Dynamic aberration calculation method and laminated microlens array scanning system

Abstract

The application discloses a kind of dynamic aberration calculation method and laminated microlens array scanning system, the method includes the following steps: step S1: determine the maximum incident field of view of unit scanning structure in laminated microlens array scanning system;Step S2: calculate the wave aberration value of rotation symmetry or zero relative displacement unit scanning structure;Step S3: calculate the aberration field offset vector of non-rotation symmetry unit scanning structure that produces relative displacement;Step S4: calculate the wave aberration value of different scanning field or relative displacement unit scanning structure.This application has adopted the vector wave aberration model of non-rotation symmetry optical system, can accurately characterize the wave aberration of laminated microlens array scanning system in scanning process, using the calculation method, the aberration of each kind of surface of multiple optical surfaces of unit scanning structure arbitrary scanning field can be conveniently completed, to effectively help designer to regulate and control the aberration distribution of system, help to eliminate the dynamic aberration of system.

Description

Technical Field

[0001] The present invention is applicable to the technical field of small infrared scanning imaging optical systems, and particularly relates to a dynamic aberration calculation method and a stacked microlens array scanning system. Background Art

[0002] In infrared imaging systems, the field of view (FOV) of infrared imaging systems is limited due to the difficulty in engineering and commercializing large-array, high-resolution infrared detectors. To address this issue, beam scanning systems can be used to expand the FOV of infrared imaging systems. Beam scanning systems include various scanning methods, including mechanical scanning, electronic scanning, and micro scanning. Stacked microlens array scanning systems, consisting of microlens arrays, have been widely used in infrared imaging systems due to their advantages, including small size, low scanning range, and high scanning frequency.

[0003] Stacked microlens array scanning systems achieve beam deflection through relative displacement between microlenses. Due to differences between actual optical systems and ideal optical systems, aberrations are inherent in real systems. However, the aberration characteristics of stacked microlens array scanning systems during the scanning process differ from those of traditional optical systems; they exhibit dynamic aberrations that continuously change as the scanning process progresses. Dynamic aberrations during scanning can degrade image quality in infrared imaging objectives. Therefore, effectively addressing dynamic aberrations in stacked microlens array scanning systems is crucial for improving the image quality of infrared imaging systems. Summary of the Invention

[0004] The object of the present invention is to provide a dynamic aberration calculation method and a stacked microlens array scanning system to regulate the aberration of the system, thereby effectively reducing the impact of dynamic aberration on the image quality of the system.

[0005] To achieve the purpose of the present invention, the technical solution provided by the present invention is as follows:

[0006] The present invention provides a dynamic aberration calculation method, which is applied to a stacked microlens array scanning system. The stacked microlens array scanning system is composed of two stacked microlens arrays, and the relative displacement between the two microlens arrays is used to achieve field of view scanning. The method comprises the following steps:

[0007] Step S1: determining the maximum incident field of view of a unit scanning structure in a stacked microlens array scanning system;

[0008] Step S2: Calculating the wavefront aberration value of the unit scanning structure with rotational symmetry or zero relative displacement;

[0009] Step S3: calculating the aberration field offset vector of the non-rotationally symmetric unit scanning structure that produces relative displacement;

[0010] Step S4: Calculating the wavefront aberration values ​​of the unit scanning structures with different scanning fields or relative displacements.

[0011] Corresponding to the above method, the present invention also provides a stacked microlens array scanning system, which is composed of two stacked groups of microlens arrays, and uses the relative displacement between the two groups of microlens arrays to achieve field of view scanning; different scanning fields correspond to different unit scanning structures, and each optical structure has a certain scanning field of view and gaze field of view; the system uses the above method to obtain the values ​​of five primary wave aberrations for different scanning fields of view.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] This application adopts a vector wave aberration model of a non-rotationally symmetric optical system, which can accurately characterize the wave aberration of the stacked microlens array scanning system during the scanning process. Using the calculation method, various aberration calculations of multiple optical surfaces in any scanning field of view of the unit scanning structure can be easily completed, thereby effectively helping designers to regulate the aberration distribution of the system and helping to eliminate the dynamic aberration of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of a method flow chart provided in an embodiment of the present invention;

[0015] Figure 2 A structural diagram of multiple scanning states provided by an embodiment of the present invention;

[0016] Figure 3 This is a result diagram of the dynamic aberration calculation of the unit scanning structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0018] like Figure 1 As shown, an embodiment of the present invention provides a dynamic aberration calculation method, which is applied to a stacked microlens array scanning system. The stacked microlens array scanning system is composed of two stacked microlens arrays, and the relative displacement between the two microlens arrays is used to achieve field of view scanning. The calculation process of the method is as follows:

[0019] Step S1: Determine the maximum incident field of view of the unit scanning structure.

[0020] Specifically, the scanning field of view angle and gaze field of view range are used to determine the maximum incident field of view of the unit scanning structure. The incident field of view is then expanded to its maximum value within the rotationally symmetric unit scanning structure. The scanning field of view angle is caused by the relative displacement between the two sets of microlenses, which causes the incident field of view angle required for normal operation of the system to change. This changed incident field of view angle is called the scanning field of view angle. The gaze field of view range is the field of view range that ensures the normal operation of the scanning system when the relative displacement between the two sets of microlenses remains unchanged.

[0021] Step S2: Calculating the wavefront aberration value of the unit scanning structure with rotational symmetry or zero relative displacement.

[0022] Specifically: first obtain the paraxial ray tracing parameters, use the obtained parameters to calculate the Seidel aberration coefficient, and then use the relationship between the Seidel aberration coefficient and the wave aberration coefficient to calculate the wave aberration coefficient.

[0023] Step S3: Calculate the aberration field offset vector of the non-rotationally symmetric unit scanning structure that produces relative displacement.

[0024] Specifically: for unit scanning structures with different relative displacements, the value of the aberration field offset vector is calculated face by face by combining the paraxial ray tracing parameters and the eccentricity parameters of the optical surface.

[0025] Step S4: Calculating the wavefront aberration values ​​of the unit scanning structures with different scanning fields or relative displacements.

[0026] Specifically, by substituting the wavefront aberration coefficient and the aberration field offset vector into the vector wavefront aberration model of the non-rotationally symmetric optical system, various types of wavefront aberration values ​​for any scanning field of view can be obtained.

[0027] The vector wave aberration model of the non-rotationally symmetric optical system can be expressed by the following expression:

[0028]

[0029] Where W represents the wavefront aberration value of the optical system, which is a function of the normalized field vector H and the normalized aperture vector ρ. (W klm ) j is the aberration of the jth surface in the optical system, p, n, m are integers from 0 to positive infinity, σ j is the aberration field offset vector of the j-th surface.

[0030] like Figure 2As shown, corresponding to the above method, the present invention also provides a stacked microlens array scanning system, which is composed of two groups of microlens arrays stacked together, and uses the relative displacement between the two groups of microlens arrays to achieve field of view scanning; it is a two-piece unit scanning structure, from bottom to top, representing the optical structure of the unit scanning structure corresponding to different scanning fields of view, and the numbers on the right are the corresponding scanning field of view angles. Each optical structure has a certain gaze field of view; the system uses the above method to obtain the values ​​of five primary wave aberrations for different scanning fields of view, and the results are shown as follows. Figure 3 shown.

[0031] Finally, it should be noted that the above embodiments are merely examples and illustrations of the present invention and are not intended to limit the present invention to the described embodiments. Furthermore, those skilled in the art will appreciate that the present invention is not limited to the above embodiments and that various variations and modifications may be made based on the teachings of the present invention, all of which fall within the scope of the present invention.

Claims

1. A dynamic aberration calculation method, characterized in that: The method is applied to a stacked microlens array scanning system, wherein the stacked microlens array scanning system is composed of two stacked microlens arrays and uses the relative displacement between the two microlens arrays to achieve field of view scanning. The method comprises the following steps: Step S1: determining the maximum incident field of view of a unit scanning structure in a stacked microlens array scanning system; Step S2: Calculating the wavefront aberration value of the unit scanning structure with rotational symmetry or zero relative displacement; Step S3: calculating the aberration field offset vector of the non-rotationally symmetric unit scanning structure that produces relative displacement; Step S4: calculating the wavefront aberration values ​​of the unit scanning structures with different scanning fields or relative displacements; In step S4, the wavefront aberration values ​​of the unit scanning structure with different scanning fields or relative displacements are calculated as follows: the wavefront aberration coefficient and the aberration field offset vector are substituted into the vector wavefront aberration model of the non-rotationally symmetric optical system to obtain various types of wavefront aberration values ​​for any scanning field; The vector wave aberration model of the non-rotationally symmetric optical system is expressed by the following expression: ； in W Represents the wavefront aberration value of the optical system, which is about the normalized field of view vector H and the normalized aperture vector ρ function, The first j The aberration of the surface, p 、 n 、 m is an integer from 0 to positive infinity, For the j The aberration field offset vector of the surface.

2. A dynamic aberration calculation method according to claim 1, characterized in that, The maximum incident field of view is determined by using the scanning field of view angle and the gaze field of view range.

3. A dynamic aberration calculation method according to claim 2, characterized in that, The scanning field of view angle is caused by the relative displacement between the two groups of micro lenses, which causes the incident field of view angle of the normal operation of the system to change. The changed incident field of view angle is called the scanning field of view angle.

4. A dynamic aberration calculation method according to claim 2, characterized in that, The gaze field range is a field range that can ensure the normal operation of the scanning system when the relative displacement between the two groups of micro lenses remains unchanged.

5. A dynamic aberration calculation method according to claim 1, characterized in that: In step S2, the wavefront aberration value of the rotationally symmetric or zero relative displacement unit scanning structure is calculated as follows: the paraxial ray tracing parameters are obtained, the Seidel aberration coefficient is calculated using the obtained parameters, and the wavefront aberration value is obtained using the relationship between the Seidel aberration coefficient and the wavefront aberration coefficient.

6. A dynamic aberration calculation method according to claim 1, characterized in that: In step S3, the aberration field offset vector of the non-rotationally symmetric unit scanning structure that produces relative displacement is calculated, specifically as follows: for unit scanning structures with different relative displacements, the value of the aberration field offset vector is calculated face by face by combining the paraxial ray tracing parameters and the eccentricity parameters of the optical surface.

7. A stacked microlens array scanning system, characterized in that: The stacked microlens array scanning system is composed of two stacked microlens arrays, and the relative displacement between the two microlens arrays is used to achieve field of view scanning; different scanning fields correspond to different unit scanning structures, and each unit scanning structure has a certain scanning field of view and gaze field of view; The system uses the dynamic aberration calculation method according to any one of claims 1 to 6 to obtain values ​​of five primary wave aberrations in different scanning fields of view.

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