CN102289080B - Method and device for generating radial polarization beam - Google Patents
Method and device for generating radial polarization beam Download PDFInfo
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Abstract
The invention discloses a method and device for generating a radial polarization beam. The method is characterized by comprising the following steps: firstly carrying out polarizing beam splitting on a collimated beam to obtain a parallel line polarization beam and a perpendicular line polarization beam in an intensity ratio of 1:1, ensuring the parallel line polarization beam and the perpendicular line polarization beam to become circular polarization beams in opposite directions of rotation respectively, carrying out 0-2pi vortex phase encoding and reverse 0-2pi vortex phase encoding with the same starting point on the right-handed and left-handed circular polarization beams respectively and combining the two beams subjected to phase encoding and deflected by a light path to obtain the radial polarization beam. The device comprises a laser, a polarizing beam splitter, a first lambada/4 wave plate, a second lambada/4 wave plate, a 0-2pi vortex phase plate, a reverse 0-2pi vortex phase plate, light path deflection devices and a beam combination device, wherein the phase start lines of the 0-2pi vortex phase plate and the reverse 0-2pi vortex phase plate coincide. The method is easy to implement and the device has a simple structure, is easy to adjust, has low manufacturing cost and good stability and dispenses with other special optical elements.
Description
Technical Field
The invention belongs to the field of applied optics, and particularly relates to a method and a device for generating radial polarized light beams, which are mainly applied to the fields of optical information storage, photoetching, super-resolution microscopy and the like.
Background
Polarization is used as the vector characteristic of light waves, and attracts more and more attention in recent years, so that the polarization-sensitive optical fiber can be widely applied to the fields of polarization difference imaging, super-resolution focusing, laser photoetching and the like. In the course of research, it was found that the polarization state of the light beam includes not only the conventional linearly polarized light, circularly polarized light, and elliptically polarized light, but also the columnar polarized light beams such as the radial polarized light (radial polarized beam) and the tangential polarized beam (azimuthally polarized beam). The polarization state and the light intensity of the columnar polarized light beam are distributed symmetrically, so that the columnar polarized light beam is widely researched. Chinese patent application publication No. CN101465512A discloses a laser for generating a cylindrical symmetric polarized light, which realizes radial polarized light or tangential polarized light by designing a special asymmetric cavity structure, but has high manufacturing cost because the resonant cavity of the existing laser needs to be changed. Chinese utility model patent No. ZL 200820165973.0 discloses a device for converting linearly polarized light into radially polarized light, but the adjustment is troublesome and the adjustment accuracy requirement is high.
Disclosure of Invention
The invention provides a method and a device for generating radial polarized light beams, which are simple to adjust and low in cost.
A method of producing a radially polarized beam of light, comprising the steps of:
(1) collimated light beams emitted by a laser are split by a polarization beam splitter to obtain parallel polarized light and vertical polarized light with the light intensity ratio of 1: 1;
(2) the parallel line polarized light is changed into right-handed circularly polarized light after passing through a first lambda/4 wave plate and the vertical line polarized light is changed into left-handed circularly polarized light after passing through a second lambda/4 wave plate;
or the parallel line polarized light is changed into left-handed circularly polarized light after passing through a first lambda/4 wave plate and the vertical line polarized light is changed into right-handed circularly polarized light after passing through a second lambda/4 wave plate;
(3) and carrying out 0-2 pi vortex phase coding on the dextrorotation circularly polarized light, carrying out reverse 0-2 pi vortex phase coding on the levorotation circularly polarized light, wherein the starting point of the reverse 0-2 pi vortex phase coding is the same as that of the 0-2 pi vortex phase coding, two beams of light after the phase coding are transmitted to the same light beam combiner after being bent by a light path for light beam coherent combination, and the light beam emitted by the light beam combiner is a radial polarized light beam.
In the step (2), the parallel line polarized light is changed into right-handed circularly polarized light after passing through the first lambda/4 wave plate and the vertical line polarized light is changed into left-handed circularly polarized light after passing through the second lambda/4 wave plate, and the method can be realized by arranging the positions of the first lambda/4 wave plate and the second lambda/4 wave plate, namely arranging the fast axis of the first lambda/4 wave plate at the position where the polarization direction of the parallel line polarized light rotates by 45 degrees along the counterclockwise direction and arranging the fast axis of the second lambda/4 wave plate at the position where the polarization direction of the vertical line polarized light rotates by 45 degrees along the clockwise direction.
Similarly, the parallel line polarized light is changed into left-handed circularly polarized light after passing through the first lambda/4 wave plate and the vertical line polarized light is changed into right-handed circularly polarized light after passing through the second lambda/4 wave plate, which can also be realized by arranging the positions of the first lambda/4 wave plate and the second lambda/4 wave plate, namely, arranging the fast axis of the first lambda/4 wave plate at the position where the polarization direction of the parallel line polarized light rotates by 45 degrees clockwise and arranging the fast axis of the second lambda/4 wave plate at the position where the polarization direction of the vertical line polarized light rotates by 45 degrees anticlockwise.
In the step (3), the two beams of light after phase encoding are incident on the same beam combining device after being deflected by the light path to carry out beam coherent combining, and radial polarized light beams are obtained. The light path is arranged in a deflection way so that two beams of light can be incident on the same beam combining device as a standard. The following description will take the example that the radial polarized light beam emitted from the beam combining device is parallel or perpendicular to the collimated light beam emitted from the laser:
so that the radial polarized light beam emitted by the light beam combining device is parallel to the collimated light beam emitted by the laser, the following two implementation modes can be respectively adopted:
(a) when the right-handed circularly polarized light and the left-handed circularly polarized light in the step (2) are respectively converted from the parallel line polarized light and the vertical linear polarized light: performing 0-2 pi vortex phase coding on the right-handed circularly polarized light, and then, emitting the coded light to a light beam combining device; and carrying out reverse 0-2 pi vortex phase encoding on the left-handed circularly polarized light, then carrying out light path turning through a light path turning device, and then leading the light to enter the light beam combining device, wherein the light beams emitted by the light beam combining device are coherent into radial polarized light beams.
(b) When the right-handed circularly polarized light and the left-handed circularly polarized light in the step (2) are respectively converted from the vertical linear polarized light and the parallel linear polarized light: after carrying out reverse 0-2 pi vortex phase encoding on the left-handed circularly polarized light, the left-handed circularly polarized light is incident on a beam combining device; and carrying out 0-2 pi vortex phase coding on the dextrorotation circularly polarized light, then carrying out light path turning through a light path turning device, and then leading the light to enter the light beam combining device, wherein the light beams emitted by the light beam combining device are coherent into radial polarized light beams.
Similarly, the radial polarized light beam emitted by the light beam combining device is perpendicular to the collimated light beam emitted by the laser, and the two methods can be respectively adopted. Namely: (a) in the method, the light path of the dextrorotation circular polarized light encoded by the 0-2 pi vortex phase is converted and then enters the light beam combining device, and the levorotation circular polarized light encoded by the reverse 0-2 pi vortex phase is directly incident to the light beam combining device. (b) In the method, the left-handed circularly polarized light coded by reverse 0-2 pi vortex phase is reflected to the beam combiner after the light path is converted, and the right-handed circularly polarized light coded by 0-2 pi vortex phase is reflected to the beam combiner.
The above method for generating a radially polarized beam may also adopt the following scheme: the method comprises the following steps:
(1) collimated light beams emitted by a laser are split by a polarization beam splitter to obtain parallel polarized light and vertical polarized light with the light intensity ratio of 1: 1;
(2') carrying out 0-2 pi vortex phase coding on the parallel linear polarized light, carrying out reverse 0-2 pi vortex phase coding on the vertical linear polarized light, wherein the starting point of the reverse 0-2 pi vortex phase coding is the same as that of the 0-2 pi vortex phase coding, and two beams of light after phase coding are incident on the same light beam combining device after being deflected by a light path to carry out light beam coherent combining;
(3') the light beam emitted by the light beam combining device is converted into a radial polarized light beam after passing through a lambda/4 wave plate, and the fast axis of the lambda/4 wave plate is arranged at the position where the polarization direction of the parallel linearly polarized light rotates 45 degrees along the counterclockwise direction.
The principle of the light path folding in step (2') is similar to that in step (3) described above.
In the step (3'), the principle that the light beam emitted by the light beam combining device is converted into the radial polarized light beam after passing through the lambda/4 wave plate is as follows:
parallel polarized light encoded by a 0-2 pi vortex phase in the light beam combining device emergent light is converted into right-handed circularly polarized light through a lambda/4 wave plate, vertical polarized light encoded by a reverse 0-2 pi vortex phase in the light beam combining device emergent light is converted into left-handed circularly polarized light through the lambda/4 wave plate, and the right-handed circularly polarized light and the left-handed circularly polarized light are coherently combined to obtain a radial polarized light beam.
An apparatus for implementing the method for generating a radially polarized beam of light, comprising:
a laser for emitting a collimated beam;
the polarization beam splitter is used for splitting the collimated light beam into parallel line polarized light and vertical line polarized light with the light intensity ratio of 1: 1;
the first lambda/4 wave plate and the second lambda/4 wave plate are used for converting the parallel line polarized light and the vertical line polarized light into right-handed circularly polarized light and left-handed circularly polarized light respectively, at the moment, the fast axis of the first lambda/4 wave plate is arranged at the position where the polarization direction of the parallel line polarized light rotates 45 degrees along the counterclockwise direction, and the fast axis of the second lambda/4 wave plate is arranged at the position where the polarization direction of the vertical line polarized light rotates 45 degrees along the clockwise direction; or the fast axis of the first lambda/4 wave plate is arranged at the position where the polarization direction of the parallel linear polarized light rotates by 45 degrees clockwise, and the fast axis of the second lambda/4 wave plate is arranged at the position where the polarization direction of the vertical linear polarized light rotates by 45 degrees anticlockwise;
the 0-2 pi vortex phase plate is used for carrying out 0-2 pi vortex phase coding on the dextrorotation circularly polarized light;
the reverse 0-2 pi vortex phase plate is used for performing reverse 0-2 pi vortex phase encoding on the left-handed circularly polarized light; the phase starting line of the reverse 0-2 pi vortex phase plate is superposed with the phase starting line of the 0-2 pi vortex phase plate;
the light path turning device is used for turning the light path of the left-handed circularly polarized light coded by the reverse 0-2 pi vortex phase or the right-handed circularly polarized light coded by the 0-2 pi vortex phase;
and the beam combining device is used for carrying out beam coherent combining on the two beams of light after the phase coding and the light path turning.
The above apparatus for implementing the method for generating a radially polarized light beam may also be configured as follows, that is, the apparatus includes:
a laser for emitting a collimated beam;
the polarization beam splitter is used for splitting the collimated light beam into parallel line polarized light and vertical line polarized light with the light intensity ratio of 1: 1;
the 0-2 pi vortex phase plate is used for carrying out 0-2 pi vortex phase encoding on the parallel linearly polarized light;
the reverse 0-2 pi vortex phase plate is used for performing reverse 0-2 pi vortex phase encoding on the vertical linearly polarized light; the phase starting line of the reverse 0-2 pi vortex phase plate is superposed with the phase starting line of the 0-2 pi vortex phase plate;
the light path turning device is used for turning the light path of the vertical linear polarized light coded by the reverse 0-2 pi vortex phase or the parallel linear polarized light coded by the 0-2 pi vortex phase;
the beam combining device is used for carrying out beam coherent combining on the two beams of light after the phase coding and the light path turning;
and the lambda/4 wave plate is used for converting parallel linear polarized light encoded by a 0-2 pi vortex phase in the emergent light beam of the light beam combining device into right-handed circularly polarized light, converting vertical linear polarized light encoded by a reverse 0-2 pi vortex phase in the emergent light beam of the light beam combining device into left-handed circularly polarized light, coherently combining the right-handed circularly polarized light and the left-handed circularly polarized light to obtain a radial polarized light beam, and the fast axis of the lambda/4 wave plate is arranged at a position where the polarization direction of the parallel linear polarized light rotates 45 degrees along the counterclockwise direction.
The light path turning device is a high-precision plane reflector, the root mean square value (RMS) of the surface shape precision of the light path turning device is 0.011 lambda, and the PV value (representing the difference value between the highest part and the lowest part of the surface) is 0.071 lambda; a plurality of planar mirrors, preferably metallic film mirrors, may be placed as desired.
The principle of the invention is as follows:
for radially polarized light, in a cross-section of the beam perpendicular to the optical axis, the polarization is expressed asWhere θ is the azimuthal coordinate in a polar coordinate system. At any time, the polarization direction at any point location in the cross-section of the beam is determined, all along the radial direction of that point. For left-handed circularly polarized light or right-handed circularly polarized light, the wave front of the whole light wave simultaneously changes in phase within the time of one period of light beam propagation, and the phase change is increased from 0 to 2 pi. For left-hand circular polarizationThe light or the right-handed circularly polarized light is linearly polarized light at any time in a time period, and the polarization direction of an electric field changes along the radius direction along with the increase of time. For left-handed or right-handed circularly polarized light, the direction in which the end of the light vector changes is left-handed or right-handed to the viewer facing the propagation of the light beam. Therefore, the calculation rule of Jones matrix is used to perform phase retardation e on the left-handed circularly polarized light-iθAnd phase delaying the right-handed circularly polarized light eiθAfter the light beams are combined, the polarization state of the combined light beams is found to meet the polarization distribution of the radial polarization light beams.
Compared with the prior art, the invention has the following beneficial technical effects:
(1) the radial polarized light beam is realized by directly utilizing the circularly polarized light, the principle is simple, and the realization is easy;
(2) the structure is simple, the adjustment is easy, and the manufacturing cost is low;
(3) the device has good stability and does not need other special optical elements.
Drawings
Fig. 1 is a schematic structural view of a first embodiment of the apparatus of the present invention.
Fig. 2 is a schematic structural diagram of a second embodiment of the device of the present invention.
FIG. 3 is a diagram showing the relationship between the fast axis direction of the λ/4 plate and the polarization directions of the vertically linearly polarized light (s-light) and the parallel linearly polarized light (p-light) in the second embodiment of the device of the present invention.
Fig. 4 is a schematic diagram of polarization of right-handed circularly polarized light in one cycle time.
FIG. 5 is a diagram of 0-2 pi phase encoding.
FIG. 6 is a schematic diagram of inverse 0-2 π phase encoding.
FIG. 7 is a schematic polarization diagram of radially polarized light.
Detailed Description
The present invention will be described in detail with reference to the following examples and drawings, but the present invention is not limited thereto.
Example 1
As shown in fig. 1, an apparatus for producing radially polarized light, comprising: the device comprises a laser 1, a polarization beam splitter 2, a first lambda/4 wave plate 3, a second lambda/4 wave plate 4, a 0-2 pi vortex phase plate 5, a reverse 0-2 pi vortex phase plate 6, a first high-precision plane reflector 7, a second high-precision plane reflector 8 and a depolarization beam splitter 9.
The method for producing radially polarized light using the apparatus as shown in fig. 1 is as follows:
(1) after collimated light beams emitted by the laser 1 are split by the polarization splitter 2, transmitted light beams are parallel linearly polarized light, reflected light beams are vertical linearly polarized light, and the light intensity ratio of the transmitted light beams to the reflected light beams is 1: 1.
(2) Parallel line polarized light is converted into right-handed circularly polarized light after passing through the first lambda/4 wave plate 3, wherein the fast axis of the first lambda/4 wave plate 3 is arranged at the position where the polarization direction of the parallel line polarized light rotates 45 degrees along the counterclockwise direction; the polarization diagram of right-handed circularly polarized light in one period time is shown in fig. 4, and the polarization direction of right-handed circularly polarized light in a beam cross section perpendicular to the optical axis can be represented by the following identity matrix:
wherein Px, Py, and i are the X-axis polarization component, the Y-axis polarization component, and the imaginary unit, respectively.
The vertically polarized light is converted into left-handed circularly polarized light after passing through a second lambda/4 wave plate 4, wherein the fast axis of the second lambda/4 wave plate is arranged at the position where the polarization direction of the vertically polarized light rotates by 45 degrees clockwise; in a beam cross section perpendicular to the optical axis, the identity matrix of the polarization direction of left-handed circularly polarized light is expressed as:
(3) and (3) carrying out 0-2 pi vortex phase encoding on the dextrorotation circularly polarized light through a 0-2 pi vortex phase plate 5. The 0-2 pi vortex phase plate 5 has a phase start line which is a straight line along the radial direction, and the phase delay can be realized by placing the 0-2 pi vortex phase plate 5 at a proper position so that the phase start line coincides with any radius in the entrance pupil light spot. In this embodiment, the phase start line L1 of the 0-2 π vortex phase plate 5 shown in FIG. 5 is taken along the positive direction of the x-axis as an example.
The vortex direction (namely, the phase encoding direction) of the 0-2 pi vortex phase plate 5 is opposite to the rotation direction of the right-handed circularly polarized light, and the phase encoding effect can be expressed by the following formula:
wherein,
and
respectively, the electric field vectors of incident light (dextrorotation circular polarized light) and emergent light after the 0-2 pi vortex phase coding is carried out by the 0-2 pi vortex phase plate 5. i is an imaginary number unit, and theta is an angle formed by a connecting line of the coordinate axis origin to the phase coding point and the positive direction of the X axis.
After the dextrorotation circular polarized light is subjected to 0-2 pi vortex phase encoding by the 0-2 pi vortex phase plate 5, the electric field vector of the light beam is expressed as follows:
and the dextrorotatory circularly polarized light after the 0-2 pi vortex phase coding is directly incident on the depolarization light splitter 9.
And the left-handed circularly polarized light is subjected to reverse 0-2 pi vortex phase encoding through a reverse 0-2 pi vortex phase plate 6. The reverse 0-2 pi vortex phase plate 6 has a phase start line which is a straight line along the radial direction, and the phase delay can be realized by placing the reverse 0-2 pi vortex phase plate 6 at a proper position so that the phase start line coincides with any radius in the entrance pupil spot.
Corresponding to the phase start line L1 of the 0-2 π vortex phase plate 5 in FIG. 5 along the positive x-axis, the phase start line L2 of the reverse 0-2 π vortex phase plate 6 in this embodiment is also along the positive x-axis, as shown in FIG. 6. At this time, the start of the inverse 0-2 pi vortex phase encoding is the same as the start of the 0-2 pi vortex phase encoding.
The vortex direction (namely, the phase coding direction) of the reverse 0-2 pi vortex phase plate 6 is opposite to the rotation direction of the left-handed circularly polarized light, and the phase coding effect can be expressed by the following formula:
wherein,
and
respectively, the electric field vectors of incident light (left-handed circularly polarized light) and emergent light after reverse 0-2 pi vortex phase encoding is carried out by a reverse 0-2 pi vortex phase plate 6.
After the left-handed circular polarization is subjected to reverse 0-2 pi vortex phase encoding through the reverse 0-2 pi vortex phase plate 6, the electric field vector of the light beam is expressed as:
and the left-handed circularly polarized light subjected to reverse 0-2 pi vortex phase encoding is subjected to light path turning by a first high-precision plane reflector 7 and a second high-precision plane reflector 8, and then is incident on a depolarizing beam splitter 9. The depolarizing beam splitter 9 coherently combines the two incident beams.
The light beam emitted from the depolarizing beamsplitter 9 is a combined coaxial collimated light beam, and the polarization state of the combined light beam can be expressed as:
the polarization state expression of the combined light beam is just the polarization expression of the radial polarized light, so that the light beam is directly converted into the radial polarized light. The polarization diagram for radially polarized light is shown in fig. 7.
In this embodiment, the first high-precision plane mirror 7 and the second high-precision plane mirror 8 are both metal film mirrors, and the root mean square value of the surface shape precision is 0.011 λ, and the PV value is 0.071 λ.
Example 2:
as shown in fig. 2, an apparatus for producing a radially polarized beam of light, comprising: the device comprises a laser 1, a polarization beam splitter 2, a 0-2 pi vortex phase plate 5, a reverse 0-2 pi vortex phase plate 6, a first high-precision plane reflector 7, a second high-precision plane reflector 8, a depolarization beam splitter 9 and a third lambda/4 wave plate 10.
Different from the embodiment 1, in this embodiment, phase encoding is performed on parallel polarized light and vertical linearly polarized light, respectively, and after the parallel polarized light and the vertical linearly polarized light after the phase encoding are combined into a coaxial collimated light beam through the depolarizing beam splitter 9, the coaxial collimated light beam is converted into right-handed circularly polarized light and left-handed circularly polarized light after the phase encoding, respectively, through the third λ/4 wave plate 10, and the combined light beam is a radial polarized light beam. The specific process for generating radially polarized light using the apparatus as shown in fig. 2 is as follows:
(1) after collimated light beams emitted by the laser 1 are split by the polarization splitter 2, transmitted light beams are parallel linearly polarized light, reflected light beams are vertical linearly polarized light, and the light intensity ratio of the transmitted light beams to the reflected light beams is 1: 1.
(2') passing the parallel linear polarized light through a 0-2 pi vortex phase plate 5 to perform 0-2 pi vortex phase coding. The 0-2 pi vortex phase plate 5 has a phase start line which is a straight line along the radial direction, and the phase delay can be realized by placing the 0-2 pi vortex phase plate 5 at a proper position so that the phase start line coincides with any radius in the entrance pupil light spot. In this embodiment, the phase encoding function is expressed by the following formula, taking the phase start line L1 of the 0-2 pi vortex phase plate 5 shown in fig. 5 as an example along the positive direction of the x axis:
wherein,
andrespectively are electric field vectors of incident light (parallel linear polarized light) and emergent light after the 0-2 pi vortex phase encoding is carried out through the 0-2 pi vortex phase plate 5. i is an imaginary number unit, and theta is an angle formed by a connecting line of the coordinate axis origin to the phase coding point and the positive direction of the X axis.
The parallel linear polarized light after the vortex phase coding of 0-2 pi is directly incident on the depolarization light splitter 9.
And the vertical linear polarized light is subjected to reverse 0-2 pi vortex phase encoding through a reverse 0-2 pi vortex phase plate 6. The reverse 0-2 pi vortex phase plate 6 has a phase start line which is a straight line along the radial direction, and the phase delay can be realized by placing the reverse 0-2 pi vortex phase plate 6 at a proper position so that the phase start line coincides with any radius in the entrance pupil spot.
Corresponding to the phase start line L1 of the 0-2 pi vortex phase plate 5 in FIG. 5 along the positive direction of the x axis, the phase start line L2 of the 0-2 pi vortex phase plate 6 in this embodiment is also along the positive direction of the x axis, as shown in FIG. 6, at this time, the starting point of the reverse 0-2 pi vortex phase encoding is the same as the starting point of the 0-2 pi vortex phase encoding, and the phase encoding effect of the reverse 0-2 pi vortex phase plate 6 can be expressed by the following formula:
wherein,
and
respectively are electric field vectors of incident light (vertical linear polarized light) and emergent light after reverse 0-2 pi vortex phase encoding is carried out by a reverse 0-2 pi vortex phase plate 6.
The vertically polarized light which is subjected to reverse 0-2 pi vortex phase encoding is incident on a depolarizing beam splitter 9 after being subjected to light path turning by a first high-precision plane reflector 7 and a second high-precision plane reflector 8. The depolarizing beam splitter 9 coherently combines the two incident beams.
(3') the beam emerging from the depolarizing beamsplitter 9 is a coaxial collimated beam. The coaxially aligned parallel polarized light and vertical polarized light which are subjected to phase encoding pass through the third λ/4 plate 10, the fast axis of the third λ/4 plate 10 is arranged at a position where the polarization direction of the parallel linearly polarized light rotates 45 degrees counterclockwise (i.e. a position where the polarization direction of the vertical linearly polarized light rotates 45 degrees clockwise), and as shown in fig. 3, the combined right circularly polarized light and the combined left circularly polarized light which are subjected to phase encoding are obtained through conversion.
The light beam polarization state after the combination of the dextrorotatory circular polarized light coded by the 0-2 pi vortex phase and the levorotatory circular polarized light coded by the reverse 0-2 pi vortex phase is shown as follows:
i.e. radially polarized light. The polarization diagram for radially polarized light is shown in fig. 7.
Claims (8)
1. A method of producing a radially polarized beam of light, comprising the steps of:
(1) collimated light beams emitted by a laser are split by a polarization beam splitter to obtain parallel polarized light and vertical polarized light with the light intensity ratio of 1: 1;
(2) the parallel line polarized light is changed into right-handed circularly polarized light after passing through a first lambda/4 wave plate and the vertical line polarized light is changed into left-handed circularly polarized light after passing through a second lambda/4 wave plate; or the parallel line polarized light is changed into left-handed circularly polarized light after passing through a first lambda/4 wave plate and the vertical line polarized light is changed into right-handed circularly polarized light after passing through a second lambda/4 wave plate;
(3) carrying out 0-2 pi vortex phase encoding on the dextrorotation circularly polarized light through a 0-2 pi vortex phase plate, wherein the 0-2 pi vortex phase plate is provided with a phase initial line which is a straight line along the radius direction of the phase initial line and is superposed with any radius in an entrance pupil spot; carrying out reverse 0-2 pi vortex phase encoding on the left-handed circularly polarized light through a reverse 0-2 pi vortex phase plate, wherein the reverse 0-2 pi vortex phase plate is provided with a phase starting line which is a straight line along the radius direction of the reverse 0-2 pi vortex phase plate, and the phase starting line is superposed with any radius in an entrance pupil spot; the starting point of the reverse 0-2 pi vortex phase code is the same as the starting point of the 0-2 pi vortex phase code, two beams of light after the phase code are deflected by a light path and then enter the same light beam combiner to be combined in a coherent manner, and the light beam emitted by the light beam combiner is a radial polarized light beam.
2. A method of producing a radially polarized beam of light, comprising the steps of:
(1) collimated light beams emitted by a laser are split by a polarization beam splitter to obtain parallel polarized light and vertical polarized light with the light intensity ratio of 1: 1;
(2') carrying out 0-2 pi vortex phase coding on the parallel linear polarized light, and carrying out reverse 0-2 pi vortex phase coding on the vertical linear polarized light, wherein the starting line of the reverse 0-2 pi vortex phase coding is overlapped with the starting line of the 0-2 pi vortex phase coding, the starting lines of the two vortex phase codes are respectively straight lines along the radius direction of the vortex phase plate, and meanwhile, the starting lines of the two vortex phase codes are overlapped with any radius in the entrance pupil spot; the starting point of the reverse 0-2 pi vortex phase code is the same as the starting point of the 0-2 pi vortex phase code, and two beams of light after the phase code are deflected by a light path and then are incident on the same light beam combining device for light beam coherent combining;
(3') the light beam emitted by the light beam combining device is converted into a radial polarized light beam after passing through a lambda/4 wave plate, and the fast axis of the lambda/4 wave plate is arranged at the position where the polarization direction of the parallel linearly polarized light rotates 45 degrees along the counterclockwise direction.
3. An apparatus for implementing the method of claim 1 for producing a radially polarized beam of light, comprising:
a laser for emitting a collimated beam;
the polarization beam splitter is used for splitting the collimated light beam into parallel line polarized light and vertical line polarized light with the light intensity ratio of 1: 1;
the first lambda/4 wave plate and the second lambda/4 wave plate are used for converting the parallel line polarized light and the vertical line polarized light into right-handed circularly polarized light and left-handed circularly polarized light respectively, at the moment, the fast axis of the first lambda/4 wave plate is arranged at the position where the polarization direction of the parallel line polarized light rotates 45 degrees along the counterclockwise direction, and the fast axis of the second lambda/4 wave plate is arranged at the position where the polarization direction of the vertical line polarized light rotates 45 degrees along the clockwise direction; or the fast axis of the first lambda/4 wave plate is arranged at the position where the polarization direction of the parallel linear polarized light rotates by 45 degrees clockwise, and the fast axis of the second lambda/4 wave plate is arranged at the position where the polarization direction of the vertical linear polarized light rotates by 45 degrees anticlockwise;
the 0-2 pi vortex phase plate is used for carrying out 0-2 pi vortex phase coding on the dextrorotation circularly polarized light, and the 0-2 pi vortex phase plate is provided with a phase starting line which is a straight line along the radius direction of the phase starting line and is superposed with any radius in the pupil entrance light spot;
the reverse 0-2 pi vortex phase plate is used for performing reverse 0-2 pi vortex phase encoding on the left-handed circularly polarized light, the reverse 0-2 pi vortex phase plate is provided with a phase starting line which is a straight line along the radius direction of the reverse 0-2 pi vortex phase plate, the phase starting line is superposed with any radius in the entrance pupil spot, and the phase starting line of the reverse 0-2 pi vortex phase plate is superposed with the phase starting line of the 0-2 pi vortex phase plate; the light path turning device is used for turning the light path of the left-handed circularly polarized light coded by the reverse 0-2 pi vortex phase or the right-handed circularly polarized light coded by the 0-2 pi vortex phase;
and the beam combining device is used for carrying out beam coherent combining on the two beams of light after the phase coding and the light path turning.
4. The apparatus of claim 3, wherein said optical path turning device is one or more high-precision plane mirrors having a surface profile precision with a root mean square value of 0.011 λ and a PV value of 0.071 λ.
5. The apparatus of claim 4 wherein said high precision planar mirror is a metal film mirror.
6. An apparatus for implementing the method of claim 2 for producing a radially polarized beam of light, comprising:
a laser for emitting a collimated beam;
the polarization beam splitter is used for splitting the collimated light beam into parallel line polarized light and vertical line polarized light with the light intensity ratio of 1: 1;
the 0-2 pi vortex phase plate is used for carrying out 0-2 pi vortex phase encoding on the parallel linearly polarized light, and the 0-2 pi vortex phase plate is provided with a phase starting line which is a straight line along the radius direction of the phase starting line and is superposed with any radius in the pupil entrance light spot;
the reverse 0-2 pi vortex phase plate is used for performing reverse 0-2 pi vortex phase encoding on the vertical linear polarized light, the reverse 0-2 pi vortex phase plate is provided with a phase starting line which is a straight line along the radius direction of the reverse 0-2 pi vortex phase plate, the phase starting line is superposed with any radius in an entrance pupil spot, and the phase starting line of the reverse 0-2 pi vortex phase plate is superposed with the phase starting line of the 0-2 pi vortex phase plate;
the light path turning device is used for turning the light path of the vertical linear polarized light coded by the reverse 0-2 pi vortex phase or the parallel linear polarized light coded by the 0-2 pi vortex phase;
the beam combining device is used for carrying out beam coherent combining on the two beams of light after the phase coding and the light path turning;
and the lambda/4 wave plate is used for converting parallel linear polarized light encoded by a 0-2 pi vortex phase in the emergent light beam of the light beam combining device into right-handed circularly polarized light, converting vertical linear polarized light encoded by a reverse 0-2 pi vortex phase in the emergent light beam of the light beam combining device into left-handed circularly polarized light, coherently combining the right-handed circularly polarized light and the left-handed circularly polarized light to obtain a radial polarized light beam, and the fast axis of the lambda/4 wave plate is arranged at a position where the polarization direction of the parallel linear polarized light rotates 45 degrees along the counterclockwise direction.
7. The apparatus of claim 6, wherein said optical path turning device is one or more high-precision plane mirrors having a surface profile precision with a root mean square value of 0.011 λ and a PV value of 0.071 λ.
8. The apparatus of claim 7 wherein said high precision planar mirror is a metal film mirror.
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| CN103576332B (en) * | 2013-11-15 | 2015-12-09 | 大族激光科技产业集团股份有限公司 | Chamber outer radial polarization laser conversion optical system and converter |
| CN103941402B (en) * | 2014-03-22 | 2016-03-16 | 中南大学 | Produce and there is the vortex light of rotational momentum and the method for vortex light array |
| CN104949630B (en) * | 2014-03-25 | 2017-06-20 | 南京理工大学 | A kind of adjustable point-diffraction interference device of large-numerical aperture fringe contrast |
| CN104485575A (en) * | 2015-01-07 | 2015-04-01 | 中国工程物理研究院激光聚变研究中心 | Single beam circular polarization smoothing system |
| CN107065213A (en) * | 2017-03-30 | 2017-08-18 | 西北工业大学 | A kind of method and device that non-uniform polarisation light beam is produced based on single Amici prism |
| CN107976821B (en) * | 2018-01-04 | 2024-05-14 | 中国人民解放军国防科技大学 | Optical converter for linearly polarized light to radially polarized light |
| CN108333789B (en) * | 2018-02-28 | 2020-10-30 | 中国人民解放军战略支援部队航天工程大学 | Vortex light preparation device based on matrix spiral phase plate multi-pass |
| CN108680511B (en) * | 2018-05-18 | 2023-08-25 | 南京信息工程大学 | Reflection enhancement type polarimeter based on circularly polarized light |
| CN109489835B (en) * | 2018-12-06 | 2020-10-16 | 深圳大学 | System and method for detecting phase and polarization of odd point light based on GS iterative algorithm |
| CN109709683B (en) * | 2019-02-22 | 2021-01-19 | 济南大学 | Device and method for generating space diffraction invariant square array vector light beam by using two-dimensional grating |
| CN111239882B (en) * | 2020-01-15 | 2021-09-28 | 南京大学 | Terahertz Bessel beam generator, preparation method and generation system |
| CN112034626B (en) * | 2020-08-25 | 2022-04-08 | 之江实验室 | High-flux 3D dark spot generating device |
| CN114217452B (en) * | 2021-12-21 | 2024-02-13 | 鑫海合星科技（大连）有限公司 | Nanoscale optical clamp imaging device and method based on vector light field regulation and control |
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| CN101465512B (en) * | 2007-12-19 | 2012-08-29 | 中国科学院福建物质结构研究所 | Symmetrical polarized light laser for novel pole |
| CN201307189Y (en) * | 2008-10-23 | 2009-09-09 | 中国计量学院 | Device for realizing conversion from linearly polarized light into radially polarized light |
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