CN114899306A - A low temperature polarized system - Google Patents

Abstract

The invention relates to a low-temperature polarization system, which comprises a refrigeration module, a constant-temperature module, a temperature regulation module, a reversal control module and a high-pressure module, wherein the refrigeration module is connected with the constant-temperature module through a pipeline; the refrigeration module is communicated with the constant temperature module; the temperature adjusting module is respectively connected with the refrigerating module and the constant temperature module; the reversing module is placed in the constant temperature module and comprises a reversing clamp and a polarizing electrode, the polarizing electrode is arranged in the reversing clamp, the reversing clamp is used for fixing a crystal to be polarized, and the polarizing electrode has a periodic structure matched with the crystal to be polarized; the high-voltage module is used for applying polarization voltage to the inversion module; the reversing module, the reversing control module and the high-voltage module are connected with each other pairwise, the reversing control module receives charge signals from the reversing module, and whether the high-voltage module is triggered to apply polarization voltage to a polarization electrode of the reversing module or not is judged automatically according to the charge signals.

Description

A low temperature polarized system

technical field

The invention relates to the field of ferroelectric crystal polarization, in particular to a low temperature polarization system.

Background technique

Periodically poled potassium titanyl phosphate (periodically poled KTP, referred to as PPKTP) is an unnatural intraocular lens with a high permanent damage threshold, no obvious photorefractive effect at room temperature, and high nonlinear coefficient. Advantages, widely used in efficient conversion of wavelengths.

PPKTP is the core device of a very competitive new type of short-wavelength light source. Due to the Boying walk-off effect of birefringence phase matching, the improvement of nonlinear conversion efficiency is limited. Quasi-phase matching does not have such a disadvantage. The non-critical matching is achieved over the crystal length, so the interaction length is not limited, and the harmonic output of the entire spectrum in the transmission range of the crystal can be obtained.

At present, the high-voltage electric field polarization technology is mainly used to obtain PPKTP crystal, but since potassium titanyl phosphate (KTP) crystal itself contains metal ion K, it has a certain conductivity, so that the yield of high-voltage electric field polarization PPKTP is very low, or Can't be polarized at all. The United States Patent for Invention Publication No. US20030102441A1 discloses a technical solution for forming a polarized structure on KTP using a scanning force microscope (SFM) scanning probe device, which discloses that the conductivity of KTP can be reduced at a low temperature of 170K , however, its way of forming polarized structures one by one on KTP by scanning probe device is extremely inefficient for producing PPKTP.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a low-temperature polarization system, which on the one hand can reduce the electrical conductivity of fast ion dielectric crystal materials to make it comparable to that of ordinary dielectric crystals, and on the other hand can efficiently produce periodically polarized crystals .

To achieve the above object, the present invention is achieved through the following technical solutions:

The invention provides a low-temperature polarization system, comprising a refrigeration module, a constant temperature module, a temperature adjustment module, an inversion module, an inversion control module and a high-voltage module; the refrigeration module and the constant temperature module are communicated with each other; the temperature adjustment module is respectively connected with The refrigeration module and the constant temperature module are connected; the inversion module is placed in the constant temperature module, and the inversion module includes a reversal clamp and a polarized electrode, and the polarized electrode is arranged in the inversion clamp, and the inversion clamp is used for fixing The crystal to be polarized, the polarized electrode has a periodic structure matching the crystal to be polarized; the high-voltage module is used to apply a polarization voltage to the inversion module; the inversion module, the inversion control module and the high-voltage The modules are connected to each other, and the inversion control module receives the charge signal from the inversion module, and automatically judges according to the charge signal whether to trigger the high-voltage module to apply a polarization voltage to the polarization electrodes of the inversion module.

Further, the polarized electrodes are arranged on both sides of the crystal to be polarized; at least one side of the polarized electrodes on both sides has a periodic structure.

Further, the polarized electrode is any one of a metal electrode or a liquid electrode.

Further, the metal electrode includes a conductive area, an insulating liquid and a first O-ring, the conductive area is disposed on the surface of the crystal to be polarized, and the conductive area can be set to a periodic structure or a planar structure according to polarization requirements, The insulating liquid immerses the entire conductive area 101 and is sealed in the first O-ring; the insulating liquid includes insulating oil and antifreeze particles evenly dispersed in the insulating oil; the insulating oil is mineral insulating oil, synthetic insulating oil and Any one or more of vegetable oils, and the antifreeze particles are any one or more of polyimide particles, polyamideimide particles, and ultra-high molecular weight polyethylene particles;

Further, the liquid electrode includes an insulating area, a conductive liquid and a second O-ring, the insulating area is arranged on the surface of the crystal to be polarized, and the insulating area can be set as a periodic structure or a long hollow according to polarization requirements. structure, the conductive liquid immerses the entire insulating area and is sealed in the second O-ring; the conductive liquid includes liquid nitrogen and metal nanoparticles uniformly dispersed in the liquid nitrogen, the metal nanoparticles are Au nanoparticles, Ag nanoparticles Any one or several of nanoparticles, Al nanoparticles, and Cu nanoparticles.

Further, the working temperature of the constant temperature module is -150 to -100 degrees Celsius.

Further, the inversion control module includes an integrator and a comparator connected with the integrator, the integrator is connected to the polarized electrode, and the comparator is connected to the high-voltage module, and the integrator is used for the charge on the polarized electrode. Integration is performed, the comparator is set with a preset charge value.

Further, the high-voltage module includes a waveform generator and a high-voltage amplifier electrically connected to the waveform generator, the waveform generator includes a trigger, and the high-voltage amplifier includes an electrode lead connected to the polarized electrode.

Further, the polarization voltage applied by the high-voltage amplifier is 1-25KV/mm.

Further, the crystal to be polarized is a ferroelectric crystal, and the ferroelectric crystal includes any one of KTP, SLT, and LN.

The present invention has the following beneficial effects:

1. The present invention provides a low-temperature polarization system, which reduces the electrical conductivity of the fast ion dielectric crystal material through a low-temperature polarization method, and at the same time, through a refrigeration module, a constant temperature module, a temperature adjustment module, an inversion module, and an inversion control module. It cooperates with the high-voltage module to realize the automation of the production of periodically polarized crystals, and greatly improves the production efficiency of periodically polarized crystals.

2. The invention has made a lot of optimization on the inversion module, and realized the polarization of the polarized crystal using metal electrodes or liquid electrodes in a low temperature environment, especially the polarized crystal in the environment of -150 degrees Celsius to -100 degrees Celsius. polarization.

3. The present invention realizes the automation of polarization through the cooperation of the integrator and the comparator, with low automation cost and high efficiency.

4. The constant temperature module of the present invention has a simple structure and good cooling effect, and realizes the technical effect of automatic constant temperature through the cooperation of the computer and various sensors.

Description of drawings

Accompanying drawing 1 is the overall structure schematic diagram of the low temperature polarization system of the present invention;

Accompanying drawing 2 is the overall structure schematic diagram of the constant temperature chamber of the present invention;

3 is a schematic structural diagram of the periodic structure of the inversion electrode in the inversion module of the present invention on the upper side of the electrode to be inverted;

4 is a schematic structural diagram of the periodic structure of the inversion electrode in the inversion module of the present invention on the lower side of the electrode to be inverted;

FIG. 5 is a schematic structural diagram of the periodic structure of the inversion electrode in the inversion module of the present invention on both sides of the electrode to be inverted.

The reference numbers in the figure are indicated as:

1. Liquid nitrogen tank; 2. Liquid nitrogen pump; 3. Flow meter; 4. First heater; 5. Computer; 6. Control circuit; 7. User interface; 8. Constant temperature chamber; 81. External cavity wall; 82, outer cavity; 83, inner cavity; 84, opening; 9, reversing clamp; 10, polarized electrode; 101, conductive area; 102, insulating liquid; 103, first O-ring; 104, insulating area ; 105, conductive liquid; 106, second O-ring; 11, temperature sensor; 12, pressure sensor; 13, second heater; 14, nitrogen valve; 15, integrator; 16, comparator; 17, waveform generation 18. High voltage amplifier; 19. Electrode lead; 20. Trigger.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1, the present invention provides a low-temperature polarization system, including a refrigeration module, a constant temperature module, a temperature adjustment module, an inversion module, an inversion control module and a high-voltage module; the refrigeration module and the constant temperature module are communicated with each other; The temperature adjustment module is respectively connected with the refrigeration module and the constant temperature module, and the temperature adjustment module can obtain the real-time temperature detection result of the constant temperature module, and adjust the cooling effect of the refrigeration module in time according to the obtained temperature detection result; the inversion module is placed in the constant temperature module , the reversing module includes a reversing fixture 9 and a polarizing electrode 10, the reversing fixture 9 is used to fix the crystal to be polarized, and the polarizing electrode 10 has a periodic structure that matches the crystal to be polarized The high-voltage module is used to apply a polarized voltage to the inversion module; the inversion module, the inversion control module and the high-voltage module are connected to each other, and the inversion control module receives the charge signal from the inversion module, and according to The charge signal determines whether to trigger the high-voltage module to apply a polarization voltage to the polarization electrode 10 of the inversion module.

Specifically, the refrigeration module includes a liquid nitrogen tank 1 , a liquid nitrogen pump 2 and a flow meter 3 that are connected in sequence to deliver liquid nitrogen to the constant temperature module, and the liquid nitrogen pump 2 includes a first heater 4 , the first heater 4 is used to heat the liquid nitrogen pump 2 to prevent the liquid nitrogen pump 2 from being unable to extract liquid nitrogen due to freezing;

The constant temperature module includes a constant temperature chamber 8, a temperature sensor 11, a pressure sensor 12, a second heater 13 and a nitrogen valve 14, which are used to provide a constant temperature environment for the inversion module. The cavity wall 81, the outer cavity 82 and the inner cavity 83, the outer cavity wall 81 is provided with an opening 84, the liquid nitrogen tank 1 communicates with the outer cavity 82 through the opening 84, and the outer cavity 82 is used to receive the cooling The liquid nitrogen of the module, the inner cavity 83 is used to place the inversion module, the temperature sensor 11 is arranged in the inner cavity 83 to monitor the temperature of the inner cavity 83, the pressure sensor 12 and the second heater 13 are arranged In the outer chamber 82, the pressure sensor 12 is used to monitor the pressure inside the outer chamber 82, the second heater 13 is used to heat the liquid nitrogen in the outer chamber 82 to adjust the temperature of the thermostatic chamber 8, and the nitrogen valve 14 is arranged at On the outer cavity wall 81, when the pressure in the outer cavity 82 exceeds a certain value, the pressure can be released through the nitrogen valve 14; further, the temperature of the thermostatic chamber 8 is controlled between -150 and -100 degrees Celsius. time, that is, the working temperature of the constant temperature module is -150 to -100 degrees Celsius;

The temperature adjustment module includes a computer 5 and a control circuit 6. The computer 5 is electrically connected to the temperature sensor 11, the pressure sensor 12, and the flow meter 3, respectively, and receives signals from the temperature sensor 11, the pressure sensor 12, and the flow meter 3, so as to grasp the The situation of liquid nitrogen in the constant temperature chamber 8, the computer 5 is also electrically connected to the second heater 13 and the control circuit 6 in the constant temperature chamber 8, and the control circuit 6 is connected to the liquid nitrogen pump 2, the first heater 4 And the nitrogen valve 14, the computer 5 regulates the temperature of the constant temperature chamber 8 through the second heater 13, and the computer 5 realizes the control of the liquid nitrogen pump 2, the first heater 4 and the nitrogen valve 14 through the control circuit 6, specifically, The computer 5 controls the liquid nitrogen extraction amount of the liquid nitrogen pump 2 through the control circuit 6, the computer 5 controls the first heater 4 through the control circuit 6 to ensure the normal operation of the liquid nitrogen pump 2, and the computer 5 controls the nitrogen valve through the control circuit 6. 14 to ensure that the pressure in the outer cavity 82 is normal;

The reversing module includes a reversing fixture 9 and a polarizing electrode 10. The polarizing electrode 10 is arranged in the reversing fixture 9. The reversing fixture 9 is used to fix the crystal to be polarized, and the polarizing electrode 10 is used to convert the polarization voltage. Applied to the corresponding position of the crystal to be polarized, so as to realize the polarization of the crystal to be polarized, the polarizing electrodes 10 are arranged on both sides of the crystal to be polarized; the crystal to be polarized is a ferroelectric crystal, and the ferroelectric Crystal includes any one of KTP, SLT, LN;

Further, as shown in FIGS. 3-5 , at least one side of the polarized electrodes 10 on both sides has a periodic structure, and the polarized electrodes 10 are any one of metal electrodes or liquid electrodes. When the polarizing electrode 10 is a metal electrode, the polarizing electrode 10 includes a conductive area 101 , an insulating liquid 102 and a first O-ring 103 , the conductive area 101 is disposed on the surface of the crystal to be polarized, and the conductive area 101 It can be set as a periodic structure or a plane structure according to polarization requirements, the insulating liquid 102 is immersed in the entire conductive area 101 and sealed in the first O-ring 103; the conductive area 101 is made of conductive metal material, and the conductive The metal material can be any one or more of Al, Au, Ag, Cr, Cu, Ni, Pd, Ta, Mo, W, Ta, preferably AuCr; the insulating liquid 102 includes insulating oil and is uniformly dispersed in the Antifreeze particles in insulating oil; the insulating oil is any one or more of mineral insulating oil, synthetic insulating oil and vegetable oil, and the antifreeze particles are polyimide particles, polyamideimide particles, ultra-high Any one or several of the molecular weight polyethylene particles, the antifreeze particles can reduce the freezing point of the insulating liquid 102, so that the insulating liquid 102 can remain liquid at temperatures between -150 and -100 degrees Celsius. When the polarizing electrode 10 is a liquid electrode, the polarizing electrode 10 includes an insulating area 104, a conductive liquid 105 and a second O-ring 106. The insulating area 104 is disposed on the surface of the crystal to be polarized, and the insulating area 104 It can be set as a periodic structure or a long hollow structure according to polarization requirements, the conductive liquid 105 is immersed in the entire insulating area 104 and sealed in the second O-ring 106; the insulating area 104 is made of insulating material, the The insulating material is any one or more of polyamideimide and ultra-high molecular weight polyethylene. The conductive liquid 105 includes liquid nitrogen and metal nanoparticles uniformly dispersed in the liquid nitrogen. The conductive liquid 105 is at -150 A liquid state can be maintained between -100 degrees Celsius, and the metal nanoparticles are any one or more of Au nanoparticles, Ag nanoparticles, Al nanoparticles, and Cu nanoparticles;

The inversion control module includes an integrator 15 and a comparator 16 connected to the integrator 15. The integrator 15 is connected to the polarized electrode 10, and the comparator 16 is connected to the high-voltage module. The electric charge on the integrator 10 is integrated, and the comparator 16 is provided with a preset electric charge value, which is used to compare the magnitude of the electric charge integration result of the integrator 15 and the electric charge preset value, and judge whether to send the electric charge to the high-voltage module according to the comparison result. Sending a start command or a restart command, the high-voltage module can apply a polarized voltage to the inversion module after receiving the start command or restart command of the inversion control module; further, the inversion control module is connected to the computer 5, which can be The computer 5 sets the trigger condition for the inversion control module to apply the polarization voltage. Specifically, the comparator 16 of the inversion control module is connected to the computer 5, and the pre-set value of the electric charge of the comparator 16 can be set by the computer 5 ;

The high-voltage module includes a waveform generator 17 and a high-voltage amplifier 18 electrically connected to the waveform generator 17, the waveform generator 17 includes a trigger 20, the high-voltage amplifier 18 includes an electrode lead 19, and the electrode lead 19 is connected to the For the polarization electrode 10, after the trigger 20 sends a trigger command to the waveform generator 17, the waveform generator 17 generates a pulse waveform and sends it to the high-voltage amplifier 18, and the high-voltage amplifier 18 amplifies the pulse waveform to generate a polarization voltage. The electrode lead 19 is applied to the polarized electrode 10, thereby completing the crystal to be polarized once; the waveform generator 17 is also connected to the comparator 16, and the waveform generator 17 receives the start command or restart command of the comparator 16 Then, the waveform generator 17 generates a pulse waveform and sends it to the high-voltage amplifier 18. The high-voltage amplifier 18 amplifies the pulse waveform to generate a polarization voltage, and the polarization voltage is applied to the polarization electrode 10 through the electrode lead 19, so that the crystal to be polarized is processed After multiple polarizations, the polarization effect of the crystal to be polarized is further improved; further, the polarization voltage applied by the high-voltage amplifier 18 is 1-25KV/mm.

The use method and working principle of the low temperature polarization system of the present invention:

The low-temperature polarization process of the present invention mainly involves a temperature control process and a polarization process: the crystal to be polarized is placed in the constant temperature module, and the user controls the refrigeration module and the constant temperature module through the temperature adjustment module, so as to realize the ambient temperature of the crystal to be polarized. Control and adjustment; when the ambient temperature of the crystal to be polarized reaches a predetermined condition, the user controls the high-voltage module to apply a polarization voltage to the inversion module through the inversion control module, thereby completing the polarization of the to-be-polarized crystal. Further, the temperature adjustment module includes a computer 5, and the computer 5 includes a user interface 7, and the user can set the constant temperature value of the constant temperature module through the user interface 7; further, the computer 5 is connected to the reverse control module, and the user can Set the trigger condition for the reverse control module to apply the polarization voltage.

Specifically, in the temperature control process, the user inputs the required polarization temperature through the user interface 7 of the computer 5, and the computer 5 controls the liquid nitrogen pump 2 to extract the liquid nitrogen in the liquid nitrogen tank 1 through the control circuit 6, and the liquid nitrogen is It is transported to the constant temperature chamber 8 under the control of the computer 5 . In the process of delivering liquid nitrogen, the computer 5 can control the first heater 4 to heat the liquid nitrogen pump 2, thereby preventing the liquid nitrogen pump 2 from being unable to extract liquid nitrogen due to freezing; the liquid nitrogen is transported to the constant temperature chamber 8 In the outer cavity 82 , the temperature in the outer cavity 82 is monitored in real time by the temperature sensor 11 , and the computer 5 heats the liquid nitrogen in the outer cavity 82 through the second heater 13 to adjust the constant temperature value in the constant temperature chamber 8 . Further, the computer 5 can also adjust the pressure in the outer cavity 82. Specifically, the computer 5 can obtain the pressure value in the outer cavity 82 in real time through the pressure sensor 12, and can control the conveying speed and the total amount of liquid nitrogen through the flow meter 3. , the opening and closing of the nitrogen valve 14 is controlled by the controllable circuit 6. Therefore, the computer combines the data of the pressure sensor 12 to reasonably control the total amount of nitrogen in the outer cavity 82 through the flow meter 3 and the nitrogen valve 14, so as to realize the pressure in the outer cavity 82. adjustment.

When the ambient temperature of the crystal to be polarized reaches a predetermined condition, the crystal to be polarized can be polarized. Specifically, the user starts the waveform generator 17 through the trigger 20 to generate a pulse waveform, and the pulse waveform signal is amplified by the high-voltage amplifier 18. The pulse waveform signal of 10 is applied to the polarized electrode 10 through the electrode lead 19 and the reversal clamp 9 in turn, thereby completing the primary polarization of the crystal to be polarized (such as KTP). The crystal to be polarized often needs to be polarized multiple times to obtain a high-quality polarized crystal. Therefore, after the first polarization is completed, it is necessary to invert the control module to generate multiple pulse signals to perform multiple polarizations of the crystal to be polarized. change. In the present invention, after the first polarization is completed, the integrator 15 and the comparator 16 are used to integrate and compare the charges in the inversion module. If the processing result is less than the preset value, a restart signal is sent to the waveform generator 17, and the A pulse waveform is generated, and if the processing result is greater than the preset value, the polarization process ends. Further, the computer 5 is connected to the reverse control module, and the user can set the preset value on the user interface 7 of the computer 5 .

The above descriptions are only the embodiments of the present invention, and do not limit the scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description of the present invention, or directly or indirectly applied in other related technical fields, will not limit the scope of the invention. Similarly, it is included in the scope of patent protection of the present invention.

Claims (10)

1. A cryogenic polarization system, comprising: the device comprises a refrigeration module, a constant temperature module, a temperature regulation module, a reverse control module and a high-pressure module; the refrigeration module is communicated with the constant temperature module; the temperature adjusting module is respectively connected with the refrigerating module and the constant temperature module; the inversion module is placed in the constant temperature module and comprises an inversion clamp (9) and a polarization electrode (10), the polarization electrode (10) is arranged in the inversion clamp (9), the inversion clamp (9) is used for fixing a crystal to be polarized, and the polarization electrode (10) is provided with a periodic structure matched with the crystal to be polarized; the high-voltage module is used for applying polarization voltage to the inversion module; the reversing module, the reversing control module and the high-voltage module are connected with each other pairwise, the reversing control module receives charge signals from the reversing module, and whether the high-voltage module is triggered to apply polarization voltage to a polarization electrode (10) of the reversing module or not is judged automatically according to the charge signals.

2. A cryogenic polarization system as claimed in claim 1, wherein: the polarization electrodes (10) are arranged on two sides of the crystal to be polarized; at least one side of the polarized electrodes (10) on both sides has a periodic structure.

3. A cryogenic polarization system as claimed in claim 2, wherein: the polarizing electrode (10) is any one of a metal electrode or a liquid electrode.

4. A cryogenic polarization system as claimed in claim 3, wherein: the metal electrode comprises a conductive area (101), insulating liquid (102) and a first O-ring (103), wherein the conductive area (101) is arranged on the surface of a crystal to be polarized, the conductive area (101) can be arranged into a periodic structure or a planar structure according to polarization requirements, and the insulating liquid (102) submerges the whole conductive area (101) and is sealed in the first O-ring (103); the insulating liquid (102) comprises insulating oil and antifreeze particles uniformly dispersed in the insulating oil; the insulating oil is any one or more of mineral insulating oil, synthetic insulating oil and vegetable oil, and the anti-freezing particles are any one or more of polyimide particles, polyamide-imide particles and ultra-high molecular weight polyethylene particles.

5. A cryogenic polarization system as claimed in claim 3, wherein: the liquid electrode comprises an insulating area (104), conducting liquid (105) and a second O-shaped ring (106), the insulating area (104) is arranged on the surface of the crystal to be polarized, the insulating area (104) can be arranged into a periodic structure or a strip hollow structure according to polarization requirements, and the conducting liquid (105) is immersed in the whole insulating area (104) and sealed in the second O-shaped ring (106); the conductive liquid (105) comprises liquid nitrogen and metal nanoparticles uniformly dispersed in the liquid nitrogen, wherein the metal nanoparticles are any one or more of Au nanoparticles, Ag nanoparticles, Al nanoparticles and Cu nanoparticles.

6. A cryogenic polarization system according to any one of claims 1 to 5, wherein: the working temperature of the constant temperature module is-150 to-100 ℃.

7. A cryogenic polarization system according to any one of claims 1 to 5, wherein: the inversion control module comprises an integrator (15) and a comparator (16) connected with the integrator (15), the integrator (15) is connected to the polarizing electrode (10), the comparator (16) is connected to the high-voltage module, the integrator (15) is used for integrating charges on the polarizing electrode (10), and the comparator (16) is provided with a preset charge value.

8. A cryogenic polarization system according to any one of claims 1 to 5, wherein: the high voltage module comprises a waveform generator (17) and a high voltage amplifier (18) electrically connected with the waveform generator (17), the waveform generator (17) comprises a trigger (20), the high voltage amplifier (18) comprises an electrode lead (19), and the electrode lead (19) is connected to the polarizing electrode (10).

9. A cryogenic polarization system according to any one of claims 1 to 5, wherein: the polarization voltage applied by the high-voltage amplifier (18) is 1-25 KV/mm.

10. A cryogenic polarization system according to any one of claims 1 to 5, wherein: the crystal to be polarized is a ferroelectric crystal, and the ferroelectric crystal comprises any one of KTP, SLT and LN.

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