阅读说明：本技术 量子光制备用ppktp晶体的定位与温控装置及方法 (Positioning and temperature control device and method of PPKTP crystal for quantum light preparation ) 是由 李蓉 翁佳豪 孟庆铭 陆伟 吴占彬 于 2020-11-13 设计创作，主要内容包括：本发明公开了量子光制备用PPKTP晶体的定位与温控装置及方法。通过PID算法或人工调控帕尔帖电流开关来控制PPKTP晶体温度,有较大滞后性和误差。本发明的磁悬浮系统对PPKTP晶体进行定位,避免PPKTP晶体扰动对量子光场制备的影响；温度传感器检测PPKTP晶体温度,PWM电流开关驱动器和SPWM电流开关驱动器通过控制内部开关元件来控制输给帕尔帖的电流方向,从而控制帕尔帖的散热面和制冷面朝向；PWM电流开关驱动器经SPWM电流开关驱动器输出PWM波给帕尔贴,增大帕尔贴输入功率；SPWM电流开关驱动器输出SPWM波给帕尔贴,缩短帕尔贴单次加热或散热时间。本发明对PPKTP晶体温度控制精度高。(The invention discloses a positioning and temperature control device and method of a PPKTP crystal for quantum light preparation. The temperature of the PPKTP crystal is controlled by a PID algorithm or manually regulating a Peltier current switch, and the temperature control method has large hysteresis and errors. The magnetic suspension system disclosed by the invention is used for positioning the PPKTP crystal, so that the influence of the disturbance of the PPKTP crystal on the preparation of a quantum light field is avoided; the temperature sensor detects the temperature of the PPKTP crystal, and the PWM current switch driver and the SPWM current switch driver control the direction of current output to the Peltier by controlling the internal switch element, so that the orientation of a heat dissipation surface and a refrigeration surface of the Peltier is controlled; the PWM current switch driver outputs PWM waves to the Peltier through the SPWM current switch driver, and the input power of the Peltier is increased; the SPWM current switch driver outputs SPWM waves to the Peltier, and single heating or heat dissipation time of the Peltier is shortened. The invention has high temperature control precision on the PPKTP crystal.)

1. Location and temperature control device of PPKTP crystal for quantum light preparation, including PPKTP crystal, peltier and temperature sensor, its characterized in that: the magnetic suspension system, the SPWM current switch driver and the PWM current switch driver are also included; the rotor is arranged in the mounting groove of the crystal upper cover bracket, the PPKTP crystal is arranged in the mounting groove of the crystal lower support bracket, and the PPKTP crystal is fixed with the rotor; the rotor and a supporting shaft fixed in the mounting groove of the crystal upper cover bracket form a revolute pair; the crystal upper cover bracket is fixed with the crystal lower support bracket; the rotor is made of magnetic materials and is positioned by a magnetic suspension system; the Peltier is arranged between the crystal lower support bracket and the crystal mounting base and is pressed by the crystal lower support bracket and the crystal mounting base; the crystal mounting base is fixed with the crystal lower support bracket; the temperature sensor is arranged in the side notches of the crystal upper cover bracket and the crystal lower support bracket and is pressed by the crystal upper cover bracket and the crystal lower support bracket; the temperature sensor measures the temperature of the PPKTP crystal, the signal output end of the temperature sensor is connected with the input end of the PWM current switch driver, the input end of the SPWM current switch driver is connected with the output end of the PWM current switch driver, and the Peltier is connected with the output end of the SPWM current switch driver; the device power supply supplies power for the PWM current switch driver and the SPWM current switch driver.

2. The apparatus of claim 1 for positioning and controlling temperature of PPKTP crystal for quantum light production, wherein: the power supply of the device is an alternating current power supply.

3. The apparatus of claim 1 for positioning and controlling temperature of PPKTP crystal for quantum light production, wherein: the PPKTP crystal is a cuboid, and the cross section of the PPKTP crystal is a square.

4. The apparatus of claim 1 for positioning and controlling temperature of PPKTP crystal for quantum light production, wherein: the temperature sensor is a cylinder, and the measuring head faces inwards.

5. The apparatus for positioning and controlling temperature of PPKTP crystal for quantum light production as claimed in claim 1, 2, 3 or 4, wherein: the magnetic suspension system consists of a magnetic suspension sensor, a magnetic suspension controller and a magnetic suspension actuator; the magnetic suspension controller is fixed on the crystal upper cover bracket through the magnetic suspension base; the magnetic suspension sensor and the two magnetic suspension actuators are fixed on the magnetic suspension controller, the magnetic suspension sensor is opposite to a rotor fixed with the PPKTP crystal, and the two magnetic suspension actuators are arranged on two sides of the supporting shaft; the magnetic suspension actuator comprises an electromagnet and a power amplifier; the signal output end of the magnetic suspension sensor is connected with the magnetic suspension controller, and the electromagnet is connected with the magnetic suspension controller through a power amplifier.

6. The method for positioning and controlling the temperature of the PPKTP crystal by the apparatus for positioning and controlling the temperature of the PPKTP crystal according to claim 5, wherein the method comprises: the method comprises the following specific steps:

the positioning process of the PPKTP crystal is as follows: when the PPKTP crystal is disturbed and deviates from the reference position, the magnetic suspension sensor detects the displacement of the rotor deviating from the reference position, the magnetic suspension controller converts the detected displacement into a control signal, the control signal is converted into control current through the two power amplifiers and then is output to the two electromagnets, and the control current generates magnetic force in the electromagnets so as to drive the rotor to return to the reference position;

the temperature control process of the PPKTP crystal is as follows: when the PWM current switch driver judges that the temperature of the PPKTP crystal detected by the temperature sensor is lower than the rated temperature and the absolute value of the difference value exceeds the threshold value, the PWM current switch driver and the SPWM current switch driver control the direction of current output to the Peltier by controlling an internal switch element, so that the upward surface of the Peltier is a heat dissipation surface and the downward surface of the Peltier is a refrigeration surface; when the PWM current switch driver judges that the temperature of the PPKTP crystal detected by the temperature sensor is higher than the rated temperature and the absolute value of the difference value exceeds the threshold value, the PWM current switch driver and the SPWM current switch driver control the direction of current output to the Peltier by controlling an internal switch element, so that the downward surface of the Peltier is a heat dissipation surface, and the upward surface of the Peltier is a refrigeration surface; in addition, when the absolute value of the difference value between the PPKTP crystal temperature and the rated temperature exceeds a threshold value, the PWM current switch driver changes the duty ratio of a signal through modulation, the amplitude of an output pulse is increased, and a PWM wave is output to the Peltier through the SPWM current switch driver, so that the input power of the Peltier is increased; after the PWM wave is transmitted into the SPWM current switch driver, the SPWM current switch driver outputs the SPWM wave to the Peltier by increasing carrier frequency and modulating the PWM wave by carrier wave, thereby shortening the time of single heating or heat dissipation of the Peltier.

7. The method for positioning and controlling the temperature of the PPKTP crystal by the apparatus for positioning and controlling the temperature of the PPKTP crystal according to claim 6, wherein the method comprises: after the temperature signal of the PPKTP crystal is input into the PWM current switch driver, the PWM current switch driver modulates the temperature signal of the PPKTP crystal through a preset carrier, outputs PWM waves, forms a series of trigger pulses, and controls the on-off of a switch element in the PWM current switch driver at the natural intersection point moment of the PWM waves and the carrier.

8. The method for positioning and controlling the temperature of the PPKTP crystal by the apparatus for positioning and controlling the temperature of the PPKTP crystal according to claim 7, wherein the method comprises: the process of outputting the PWM wave is: comparing the carrier wave with the modulation wave, and replacing the pulses with equal width and unequal amplitude by rectangular pulse sequences with equal amplitude and unequal width in corresponding quantity according to the area equivalent principle of the sampling control theory.

9. The method for positioning and controlling the temperature of the PPKTP crystal by the apparatus for positioning and controlling the temperature of the PPKTP crystal according to claim 6, wherein the method comprises: after the PWM wave is input into the SPWM current switch driver, the SPWM current switch driver modulates the PWM wave through a preset carrier wave, outputs the SPWM wave, forms a series of trigger pulses, and controls the on-off of a switch element in the SPWM current switch driver through a natural sampling method or a regular sampling method.

Technical Field

The invention belongs to the technical field of quantum light field preparation, and particularly relates to a positioning and temperature control device and method of a PPKTP crystal for quantum light preparation.

Background

At present, the preparation of quantum optical field is generated by PPKTP crystal through single frequency laser. One of the stability factors in quantum optical field generation is the need of extremely high crystal temperature control precision, for example, the temperature of the PPKTP crystal needs to be controlled at 23 ℃, and the temperature error does not exceed 0.01 ℃. At present, the temperature control of the crystal is the conventional PID algorithm control in the industry, or the temperature of the PPKTP crystal is controlled by manually regulating the Peltier current switch, the method has large hysteresis and error, the stability of the quantum light field preparation is greatly influenced, and the method becomes a main difficulty which restricts the process of the quantum light field preparation from a laboratory to the industrial application. In addition, the existing installation mode of the PPKTP crystal enables the PPKTP crystal to be easily disturbed, and the stability of quantum light field preparation is seriously influenced.

Disclosure of Invention

The invention aims to provide a positioning and temperature control device and method for a PPKTP crystal for quantum light preparation, aiming at the defects of the prior art.

The technical scheme adopted by the invention is as follows:

the invention discloses a positioning and temperature control device of a PPKTP crystal for quantum light preparation, which comprises the PPKTP crystal, a magnetic suspension system, a Peltier, a temperature sensor, an SPWM current switch driver and a PWM current switch driver. The rotor is arranged in the mounting groove of the crystal upper cover bracket, the PPKTP crystal is arranged in the mounting groove of the crystal lower support bracket, and the PPKTP crystal is fixed with the rotor; the rotor and a supporting shaft fixed in the mounting groove of the crystal upper cover bracket form a revolute pair; the crystal upper cover bracket is fixed with the crystal lower support bracket; the rotor is made of magnetic material and is positioned by a magnetic suspension system. The Peltier is arranged between the crystal lower support bracket and the crystal mounting base and is pressed by the crystal lower support bracket and the crystal mounting base; the crystal mounting base is fixed with the crystal lower support bracket; the temperature sensor is arranged in the side notches of the crystal upper cover bracket and the crystal lower support bracket and is pressed by the crystal upper cover bracket and the crystal lower support bracket; the temperature sensor measures the temperature of the PPKTP crystal, the signal output end of the temperature sensor is connected with the input end of the PWM current switch driver, the input end of the SPWM current switch driver is connected with the output end of the PWM current switch driver, and the Peltier is connected with the output end of the SPWM current switch driver. The device power supply supplies power for the PWM current switch driver and the SPWM current switch driver.

Preferably, the power supply of the device is an alternating current power supply.

Preferably, the PPKTP crystal is a cuboid, and the cross section of the PPKTP crystal is square.

Preferably, the temperature sensor is a cylinder with the measuring head facing inwards.

Preferably, the magnetic suspension system consists of a magnetic suspension sensor, a magnetic suspension controller and a magnetic suspension actuator; the magnetic suspension controller is fixed on the crystal upper cover bracket through the magnetic suspension base. The magnetic suspension sensor and the two magnetic suspension actuators are fixed on the magnetic suspension controller, the magnetic suspension sensor is opposite to a rotor fixed with the PPKTP crystal, and the two magnetic suspension actuators are arranged on two sides of the supporting shaft; the magnetic suspension actuator comprises an electromagnet and a power amplifier; the signal output end of the magnetic suspension sensor is connected with the magnetic suspension controller, and the electromagnet is connected with the magnetic suspension controller through a power amplifier.

The method for positioning and controlling the temperature of the PPKTP crystal by the PPKTP crystal positioning and temperature control device for quantum light preparation comprises the following steps:

the positioning process of the PPKTP crystal is as follows: when the PPKTP crystal is disturbed to deviate from the reference position, the magnetic suspension sensor detects the displacement of the rotor from the reference position, the magnetic suspension controller converts the detected displacement into a control signal, the control signal is converted into control current through the two power amplifiers and then is output to the two electromagnets, and the control current generates magnetic force in the electromagnets so as to drive the rotor to return to the reference position.

The temperature control process of the PPKTP crystal is as follows: when the PWM current switch driver judges that the temperature of the PPKTP crystal detected by the temperature sensor is lower than the rated temperature and the absolute value of the difference value exceeds the threshold value, the PWM current switch driver and the SPWM current switch driver control the direction of current output to the Peltier by controlling an internal switch element, so that the upward surface of the Peltier is a heat dissipation surface and the downward surface of the Peltier is a refrigeration surface; when the PWM current switch driver judges that the PPKTP crystal temperature detected by the temperature sensor is higher than the rated temperature and the absolute value of the difference value exceeds the threshold value, the PWM current switch driver and the SPWM current switch driver control the current direction output to the Peltier by controlling the internal switch element, so that the downward surface of the Peltier is a heat dissipation surface, and the upward surface of the Peltier is a refrigeration surface. In addition, when the absolute value of the difference value between the PPKTP crystal temperature and the rated temperature exceeds a threshold value, the PWM current switch driver changes the duty ratio of a signal through modulation, the amplitude of an output pulse is increased, and a PWM wave is output to the Peltier through the SPWM current switch driver, so that the input power of the Peltier is increased; after the PWM wave is transmitted into the SPWM current switch driver, the SPWM current switch driver outputs the SPWM wave to the Peltier by increasing carrier frequency and modulating the PWM wave by carrier wave, thereby shortening the time of single heating or heat dissipation of the Peltier.

Preferably, after the temperature signal of the PPKTP crystal is input into the PWM current switch driver, the PWM current switch driver modulates the temperature signal of the PPKTP crystal by a preset carrier, outputs a PWM wave to form a series of trigger pulses, and controls the on/off of the switching element inside the PWM current switch driver at a time of a natural intersection of the PWM wave and the carrier.

More preferably, the process of outputting the PWM wave is: comparing the carrier wave with the modulation wave, and replacing the pulses with equal width and unequal amplitude by rectangular pulse sequences with equal amplitude and unequal width in corresponding quantity according to the area equivalent principle of the sampling control theory.

Preferably, after the PWM wave is input to the SPWM current switch driver, the SPWM current switch driver modulates the PWM wave by a preset carrier, outputs the SPWM wave, forms a series of trigger pulses, and controls on/off of the switching element inside the SPWM current switch driver by a natural sampling method or a regular sampling method.

The invention has the following beneficial effects:

according to the invention, PWM and SPWM driving sources are introduced to replace the traditional Peltier temperature control mode, and the Peltier can accurately control the PPKTP crystal temperature in real time based on the characteristics of PWM and SPWM series switch control and the mode of utilizing duty ratio and frequency modulation, so that the temperature error can be controlled within 0.01 ℃, and the stability of quantum optical field preparation is improved. Meanwhile, a magnetic suspension technology is introduced, so that the influence of PPKTP crystal disturbance on quantum optical field preparation is reduced. Therefore, the invention overcomes the problem that the control precision of the traditional Peltier temperature control mode on the temperature of the PPKTP crystal is not high.

Drawings

FIG. 1 is a schematic diagram of the structure of the apparatus of the present invention.

Detailed Description

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

As shown in figure 1, the PPKTP crystal positioning and temperature control device for quantum light preparation comprises a PPKTP crystal 3, a magnetic suspension system, a Peltier, a temperature sensor, an SPWM current switch driver 9 and a PWM current switch driver 7. The rotor is arranged in the mounting groove of the crystal upper cover bracket 1, the PPKTP crystal 3 is arranged in the mounting groove of the crystal lower support bracket 2, and the PPKTP crystal 3 is fixed with the rotor; the rotor and a supporting shaft fixed in the mounting groove of the crystal upper cover bracket 1 form a revolute pair; the crystal upper cover bracket 1 is fixed with the crystal lower support bracket 2; the rotor is made of magnetic material and is positioned by a magnetic suspension system. The Peltier 4 is arranged between the crystal lower support bracket 2 and the crystal mounting base 5 and is pressed by the crystal lower support bracket 2 and the crystal mounting base 5; the crystal mounting base 5 is fixed with the crystal lower support bracket 2; the peltier 4 is energized in a circuit formed by two different conductors a and B, so that one of the connections emits some other heat in addition to joule heating, while the other absorbs heat, and the phenomenon caused by the peltier effect is reversible, the heat emitting and absorbing connections changing when the current direction is changed, the heat absorbed and emitted being proportional to the current intensity I and to the nature of the two conductors and the temperature of the hot side. The temperature sensor 6 is arranged in the side notches of the crystal upper cover bracket 1 and the crystal lower support bracket 2 and is pressed by the crystal upper cover bracket 1 and the crystal lower support bracket 2; the temperature sensor 6 is used for measuring the temperature of the PPKTP crystal 3. The signal output end of the temperature sensor 6 is connected with the input end of a PWM current switch driver 7 (namely a PWM controller), the input end of an SPWM current switch driver 9 is connected with the output end of the PWM current switch driver 7, and the Peltier 4 is connected with the output end of the SPWM current switch driver 9. The device power supply 8 supplies power to the PWM current switch driver 7 and the SPWM current switch driver 9.

As a preferred embodiment, the device power supply 8 is an ac power supply.

As a preferred embodiment, the PPKTP crystal is a cuboid, and the cross section of the PPKTP crystal is a square.

In a preferred embodiment, the temperature sensor is a cylinder with the probe facing inward.

As a preferred embodiment, the magnetic suspension system is composed of a magnetic suspension sensor 12 (displacement sensor), a magnetic suspension controller 10 and a magnetic suspension actuator 13; the magnetic suspension controller 10 is fixed on the crystal upper cover bracket 1 through a magnetic suspension base 11. The magnetic suspension sensor 12 and the two magnetic suspension actuators 13 are fixed on the magnetic suspension controller 10, the magnetic suspension sensor 12 is over against a rotor fixed with the PPKTP crystal 3, the two magnetic suspension actuators 13 are arranged on two sides of the supporting shaft, and the PPKTP crystal 3 is easily controlled by the magnetic suspension controller 10. The magnetic suspension actuator 13 comprises an electromagnet and a power amplifier; the signal output end of the magnetic suspension sensor 12 is connected with the magnetic suspension controller 10, and the electromagnet is connected with the magnetic suspension controller 10 through a power amplifier.

The method for positioning and controlling the temperature of the PPKTP crystal by the PPKTP crystal positioning and temperature control device for quantum light preparation comprises the following steps:

the positioning process of the PPKTP crystal is as follows: when the PPKTP crystal 3 is disturbed and deviates from the reference position, the magnetic suspension sensor detects the displacement of the rotor deviating from the reference position, the magnetic suspension controller 10 converts the detected displacement into a control signal, the control signal is converted into control current through the two power amplifiers and then is output to the two electromagnets, and the control current generates magnetic force in the electromagnets so as to drive the rotor to return to the reference position. Therefore, no matter what kind of disturbance is applied to the PPKTP crystal 3, the PPKTP crystal 3 can be always in a stable equilibrium state, and the continuity and stability of the control are maintained.

The temperature control process of the PPKTP crystal is as follows: when the PWM current switch driver 7 judges that the temperature of the PPKTP crystal 3 detected by the temperature sensor 6 is lower than the rated temperature and the absolute value of the difference value exceeds the threshold value (preferably 0.01 ℃), the PWM current switch driver 7 and the SPWM current switch driver 9 control the direction of current transmitted to the Peltier 4 by controlling an internal switch element, so that the upward surface of the Peltier 4 is a heat dissipation surface, the downward surface is a refrigeration surface, and the requirement of temperature rise of the PPKTP crystal 3 is met; when the PWM current switch driver 7 judges that the temperature of the PPKTP crystal 3 detected by the temperature sensor 6 is higher than the rated temperature and the absolute value of the difference value exceeds the threshold value, the PWM current switch driver 7 and the SPWM current switch driver 9 control the current direction transmitted to the Peltier 4 by controlling the internal switch element, so that the downward surface of the Peltier 4 is a heat dissipation surface, the upward surface is a refrigeration surface, and the requirement of cooling the PPKTP crystal 3 is met. In addition, when the absolute value of the difference value between the temperature of the PPKTP crystal 3 and the rated temperature exceeds the threshold value, the PWM current switch driver 7 changes the duty ratio of a signal through modulation, the amplitude of an output pulse is increased, and a PWM wave is output to the Peltier 4 through the SPWM current switch driver 9, so that the input power of the Peltier 4 is increased, and the working efficiency of the Peltier 4 is improved; after the PWM wave is transmitted into the SPWM current switch driver 9 (SPWM driver for short), the SPWM current switch driver 9 outputs the SPWM wave to the peltier by increasing the carrier frequency and modulating the PWM wave by the carrier wave.

After the temperature signal of the PPKTP crystal 3 is input into the PWM current switch driver 7, the PWM current switch driver 7 modulates the temperature signal of the PPKTP crystal 3 by a preset carrier, outputs a PWM wave, forms a series of trigger pulses, and controls the on/off of the switching element inside the PWM current switch driver 7 at the time of the natural intersection point of the PWM wave and the carrier. The process of outputting the PWM wave is: comparing the carrier wave with the modulation wave, and replacing the pulses with equal width and unequal amplitude by rectangular pulse sequences with equal amplitude and unequal width in corresponding quantity according to the area equivalent principle of the sampling control theory.

After the PWM wave is input to the SPWM current switch driver 9, the SPWM current switch driver 9 modulates the PWM wave by a preset carrier, outputs the SPWM wave, and forms a series of trigger pulses, and controls the on/off of the switching elements inside the SPWM current switch driver 9 by a natural sampling method (i.e., the same time as the amplitude of the modulated wave is the on/off time of the switching elements) or a regular sampling method (i.e., the negative peak time of the modulated wave, and the same time as the carrier with the same amplitude of the modulated wave is the on/off time of the switching elements). Meanwhile, the SPWM current switch driver 9 can modulate SPWM waves with different frequencies by adjusting carrier frequency, more accurately control the single heating or radiating time of the Peltier 4, ensure that the temperature of the PPKTP crystal is controlled at 23 ℃ and the temperature error is not more than 0.01 ℃.

In conclusion, the invention ensures that the temperature of the PPKTP crystal 3 is stabilized at the rated temperature (the upper and lower floating ranges are smaller), and improves the stability of quantum optical field preparation.

The above description is only for the preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification and the drawings can be directly or indirectly applied to other related technical fields and are included in the scope of the present invention.