A device and method for calibrating response parameters of a liquid crystal phase retarder

Abstract

The embodiment of the present invention discloses a calibration device and method for corresponding parameters of a liquid crystal phase retarder. The controller provides the corresponding initial driving voltage and the termination driving voltage to the liquid crystal phase retarder according to the preset TNE parameter measurement calibration range and the corresponding TNE parameter measurement calibration quantity, and adds a TNE overshoot voltage between each pair of the initial driving voltage and the termination driving voltage; then, according to the output signal of the light intensity detector, the TNE overshoot voltage value and duration are adjusted to determine the optimal TNE overshoot voltage value and optimal duration required for the rapid transition of the initial and final states, so as to obtain the measured and calibrated TNE parameters, and finally, the TNE parameters between any initial driving voltage and the termination driving voltage within the calibration range are obtained by the interpolation method. In this way, the calibration quantity of the overvoltage parameter can be greatly reduced, thereby compressing the calibration time to the order of minutes, improving the efficiency of the calibration, and saving time and effort.

Description

Technical Field

[0001] The present invention relates to the field of optical device calibration, and in particular to a device and method for calibrating corresponding parameters of a liquid crystal phase retarder. Background Art

[0002] Optical phase retarders are key devices in modern optical fields such as high-precision polarization control, high-precision optical measurement, adaptive optics, and optical information processing. Optical phase retarders include mechanical phase retarders, electro-optical phase retarders, acousto-optic phase retarders, and liquid crystal phase retarders. Among them, liquid crystal phase retarders have the advantages of small optical distortion, low optical power loss, and low cost, so they have been widely used. However, liquid crystal phase retarders have a slow response speed. For example, liquid crystal phase retarders usually use nematic liquid crystal materials. As the driving voltage decreases, the orientation of liquid crystal molecules changes, and the phase delay gradually increases. The response time of liquid crystal molecules is usually on the order of tens of milliseconds.

[0003] In order to solve the above problems, TNE (Transient Nematic Effect) driving technology came into being, that is, when the external driving voltage changes, an overshoot voltage ranging from a few milliseconds to tens of milliseconds is added between the initial driving voltage and the final driving voltage, so that the orientation of the liquid crystal molecules is more quickly directed to the target direction, thereby obtaining a faster response speed. However, different initial driving voltages and final driving voltages correspond to different overshoot parameters (i.e., overshoot voltage values ​​and overshoot voltage durations). Inappropriate overshoot voltage parameters may even cause the response speed to be slower than when the TNE driving technology is not used. Therefore, in order to obtain the optimal response time, it is necessary to calibrate the overshoot parameters one by one for different initial driving voltages and final driving voltages, and finally obtain the TNE parameter matrix. However, the amplitude range of the initial driving voltage and the final driving voltage of the liquid crystal phase retarder is usually 0 to tens of volts, which will generate a large number of overshoot parameters, resulting in a time-consuming and labor-intensive calibration process, or even inability to complete the calibration. Summary of the invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0005] In a first aspect, an embodiment of the present invention provides a device for calibrating corresponding parameters of a liquid crystal phase retarder, comprising a light source, a light intensity detector and a controller; a light source, a polarizer, a liquid crystal phase retarder, a wave plate, an analyzer and a light intensity detector are sequentially arranged between the light source and the light intensity detector along a direction from the light source to the light intensity detector; the controller is connected to the liquid crystal phase retarder and the light intensity detector respectively;

[0006] The light source is used to emit collimated light;

[0007] The polarizer is used to convert the collimated light into polarized light, and the polarization direction of the polarized light forms a preset angle with the optical axis of the liquid crystal phase retarder;

[0008] The wave plate is used to modulate the polarized light after being processed by the liquid crystal phase retarder into linear polarized light, and the polarization direction of the linear polarized light is different from the polarization direction of the polarizer;

[0009] The polarizer and light intensity detector are used to detect the polarization state of the linearly polarized light;

[0010] The controller is used to obtain a preset TNE parameter measurement calibration range and a corresponding number of TNE parameter measurement calibrations; provide a corresponding initial driving voltage and a termination driving voltage to the liquid crystal phase retarder according to the preset TNE parameter measurement calibration range and the corresponding number of TNE parameter measurement calibrations, and add a TNE overshoot voltage between each pair of the initial driving voltage and the termination driving voltage; and adjust the TNE overshoot voltage value and duration according to the output signal of the light intensity detector, determine the optimal TNE overshoot voltage value and optimal duration required for the rapid transition of the initial and final states, so as to obtain the measured and calibrated TNE parameters, and perform two-dimensional difference processing on all the measured and calibrated TNE parameters to obtain a TNE parameter matrix.

[0011] Optionally, the degree of change of the historical TNE parameter between adjacent initial and final driving voltages within the preset TNE parameter measurement calibration range is proportional to the number of corresponding TNE parameter measurement calibrations.

[0012] Optionally, the polarizer includes a first linear polarizer, and the analyzer includes a second linear polarizer.

[0013] Optionally, the polarizer includes a first polarization beam splitter prism, and the analyzer includes a second polarization beam splitter prism.

[0014] Optionally, the wave plate is a quarter wave plate.

[0015] In a second aspect, an embodiment of the present invention provides a method for calibrating corresponding parameters of a liquid crystal phase retarder, which is applied to a device for calibrating corresponding parameters of the above-mentioned liquid crystal phase retarder, comprising:

[0016] The light source is used to emit collimated light;

[0017] The polarizer converts the collimated light into polarized light, and the polarization direction of the polarized light forms a preset angle with the optical axis of the liquid crystal phase retarder;

[0018] The controller obtains a preset TNE parameter measurement calibration range and a corresponding number of TNE parameter measurement calibrations; provides a corresponding initial driving voltage and a termination driving voltage to the liquid crystal phase retarder according to the preset TNE parameter measurement calibration range and the corresponding number of TNE parameter measurement calibrations, and adds a TNE overshoot voltage between each pair of the initial driving voltage and the termination driving voltage;

[0019] The wave plate modulates the polarized light after being processed by the liquid crystal phase retarder into linear polarized light, and the polarization direction of the linear polarized light is different from the polarization direction of the polarizer;

[0020] The polarizer and the light intensity detector detect the polarization state of the linearly polarized light;

[0021] The controller adjusts the TNE overshoot voltage value and duration according to the output signal of the light intensity detector, determines the optimal TNE overshoot voltage value and optimal duration required for the rapid transition between the initial and final states, so as to obtain the TNE parameters for measurement and calibration;

[0022] All measured and calibrated TNE parameters are subjected to two-dimensional difference processing to obtain the TNE parameter matrix.

[0023] According to a calibration device and method for corresponding parameters of a liquid crystal phase retarder provided by an embodiment of the present invention, the controller presets a TNE parameter measurement calibration range and the corresponding number of TNE parameter measurement calibrations, provides the corresponding initial drive voltage and termination drive voltage to the liquid crystal phase retarder, and adds a TNE overshoot voltage between each pair of initial drive voltage and termination drive voltage; then, according to the output signal of the light intensity detector, adjusts the TNE overshoot voltage value and duration, determines the optimal TNE overshoot voltage value and optimal duration required for the rapid transition of the initial and final states, so as to obtain the measured and calibrated TNE parameters, and finally obtains the TNE parameters between any initial drive voltage and termination drive voltage within the calibration range by an interpolation method. In this way, the number of calibrations of the overvoltage parameters can be greatly reduced, thereby compressing the calibration time to the order of minutes, improving the efficiency of the calibration, and saving time and effort. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following drawings of the present invention are used as part of the embodiments of the present invention for understanding the present invention. The embodiments of the present invention are shown in the drawings and the description thereof is used to explain the principle of the present invention.

[0025] In the attached figure:

[0026] Figure 1 A structural diagram of a device for calibrating corresponding parameters of a liquid crystal phase retarder according to an optional embodiment of the present invention;

[0027] Figure 2 A structural diagram of a device for calibrating corresponding parameters of a liquid crystal phase retarder according to another optional embodiment of the present invention;

[0028] Figure 3 The figure is a flow chart of a method for calibrating corresponding parameters of a liquid crystal phase retarder according to an optional embodiment of the present invention.

[0029] Among them, 1 is a light source, 2 is a first linear polarizer, 3 is a liquid crystal phase retarder, 4 is a wave plate, 5 is a second linear polarizer, 6 is a light intensity detector, 7 is a controller, 8 is a first polarization beam splitter prism, and 9 is a second polarization beam splitter prism. DETAILED DESCRIPTION

[0030] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, integral bodies, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integral bodies, steps, operations, elements, components and / or combinations thereof.

[0032] Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the concept of these exemplary embodiments to those of ordinary skill in the art.

[0033] First, as Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a calibration device for corresponding parameters of a liquid crystal phase retarder 3, comprising a light source 1, a light intensity detector 6 and a controller 7; the light source 1, a polarizer, a liquid crystal phase retarder 3, a wave plate 4, an analyzer and a light intensity detector 6 are arranged in sequence between the light source 1 and the light intensity detector 6 along the direction from the light source 1 to the light intensity detector 6; the controller 7 is connected to the liquid crystal phase retarder 3 and the light intensity detector 6 respectively;

[0034] A light source 1, for emitting collimated light;

[0035] The polarizer is used to convert collimated light into polarized light, and the polarization direction of the polarized light is at a preset angle with the optical axis of the liquid crystal phase retarder 3; wherein the preset angle can be set by the staff, and in some implementations, the preset angle is 45°.

[0036] The wave plate 4 is used to modulate the polarized light after being processed by the liquid crystal phase retarder 3 into linear polarized light, and the polarization direction of the linear polarized light is different from the polarization direction of the polarizer; wherein the difference in the polarization directions of the two is related to the driving voltage of the liquid crystal phase retarder 3 (i.e., the light phase delay amount generated by the liquid crystal phase retarder 3). Furthermore, the change in the amplitude of the driving voltage of the liquid crystal phase retarder 3 will change the orientation of the liquid crystal molecules, and the change in the orientation of the liquid crystal molecules will cause the light phase delay to change, so the amplitude of the driving voltage corresponds to the light phase delay amount, that is, the change in the polarization direction of the linear polarized light is also related to the light phase delay amount.

[0037] The polarizer and the light intensity detector 6 are used to detect the polarization state of the linearly polarized light; wherein the electrical signal intensity of the light intensity detector 6 reflects the polarization state of the linearly polarized light, and also reflects the real-time delay amount of the liquid crystal phase retarder 3 .

[0038] The controller 7 is used to obtain a preset TNE parameter measurement calibration range and a corresponding number of TNE parameter measurement calibrations; provide a corresponding initial drive voltage and a termination drive voltage to the liquid crystal phase retarder 3 according to the preset TNE parameter measurement calibration range and the corresponding number of TNE parameter measurement calibrations, and add a TNE overshoot voltage between each pair of initial drive voltage and termination drive voltage; and adjust the TNE overshoot voltage value and duration according to the output signal of the light intensity detector 6, determine the optimal TNE overshoot voltage value and optimal duration required for the rapid transition between the initial and final states, so as to obtain the measured and calibrated TNE parameters, perform two-dimensional difference processing on all the measured and calibrated TNE parameters, and obtain a TNE parameter matrix.

[0039] The controller 7 may be a host computer, a notebook computer, a server or other equipment, and this embodiment does not impose strict limitations on the controller 7 .

[0040] The optimal TNE overshoot voltage value and the optimal duration are the voltage assignment and duration of the TNE overshoot voltage that make the liquid crystal phase retarder 3 jump the fastest.

[0041] The preset TNE parameter measurement calibration range and the corresponding number of TNE parameter measurement calibrations can be set by the staff according to the historical TNE parameter matrix, and this application does not impose strict restrictions. In some embodiments, if the gradient of change of historical TNE parameters within the preset TNE parameter measurement calibration range is large, intensive measurement and calibration are performed, that is, when the difference between two adjacent historical TNE parameters within the preset TNE parameter measurement calibration range is large, the number of TNE parameter measurement and calibration corresponding to the preset TNE parameter measurement calibration range is also larger; if the gradient of change of historical TNE parameters within the preset TNE parameter measurement calibration range is small, sparse measurement and calibration are performed, that is, when the difference between two adjacent historical TNE parameters within the preset TNE parameter measurement calibration range is small, the number of TNE parameter measurement and calibration corresponding to the preset TNE parameter measurement calibration range is also smaller, so that the numerical difference between adjacent TNE parameters measured is ultimately less than 20%, and the difference between the initial driving voltage amplitude or the termination driving voltage amplitude corresponding to adjacent TNE parameters is greater than 0.02 volts, so that the measured and calibrated TNE parameters are reduced to hundreds to thousands, and the number of measured and calibrated TNE parameters is reduced by more than a thousand times, thereby greatly reducing the number and time consumption of measurement and calibration. Then, through a two-dimensional difference algorithm, hundreds to thousands of TNE parameters are expanded to hundreds of thousands of TNE parameters, thereby obtaining the final TNE parameter matrix.

[0042] According to an embodiment of the present invention, a device and method for calibrating corresponding parameters of a liquid crystal phase retarder are provided. The controller 7 provides a corresponding initial driving voltage and a termination driving voltage to the liquid crystal phase retarder 3 based on a preset TNE parameter measurement calibration range and a corresponding number of TNE parameter measurement calibrations, and adds a TNE overshoot voltage between each pair of the initial driving voltage and the termination driving voltage; then, according to the output signal of the light intensity detector 6, the TNE overshoot voltage value and duration are adjusted to determine the optimal TNE overshoot voltage value and optimal duration required for the rapid transition between the initial and final states, so as to obtain the measured and calibrated TNE parameters. In this way, the number of calibrations of the overvoltage parameters can be greatly reduced, thereby compressing the calibration time to the order of minutes, improving the efficiency of the calibration, and saving time and effort.

[0043] Furthermore, in the above embodiment, the degree of change of the historical parameters within the preset TNE parameter measurement calibration range is proportional to the number of corresponding TNE parameter measurement calibrations.

[0044] In some embodiments, Figure 1 As shown, the polarizer includes a first linear polarizer 2 , and the analyzer includes a second linear polarizer 5 .

[0045] Among them, linear polarizers have very excellent extinction ratio and transmittance, and have a large acceptance angle.

[0046] In another embodiment, if Figure 2 As shown, the polarizer includes a first polarization beam splitter prism 8 , and the analyzer includes a second polarization beam splitter prism 9 .

[0047] Among them, the polarization beam splitter prism has the characteristics of low stress, high extinction ratio, good imaging quality and small beam deflection angle.

[0048] Furthermore, in the above embodiment, the wave plate 4 is a quarter wave plate.

[0049] Second, as Figure 3 As shown, an embodiment of the present invention provides a calibration method for corresponding parameters of a liquid crystal phase retarder 3, and a calibration device for corresponding parameters of the liquid crystal phase retarder 3 is applied to the above-mentioned liquid crystal phase retarder 3, including:

[0050] Step S101: light source 1 is used to emit collimated light;

[0051] Step S102: the polarizer converts the collimated light into polarized light, and the polarization direction of the polarized light forms a preset angle with the optical axis of the liquid crystal phase retarder 3;

[0052] Step S103: the controller 7 provides a corresponding initial driving voltage and a termination driving voltage to the liquid crystal phase retarder 3 according to the preset TNE parameter measurement calibration range and the corresponding TNE parameter measurement calibration number, and adds a TNE overshoot voltage between each pair of the initial driving voltage and the termination driving voltage;

[0053] Step S104: the wave plate 4 modulates the polarized light after being processed by the liquid crystal phase retarder 3 into linearly polarized light, and the polarization direction of the linearly polarized light is different from the polarization direction of the polarizer;

[0054] Step S105: the polarization analyzer and the light intensity detector 6 detect the polarization state of the linearly polarized light;

[0055] Step S106: the controller 7 adjusts the TNE overshoot voltage value and duration according to the output signal of the light intensity detector 6, determines the optimal TNE overshoot voltage value and optimal duration required for the rapid transition between the initial and final states, and obtains the TNE parameters for measurement and calibration;

[0056] Step S107: Perform two-dimensional difference processing on all measured and calibrated TNE parameters to obtain a TNE parameter matrix.

[0057] The specific definition of the calibration method of the corresponding parameters of the liquid crystal phase retarder 3 can be found in the above definition of the calibration device of the corresponding parameters of the liquid crystal phase retarder 3, which will not be repeated here.

[0058] According to the calibration method of the corresponding parameters of a liquid crystal phase retarder 3 provided in the embodiment of the present invention, the controller 7 provides the corresponding initial driving voltage and the termination driving voltage to the liquid crystal phase retarder 3 according to the preset TNE parameter measurement calibration range and the corresponding number of TNE parameter measurement calibrations, and adds a TNE overshoot voltage between each pair of the initial driving voltage and the termination driving voltage; then, according to the output signal of the light intensity detector 6, the TNE overshoot voltage value and duration are adjusted to determine the optimal TNE overshoot voltage value and the optimal duration required for the rapid transition between the initial and final states, so as to obtain the measured and calibrated TNE parameters, and finally, the TNE parameters between any initial driving voltage and the termination driving voltage within the calibration range are obtained by the interpolation method. In this way, the number of calibrations of the overvoltage parameters can be greatly reduced, thereby compressing the calibration time to the order of minutes, improving the efficiency of the calibration, and saving time and effort.

[0059] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A device for calibrating corresponding parameters of a liquid crystal phase retarder, characterized in that: It comprises a light source, a light intensity detector and a controller; a light source, a polarizer, a liquid crystal phase retarder, a wave plate, an analyzer and a light intensity detector are arranged in sequence between the light source and the light intensity detector along the direction from the light source to the light intensity detector; the controller is connected to the liquid crystal phase retarder and the light intensity detector respectively; The light source is used to emit collimated light; The polarizer is used to convert the collimated light into polarized light, and the polarization direction of the polarized light forms a preset angle with the optical axis of the liquid crystal phase retarder; The wave plate is used to modulate the polarized light after being processed by the liquid crystal phase retarder into linear polarized light, and the polarization direction of the linear polarized light is different from the polarization direction of the polarizer; The polarizer and light intensity detector are used to detect the polarization state of the linearly polarized light; The controller is used to obtain a preset TNE parameter measurement calibration range and a corresponding number of TNE parameter measurement calibrations; provide a corresponding initial driving voltage and a termination driving voltage to the liquid crystal phase retarder according to the preset TNE parameter measurement calibration range and the corresponding number of TNE parameter measurement calibrations, and add a TNE overshoot voltage between each pair of the initial driving voltage and the termination driving voltage; and adjust the TNE overshoot voltage value and duration according to the output signal of the light intensity detector, determine the optimal TNE overshoot voltage value and optimal duration required for the rapid transition of the initial and final states, so as to obtain the measured and calibrated TNE parameters, and perform two-dimensional difference processing on all the measured and calibrated TNE parameters to obtain a TNE parameter matrix.

2. The device for calibrating corresponding parameters of a liquid crystal phase retarder according to claim 1, characterized in that: The degree of change of the historical TNE parameter between adjacent initial and final driving voltages within the preset TNE parameter measurement calibration range is proportional to the number of corresponding TNE parameter measurement calibrations.

3. The device for calibrating corresponding parameters of a liquid crystal phase retarder according to claim 1, characterized in that: The polarizer includes a first linear polarizer, and the analyzer includes a second linear polarizer.

4. The device for calibrating corresponding parameters of a liquid crystal phase retarder according to claim 1, characterized in that: The polarizer includes a first polarization beam splitter prism, and the analyzer includes a second polarization beam splitter prism.

5. The device for calibrating corresponding parameters of a liquid crystal phase retarder according to claim 1, characterized in that: The wave plate is a quarter wave plate.

6. A method for calibrating corresponding parameters of a liquid crystal phase retarder, applied to the device for calibrating corresponding parameters of a liquid crystal phase retarder according to any one of claims 1 to 4, characterized in that: include: The light source is used to emit collimated light; The polarizer converts the collimated light into polarized light, and the polarization direction of the polarized light forms a preset angle with the optical axis of the liquid crystal phase retarder; The controller obtains a preset TNE parameter measurement calibration range and a corresponding number of TNE parameter measurement calibrations; provides a corresponding initial driving voltage and a termination driving voltage to the liquid crystal phase retarder according to the preset TNE parameter measurement calibration range and the corresponding number of TNE parameter measurement calibrations, and adds a TNE overshoot voltage between each pair of the initial driving voltage and the termination driving voltage The wave plate modulates the polarized light after being processed by the liquid crystal phase retarder into linear polarized light, and the polarization direction of the linear polarized light is different from the polarization direction of the polarizer; The polarizer and the light intensity detector detect the polarization state of the linearly polarized light; The controller adjusts the TNE overshoot voltage value and duration according to the output signal of the light intensity detector, determines the optimal TNE overshoot voltage value and optimal duration required for the rapid transition between the initial and final states, so as to obtain the TNE parameters for measurement and calibration; All measured and calibrated TNE parameters are subjected to two-dimensional difference processing to obtain the TNE parameter matrix.

Images