Non-continuous short pulse laser incoherent polarization time sequence synthesis device

Abstract

The invention discloses a discontinuous short pulse laser incoherent polarization time sequence synthesis device, and relates to the technical field of laser synthesis. The device comprises a beam combiner, and the beam combiner is used for combining multiple paths of lasers with mutually vertical polarization states of a main laser beam and an auxiliary laser beam into coaxially propagating light beams, so that the space structures of the two laser beams in a near field and a far field are completely overlapped, and the directivity is the same. The polarization state of the synthesized laser is consistent, and light amplification can be realized through the same amplifier; the device is suitable for synthesizing sub-laser with a wide repetition frequency range and supports repetition frequencies from several hertz to hundreds of hertz; in addition, the device can synthesize three or more paths of laser, the repetition frequency of the synthesized laser is the sum of the repetition frequencies of all sub-lasers, and the device has high expansibility and flexibility and is suitable for various complex laser application scenes.

Description

Technical Field

[0001] The invention belongs to the field of laser synthesis, and in particular relates to a discontinuous short pulse laser incoherent polarization timing synthesis device. Background Art

[0002] At present, for laser applications, the pursuit of greatly improving the laser repetition frequency and output power, the technology usually used is polarization synthesis technology. Through polarization synthesis technology, the lasers of two sub-lasers are synthesized into one beam through a polarization device, thereby improving the overall repetition frequency and output power of the laser.

[0003] The basic principle of traditional incoherent polarization synthesis is to combine two linearly polarized laser beams into one laser beam through a polarization beam combiner (PBC). Figure 1 As shown, laser 1 and laser 2 are two linearly polarized light beams, whose polarization states are perpendicular to each other, and are synthesized by a polarization beam combiner (PBC). The synthesized light beams have a coaxial full-space structure and the same laser directivity.

[0004] However, the light beam formed by polarization synthesis technology does not control the phase between the light beams involved in the synthesis, resulting in the synthesized light beam containing two orthogonal polarization states of light at the same time. Therefore, the obtained light beam cannot pass through the polarizer or polarizer again, and therefore cannot be polarized again with the third and subsequent laser beams, limiting the number of laser synthesis times.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a discontinuous short pulse laser incoherent polarization timing synthesis device, which solves the problems raised in the above background technology.

[0007] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0008] A discontinuous short pulse laser incoherent polarization timing synthesis device, used for synthesizing a main laser beam and a subsidiary laser beam, comprising:

[0009] Beam combiner: The beam combiner is used to combine the main laser beam and the auxiliary laser beam with mutually perpendicular polarization states into a coaxially propagating beam, so that the spatial structures of the two laser beams in the near field and far field are completely overlapped and have the same directivity;

[0010] A synthesis turntable, on which a plurality of polarization state 90° rotators are fixed, and the polarization state 90° rotators are evenly distributed with the center of the circle as the axis of symmetry, so that each laser pulse passes through or avoids the polarization state 90° rotator at a specific time;

[0011] The polarization state 90° rotator is arranged below the beam combiner and is used to adjust the polarization state of the laser pulse so that its polarization direction is consistent with the polarization direction of the unadjusted beam;

[0012] A rotation drive mechanism, the output end of which is connected to the composite turntable, is used to drive the composite turntable to rotate at a set speed.

[0013] Optionally, it also includes a timing control system, which includes a signal generator and a rotation drive mechanism controller, wherein the signal generator is used to control the laser pulse output time interval of the main laser beam and the sub-laser beam, and the rotation drive mechanism controller is used to control the rotation mode and speed of the rotation drive mechanism, so that the laser pulse passes through the polarization state 90° rotator according to a preset timing.

[0014] Optionally, during use, the timing control system performs the following steps:

[0015] According to the type of laser, the repetition frequency and pulse width of the laser pulse, the output pulse delay of the main laser beam and the auxiliary laser beam is set, and the rotation speed and mode (continuous rotation or pulse rotation) of the rotation drive mechanism are determined to determine the number and distribution of the polarization state 90° rotators on the synthesis turntable;

[0016] The signal generator accurately triggers the laser, so that the main laser beam and the auxiliary laser beam emit pulses in sequence according to the set timing relationship. The pulse of the main laser beam is output first as a reference signal, and the pulse of the auxiliary laser beam is output after a delay of a period of time;

[0017] As the laser pulse is triggered, the servo motor starts to rotate under the control of the timing control system. The servo motor drives the synthesis turntable to rotate at a set speed, so that the polarization state 90° rotator is always at an angle position that matches the laser pulse;

[0018] When the laser pulse passes through the synthesis turntable, the timing control system ensures that the pulse strictly matches the position of the rotator. The pulse of the main laser beam bypasses the polarization state 90° rotator and maintains its original polarization state; the pulse of the auxiliary laser beam passes through the rotator accurately, so that its polarization state is rotated 90° to keep consistent with the polarization direction of the main laser beam;

[0019] During the process of laser pulse output and servo motor rotation, the timing control system will dynamically adjust the delay and rotation speed according to the real-time feedback signal. If a deviation is detected in the time interval between laser pulses or the rotation speed of the servo motor, the system will immediately correct it to optimize the pulse delay and rotation speed.

[0020] Optionally, the laser is one or more of short pulse, discontinuous, and linearly polarized lasers.

[0021] Optionally, a plurality of light holes are provided between the top and bottom of the combining turntable, the polarization state 90° rotators are fixed in the light holes of the combining turntable, and the angles between every two adjacent polarization state 90° rotators are the same.

[0022] Optionally, the beam combiner is one of a thin film polarizer, a polarization beam combiner, and a polarization beam splitter.

[0023] Optionally, when the synthesizer is a thin-film polarizer, the horizontally polarized light output by the main laser beam is completely transmitted through the beam-combining polarizer, and the vertically polarized light output by the sub-laser beam is reflected on the beam-combining polarizer at the Brewster angle and synthesized into the main laser beam optical path for synthesis.

[0024] Optionally, the rotary drive mechanism includes but is not limited to one of a servo motor, a rotary cylinder, and a stepper motor.

[0025] Optionally, the polarization state 90° rotator is one of a half-wave plate and a 90° rotor.

[0026] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all the advantages described below at the same time:

[0027] The polarization state of the laser synthesized by the present invention is consistent. This feature enables the laser to achieve efficient light amplification through the same amplifier, avoiding energy loss and complex adjustment operations caused by polarization mismatch. This not only simplifies the system design of the subsequent amplification link, but also improves the stability and reliability of the overall optical path. In addition, the device can synthesize sub-lasers with a wide range of repetition frequencies, supporting repetition frequencies from a few hertz to hundreds of hertz, and is suitable for a variety of laser output requirements, including low-frequency high-power pulsed lasers and high-frequency low-energy pulsed lasers and other application scenarios. More importantly, the device can not only synthesize two lasers, but can also be expanded to polarization synthesis of three or more lasers. The repetition frequency of the synthesized laser is the sum of the repetition frequencies of all sub-lasers, thus breaking through the limitations of traditional polarization synthesis technology on the number and frequency of synthesized beams.

[0028] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described below are only some embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] In the figure:

[0031] Figure 1 This is the principle diagram of traditional incoherent polarization synthesis;

[0032] Figure 2 It is the relationship between the delay and timing between the laser pulses of the present invention;

[0033] Figure 3 It is a schematic diagram of the optical path of the polarization timing synthesis device of the present invention;

[0034] Figure 4 It is a schematic diagram of a synthetic turntable of the present invention.

[0035] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0036] 1. Beam combiner; 2. Synthesis turntable; 3. Polarization state 90° rotator; 4. Rotation drive mechanism; 5. Main laser beam; 6. Sub laser beam.

[0037] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0038] The present invention will now be described in further detail with reference to the accompanying drawings.

[0039] See also Figure 1-4 As shown, in this embodiment, a discontinuous short pulse laser incoherent polarization timing synthesis device is provided, which is used to synthesize a main laser beam and a sub-laser beam, including:

[0040] A beam combiner 1 is used to combine the main laser beam 5 and the auxiliary laser beam 6, whose polarization states are perpendicular to each other, into a coaxially propagating beam, so that the spatial structures of the two laser beams in the near field and the far field are completely overlapped and have the same directivity;

[0041] A synthesis turntable 2, on which a plurality of polarization state 90° rotators 3 are fixed, the polarization state 90° rotators 3 are evenly distributed with the center of the circle as the axis of symmetry, so that each laser pulse passes through or avoids the polarization state 90° rotator 3 at a specific time; the shape of the synthesis turntable 2 includes but is not limited to a circle, a sphere or other mechanical shapes with low wind resistance.

[0042] refer to Figure 4 In the schematic diagram of this patent, the four polarization state 90° rotators 3 are distributed in a centrally symmetrical structure with the center of the circular turntable as the symmetry axis. The angle between the polarization state 90° rotators 3 is 90 degrees, and the distance from the center of the disk is the same. The polarization state 90° rotators 3 are fixed in the light-transmitting hole of the synthesis turntable 2;

[0043] refer to Figure 3The synthesis turntable 2 is fixed on the shaft of the servo motor and placed in the optical path as shown in the schematic diagram. The placement angle of the synthesis turntable 2 is adjusted so that the laser to be synthesized is incident on the end face of the crystal of the 90° rotator 3 with a vertical polarization state. It is ensured that when the turntable rotates at a high speed, the directivity of the laser to be synthesized is not deflected after passing through the 90° rotator 3 with a polarization state;

[0044] The polarization state 90° rotator 3 is arranged below the beam combiner 1 and is used to adjust the polarization state of the laser pulse so that its polarization direction is consistent with the polarization direction of the unadjusted light beam;

[0045] The rotating drive mechanism 4, the output end of which is connected to the combining turntable 2, is used to drive the combining turntable 2 to rotate at a set speed. The repetition frequency of the combined laser beam can be different

[0046] A discontinuous short pulse laser incoherent polarization timing synthesis device also includes a timing control system, which includes a signal generator and a rotation drive mechanism 4 controller, wherein the signal generator is used to control the laser pulse output time interval of the main laser beam 5 and the auxiliary laser beam 6, and the rotation drive mechanism 4 controller is used to control the rotation mode and speed of the rotation drive mechanism 4, so that the laser pulse passes through the polarization state 90° rotator 3 according to a preset timing. The timing control system can control the output delay between the laser pulses to be synthesized, such as Figure 2 By optimizing and adjusting the output delay between laser pulses, it is possible that when the beam combining turntable rotates at high speed, each pulse of one laser does not pass through the polarization state 90° rotator 3, while each pulse of the other laser accurately passes through the polarization state 90° rotator 3 on the combining turntable 2.

[0047] In this embodiment, the timing control system performs the following steps during use:

[0048] According to the type of laser, the repetition frequency and pulse width of the laser pulse, the output pulse delay of the main laser beam 5 and the auxiliary laser beam 6 is set, and the rotation speed and mode of the rotation drive mechanism 4 are set to be continuous rotation or pulse rotation, and the number and distribution of the polarization state 90° rotators 3 on the synthesis turntable 2 are determined;

[0049] The signal generator accurately triggers the laser, so that the main laser beam 5 and the auxiliary laser beam 6 emit pulses in sequence according to the set timing relationship. The pulse of the main laser beam 5 is output first as a reference signal, and the pulse of the auxiliary laser beam 6 is output after a delay of a period of time;

[0050] As the laser pulse is triggered, the servo motor starts to rotate under the control of the timing control system. The servo motor drives the synthesis turntable 2 to rotate at a set speed, so that the polarization state 90° rotator 3 is always at an angle position matching the laser pulse;

[0051] When the laser pulse passes through the synthesis turntable 2, the timing control system ensures that the pulse strictly matches the position of the rotator. The pulse of the main laser beam 5 bypasses the polarization state 90° rotator 3 and maintains its original polarization state; the pulse of the auxiliary laser beam 6 passes through the rotator accurately, so that its polarization state is rotated 90° and is consistent with the polarization direction of the main laser beam 5;

[0052] During the laser pulse output and servo motor rotation process, the timing control system will dynamically adjust the delay and rotation speed according to the real-time feedback signal. If the time interval between laser pulses or the speed of the servo motor is detected to be deviated, the system will immediately correct it to optimize the pulse delay and rotation speed. For example: According to the repetition frequency of 100Hz and pulse width of 10ns of the main laser beam 5 and the auxiliary laser beam 6, the timing control system sets the following parameters: the pulse delay between the main laser beam 5 and the auxiliary laser beam 6 is set to 5ms, which corresponds to half of the time interval of 100Hz repetition frequency. The speed of the servo motor is set to 25 revolutions per second and 50Hz. Four polarization state 90° rotators are fixed on the synthesis turntable 2, so the speed of the servo motor can meet the synthesis requirement of 200Hz. And select the "continuous rotation" mode to ensure that the synthesis turntable 2 runs at a constant speed.

[0053] The signal generator triggers the two lasers in sequence according to the set timing parameters: the pulse of the main laser beam 5 is emitted first as a reference signal; the pulse of the auxiliary laser beam 6 is emitted after a delay of 5ms, forming a specific timing relationship with the main laser beam 5.

[0054] As the laser pulse is triggered, the servo motor starts and rotates at a set high speed of 25 revolutions per second to drive the synthesis turntable 2. The four polarization state 90° rotators on the synthesis turntable 2 are distributed in a centrally symmetrical manner to ensure that the position of the rotator matches each laser pulse when it arrives.

[0055] When the laser pulse reaches the synthesis turntable 2: the pulsed horizontal polarized light of the main laser beam 5 directly bypasses the polarization state 90° rotator and maintains its original polarization state; the pulse of the auxiliary laser beam 6 accurately passes through the polarization state 90° rotator, and its polarization state is rotated 90°, which is consistent with the polarization state of the main laser beam 5. In this way, the synthesized laser beam is completely consistent in space and polarization state, and the repetition frequency reaches 200Hz after the two beams are superimposed.

[0056] During the laser pulse synthesis process, the timing control system will continue to receive real-time feedback signals, such as the speed of the servo motor and the time interval of the laser pulse. If the pulse delay of the auxiliary laser beam 6 is detected to be slightly deviated, such as 5.1ms, the system will immediately adjust the trigger timing of the signal generator and correct the delay back to 5ms. If the speed of the servo motor changes to 24.8 revolutions per second due to load fluctuations, the system will adjust the drive power of the motor in real time and restore it to 25 revolutions per second to ensure that the position of the rotator is synchronized with the pulse.

[0057] In this embodiment, the laser is one or more of short pulse, discontinuous, and linearly polarized lasers.

[0058] In this embodiment, a plurality of light-through holes are provided between the top and bottom of the combining turntable 2, and the polarization state 90° rotators 3 are fixed in the light-through holes of the combining turntable 2, and the angles between every two adjacent polarization state 90° rotators 3 are the same.

[0059] In this embodiment, the beam combiner 1 is one of a thin film polarizer, a polarization beam combiner 1, and a polarization beam splitter.

[0060] In this embodiment, the rotation driving mechanism 4 includes but is not limited to one of a servo motor, a rotary cylinder, and a stepping motor.

[0061] In this embodiment, the polarization state 90° rotator 3 is one of a half-wave plate and a 90° rotator.

[0062] In this embodiment, the device can be used to polarization synthesize more than two lasers, that is, after the main laser beam 5 is synthesized with the auxiliary laser beam 6-1, it can continue to be polarization synthesized with the auxiliary laser beam 6-2, auxiliary laser beam 6-3 and other lasers.

[0063] Example 1: When the synthesizer is a thin film polarizer, the horizontally polarized light output by the main laser beam 5 is completely transmitted through the beam-combining polarizer, and the vertically polarized light output by the sub-laser beam 6 is reflected on the beam-combining polarizer at the Brewster angle and synthesized into the optical path of the main laser beam 5 for synthesis.

[0064] Example 2: When the synthesizer 1 is a polarization beam combiner PBC or a polarization beam splitter PBS, the horizontally polarized light output by the main laser beam 5 is completely transmitted through the beam combiner 1, and the vertically polarized light output by the sub-laser beam 6 is reflected on the polarization beam combiner PBC or the polarization beam splitter PBS at the required angle of the polarization beam combiner PBC or the polarization beam splitter PBS and coupled into the main optical path of the main laser beam 5.

[0065] Step 1, the horizontally polarized main laser beam 5 and the vertically polarized auxiliary laser beam 6 are first polarized and synthesized by a beam combiner 1. The beam combiner 1 ensures that the two beams are completely coaxial in space, that is, the optical path structures of the two beams in the near field and the far field are completely overlapped and have the same directivity;

[0066] Step 2: The timing control system accurately adjusts the delay difference between the pulses of the main laser beam 5 and the auxiliary laser beam 6. By synchronously controlling the signal generator and the laser, the pulses of the two laser beams are output at a preset time interval. Figure 2 As shown in the timing relationship, the adjustment of the timing control system ensures that the laser pulse can achieve the best match when passing through the polarization state 90° rotator 3, thereby realizing efficient synthesis in time and space.

[0067] Step 3, determine the rotation speed of the servo motor according to the repetition frequency of the laser and the number of polarization state 90° rotators 3 on the synthesis turntable 2. The rotation speed of the servo motor is precisely matched with the time interval of the laser pulse to ensure that the polarization state rotator is synchronized with the laser pulse at the appropriate time position;

[0068] Step 4: The servo motor controller drives the servo motor to rotate at high speed according to the set speed, and the timing control system further accurately adjusts the rotation delay of the servo motor. The operation of the servo motor ensures that the polarization state 90° rotator 3 on the synthesis turntable 2 rotates according to the preset angle, so that each pulse of the main laser beam 5 can avoid the polarization state rotator and maintain the original polarization state, and each pulse of the auxiliary laser beam 6 accurately passes through the polarization state rotator to rotate its polarization state by 90°.

[0069] Step 5, after the synthesis of the main laser beam 5 and the auxiliary laser beam 6 is completed, the third and above lasers can be further added by repeating the above steps to gradually realize the polarization synthesis of multiple lasers.

[0070] The present invention is not limited to the above-mentioned embodiments. Anyone should be aware that any structural changes made under the enlightenment of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention. The technology, shape, and structural parts not described in detail in the present invention are all well-known technologies.

Claims

1. A discontinuous short-pulse laser incoherent polarization timing synthesis device, a beam combiner (1), the beam combiner (1) being used to combine a main laser beam (5) and a subsidiary laser beam (6) with multiple polarization states perpendicular to each other into a coaxially propagating beam, so that the spatial structures of the two laser beams in the near field and the far field are completely overlapped and have the same directivity; A synthesis turntable (2), wherein a plurality of polarization state 90° rotators (3) are fixed on the synthesis turntable (2), and the polarization state 90° rotators (3) are evenly distributed with the center of the circle as the symmetry axis, so that each laser pulse passes through or avoids the polarization state 90° rotator (3) at a specific time; The polarization state 90° rotator (3) is arranged below the beam combiner (1) and is used to adjust the polarization state of the laser pulse so that its polarization direction is consistent with the polarization direction of the unadjusted light beam; A rotation drive mechanism (4), the output end of which is connected to the composite turntable (2) and is used to drive the composite turntable (2) to rotate at a set speed.

2. The non-continuous short pulse laser incoherent polarization timing synthesis device according to claim 1, characterized in that: It also includes a timing control system, which includes a signal generator and a rotation drive mechanism (4) controller, wherein the signal generator is used to control the laser pulse output time interval of the main laser beam (5) and the auxiliary laser beam (6), and the rotation drive mechanism (4) controller is used to control the rotation mode and speed of the rotation drive mechanism (4), so that the laser pulse passes through the polarization state 90° rotator (3) according to a preset timing.

3. The non-continuous short pulse laser incoherent polarization timing synthesis device according to claim 1, characterized in that: During use, the timing control system performs the following steps: According to the type of laser, the repetition frequency and pulse width of the laser pulse, the output pulse delay of the main laser beam (5) and the auxiliary laser beam (6) is set, and the rotation speed and mode of the rotation drive mechanism (4) are determined to determine the number and distribution of the polarization state 90° rotators (3) on the synthesis turntable (2); The laser is accurately triggered by a signal generator, so that the main laser beam (5) and the auxiliary laser beam (6) emit pulses in sequence according to a set timing relationship, the pulse of the main laser beam (5) is output first as a reference signal, and the pulse of the auxiliary laser beam (6) is output after a delay of a period of time; As the laser pulse is triggered, the servo motor starts to rotate under the control of the timing control system. The servo motor drives the synthesis turntable (2) to rotate at a set speed, so that the polarization state 90° rotator (3) is always at an angle position matching the laser pulse; When the laser pulse passes through the synthesis turntable (2), the timing control system ensures that the pulse and the position of the rotator are strictly matched, and the pulse of the main laser beam (5) bypasses the polarization state 90° rotator (3) to maintain its original polarization state; the pulse of the auxiliary laser beam (6) passes through the rotator accurately, so that its polarization state is rotated by 90° and is consistent with the polarization direction of the main laser beam (5); During the process of laser pulse output and servo motor rotation, the timing control system will dynamically adjust the delay and rotation speed according to the real-time feedback signal. If a deviation is detected in the time interval between laser pulses or the rotation speed of the servo motor, the system will immediately correct it to optimize the pulse delay and rotation speed.

4. The non-continuous short pulse laser incoherent polarization timing synthesis device according to claim 1, characterized in that: The laser is one or more of short pulse laser, discontinuous laser and linear polarization laser.

5. The non-continuous short pulse laser incoherent polarization timing synthesis device according to claim 1, characterized in that: A plurality of light-through holes are provided between the top and bottom of the synthesis rotating disk (2), and the polarization state 90° rotators (3) are fixed in the light-through holes of the synthesis rotating disk (2), and the angles between every two adjacent polarization state 90° rotators (3) are the same.

6. The non-continuous short pulse laser incoherent polarization timing synthesis device according to claim 1, characterized in that: The beam combiner (1) is one of a thin film polarizer, a polarization beam combiner and a polarization beam splitter.

7. The non-continuous short pulse laser incoherent polarization timing synthesis device according to claim 1, characterized in that: When the synthesizer is a thin-film polarizer, the horizontally polarized light output by the main laser beam (5) is completely transmitted through the beam-combining polarizer, and the vertically polarized light output by the auxiliary laser beam (6) is reflected on the beam-combining polarizer at the Brewster angle and synthesized into the optical path of the main laser beam (5) for synthesis.

8. The non-continuous short pulse laser incoherent polarization timing synthesis device according to claim 1, characterized in that: The rotary drive mechanism (4) includes but is not limited to one of a servo motor, a rotary cylinder, and a stepper motor.

9. The non-continuous short pulse laser incoherent polarization timing synthesis device according to claim 1, characterized in that: The polarization state 90° rotator (3) is one of a half-wave plate and a 90° rotator.

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