CN117213800A - Detection method and detection system for polarization parameters of optical module - Google Patents
Detection method and detection system for polarization parameters of optical module Download PDFInfo
- Publication number
- CN117213800A CN117213800A CN202311117300.3A CN202311117300A CN117213800A CN 117213800 A CN117213800 A CN 117213800A CN 202311117300 A CN202311117300 A CN 202311117300A CN 117213800 A CN117213800 A CN 117213800A
- Authority
- CN
- China
- Prior art keywords
- optical module
- polarizer
- light
- delay element
- phase delay
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 173
- 238000001514 detection method Methods 0.000 title claims abstract description 82
- 230000010287 polarization Effects 0.000 title claims abstract description 73
- 239000013598 vector Substances 0.000 claims abstract description 104
- 238000000034 method Methods 0.000 claims description 23
- 239000011159 matrix material Substances 0.000 claims description 19
- 230000014509 gene expression Effects 0.000 claims description 15
- 238000000572 ellipsometry Methods 0.000 claims description 8
- 238000007689 inspection Methods 0.000 claims 1
- 238000003384 imaging method Methods 0.000 description 3
- 235000012771 pancakes Nutrition 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008033 biological extinction Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Landscapes
- Testing Of Optical Devices Or Fibers (AREA)
Abstract
The embodiment of the application provides a detection method and a detection system for polarization parameters of an optical module. The detection method of the polarization parameters of the optical module is applied to a detection system of the polarization parameters of the optical module, and the detection system comprises the following steps: the device comprises a light source assembly, a phase delay element, a polarizer and a detection module, wherein the phase delay element rotates at an angular frequency omega. In the case where the optical module to be detected is disposed between the light source module and the phase delay element, the detection method includes: polarized light of a plurality of view fields is controlled to be projected to the detection module through the optical module, the phase delay element and the polarizer in sequence; when the included angle between the fast axis of the phase delay element and the horizontal direction is alpha, the intensity of the light emitted by the polarizer is obtained, wherein alpha=ωt, and t is the rotation time of the phase delay element; according to the intensity of the light emitted by the polarizer, obtaining a Stokes vector of the light emitted by the optical module; and obtaining the polarization parameters of the optical module according to the Stokes vector of the emergent light of the optical module.
Description
Technical Field
The embodiment of the application relates to the technical field of polarization parameter detection, in particular to a detection method and a detection system for polarization parameters of an optical module.
Background
The imaging quality of a VR (virtual reality technology) Pancake optical module can be affected by links such as film quality, film pasting technology, assembly technology and the like, so that the detection of the polarization parameters of outgoing light rays of the optical module is very important.
Currently, detection of emitted light of a VR band optical module is often performed by using a polarimeter or a power detection method. However, when using polarimeter detection, polarimeters are expensive; the power detection method is only suitable for detecting the central emergent light of the VR Pancake optical module, cannot be used for detecting emergent light of a plurality of fields of view, and has no convenience in use.
Therefore, how to accurately detect the polarization parameter of the outgoing light of the VR Pancake optical module is a technical problem to be solved.
Disclosure of Invention
The application aims to provide a detection method of polarization parameters of an optical module and a new technical scheme of a detection system.
In a first aspect, the present application provides a method for detecting polarization parameters of an optical module. The detection method is applied to the detection system of the polarization parameters of the optical module, and the detection system comprises the following steps: the device comprises a light source assembly, a phase delay element, a polarizer and a detection module, wherein the phase delay element rotates at an angular frequency omega; the optical module to be detected is arranged between the light source component and the phase delay element;
in the case where an optical module to be detected is disposed between the light source module and the phase delay element, the detection method includes:
polarized light of a plurality of view fields is controlled to be projected to the detection module through the optical module, the phase delay element and the polarizer in sequence;
when the included angle between the fast axis of the phase delay element and the horizontal direction is alpha, the intensity of the outgoing light of the polarizer is obtained, wherein alpha=ωt, and t is the rotation time of the phase delay element;
according to the intensity of the light emitted by the polarizer, obtaining a Stokes vector of the light emitted by the optical module;
and obtaining the polarization parameters of the optical module according to the Stokes vector of the emergent light of the optical module.
Optionally, according to the intensity of the light emitted by the polarizer, obtaining the stokes vector of the light emitted by the optical module specifically includes:
acquiring a relational expression existing between the intensity of the light emitted by the polarizer and the Stokes vector of the light emitted by the optical module;
performing Fourier transform on the relational expression, and acquiring the Fourier transform coefficient according to the intensity of the emergent light of the polarizer;
and acquiring a Stokes vector of the emergent light of the optical module according to the Fourier transform coefficient.
Optionally, obtaining a relational expression existing between the intensity of the polarizer emergent ray and the stokes vector of the optical module emergent ray specifically includes:
setting Stokes vector of the emergent light of the optical module as S VR ；
According to the Stokes vector S VR Acquiring a Stokes vector S' of the emergent light of the phase delay element;
according to the Stokes vector S', a Stokes vector Sout of the light rays emitted by the polarizer is obtained;
and obtaining a relational expression existing between the intensity of the light emitted by the polarizer and the Stokes vector of the light emitted by the optical module according to the Stokes vector Sout.
Optionally, according to the Stokes vector S VR The stokes vector S' for obtaining the outgoing light of the phase delay element specifically includes:
according to the Stokes vectorQuantity S VR And the Mueller matrix of the phase delay element with the included angle alpha between the fast axis and the horizontal direction is used for obtaining the Stokes vector S' of the emergent light of the phase delay element.
Optionally, obtaining the stokes vector Sout of the polarizer outgoing light according to the stokes vector S' specifically includes:
and obtaining a Stokes vector Sout of the outgoing light of the polarizer according to the Stokes vector S' and the Mueller matrix of the polarizer.
Optionally, the polarization parameters of the optical module include: polarization, ellipsometry and azimuth angle of emergent light of the optical module.
Optionally, the rotation of the phase delay element at an angular frequency ω specifically includes:
the phase delay element is driven to rotate at an angular frequency ω by a stepper motor having steps n, steps aj, α=ωt=n×aj.
Optionally, the phase delay element is a quarter wave plate.
Optionally, the polarizer is a horizontal linear polarizer.
In a second aspect, an embodiment of the present application provides a detection system for a polarization parameter of an optical module, where the detection system includes:
the device comprises a light source assembly, a phase delay element, a polarizer and a detection module, wherein the phase delay element rotates at an angular frequency omega;
the light source component is used for emitting polarized light of a plurality of view fields;
when the optical module to be tested is placed between the light source assembly and the phase delay element, the optical module, the phase delay element, the polarizer and the detection module are sequentially arranged along the same optical axis.
Optionally, the light source assembly includes: a light source, a quick reflector, a lens group and a polarizer, wherein the lens group comprises at least one lens;
light rays emitted by the light source are projected to the optical module to be tested through the quick reflector, the lens group and the polarizer in sequence.
Optionally, the detection system further comprises a stepper motor driving the phase delay element to rotate at an angular frequency ω.
Optionally, the polarizer is a horizontal linear polarizer and the phase retardation element is a quarter-wave plate.
Optionally, the optical module to be tested is an optical module capable of forming a folded light path.
In the technical scheme provided by the embodiment of the application, the Stokes vector of the emergent light of the optical module is obtained through the detected light intensity of the emergent light of the polarizer; and then, based on the Stokes vector of the emergent ray of the optical module, acquiring the polarization parameter of the emergent ray of the optical module. The method for detecting the polarization parameters of the optical module provided by the embodiment of the application can quantitatively acquire the polarization parameters of the emergent rays of the optical module.
Other features of the present specification and its advantages will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and together with the description, serve to explain the principles of the specification.
Fig. 1 is a block diagram of a detection system for polarization parameters of an optical module according to an embodiment of the present application.
Reference numerals illustrate:
1. a light source assembly; 10. a light source; 11. a fast mirror; 12. a first lens; 13. a second lens; 14. a polarizer;
2. an optical module to be tested;
3. a phase delay element;
4. a polarizer;
5. and a detection module.
Detailed Description
Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise.
The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses.
Techniques and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate.
In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.
The VR optical module generally includes a lens group, a light splitting element, a polarizing element and a phase retardation film, and the imaging quality of the VR optical module is affected by factors such as the film quality of the light splitting element, the polarizing element and the phase retardation film. Therefore, it is important to detect the polarization parameters of the outgoing light of the VR optical module.
Currently, polarimeters or power detection methods are used for detecting polarization parameters of VR optical modules. But polarimeters are expensive. The power detection method is that after the VR optical module emits light, a linear polaroid capable of rotating in whole circle is placed, and the polarization state is judged according to the light intensity change and whether extinction is carried out. However, this method of power detection is more suitable for qualitative discrimination of different polarization states of the outgoing light. Moreover, the power detection result is often affected by the excitation light source and the detector, and when the optical axis of the film material is changed at a small angle, the small change of the light intensity is difficult to accurately detect because the resolution of the detector cannot meet the requirement. Moreover, the power detection method is only suitable for detecting the emergent light of the VR Pancake center, cannot be used for detecting the whole VR Pancake, and has no convenience in use.
Based on the technical problems, the embodiment of the application provides a novel detection method and a detection system for polarization parameters of an optical module. Specifically, based on the Stokes vector of the emergent light of the optical module, the polarization parameter of the optical module is obtained, and the quantitative analysis of the polarization state of the emergent light of the optical module is realized.
The method and system for detecting the polarization parameters of the optical module according to the embodiments of the present application are described in detail below with reference to the accompanying drawings.
According to an embodiment of the present application, a method for detecting polarization parameters of an optical module is provided. The method for detecting the polarization parameters of the optical module is applied to a detection system of the polarization parameters of the optical module. Referring to fig. 1, the detection system includes: a light source assembly 1, a phase delay element 3, a polarizer 4 and a detection module 5, wherein the phase delay element 3 rotates at an angular frequency ω; the optical module to be detected is arranged between the light source component 1 and the phase delay element 3.
In the case where an optical module to be detected is provided between the light source module 1 and the phase delay element 3, the detection method includes the steps of:
step 1: polarized light controlling a plurality of fields of view is projected to the detection module 5 through the optical module, the phase delay element 3 and the polarizer 4 in sequence.
Step 2: when the included angle between the fast axis of the retarder 3 and the horizontal direction is α, the intensity of the light emitted by the polarizer 4 is obtained, where α=ωt, and t is the rotation time of the retarder 3.
Step 3: and acquiring Stokes vectors of the light rays emitted by the optical module according to the intensity of the light rays emitted by the polarizer 4.
Step 4: and obtaining the polarization parameters of the optical module according to the Stokes vector of the emergent light of the optical module.
According to the method for detecting the polarization parameters of the optical module, the optical module 2 to be detected is placed between the light source component 1 and the phase delay element 3, and the polarization parameters of the optical module are detected, for example, the polarization state and the light intensity of the emergent light of the optical module can be quantitatively detected. Specifically, the phase delay element 3 rotated at the angular frequency ω detects the outgoing light of the VR Pancake optical module in combination with the polarizer 4 and the detection module 5, so that the polarization state of the outgoing light of the VR Pancake in the large field of view can be detected quickly and accurately at low cost, including completely polarized light (elliptically polarized light) and partially polarized light. Therefore, the method for detecting the polarization parameters of the optical module provided by the embodiment of the application can be used for rapidly, accurately and low-cost detecting the polarization parameters of the emergent rays of the VR Pancake optical module.
In step 1, polarized light of a plurality of fields of view is controlled to be projected to the detection module 5 sequentially through the optical module, the phase delay element 3 and the polarizer 4. For example, the light source assembly 1 emits polarized light of a plurality of fields, and the polarized light of the plurality of fields sequentially passes through the optical module, the phase delay element 3 and the polarizer 4 and is finally received by the detection module 5. For example, the detection module 5 may be a CCD camera.
In step 2, the intensity of the light emitted from the polarizer 4 is obtained when the fast axis of the retarder 3 forms an angle α with the horizontal direction, where α=ωt. Specifically, polarized light of a plurality of fields of view exiting from the polarizer 4 is finally received by the detection module 5. After the detection module 5 receives polarized light of a plurality of fields of view emitted from the polarizer 4, the light intensity of the polarized light of a plurality of fields of view emitted from the polarizer 4 can be detected by the detection module 5. Since the retarder 3 rotates at the angular frequency ω, the detecting module 5 can detect the intensities of the polarized light rays of the multiple fields of view emitted by the polarizer 4 when the angle α between the fast axis of the retarder 3 and the horizontal direction is detected in real time.
In step 3, when the detection module 5 detects that the angle between the fast axis of the phase delay element 3 and the horizontal direction is α, the stokes vector of the light emitted from the optical module can be obtained according to the intensities of the polarized light of the multiple fields emitted from the polarizer 4 under the condition that the polarized light of the multiple fields emitted from the polarizer 4. The stokes vector of the light emitted by the optical module can represent the polarization state and the intensity of the light beam.
For example, the Stokes vector for obtaining the outgoing light of the optical module is S VR 。
Wherein S is 0 Representing the total light intensity, S 1 Representing the light intensity difference between the horizontally linearly polarized light and the vertically linearly polarized light; s is S 2 Representing the light intensity difference between 45-degree linearly polarized light and-45-degree linearly polarized light; s is S 3 Indicating the light intensity difference between right circularly polarized light and left circularly polarized light.
Wherein S is 0 、S 1 、S 2 And S is 3 Are each represented by the intensity of polarized light of a plurality of fields of view that can be emitted by the polarizer 4.
In step 4, according to the calculated Stokes vector S of the outgoing light of the optical module VR The polarization parameters of the outgoing light of the optical module can be obtained.
For example, the polarization parameters of the light exiting the optical module include the polarization degree, the ellipsometry degree and the azimuth angle of the light exiting the optical module.
The polarization degree DOP of the emergent light of the optical module can be obtained through a formula (2);
the azimuth angle psi of the emergent light of the optical module can be obtained through a formula (3);
the ellipsometry χ of the outgoing light of the optical module can be obtained by the formula (4):
therefore, in the embodiment of the present application, according to the intensities of the light rays of multiple fields of view emitted by the polarizer 4 when the angle between the fast axis of the phase delay element 3 and the horizontal direction obtained by the detection module is α, each element (S) in the formula (1) is calculated 0 、S 1 、S 2 And S is 3 ) Wherein each element (S 0 、S 1 、S 2 And S is 3 ) Is also related to the included angle between the fast axis of the phase delay element 3 and the horizontal direction; then, the polarization degree and ellipsometry of the outgoing light rays (polarized light of a plurality of fields of view) of the optical module are calculated according to the formula (2), the formula (4) and the formula (3) in the numerical value of each element calculated according to the formula (1), and the azimuth angle of the outgoing light rays of the optical module is calculated.
According to the method for detecting the polarization parameters of the optical module, the combination mode of the polarizer 4 and the detection module 5 is combined with the phase delay element 3 rotating at the angular frequency omega to detect the emergent light of the VR Pancake optical module, so that the polarization state of the VR Pancake emergent light in a large field of view range can be detected rapidly and accurately at low cost. Therefore, the method for detecting the polarization parameters of the optical module provided by the embodiment of the application can be used for rapidly, accurately and low-cost detecting the polarization parameters of the emergent rays of the VR Pancake optical module.
In one example, according to the intensity of the light emitted by the polarizer 4, the method for obtaining the stokes vector of the light emitted by the optical module specifically includes the following steps:
s01: acquiring a relational expression existing between the intensity of the light rays emitted by the polarizer 4 and the Stokes vector of the light rays emitted by the optical module;
s02: performing Fourier transform on the relational expression, and acquiring the Fourier transform coefficient according to the intensity of the light rays emitted by the polarizer 4;
s03: and acquiring a Stokes vector of the emergent light of the optical module according to the Fourier transform coefficient.
In step S01, the intensity of the light emitted from the polarizer 4 is related to the stokes vector of the light emitted from the optical module and the rotation angle of the retarder 3. For example, the angle between the fast axis of the retarder 3 and the horizontal direction is α, α=ωt.
For example, in the case where the phase retarder 3 is a quarter-wave plate and the polarizer 4 is a horizontal linear polarizer, the expression of the relationship between the intensity of the light emitted from the polarizer 4 and the stokes vector of the light emitted from the optical module is:
wherein in the formula (5), α is an angle between the fast axis of the phase delay element 3 and the horizontal direction, S 0 、S 1 、S 2 And S is 3 Are elements in the Stokes vector matrix of the emergent rays of the optical module.
In step S02, the fourier transform is performed on equation (5), and the fourier transform coefficient is obtained from the intensity of the light emitted from the polarizer 4. Specifically, by fourier transform, a relationship between the fourier transform coefficient and the intensity of the detected polarizer-exiting light can be obtained.
For example, formula (5) is written as a fourier series form, where the fourier series form corresponding to formula (5) is formula (6):
then, in the fourier transform of the formula (6), the relation between the fourier transform coefficients A, B, C and D and the intensity of the detected light emitted from the polarizer 4 can be obtained. Equation (7) below shows the relationship between the fourier transform coefficient a and the intensity of the detected polarizer exit light, equation (8) shows the relationship between the fourier transform coefficient B and the intensity of the detected polarizer exit light, equation (9) shows the relationship between the fourier transform coefficient C and the intensity of the detected polarizer exit light, and equation (10) shows the relationship between the fourier transform coefficient D and the intensity of the detected polarizer exit light. Wherein the method comprises the steps of
In step S03, a stokes vector of the light emitted from the optical module is obtained according to the fourier transform coefficient. Specifically, according to the above formulas (7) - (8), parameters in a stokes vector matrix of the outgoing light of the optical module are obtained.
Specifically, from the formula (5) and the formula (6), it can be known that:
B＝S 3 (12)
from the formula (11) -the formula (14), it can be known that:
S 0 ＝A-C (15)
S 1 ＝2C (16)
S 2 ＝2D (17)
S 3 ＝B (18)
therefore, according to the formulas (7) - (10) and (15) - (18), parameters in the stokes vector matrix of the outgoing light of the optical module can be obtained, so that the stokes vector of the outgoing light of the optical module can be obtained. According to the Stokes vector of the outgoing light of the optical module, the polarization degree and the ellipsometry of the outgoing light (polarized light of a plurality of fields of view) of the optical module are calculated respectively by combining the formulas (2) and (4), and the azimuth angle of the outgoing light of the optical module is calculated.
In one example, the obtaining the expression of the relationship between the intensity of the light emitted by the polarizer 4 and the stokes vector of the light emitted by the optical module specifically includes the following steps:
s001: setting Stokes vector of the emergent light of the optical module as S VR ；
S002: according to the Stokes vector S VR Acquiring a Stokes vector S' of the light emitted by the phase delay element 3;
s003: according to the Stokes vector S', a Stokes vector Sout of the light emitted by the polarizer 4 is obtained;
s004: and obtaining a relational expression existing between the intensity of the light emitted by the polarizer 4 and the Stokes vector of the light emitted by the optical module according to the Stokes vector Sout.
Specifically, in step S001, a stokes vector of the light emitted from the optical module is set as S VR 。
For example, let the stokes vector of the outgoing light of the optical module be:
wherein S is 0 Representing the total light intensity, S 1 Representing the light intensity difference between the horizontally linearly polarized light and the vertically linearly polarized light; s is S 1 Representing the light intensity difference between 45-degree linearly polarized light and-45-degree linearly polarized light; s is S 3 Indicating the light intensity difference between right circularly polarized light and left circularly polarized light.
In step S002, based on the Stokes vector S VR The stokes vector S' of the light emitted by the phase delay element 3 is obtained, specifically, the stokes vector of the light emitted by a certain component is the product of the mueller matrix of the component and the stokes vector of the light emitted by the previous component.
For example according to the Stokes vector S VR And the mueller matrix of the phase delay element 3 with the angle alpha between the fast axis and the horizontal direction, so as to obtain a stokes vector S' of the light emitted by the phase delay element 3.
In a specific embodiment, the phase delay element 3 is a quarter-wave plate, and the muller matrix of the quarter-wave plate with the fast axis having an angle α with respect to the horizontal direction can be expressed as:
the quarter wave plate rotates at an angular velocity ω (α=ωt).
After the emergent light of the optical module passes through the rotated quarter wave plate, the Stokes vector of the emergent light is as follows:
the following are to be described: the phase delay element 3 may also be a half-wave plate, which allows the light emitted from the optical module to pass through, and the stokes vector of the light emitted from the optical module after passing through the rotated half-wave plate is the product of the mueller matrix of the half-wave plate and the stokes vector of the light emitted from the optical module.
In step S003, a stokes vector S' of the light emitted from the polarizer 4 is obtained according to the stokes vector S out The method comprises the steps of carrying out a first treatment on the surface of the Specifically, the stokes vector of the emergent ray of a certain component is the product of the mueller matrix of the component and the stokes vector of the emergent ray of the upper component.
For example according to the SiasA stokes vector S' and a mueller matrix of the polarizer 4, resulting in a stokes vector S of the light exiting the polarizer 4 out 。
In a specific embodiment, polarizer 4 is a horizontally linear polarizer. The muller matrix of the horizontal linear polarizer (i.e., the muller matrix of the light transmission axis of the horizontal linear polarizer in the horizontal direction) is expressed as:
the relation between the emergent light of the horizontal linear polaroid and the emergent light of the optical module is as follows:
S out ＝NMS VR (22)
the light exiting through the horizontal linear polarizer is expressed as stokes vector of the light exiting through the horizontal linear polarizer is expressed as:
the polarizer 4 may be a circular polarizer. According to the principles set forth above, the Stokes vector of light rays exiting through the circular polarizer can be obtained.
In step S004, according to the Stokes vector S out And acquiring a relational expression existing between the intensity of the light rays emitted by the polarizer 4 and the Stokes vector of the light rays emitted by the optical module.
Specifically, only the outgoing light S is calculated out The first component of (a) i.e. the total intensity can be detected, S' 0 ＝I(α)
Thus, equation (5) above shows the relationship between the intensity of the light exiting the polarizer 4 and the Stokes vector of the light exiting the optical module, whereIn the formula (5), α is an angle between the fast axis of the phase delay element 3 and the horizontal direction, S 0 、S 1 、S 2 And S is 3 Are elements in the Stokes vector matrix of the emergent rays of the optical module. And then carrying out Fourier transform on the formula (5), and acquiring the Fourier transform coefficient according to the intensity of the emergent light of the polarizer 4. Specifically, by fourier transform, a relationship between the fourier transform coefficient and the intensity of the detected polarizer-exiting light can be obtained. Then, the relation between the fourier transform coefficients A, B, C and D and the intensity of the detected light emitted from the polarizer 4 can be obtained by fourier transform on the above formula (6). For example, equation (7) above shows the relationship between the fourier transform coefficient a and the intensity of the detected polarizer exit light, equation (8) shows the relationship between the fourier transform coefficient B and the intensity of the detected polarizer exit light, equation (9) shows the relationship between the fourier transform coefficient C and the intensity of the detected polarizer exit light, and equation (10) shows the relationship between the fourier transform coefficient D and the intensity of the detected polarizer exit light.
Therefore, according to the above formula (7) -formula (10) and the above formula (15) -formula (18), parameters in the stokes vector matrix of the outgoing light of the optical module can be obtained, so as to obtain the stokes vector of the outgoing light of the optical module. According to the Stokes vector of the outgoing light of the optical module, the polarization degree and the ellipsometry of the outgoing light (polarized light of a plurality of fields of view) of the optical module are calculated respectively by combining the above formulas (2) - (4), and the azimuth angle of the outgoing light of the optical module is calculated.
In one example, the rotation of the phase delay element 3 at an angular frequency ω comprises:
the phase delay element 3 is driven to rotate at an angular frequency ω by a stepper motor having steps n, steps aj, α=ωt=n×aj.
In a specific embodiment, the phase delay element 3 is driven in rotation by a stepper motor. The quarter wave plate is driven in rotation, for example by a stepper motor.
Specifically, the quarter wave plate is placed on a fixed base, and can be driven to rotate through a stepping motor in n steps: ωt=nα j (α j Step size, N is the total number of steps). Wherein according to α=ωt=nα j The equation (24) can be obtained by transforming the equation (6).
Wherein the relationship between the fourier transform coefficients A, B, C and D and the intensity of the detected light exiting the polarizer 4 can be obtained by fourier transform, wherein equations (25) - (28) show the relationship between the fourier transform coefficients A, B, C and D and the intensity of the detected light exiting the polarizer 4.
Thus, in the embodiment of the present application, given the step size and the step number of the stepper motor and the intensity of the detected light emitted from the polarizer 4, the stokes vector of the light emitted from the optical module can be obtained. And then obtaining the polarization parameters of the optical module according to the Stokes vector of the emergent light of the optical module.
In one example, the phase delay element 3 is a quarter wave plate. The polarizer 4 is a horizontal linear polarizer.
In this embodiment, the types of the phase delay element 3 and the polarizer 4 are limited, the mueller matrix of the quarter-wave plate and the horizontal linear polarizer is simple, and the difficulty of acquiring the stokes vector of the optical module can be reduced. In addition, the types of the phase delay element 3 and the polarizer 4 are limited, so that the polarization state of the light emitted by the optical module with a large field of view range can be detected more easily, and the polarization state comprises completely polarized light (elliptical polarized light) and partially polarized light.
In a second aspect, an embodiment of the present application provides a detection system for a polarization parameter of an optical module, referring to fig. 1, the detection system includes:
a light source assembly 1, a phase delay element 3, a polarizer 4 and a detection module 5, the phase delay element 3 rotating at an angular frequency ω;
the light source assembly 1 is used for emitting polarized light of a plurality of fields of view;
when the optical module to be tested 2 is placed between the light source assembly 1 and the phase delay element 3, the optical module, the phase delay element 3, the polarizer 4 and the detection module 5 are sequentially arranged along the same optical axis.
In the embodiment of the present application, the light source assembly 1 emits polarized light of a plurality of fields of view. For example, the light source unit 1 emits linearly polarized light having a plurality of fields of view, so that the linearly polarized light having a plurality of fields of view is incident on the optical module, and the light emitted from the optical module passes through the phase delay element 3 rotated at the angular frequency ω, passes through the polarizer 4, and is finally received by the detection module 5. The Stokes vector of the emergent light of the optical module can be detected by the method, so that polarization parameters such as polarization degree, ellipsometry, azimuth angle and the like can be calculated.
For example, the detection module 5 may be an area array CCD.
In an alternative embodiment, a quarter wave plate rotated at an angular frequency ω in combination with a horizontal linear polarizer and a CCD may be replaced by an expensive polarization camera if only linearly polarized light is measured.
In one example, referring to fig. 1, the light source assembly 1 includes: a light source 10, a quick mirror 11, a lens group comprising at least one lens, and a polarizer 14;
the light emitted from the light source 10 is projected to the optical module 2 to be tested through the quick reflector 11, the lens group and the polarizer 14 in sequence.
Specifically, the lens group includes a first lens 12 and a second lens 13, the light emitted from the laser passes through the fast mirror 11, the first lens 12 and the second lens 13, and F1 and F2 are focal lengths of the first lens 12 and the second lens 13, respectively, and then passes through the polarizer 14 to generate linearly polarized light with multiple fields of view.
In one example, the detection system further comprises a stepper motor driving the phase delay element 3 to rotate at an angular frequency ω.
In the embodiment of the present application, the phase delay element 3 is driven by a stepping motor, wherein the stokes vector of the outgoing light of the optical module can be obtained given the step size and the step number of the stepping motor and the intensity of the detected outgoing light of the polarizer 4. And then obtaining the polarization parameters of the optical module according to the Stokes vector of the emergent light of the optical module.
In one example, referring to fig. 1, the polarizer 4 is a horizontal linear polarizer and the phase retarder 3 is a quarter-wave plate.
In this embodiment, the types of the phase delay element 3 and the polarizer 4 are limited, the mueller matrix of the quarter-wave plate and the horizontal linear polarizer is simple, and the difficulty of acquiring the stokes vector of the optical module can be reduced. In addition, the types of the phase delay element 3 and the polarizer 4 are limited, so that the polarization state of the light emitted by the optical module with a large field of view range can be detected more easily, and the polarization state comprises completely polarized light (elliptical polarized light) and partially polarized light.
In one example, the optical module to be tested 2 is an optical module capable of forming a folded optical path.
Specifically, the imaging quality of VR (virtual reality technology) Pancake can be affected by links such as film quality, film pasting technology, assembly technology and the like, and by adopting the detection system for the polarization parameters of the optical module provided by the embodiment of the application and by using the detection method for the polarization parameters of the optical module provided by the embodiment of the application, the polarization parameters of VR Pancake emergent light can be rapidly and accurately obtained.
The specific implementation manner of the optical module polarization parameter detection system according to the embodiment of the present application may refer to each embodiment of the optical module polarization parameter detection method, so that the optical module polarization parameter detection system at least has all the beneficial effects brought by the technical solutions of the embodiments, and will not be described in detail herein.
The foregoing embodiments mainly describe differences between the embodiments, and as long as there is no contradiction between different optimization features of the embodiments, the embodiments may be combined to form a better embodiment, and in consideration of brevity of line text, no further description is given here.
While certain specific embodiments of the application have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the application. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the application. The scope of the application is defined by the appended claims.
Claims (14)
1. The method for detecting the polarization parameters of the optical module is characterized by being applied to a detection system of the polarization parameters of the optical module, and the detection system comprises the following steps: the device comprises a light source assembly, a phase delay element, a polarizer and a detection module, wherein the phase delay element rotates at an angular frequency omega; the optical module to be detected is arranged between the light source component and the phase delay element;
in the case where an optical module to be detected is disposed between the light source module and the phase delay element, the detection method includes:
polarized light of a plurality of view fields is controlled to be projected to the detection module through the optical module, the phase delay element and the polarizer in sequence;
when the included angle between the fast axis of the phase delay element and the horizontal direction is alpha, the intensity of the outgoing light of the polarizer is obtained, wherein alpha=ωt, and t is the rotation time of the phase delay element;
according to the intensity of the light emitted by the polarizer, obtaining a Stokes vector of the light emitted by the optical module;
and obtaining the polarization parameters of the optical module according to the Stokes vector of the emergent light of the optical module.
2. The method according to claim 1, wherein obtaining the stokes vector of the light emitted from the optical module according to the intensity of the light emitted from the polarizer specifically comprises:
acquiring a relational expression existing between the intensity of the light emitted by the polarizer and the Stokes vector of the light emitted by the optical module;
performing Fourier transform on the relational expression, and acquiring the Fourier transform coefficient according to the intensity of the emergent light of the polarizer;
and acquiring a Stokes vector of the emergent light of the optical module according to the Fourier transform coefficient.
3. The method according to claim 2, wherein obtaining a relational expression existing between the intensity of the polarizer outgoing light and the stokes vector of the optical module outgoing light specifically includes:
setting Stokes vector of the emergent light of the optical module as S VR ；
According to the Stokes vector S VR Acquiring a Stokes vector S' of the emergent light of the phase delay element;
according to the Stokes vector S', a Stokes vector Sout of the light rays emitted by the polarizer is obtained;
and obtaining a relational expression existing between the intensity of the light emitted by the polarizer and the Stokes vector of the light emitted by the optical module according to the Stokes vector Sout.
4. A detection method according to claim 3, characterized in that according to the stokes vector S VR The stokes vector S' for obtaining the outgoing light of the phase delay element specifically includes:
according to the Stokes vector S VR And the Mueller matrix of the phase delay element with the included angle alpha between the fast axis and the horizontal direction is used for obtaining the Stokes vector S' of the emergent light of the phase delay element.
5. The method according to claim 3 or 4, wherein obtaining a stokes vector Sout of the polarizer outgoing light ray according to the stokes vector S' specifically comprises:
and obtaining a Stokes vector Sout of the outgoing light of the polarizer according to the Stokes vector S' and the Mueller matrix of the polarizer.
6. The method according to claim 1, wherein the polarization parameters of the optical module include: polarization, ellipsometry and azimuth angle of emergent light of the optical module.
7. The method according to claim 1, wherein the phase delay element rotates at an angular frequency ω, specifically comprising:
the phase delay element is driven to rotate at an angular frequency ω by a stepper motor having steps n, steps aj, α=ωt=n×aj.
8. The method of claim 1, wherein the phase delay element is a quarter wave plate.
9. The method of claim 1, wherein the polarizer is a horizontally linear polarizer.
10. A detection system for polarization parameters of an optical module, the detection system comprising:
the device comprises a light source assembly, a phase delay element, a polarizer and a detection module, wherein the phase delay element rotates at an angular frequency omega;
the light source component is used for emitting polarized light of a plurality of view fields;
when the optical module to be tested is placed between the light source assembly and the phase delay element, the optical module, the phase delay element, the polarizer and the detection module are sequentially arranged along the same optical axis.
11. The detection system of claim 10, wherein the light source assembly comprises: a light source, a quick reflector, a lens group and a polarizer, wherein the lens group comprises at least one lens;
light rays emitted by the light source are projected to the optical module to be tested through the quick reflector, the lens group and the polarizer in sequence.
12. The detection system of claim 10, further comprising a stepper motor that drives the phase delay element to rotate at an angular frequency ω.
13. The detection system of claim 10, wherein the polarizer is a horizontal linear polarizer and the phase delay element is a quarter wave plate.
14. The inspection system of claim 10, wherein the optical module to be inspected is an optical module capable of forming a folded optical path.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311117300.3A CN117213800A (en) | 2023-08-31 | 2023-08-31 | Detection method and detection system for polarization parameters of optical module |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311117300.3A CN117213800A (en) | 2023-08-31 | 2023-08-31 | Detection method and detection system for polarization parameters of optical module |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117213800A true CN117213800A (en) | 2023-12-12 |
Family
ID=89041713
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311117300.3A Pending CN117213800A (en) | 2023-08-31 | 2023-08-31 | Detection method and detection system for polarization parameters of optical module |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117213800A (en) |
-
2023
- 2023-08-31 CN CN202311117300.3A patent/CN117213800A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10119904B2 (en) | Birefringence measurement device and birefringence measurement method | |
| JP4455024B2 (en) | Birefringence measuring device | |
| TW201239338A (en) | Mueller matrix spectroscopy using chiroptic | |
| US3177761A (en) | Polariscope having simultaneously rotatable waveplates | |
| CN116438445B (en) | Vortex polarimeter | |
| KR101761251B1 (en) | Spectroscopic ellipsometer | |
| US11530953B2 (en) | Snapshot Mueller matrix polarimeter | |
| US6618145B1 (en) | Spectroplarimetric reflectometer | |
| US11346769B2 (en) | Fast generalized multi-wavelength ellipsometer | |
| CN117213800A (en) | Detection method and detection system for polarization parameters of optical module | |
| US20220003910A1 (en) | Aligning a polarization device using a spatially variant polarization element | |
| CN112747899B (en) | Measuring method and measuring device for polarizing element | |
| CN115031928A (en) | Optical detection system and method of operation thereof | |
| CN211122503U (en) | Wide-range imaging type birefringence distribution measuring device | |
| JP5446644B2 (en) | Bonding angle measuring device for elliptical polarizing plate | |
| CN117213803A (en) | Detection method and detection system for relative included angle of optical composite film | |
| CN117213801A (en) | Detection method and detection system for optical axis angle of optical film | |
| CN110763633A (en) | Wide-range imaging type birefringence distribution measuring device and method | |
| US20230116262A1 (en) | Apparatus and method for estimating a phase retarder and method of manufacturing the phase retarder using the same | |
| CN117213802A (en) | Optical module alignment method and alignment system | |
| WO2022092006A1 (en) | Inspection method | |
| JP2020507810A (en) | Method of assembling optical system and method of minimizing distortion due to retardance in optical assembly | |
| JPH0777490A (en) | Measuring method for double refraction | |
| KR20230046195A (en) | Apparatus, method for estimating a phase retarder and method of manufacturing the phase retarder using the same | |
| CN115389430A (en) | Method and equipment for detecting polarization composite sheet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |