsed seed source and continuous seed source) to an fiber collimator before they enter a solid-state amplifier for energy amplification. The final laser output uses a beam splitter to separate the two different wavelengths. The laser's pulse output is controlled by a pulse selector. When the laser is not outputting pulses, the pulse selector is off. In this case, the continuous seed source is activated to maintain energy conservation in the solid-state amplifier, ensuring that giant pulses do not occur during the next main pulse amplification. The entire system achieves nanosecond-level precise laser pulse output and high pulse energy stability without requiring a spatial acousto-optic modulator, saving costs and providing superior laser output power and mode. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of a fiber hybrid solid-state laser amplification system provided in an embodiment of the present invention;

[0021] Figure 2 Provided for embodiments of the present invention Figure 1 Enlarged view on the left;

[0022] Figure 3 Provided for embodiments of the present invention Figure 1 Enlarged view on the right. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] like Figures 1-3The fiber hybrid solid-state laser amplification system provided by this invention includes a 1064nm fiber pulse seed source (generally a ytterbium-doped fiber seed source), which selects the desired seed light pulse through a pulse selector. The system also includes a 914nm continuous laser seed source (generally a semiconductor laser, such as a 915nm LD module), which uses a 914nm semiconductor laser. A fiber combiner allows the 914nm continuous light and the 1064nm pulse seed source to enter the fiber collimator together. The two beams enter an Nd:YVO4 gain medium, and the pump light is coupled into the gain medium, amplifying the seed source energy. After amplification, the 914nm continuous laser and the 1064nm pulse laser are separated by a beam splitter.

[0025] Optical fiber seed sources are generally ytterbium-doped optical fiber seed sources.

[0026] The gain medium of Nd:YVO4 can be rod-shaped, slab-shaped, or sheet-shaped. It has three emission spectra: 914, 1064, and 1342 nm. The LD laser has a 914 nm laser beam, which can be amplified by an Nd:YVO4 amplifier.

[0027] The 914nm semiconductor laser can be a 914nm wavelength-locked fiber-coupled semiconductor laser or a 915nm wavelength-unlocked fiber-coupled semiconductor laser.

[0028] The pump source for the gain medium can be an 808nm, 878nm, or 888nm fiber-coupled semiconductor laser.

[0029] The 914 / 1064 beam splitter uses a double-coated lens (one anti-reflective coating and one total reflection coating) to separate two beams of light.

[0030] The control circuit receives external trigger signals and processes them to control the switching of the pulse selector and the 914nm semiconductor laser.

[0031] In laser solid-state amplification systems, the amplification factor of pulse energy is strongly related to the gain medium. The pulse interval is the energy storage time of the gain medium; the longer the energy storage time, the higher the amplified pulse energy. When the laser repetition frequency is constant, the time interval between pulses is fixed, therefore the energy storage time of the gain medium is consistent, and the amplified pulse energy is consistent. During laser processing, the time interval of the laser pulses to be processed is random. When a random trigger signal is given externally (the signal frequency must be less than the repetition frequency set by the laser), the control circuit will cause the pulse selector to release a 1064nm seed light of the same frequency. The control circuit will then use a 914nm seed light to fill the pulse interval of the 1064nm seed light. After both beams enter the amplifier, the 914nm light consumes more of the Nd:YVO4 energy, ensuring that the energy storage time of the gain medium is the same when the 1064nm pulse enters the amplifier, thus resulting in consistent 1064nm pulse energy after amplification. Finally, the two beams can be separated using a beam splitter. The 1064nm pulsed light is the laser for processing, while the 914nm continuous light enters the laser absorber and is absorbed.

[0032] like Figure 1 In this embodiment, when the laser's reference frequency is 1MHz, four trigger signals are externally supplied. The interval between the first and second signals is 1µs, between the second and third signals is 3.5µs, and between the third and fourth signals is 1.5µs. At this time, the pulse selector releases a 1064nm seed pulse according to the timing of the trigger signals. Between the second and third signals, a 2.5µs 914nm seed source is released to consume the upper energy level particles of Nd:YVO4, and between the third and fourth signals, a 0.5µs 914nm seed source is released to consume the upper energy level particles of Nd:YVO4. This ensures that the energy storage time of Nd:YVO4 corresponding to the four pulses of the main pulse is 1µs, resulting in consistent amplified energy. Finally, a beam splitter separates the two beams of light with different wavelengths.

[0033] This invention provides a fiber-optic hybrid solid-state laser amplification system. The system involves coupling two seed sources of different wavelengths (pulsed seed source and continuous seed source) to an fiber collimator before they enter a solid-state amplifier for energy amplification. The final laser output uses a beam splitter to separate the two different wavelengths. The laser's pulse output is controlled by a pulse selector. When the laser is not outputting pulses, the pulse selector is off. In this case, the continuous seed source is activated to maintain energy conservation in the solid-state amplifier, ensuring that giant pulses do not occur during the next main pulse amplification. The entire system achieves nanosecond-level precise laser pulse output and high pulse energy stability without requiring a spatial acousto-optic modulator, saving costs and providing superior laser output power and mode.

[0034] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fiber-optic hybrid solid-state laser amplification system, characterized in that: The system includes an optical fiber seed source, a pulse selector, a continuous laser seed source, an optical fiber combiner, an optical fiber collimator, a solid-state amplifier, a pump source, and a control circuit for receiving external trigger signals. The control circuit processes the signals and controls the switching of the pulse selector and the continuous laser seed source. The continuous laser seed source is connected to the optical fiber combiner, and the optical fiber seed source is connected to the optical fiber combiner via the pulse selector. The optical fiber combiner allows the continuous laser from the continuous laser seed source and the pulsed laser from the optical fiber seed source to enter the optical fiber collimator together. The output light of the optical fiber collimator enters the solid-state amplifier. The pump light emitted from the pump source is coupled into the gain medium of the solid-state amplifier. The output light of the solid-state amplifier separates the continuous laser and the pulsed laser through a beam splitter. The pulse output of the fiber optic seed source is controlled by a pulse selector. When the fiber optic seed source is not outputting pulses, the pulse selector is in the off state. At this time, the continuous laser seed source is turned on to enter the solid-state amplifier to maintain the energy conservation of the solid-state amplifier, so that the next pulse amplification of the fiber optic seed source will not produce a giant pulse phenomenon. When a random trigger signal is given from the outside, the control circuit will cause the pulse selector to release a pulsed laser of the same frequency. The control circuit will also cause the continuous laser to fill the pulse interval of the pulsed laser. After the pulsed laser and the continuous laser enter the solid-state amplifier, the continuous laser consumes more of the energy stored in the gain medium, so that when the pulse of the pulsed laser enters the solid-state amplifier, the energy storage time of the gain medium is the same, and the amplified pulse energy is consistent.

2. The fiber hybrid solid-state laser amplification system as described in claim 1, characterized in that: The optical fiber seed source is a ytterbium-doped optical fiber seed source.

3. The fiber hybrid solid-state laser amplification system as described in claim 1, characterized in that: The continuous laser seed source is a semiconductor laser.

4. The fiber hybrid solid-state laser amplification system as described in claim 1, characterized in that: The solid-state amplifier uses Nd:YVO4 gain dielectric.

5. The fiber hybrid solid-state laser amplification system as described in claim 1, characterized in that: The pump source is a fiber-coupled semiconductor laser.

6. The fiber hybrid solid-state laser amplification system as described in claim 1, characterized in that: The beam splitter uses a double-coated lens, which is coated with an anti-reflective coating and a total reflection coating.

7. The fiber hybrid solid-state laser amplification system as described in claim 1, characterized in that: The continuous laser output from the beam splitter enters the laser absorber and is absorbed.

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