阅读说明：本技术 一种生成新型偏振态非均匀变化矢量光场的装置和方法 (Device and method for generating novel polarization state non-uniform change vector light field ) 是由 顾兵 呙明贤 沈博 芮光浩 崔一平 于 2021-08-11 设计创作，主要内容包括：本发明公开了一种生成新型偏振态非均匀变化矢量光场的装置和方法。所述新型矢量光场装置包括生成系统及检测系统。生成系统包括激光器、半波片、偏振分光棱镜、涡旋半波片、反射镜以及1/4波片。检测系统包括1/4波片、检偏器及CCD相机。本发明在实验上生成了具有不同周期水平基矢和竖直基矢的矢量光场,因此其偏振态在空间上具有非均匀变化的特征。通过在偏振分光棱镜(8)后加入1/4波片,可以进一步生成新型杂化矢量光场。本发明光路简单,易于实现。通过改变涡旋半波片的阶数可以实现对矢量光场的偏振态调控。所生成的新型偏振态非均匀变化矢量光场可以作为一种新型的空间结构光场应用在粒子操控、高分辨成像和光学微加工等领域。(The invention discloses a device and a method for generating a novel polarization state non-uniform change vector light field. The novel vector light field device comprises a generating system and a detecting system. The generation system includes a laser, a half-wave plate, a polarization splitting prism, a vortex half-wave plate, a mirror, and an 1/4 wave plate. The detection system comprises an 1/4 wave plate, an analyzer and a CCD camera. The invention generates vector light field with different periods of horizontal basis vector and vertical basis vector experimentally, so that the polarization state of the vector light field has the characteristic of non-uniform change in space. By adding 1/4 wave plate after the polarization beam splitter prism (8), a novel hybrid vector light field can be further generated. The invention has simple light path and is easy to realize. The polarization state of the vector light field can be regulated and controlled by changing the order of the vortex half-wave plate. The generated novel polarization state non-uniform change vector light field can be used as a novel space structure light field to be applied to the fields of particle control, high-resolution imaging, optical micromachining and the like.)

1. A device for generating a novel polarization state non-uniform variation vector light field is characterized in that: the device comprises a laser (1), a half-wave plate (2), a first polarization splitting prism (3), a first vortex half-wave plate (4), a first reflecting mirror (5), a second reflecting mirror (6), a second vortex half-wave plate (7), a second polarization splitting prism (8), an 1/4 wave plate (9), an analyzer (10) and a CCD camera (11); output linear polarization light beam by laser instrument (1), change polarization direction through half-wave plate (2), rethread first polarization beam splitter prism (3) with linearly polarized light beam splitting, the light intensity ratio between two light paths about controlling behind first polarization beam splitter prism (3) is 1: 1, an upper half beam P polarization of an upper light path generates a vector light field of any polarization topological charge through a first vortex half-wave plate (4) and a first reflector (5) and is sent to a second polarization beam splitter prism (8), and a lower half beam S polarization of a lower light path generates a vector light field of any polarization topological charge through a second reflector (6) and a second vortex half-wave plate (7) and is sent to the second polarization beam splitter prism (8); the second polarization beam splitter prism (8) combines the light beams, and the combined light beams pass through an 1/4 wave plate (9) and an analyzer (10) to detect the light intensity and polarization distribution of the generated novel polarization state non-uniform change vector light field.

2. The device for generating the novel polarization state non-uniform variation vector light field according to claim 1, wherein: the transverse distribution of the light intensity of the light beam output by the laser (1) is a Gaussian or nearly Gaussian incident field and is a linearly polarized light beam.

3. The device for generating the novel polarization state non-uniform variation vector light field according to claim 1, wherein: the first polarization beam splitter prism (3) and the second polarization beam splitter prism (8) split linearly polarized light, transmitted light is P polarization, and reflected light is S polarization.

4. The device for generating the novel polarization state non-uniform variation vector light field according to claim 1, wherein: the half-wave plate (2) corresponds to 1064nm laser wavelength, and the direction of the fast axis of the wave plate is adjustable.

5. The device for generating the novel polarization state non-uniform variation vector light field according to claim 1, wherein: the first vortex half-wave plate (4) and the second vortex half-wave plate (7) are matched with the laser wavelength of 1064nm, and can convert linearly polarized light beams into common vector light fields with uniformly changed polarization states in space.

6. The device for generating the novel polarization state non-uniform variation vector light field according to claim 5, wherein: the first vortex half-wave plate (4) and the second vortex half-wave plate (7) are equal or unequal in order.

7. The device for generating the novel polarization state non-uniform variation vector light field according to claim 1, wherein: the optical paths between the first polarization beam splitter prism (3) and the first reflector (5) and between the second reflector (6) and the second polarization beam splitter prism (8) are equal, and the corresponding upper and lower beams have the same phase when combined.

8. The device for generating the novel polarization state non-uniform variation vector light field according to claim 1, wherein: the CCD camera is a laser beam quality analyzer and can detect the light intensity of the laser beam.

9. A method for generating a new type of non-uniform polarization state change vector optical field according to the apparatus of claim 1, wherein the method comprises:

step 1: building a light path, and controlling the light paths of the upper and lower light paths to be equal;

step 2: turning on the laser (1) and outputting a Gaussian linear polarization laser beam;

and step 3: the half-wave plate (2) is rotated to a certain angle, so that the light intensity of the upper and lower laser beams is the same, and if the light intensity of the upper and lower laser beams is different, the synthesis of a subsequent vector light field is influenced;

and 4, step 4: vertical basis vectors of a novel polarization state non-uniform change vector light field are generated in the upper half optical path by using a first vortex half-wave plate (4) and a second vortex half-wave plate (7) with different ordersHorizontal basis vector for generating novel polarization state non-uniform change vector light field on lower half optical path

And 5: through fine adjustment of the first reflector (5), the second reflector (6) and the second polarization beam splitter prism (8), vertical and horizontal basis vector spaces generated by the upper and lower light paths are overlapped to generate a novel polarization state non-uniform change vector light field;

step 6: and 1/4 a wave plate (9), an analyzer (10) and a CCD camera (11) are used for measuring and analyzing the polarization distribution condition of the generated vector light field.

10. The method according to claim 9, wherein the step 5 and the step 6 are inserted with the step P between the step 5 and the step 6, and the polarization state of the vector light field is analyzed when the step 5 and the step 6 are used for generating the novel polarization state non-uniform change hybrid vector light field, that is:

and 5: through fine adjustment of the first reflector (5), the second reflector (6) and the second polarization beam splitter prism (8), vertical and horizontal basis vector spaces generated by the upper and lower light paths are overlapped to generate a novel polarization state non-uniform change vector light field; step P: 1/4 wave plate (9) is added behind the second polarization beam splitter prism (8) to generate a novel polarization state non-uniform change hybrid vector light field, the fast axis direction of 1/4 wave plate (9) is adjusted, and the polarization state of the novel hybrid vector light field is further adjusted;

step 6: and 1/4 a wave plate (9), an analyzer (10) and a CCD camera (11) are used for measuring and analyzing the polarization distribution condition of the generated vector light field.

Technical Field

The invention belongs to the field of light field regulation and control, and relates to a novel vector light field generation technology.

Background

The vector light field refers to a light field having different polarization state distributions at different positions on the same wave vibration plane at the same time, and is also referred to as a non-uniform polarization light field or a space-variant polarization light field. This concept is proposed with respect to scalar light fields, such as the linear, elliptical, and circularly polarized light fields commonly studied, which have a spatially uniform distribution of polarization states. However, for the vector light field, the polarization state distribution of the vector light field is changed spatially, and the characteristic causes the vector light field to have novel transmission and focusing characteristics, so that the vector light field has important academic significance and application value in a plurality of subject fields.

The existing vector light field generation technologies mainly include the following: (1) active generation techniques, by designing the optical resonator to oscillate the laser, produce a vector optical field [ Di Lin, Kegui Xia, Jianlang Li, Ruxin Li, Ken-ichi Ueda, Guoqiang Li, and Xiaojun Li, "efficiency, high-power, and radial polarized fiber laser," Opt. Lett.35,2290-2292(2010) ]. (2) The vector light field (e.g., vortex half-wave plate) [ Junli Qi, Weihua Wang, Bo Shi, Hui Zhang, Yanan Shen, Haifei Deng, Wenjing Pu, Xin Liu, Huihui Shan, Xiaomin Ma, Lianqiang Zhang, Wei Lu, Meiche Fu, and Xiujian Li, "contact and effect direct-view generation of the arbitrational laser beams by a vortex half-wave plate," photon. Res.9,803-813(2021) ]isdirectly generated using optical elements. (3) Using a 4f system, a vector light field is generated by the superposition interference of light beams [ Xi-Lin Wang, Jianping Ding, Wei-Jiang Ni, Cheng-Shan Guo, and Hui-Tian Wang, "Generation of an annular vector beam with a spatial light modulator and a common path interferometric arrangement," opt.Lett.32,3549-3551(2007) ].

However, existing vector light field generation methods tend to be used to generate vector light fields having two synchronously varying orthogonal components in space. For example, for a local linear polarization vector light field, its light field expression can be written as:

due to basal vectorAndthe corresponding period parameters m are equal, so that the generated vector light field polarization structure is necessarily changed synchronously on two orthogonal components. No report on the generation ofAndthe expression of the vector light field can be written asBecause m is₁And m₂Is different, a vector light field with novel polarization characteristics can be generated. The vector light field has wide application in laser processing, optical capture, super-resolution imaging and other aspects, so that the generation of the novel polarization state non-uniform change vector light field has very important significance for researching the interaction of light and substances and in the field of light field regulation and control.

Disclosure of Invention

The technical problem is as follows: in order to solve the problems, the invention provides a device and a method for generating a novel polarization state non-uniform change vector light field. By incorporating polarizing beam-splitting prisms in the light pathAndand regulating and controlling the component. Meanwhile, the vortex half-wave plates with different orders are used to enable the upper and lower light beams to have different period parameters m₁And m₂And finally, light is combined through a polarization beam splitter prism. The upper half of the optical path controlThe y component of the model vector light field, and the x component of the novel vector light field can be controlled by the lower half optical path. By the regulation and control method, a novel polarization state non-uniform change vector light field with different polarization structures can be generated, and a novel structure light source is provided for researching the interaction of light and substances.

The technical scheme is as follows: the device for generating the novel polarization state non-uniform change vector light field comprises a laser, a half-wave plate, a first polarization splitting prism, a first vortex half-wave plate, a first reflector, a second vortex half-wave plate, a second polarization splitting prism, an 1/4 wave plate, an analyzer and a CCD camera; output linear polarization light beam by the laser instrument changes the polarization direction through the half-wave plate, and rethread first polarization beam splitter prism is with the linear polarization beam splitting, and the light intensity ratio between two upper and lower light paths is 1 behind the control first polarization beam splitter prism: 1, an upper half beam P polarization of an upper optical path generates a vector light field of any polarization topological load through a first vortex half-wave plate and a first reflector and is sent to a second polarization beam splitter prism, and a lower half beam S polarization of a lower optical path generates a vector light field of any polarization topological load through a second reflector and a second vortex half-wave plate and is sent to the second polarization beam splitter prism; the second polarization beam splitter prism is used for combining the light beams, and the combined light beams are detected by the 1/4 wave plate and the analyzer to generate the light intensity and polarization distribution of the novel polarization state non-uniform change vector light field.

Wherein:

the transverse distribution of the light intensity of the laser output beam is a Gaussian or nearly Gaussian incident field and is a linearly polarized light beam.

The first polarization beam splitter prism and the second polarization beam splitter prism are used for splitting linearly polarized light, the transmitted light is P polarization, and the reflected light is S polarization.

The half-wave plate corresponds to 1064nm laser wavelength, and the direction of the fast axis of the wave plate is adjustable.

The first vortex half-wave plate and the second vortex half-wave plate are matched with laser wavelength of 1064nm, and the linearly polarized light beam can be converted into a common vector light field with uniformly changed polarization state in space.

The orders of the first vortex half-wave plate and the second vortex half-wave plate can be equal or unequal.

The optical paths from the first polarization beam splitter prism to the first reflector and from the second reflector to the second polarization beam splitter prism are equal, and the corresponding upper and lower beams have the same phase when combined.

The CCD camera is a laser beam quality analyzer and can detect the light intensity of the laser beam.

The method for generating the novel polarization state non-uniform change vector light field by the device comprises the following steps:

step 1: building a light path, and controlling the light paths of the upper and lower light paths to be equal;

step 2: turning on a laser and outputting a Gaussian linear polarized laser beam;

and step 3: rotating the half-wave plate to a certain angle to enable the light intensity of the upper and lower laser beams to be the same, and if the light intensity of the upper and lower laser beams is different, the synthesis of a subsequent vector light field is influenced;

and 4, step 4: by using the first vortex half-wave plate and the second vortex half-wave plate with different orders, the vertical basis vector of the novel polarization state non-uniform change vector light field is generated in the upper half part of the light pathHorizontal basis vector for generating novel polarization state non-uniform change vector light field on lower half optical path

And 5: the vertical and horizontal basis vector spaces generated by the upper and lower parts of light paths are superposed by finely adjusting the first reflector, the second reflector and the second polarization beam splitter prism to generate a novel polarization state non-uniform change vector light field;

step 6: the polarization distribution of the generated vector light field is measured and analyzed by using an 1/4 wave plate, an analyzer and a CCD camera.

And 5, step 6, when generating the novel polarization state non-uniform change hybrid vector light field, inserting step P between step 5 and step 6, and analyzing the polarization state of the vector light field, namely:

and 5: the vertical and horizontal basis vector spaces generated by the upper and lower parts of light paths are superposed by finely adjusting the first reflector, the second reflector and the second polarization beam splitter prism to generate a novel polarization state non-uniform change vector light field;

step P: 1/4 wave plates are added behind the second polarization beam splitter prism to generate a novel polarization state non-uniform change hybrid vector light field, the fast axis direction of the 1/4 wave plate is adjusted, and the polarization state of the novel hybrid vector light field is further adjusted and controlled;

step 6: the polarization distribution of the generated vector light field is measured and analyzed by using an 1/4 wave plate, an analyzer and a CCD camera.

Has the advantages that: the invention provides a device and a method for generating a novel polarization state non-uniform change vector light field. By incorporating polarizing beam-splitting prisms in the light pathAndand regulating and controlling the component. Meanwhile, the upper path of light beam and the lower path of light beam have different vortex orders m by using vortex half-wave plates with different orders₁And m₂Thereby generating a novel vector light field. On the basis, 1/4 wave plates can be added behind the polarization beam splitter prism, and the generation of a novel hybrid vector light field can be realized by utilizing the phase retardation characteristic of 1/4 wave plates. The method provided by the invention has the advantages of simple principle, simple and convenient device and high vector light field generation quality. By the regulation and control device and the regulation and control method, a novel polarization state non-uniform change vector light field with different polarization structures can be generated, and a novel structure light source is generated.

Drawings

Fig. 1 is a schematic structural diagram of an apparatus for generating a novel polarization state non-uniform variation vector light field according to the present invention.

FIG. 2 is a simulated light intensity and polarization state of a novel polarization state non-uniform variation vector light fieldDistribution of m corresponding to₁Is 1, m₂Is 0.5. (a) Is the upper half of the optical path m₂0.5 simulated light intensity distribution graph after passing through the polarization beam splitting prism; (b) is the lower half part of the optical path m₁1 is the simulated light intensity distribution graph after passing through the polarization splitting prism. (c) For generating novel polarization state non-uniform variation vector light field simulation light intensity and polarization state distribution diagram, corresponding m₁＝1，m₂＝0.5。

FIG. 3 shows the distribution of light intensity and polarization state of the experimentally generated novel polarization state non-uniform variation vector light field, which corresponds to m₁Is 1, m₂Is 0.5. (a) For the upper half of the optical path m in the experiment₂0.5 light intensity distribution graph after passing through the polarization beam splitting prism; (b) is the lower half of the optical path m in the experiment₁1 is the light intensity distribution graph after passing through the polarization splitting prism. (c) For the light intensity and polarization state distribution diagram of the novel polarization state non-uniform variation vector light field generated in the experiment, the corresponding m₁＝1，m₂＝0.5。

FIG. 4 shows the light intensity and polarization distribution of the simulated novel polarization state non-uniform variation hybrid vector light field, which corresponds to m₁Is 2, m₂The fast axis direction of the 1/4 wave plate is parallel to the horizontal direction. (a) Is the upper half of the optical path m₂1, passing through a polarization beam splitting prism to obtain an analog light intensity distribution graph; (b) is the lower half part of the optical path m₁2 is the simulated light intensity distribution graph after passing through the polarization splitting prism. (c) Simulating light intensity and polarization state distribution diagram of the generated novel polarization state non-uniform change hybrid vector light field, and corresponding m₁＝2，m₂＝1。

FIG. 5 shows the light intensity and polarization distribution of the experimentally generated novel polarization state non-uniform variation hybrid vector light field, which corresponds to m₁Is 2, m₂The fast axis direction of the 1/4 wave plate is parallel to the horizontal direction. (a) Upper half of the optical path m generated for the experiment₂1, passing through a polarization beam splitting prism to obtain a light intensity distribution graph; (b) the lower half part of the optical path m generated for the experiment₁2 is the light intensity distribution graph after passing through the polarization beam splitting prism. (c) The light intensity and polarization state distribution diagram of the novel polarization state non-uniform change hybrid vector light field generated for the experiment and the correspondingm₁＝2，m₂＝1。

Description of reference numerals: the laser comprises a laser 1, a half-wave plate 2, a first polarization splitting prism 3, a first vortex half-wave plate 4, a first reflecting mirror 5, a second reflecting mirror 6, a second vortex half-wave plate 7, a second polarization splitting prism 8, a 1/4 wave plate 9, an analyzer 10 and a CCD camera 11.

Detailed Description

The technical solutions provided by the present invention will be described in detail below with reference to specific examples, and it should be understood that the following specific embodiments are only illustrative of the present invention and are not intended to limit the scope of the present invention.

The invention relates to a device for generating a novel polarization state non-uniform change vector light field, which comprises a laser, a half-wave plate, a first polarization splitting prism, a first vortex half-wave plate, a first reflector, a second vortex half-wave plate, a second polarization splitting prism, an 1/4 wave plate, an analyzer and a CCD camera; output linear polarization light beam by the laser instrument changes the polarization direction through the half-wave plate, and rethread first polarization beam splitter prism is with the linear polarization beam splitting, and the light intensity ratio between two upper and lower light paths is 1 behind the control first polarization beam splitter prism: 1, an upper half beam P polarization of an upper optical path generates a vector light field of any polarization topological load through a first vortex half-wave plate and a first reflector and is sent to a second polarization beam splitter prism, and a lower half beam S polarization of a lower optical path generates a vector light field of any polarization topological load through a second reflector and a second vortex half-wave plate and is sent to the second polarization beam splitter prism; the second polarization beam splitter prism is used for combining the light beams, and the combined light beams are detected by the 1/4 wave plate and the analyzer to generate the light intensity and polarization distribution of the novel polarization state non-uniform change vector light field.

Wherein:

the transverse distribution of the light intensity of the laser output beam is a Gaussian or nearly Gaussian incident field and is a linearly polarized light beam.

The first polarization beam splitter prism and the second polarization beam splitter prism are used for splitting linearly polarized light, the transmitted light is P polarization, and the reflected light is S polarization.

The half-wave plate corresponds to 1064nm laser wavelength, and the direction of the fast axis of the wave plate is adjustable.

The first vortex half-wave plate and the second vortex half-wave plate are matched with laser wavelength of 1064nm, and the linearly polarized light beam can be converted into a common vector light field with uniformly changed polarization state in space.

The first vortex half-wave plate and the second vortex half-wave plate have equal or unequal orders.

The optical paths from the first polarization beam splitter prism to the first reflector and from the second reflector to the second polarization beam splitter prism are equal, and the corresponding upper and lower beams have the same phase when combined.

The CCD camera is a laser beam quality analyzer and can detect the light intensity of the laser beam.

Example 1: generating a novel polarization state non-uniform variation vector light field

According to the aforementioned operational steps and methods, if an expression is desired, the expression isThe novel polarization state non-uniform change vector light field needs to use the order m on the lower half part of the light path₁The order of the upper half optical path is m₂The half-wave plate of (1). Because the transmitted light of the polarization beam splitter prism isComponent, reflected light isAnd (4) components.

The Jones matrix theory is used for analyzing the synthesis process of the novel polarization state non-uniform change vector light field.

Step 1, turning on the laser 1 to output linearly polarized laser:

step 2, rotating the half-wave plate, wherein the included angle between the fast axis direction of the half-wave plate and the polarization direction of the emergent laser is 22.5 degrees, so that Ex and Ey components are equal:

and 3, adding a polarization beam splitter prism behind the half-wave plate, and respectively obtaining a horizontal polarization basis vector and a vertical polarization basis vector on the upper half part of the optical path and the lower half part of the optical path:

step 4, adding order m to the upper half optical path₂The order of the vortex half-wave plate is m added in the lower half part of the optical path₁The vortex half-wave plate of (a),is the azimuth angle in space in a plane perpendicular to the direction of propagation of the beam:

step 5, the polarization beam splitter prism 8 can synthesize the two basis vector components into a novel polarization state non-uniform change vector light field:

therefore, according to the device and the method provided by the invention, a novel polarization state non-uniform change vector light field can be generated. The polarization state distribution of the generated novel vector light field can be recorded and analyzed through the 1/4 wave plate 9, the analyzer 10 and the CCD camera 11.

Example 2: generation of novel polarization state non-uniform change hybrid vector light field

If a novel polarization state non-uniform change hybrid vector light field needs to be generated, an 1/4 wave plate needs to be added behind the polarization beam splitter prism 8. The novel polarization state non-uniform change hybrid vector light field is different from the novel polarization state non-uniform change vector light field mentioned in example 1 in that it is not a local linear polarization vector light field but a vector light field having coexistence of linear polarization, circular polarization and elliptical polarization on a beam cross section. The generation of the novel polarization state non-uniform change hybrid vector optical field with different polarization structures can be realized by rotating the fast axis direction of the 1/4 wave plate.

Therefore, according to the device and the method provided by the invention, a novel polarization state non-uniform change hybrid vector light field can be generated. The polarization distribution of the generated novel polarization state non-uniform change hybrid vector light field can be recorded and analyzed through the 1/4 wave plate 9, the analyzer 10 and the CCD camera 11.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.