CN-113391489-B - Method and device for rotating polarization direction of linearly polarized light without jump

CN113391489BCN 113391489 BCN113391489 BCN 113391489BCN-113391489-B

Abstract

The invention relates to a method and a device for non-jump rotation of polarization direction of linearly polarized light, which are applied to the related fields of image display, light field regulation and control, optical micromanipulation, ophthalmic medical treatment and the like. The incident linearly polarized light is subjected to the birefringence effect of the liquid crystal molecules, the two-direction components of the fast axis and the slow axis of the incident linearly polarized light obtain half-wavelength phase difference, and the alternating voltage is used for controlling the liquid crystal molecules to rotate parallel to the liquid crystal substrate so as to emit the rotating linearly polarized light. The invention can realize the controllable rotation rate of the rotating linearly polarized light and no jump in the rotating process. The liquid crystal unit array structure can form a unified regulation array, and can be applied to a sea Ding Geguang amblyopia therapeutic instrument, an optical control device and the like under specific conditions.

Inventors

SHI JINWEI
JIANG ANWEN
YU HAOYUN

Assignees

北京师范大学
北京师范大学

Dates

Publication Date: 20260421
Application Date: 20210618
Priority Date: 20210618

Claims (8)

1. A linearly polarized light rotating apparatus, comprising: The liquid crystal display device comprises a liquid crystal unit, a light receiving unit and a light receiving unit, wherein a polarizer is arranged on the light entering side of the liquid crystal unit; The liquid crystal cell includes: A first glass substrate and a second glass substrate disposed opposite to each other; And a liquid crystal layer between the first glass substrate and the second glass substrate; The electrodes are respectively arranged between the first glass substrate and the liquid crystal layer and are a first electrode group which is arranged in parallel with each other, and a second electrode group which is arranged between the liquid crystal layer and the second glass substrate and is arranged in parallel with each other and has the direction orthogonal to the first electrode group; the electrodes are used for applying voltage, forming potential difference parallel to the first glass substrate on the liquid crystal layer, and controlling the liquid crystal molecules to rotate on a plane parallel to the first glass substrate and the second glass substrate through the direction of an electric field; Incident light enters the liquid crystal unit through the polaroid and is perpendicular to the first glass substrate, the incident light passes through different optical paths in a fast-axis polarization direction component and a slow-axis polarization direction component, and the thickness of the liquid crystal layer is that the optical path difference is The thickness of each wavelength refers to the height of the glass substrate in the vertical direction of the plane of the glass substrate, wherein m is any positive integer.
2. The linearly polarized light rotating apparatus according to claim 1, wherein, The first electrode group is formed by arranging two electrodes in parallel, one electrode is grounded, and the other electrode is applied with alternating voltage; The second electrode group is formed by arranging two electrodes in parallel, one electrode is grounded, and the other electrode is applied with a phase difference with the first electrode group Wherein n is any integer.
3. The linearly polarized light rotating apparatus according to claim 1, wherein, The first electrode group is formed by arranging three electrodes in parallel, the electrodes on two sides are grounded, and alternating voltage is applied to the middle electrode; The second electrode group is formed by arranging three electrodes in parallel, two electrodes are grounded, and the phase difference between the middle electrode and the first electrode group is applied Wherein n is any integer.
4. The linearly polarized light rotating apparatus according to claim 1, wherein, The first electrode group is formed by arranging three electrodes in parallel, the middle electrode is grounded, and alternating voltage is applied to the electrodes at the two sides; the second electrode group is formed by arranging three electrodes in parallel, the middle electrode is grounded, and the phase difference between the two electrodes and the first electrode group is applied Wherein n is any integer.
5. A linearly polarized light rotating apparatus according to any one of claims 3 to 4, further comprising: and forming a spacer layer in part or all of the inactive area for controlling the thickness of the liquid crystal material and helping to reduce negative electro-optic effect, wherein the inactive area refers to an area of liquid crystal molecules which are reversely rotated relative to the emergent deflection direction at the periphery of the working area due to electrode arrangement and the opposite direction of the working area.
6. A linearly polarized light rotating apparatus according to any one of claims 3 to 5, further comprising: repeatedly arranging the liquid crystal units; The repeated liquid crystal units are arranged along the direction parallel to the electrodes of the first electrode group or the electrodes of the second electrode group; the electrodes on the common boundary of adjacent liquid crystal cells; Adjacent electrodes are connected along the electrode placement direction to form an N-by-M array; The frequency and phase of the alternating electrode applied by each liquid crystal unit can be regulated and controlled uniformly, wherein N and M are any positive integers.
7. The linearly polarized light rotating apparatus of claim 6 further comprising: The ultraviolet light has definite wavelength of incident light, the wavelength range of the incident light is between 460 nm and 500 nm, the frequency of alternating voltage applied by the electrodes is between 0.41 and Hz and 0.83 and Hz, namely the rotation frequency of emergent linear polarized light is between 50 r/min and 100r/min, and the ultraviolet light is used for brushing the amblyopia therapeutic instrument by the sea Ding Geguang driven by an electric field.
8. A method of rotating linearly polarized light, applied to the linearly polarized light rotating apparatus according to any one of claims 1 to 7, comprising: Applying a voltage in a direction parallel to the first glass substrate plane, i.e. in a plane perpendicular to the incident light; and controlling the liquid crystal molecules in the liquid crystal layer to rotate parallel to the plane of the first glass substrate through voltage.

Description

Method and device for rotating polarization direction of linearly polarized light without jump Technical Field The invention relates to a linear polarized light polarization direction non-jump rotation method and device applied to the related fields of image display, light field regulation, optical micromanipulation, ophthalmic medical treatment and the like, and in a specific embodiment, relates to a sea Ding Geguang amblyopia treatment instrument optimization device, liquid crystal display, vector light field generation and optical manipulation device. Background The linear polarized light can rotate continuously without angle limitation, namely without jump, and has wide application requirements in the fields of Haiding brush amblyopia therapy, liquid crystal display, optical micromanipulation and the like. Amblyopia is a common ophthalmic disorder caused by dysgenesis of vision in children. The Haiding brush therapy is a better treatment effect method for treating amblyopia, and when looking at blue linearly polarized light with the rotation rate of 50-100r/min (namely 0.83-1.67 Hz), a brush-shaped image can rotate at a slow speed in the visual field range, and the amblyopia can be treated by looking at the rotating blue linearly polarized light. In the field of optical micromanipulation, circular polarized light or vortex light has angular momentum capable of forming optical traps for trapping or manipulating particles. The non-uniform polarization distribution of the independently regulated vector light field has important influence on the space-time evolution of the light field and the interaction between the light field and the substance. The screen display, the spatial light modulator and the like need to adjust the transmittance by changing the incident polarized light direction corresponding to the pixel points, so as to achieve the aim of image display. Therefore, development of a rotation device without jumping the polarization direction of linearly polarized light is urgently needed. The current mainstream apparatus for rotating the polarization direction of linearly polarized light includes a liquid crystal phase retarder, a spatial light modulator, a photoelastic modulator, etc., but the above-mentioned apparatus for rotating the polarization direction can only achieve continuous regulation and control within a limited angle range (usually within 180 °), beyond which the problem of rotation jump of the polarization direction is faced, and continuous rotation without angle limitation cannot be achieved. This is because the common design concept of the phase retarder is to change the polarization direction of the outgoing light by changing the optical rotation of the liquid crystal or the magnitude of the birefringence of the material. Taking a phase retarder as an example, a voltage is applied to the ITO layer of the liquid crystal substrate, so that liquid crystal molecules longitudinally deflect along the light propagation direction, and the birefringence and optical rotation are changed, thereby influencing the emergent polarization characteristic of incident linearly polarized light and achieving the purpose of phase retardation. The most direct device for rotating the polarization direction of linearly polarized light without jumping is a half-wave plate (for linearly polarized light) or a polarizing plate (for natural light) driven by a mechanical motor, and a therapeutic apparatus (CN 2875382Y) such as a sea Ding Geguang brush is driven by the mechanical motor to work. However, the mechanical motor drives the rotating linear polarized light to have the problems of inaccurate control and larger mechanical disturbance, and the size is larger, so that the linear polarized light cannot be integrated, and the development of portable equipment is not facilitated. The optical heterodyne interferometry can realize high-speed non-jump polarization regulation and control, such as https:// doi.org/10.29026/oea.2020.200022 (OPTO-ELECTRONIC ADVANCES,2020,3 (8), 200022), but the method has high requirements on the accuracy of the optical path, and the acousto-optic modulation device has large volume, low efficiency and high cost and is difficult to be applied to various situations. In addition, the device for modulating the liquid crystal and changing the direction of the linearly polarized light by using the horizontal electric field, such as IPS (CN 101666949B) and FFS (CN 1302450C) display panel technology, can modulate the polarization direction of the polarized light by arranging and rotating the liquid crystal parallel to the substrate by using the horizontal electric field provided by the single-layer electrode, but still can only implement linear polarization rotation modulation with a limited angle to control gray scale, and still cannot implement non-jump rotation of the polarization direction of the linearly polarized light. The structure of the device is only related to a single-layer el