CN113267899B - Method for generating multiple coaxial orbit orbital angular momentum states at one time - Google Patents

Method for generating multiple coaxial orbit orbital angular momentum states at one time Download PDF

Info

Publication number
CN113267899B
CN113267899B CN202110632726.7A CN202110632726A CN113267899B CN 113267899 B CN113267899 B CN 113267899B CN 202110632726 A CN202110632726 A CN 202110632726A CN 113267899 B CN113267899 B CN 113267899B
Authority
CN
China
Prior art keywords
angular momentum
grating
orbital angular
circular array
coaxial
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110632726.7A
Other languages
Chinese (zh)
Other versions
CN113267899A (en
Inventor
赵生妹
季佳滢
王乐
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nanjing University of Posts and Telecommunications
Original Assignee
Nanjing University of Posts and Telecommunications
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nanjing University of Posts and Telecommunications filed Critical Nanjing University of Posts and Telecommunications
Priority to CN202110632726.7A priority Critical patent/CN113267899B/en
Publication of CN113267899A publication Critical patent/CN113267899A/en
Application granted granted Critical
Publication of CN113267899B publication Critical patent/CN113267899B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
    • G02B27/0927—Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
    • G02B27/0938—Using specific optical elements
    • G02B27/0944—Diffractive optical elements, e.g. gratings, holograms
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/28—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising
    • G02B27/286—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
    • G02B27/4233—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive element [DOE] contributing to a non-imaging application
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/18—Diffraction gratings
    • G02B5/1866—Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials
    • G02B5/1871—Transmissive phase gratings

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)

Abstract

The invention discloses a method for generating a plurality of coaxial orbital angular momentum states at one time, which comprises the following steps: step 1: after being collimated by a collimator, Gaussian light from a laser is sent to a beam deflection device; step 2: through the control of the controller of the light beam deflection device, the Gaussian light beam is deflected at different angles, the emergent Gaussian light beam irradiates different positions of the circular array vortex Dammann grating after passing through a collimation system consisting of a plurality of lenses, the light beam transmitted by the circular array vortex Dammann grating is converted into coaxial orbital angular momentum light beams with different topological charge values, and a plurality of concentric circle patterns are displayed on a focal plane. The invention applies the light beam deflection device and the improved circular array vortex Dammann grating to the field of generation of orbital angular momentum light beams, and realizes a novel rapid generation method of a plurality of coaxial orbital angular momentum states.

Description

Method for generating multiple coaxial orbit orbital angular momentum states at one time
Technical Field
The invention relates to the field of orbital angular momentum, in particular to a method for generating a plurality of coaxial orbital angular momentum states at one time.
Background
Orbital Angular Momentum (OAM) is one of the leading edges and hot spots in the field of quantum optics in recent years. In the classical electromagnetic field theory, the angular momentum of an electromagnetic field is divided into spin angular momentum, which is related to circular polarization, and orbital angular momentum, which is related to a spatial helical phase structure. During free space transmission, the Spin Angular Momentum (SAM) and the Orbital Angular Momentum (OAM) remain unchanged. In 1992, Allen et al indicated a beam with a helical phase factor exp (il θ), with each photon with a
Figure BDA0003104275980000011
Wherein l is the azimuth index of the light beam, also called topological charge, and the value can be from negative infinity to positive infinity, and the size determines the space distribution condition of the light beam,
Figure BDA0003104275980000012
where h is the Planckian constant. Subsequently, researchers at Queensland university in 1995 first experimentally verified the existence of photon orbital angular momentum, nearlyThe research in the years also finds that the topological charge value of the orbital angular momentum can be not only integer but also fractional.
With the increasing attention of orbital angular momentum in quantum information processing and modern communications, a variety of methods for generating OAM states have emerged. The OAM state can be directly output from the laser cavity; the other type is that a gaussian mode is output from a laser and then converted into a required OAM state by a converter, and the latter method has different conversion paths, and common generation methods include: helical phase plate method, computer holography method, Q-disk generation method, and mode conversion method, etc.
There are many common generating devices. Adaptive optics techniques, such as Spatial Light Modulators (SLMs) or Digital Micromirror Devices (DMDs), are currently used to change the phase and amplitude of the light beam front. Another approach is to illuminate one of a plurality of static phase plates using a plurality of electro-optical modulators (EOMs) and then recombine using a plurality of beam splitters to produce different spatial modes. The invention provides a method for generating a plurality of coaxial orbit angular momentum states at one time by combining beam deflection with an improved circular array vortex Dammann grating.
The beam deflecting means may be implemented using an optical deflector. An optical deflector, also called a light beam scanner, is a device that can change the direction of light beam propagation in space according to a certain rule. Most optical deflectors mechanically rotate a mirror (or polygon) to change the angle of incidence of a light beam onto the mirror, thereby deflecting the reflected light beam. Another type of conventional optical deflector utilizes an electro-optic effect or an acousto-optic effect to change a refractive index of a transparent medium to achieve the purpose of deflecting a light beam, and such a type of optical deflector is often only suitable for deflecting a laser beam with a single wavelength. Commonly used optical deflectors include turning mirrors, vibrating mirrors, acousto-optic deflectors, and the like.
The phase grating modulated by the space coordinates of the Dammann grating can generate one-dimensional or two-dimensional array beams with rectangular equal intensity by utilizing the diffraction grating with a special aperture function. Dammann gratings are used for star coupling of optical fibers and for coherent superposition of multiple laser sources. In recent years, it has been used in optical interconnects for optical computing, reading information in parallel or as a beam splitting device. The conventional Dammann grating generates a square diffraction field distribution, and the application of the conventional Dammann grating is limited in some special occasions.
In the prior art, application publication No. CN101726868A discloses a method and an apparatus for realizing multiplexing coding of orbital angular momentum states of light beams, and specifically discloses a laser, a polarizer, a beam expander, a spatial light modulator, a wave plate, and a fourier transform lens, which form a plurality of light beams in different orbital angular momentum states uniformly distributed on a circumference with an incident light optical axis as a center on a back focal plane of the fourier transform lens. Application publication No. CN104280802A discloses a composite Dammann vortex grating, which is composed of two basic topological charges + -l carrying same size and opposite sign0The Dammann vortex grating is a binary pure phase modulation device formed by sequentially and alternately combining annular regions with equal width from inside to outside, however, the composite Dammann vortex grating can only generate a plurality of petal-shaped light spots with different topological charges.
Disclosure of Invention
In order to solve the problems, the invention provides a method for generating a plurality of coaxial orbital angular momentum states at one time.
In order to achieve the purpose, the invention is realized by the following technical scheme:
the invention relates to a method for generating a plurality of coaxial orbital angular momentum states at one time, which comprises the following steps:
step 1: after being collimated, the Gaussian light from the laser is sent into a beam deflection device;
step 2: the controller of the light beam deflection device is controlled to control the deflection angle of the outgoing light beam, the outgoing light beam irradiates different circular array vortex Dammann gratings after passing through a collimation system consisting of a plurality of lenses, the light beam transmitted by the circular array vortex Dammann gratings is converted into a plurality of coaxial orbital angular momentum light beams with different topological charge values, and a plurality of concentric circle patterns are displayed on a focal plane.
The invention is further improved in that: the circular array vortex Dammann grating in the step 2 is a phase grating modulated by space coordinates, and can generate one-dimensional or two-dimensional circular array beams with equal intensity by utilizing a diffraction grating with a specific aperture function.
The invention is further improved in that: the phase structure of the circular array vortex Dammann grating is as follows:
Figure BDA0003104275980000031
where φ is the phase function, N is the total number of diffraction orders, an even positive integer, T is the period of the grating, T is the phase functionx、Ty、TrRepresents a period designed in the horizontal, vertical and radial directions of the grating, wherein
Figure BDA0003104275980000032
N is the order of diffraction from-N/2 to N/2, θ is the azimuth angle in polar coordinates, l is the topological charge of the OAM light, is a non-zero integer, | En|21/N is the energy of the nth order, corresponding to the normalization of the total energy, EnThe light beams incident on the circular array vortex Dammann grating with the plane wave front are diffracted into N orders according to the formula, and the light beams with topological charges N multiplied by l have equal energy, so that a plurality of concentric circular orbital angular momentum light beam arrays are obtained.
The invention has the beneficial effects that: the light beam deflection device and the improved circular array vortex Dammann grating are applied to the field of generation of orbital angular momentum light beams, a novel rapid generation method of a plurality of coaxial orbital angular momentum is realized, and the formed array light beams have the characteristic of equal intensity. The beam is deflected at different angles based on the rapidity and flexibility of the beam deflection device, and the capability of deflecting the beam to any angle is utilized. Then, the incident light beams are projected onto a modified circular array vortex Dammann grating capable of generating a plurality of coaxial orbital angular momentum phases, and the generation of the plurality of coaxial orbital angular momentum light beams is achieved. The traditional Dammann grating generates a square diffraction field with one-dimensional and two-dimensional equal-intensity points, which is not axisymmetric, and most optical systems are axisymmetric. The circular array vortex Dammann grating can realize one-time generation of a plurality of coaxial orbital angular momentum beams.
Drawings
FIG. 1 is a schematic diagram of multiple coaxial orbital angular momentum beam generation.
Fig. 2 is a schematic diagram of a simulation of a circular array vortex dammann grating 1.
Fig. 3 is a schematic diagram of a simulation of a circular array vortex dammann grating 2.
Fig. 4 is a graph of simulation results of the coaxial orbital angular momentum array 1.
Fig. 5 is a graph showing simulation results of the coaxial orbital angular momentum array 2.
Detailed Description
For the purpose of enhancing understanding of the present invention, the present invention will be further described in detail with reference to the following examples, which are provided for illustration only and are not to be construed as limiting the scope of the present invention.
As shown in fig. 1 to 5, in this embodiment, in consideration of the current situation that the conventional orbital angular momentum beam generation method cannot achieve generation of multiple coaxial orbital angular momentums, a method combining characteristics of beam deflection and circular array vortex dammann gratings is proposed, and a beam deflection device is controlled to deflect a beam at different angles and make the beam strike different positions of the circular array vortex dammann gratings, so as to achieve generation of multiple coaxial orbital angular momentums at one time. The invention relates to a method for generating a plurality of coaxial orbital angular momentum state light beams at one time, which comprises the following steps:
step 1: after being collimated, the Gaussian light from the laser is sent into a beam deflection device;
step 2: the deflection angle of the emergent light beam is controlled by a controller for controlling the light beam deflection device, the emergent light beam passes through a collimation system consisting of a plurality of lenses, the collimation system can be composed of L1, L2 and L3 lenses, the deflection angle is amplified, the light beam irradiates on different positions of the circular array vortex Dammann grating, and the circular array vortex Dammann grating at different positions corresponds to the phase of coaxial orbital angular momentum capable of generating different numbers of topological values. Therefore, the light beams transmitted by the circular array vortex Dammann grating are converted into a plurality of coaxial orbital angular momentum light beams with different topological charge values, and therefore, the generation of the coaxial orbital angular momentum light beams with different number of topological charges is realized by adjusting the controller, and a plurality of concentric circle patterns are displayed on a focal plane.
The beam deflection device in step 1 is a device capable of deflecting the outgoing beam at a certain angle compared with the incoming beam, such as a turning mirror, a vibrating mirror, an acousto-optic modulator (AOM), an acousto-optic deflector (AOD), and the like. Based on the deflection angle, the output light beam is deflected and irradiates different positions of the circular array vortex Dammann grating according to the deflection angle. The speed of adjustment of the beam deflection device determines the speed of the invention for generating a plurality of coaxial orbital angular momentum states at a time, and the speed of adjustment of the beam deflection device is much greater than the conventional generation speed.
The circular array vortex Dammann grating in the step 2 is a phase grating modulated by space coordinates, and can generate one-dimensional or two-dimensional circular array beams with equal intensity by utilizing a diffraction grating with a specific aperture function. The conventional Dammann grating generates a square diffraction field distribution, and the application of the conventional Dammann grating is limited in some special occasions. Since most optical systems are axisymmetric, the circular array vortex Dammann grating has important applications. The phase structure of the circular array vortex Dammann grating is as follows:
Figure BDA0003104275980000041
where φ is the phase function, N is the total number of diffraction orders, an even positive integer, T is the period of the grating, T is the phase functionx、Ty、TrRepresents a period designed in the horizontal, vertical and radial directions of the grating, wherein
Figure BDA0003104275980000051
N is the order of diffraction from-N/2 to N/2, θ is the azimuth angle in polar coordinates, l is the topological charge of the OAM light, is a non-zero integer, | En|21/N is the energy of the nth order, corresponding to the normalization of the total energy, EnThe light beams incident on the circular array vortex Dammann grating with the plane wave front are diffracted into N orders according to the formula, and the light beams with topological charges N multiplied by l have equal energy, so that a plurality of concentric circular orbital angular momentum light beam arrays are obtained.
A circular array vortex Dammann grating is designed according to the formula and is divided into two areas, orbital angular momentum states of two circular rings in one row and four rows and 1 position and orbital angular momentum states of four circular rings in one row and two columns and 1 position can be generated respectively, and specific simulation results are shown in figures 2 and 3. When an incident beam is deflected by a light beam and then irradiates on a circular array vortex Dammann grating region 1, a coaxial orbital angular momentum array 1 is generated, wherein l is 3, l is 1, l is-1, and l is-3; when an incident light beam is deflected and then irradiates on a circular array vortex Dammann grating region 2, a coaxial orbital angular momentum array 2 is generated, wherein the coaxial orbital angular momentum array is 4 coaxial orbital angular momentums of l-1 and l-1 respectively. Therefore, the rapid generation of a plurality of coaxial orbital angular momentum states is completed.

Claims (1)

1. A method of generating a plurality of coaxial orbital angular momentum states at a time, comprising: the method comprises the following steps:
step 1: after being collimated by a collimator, Gaussian light from a laser is sent to a beam deflection device;
step 2: under the control of a controller of the light beam deflection device, the Gaussian light beams are deflected at different angles, the emitted Gaussian light beams are irradiated on different positions of the circular array vortex Dammann grating after passing through a collimation system consisting of a plurality of lenses, the light beams transmitted by the circular array vortex Dammann grating are converted into a plurality of coaxial orbital angular momentum light beams with different topological charge values, and a plurality of concentric circle patterns are displayed on a focal plane;
the circular array vortex Dammann grating in the step 2 is a phase grating modulated by space coordinates, a diffraction grating with a specific aperture function is utilized to generate one-dimensional or two-dimensional circular array beams with equal intensity, and the phase structure of the circular array vortex Dammann grating is as follows:
Figure FDA0003530706280000011
where φ is the phase function, N is the total number of diffraction orders, an even positive integer, T is the period of the grating, T is the phase functionx、Ty、TrRepresents a period designed in the horizontal, vertical and radial directions of the grating, wherein
Figure FDA0003530706280000012
N is the order of diffraction from-N/2 to N/2, θ is the azimuth angle in polar coordinates, l is the topological charge of the OAM light, is a non-zero integer, | En|21/N is the energy of the nth order, corresponding to the normalization of the total energy, EnIs the weight coefficient before the nth phase.
CN202110632726.7A 2021-06-07 2021-06-07 Method for generating multiple coaxial orbit orbital angular momentum states at one time Active CN113267899B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110632726.7A CN113267899B (en) 2021-06-07 2021-06-07 Method for generating multiple coaxial orbit orbital angular momentum states at one time

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110632726.7A CN113267899B (en) 2021-06-07 2021-06-07 Method for generating multiple coaxial orbit orbital angular momentum states at one time

Publications (2)

Publication Number Publication Date
CN113267899A CN113267899A (en) 2021-08-17
CN113267899B true CN113267899B (en) 2022-04-12

Family

ID=77234411

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110632726.7A Active CN113267899B (en) 2021-06-07 2021-06-07 Method for generating multiple coaxial orbit orbital angular momentum states at one time

Country Status (1)

Country Link
CN (1) CN113267899B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115113409B (en) * 2022-08-26 2022-12-30 成都莱普科技股份有限公司 Linear flat-top light spot generation system, method and equipment based on Dammann grating

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102681063A (en) * 2012-04-12 2012-09-19 中国科学院上海光学精密机械研究所 Spiral Dammam zone plate and device for producing three-dimensional dipole vortex Dammam arrays
CN104144025A (en) * 2014-05-29 2014-11-12 深圳大学 Multiplexing and demultiplexing method and system utilizing optical vortex Dammann gratings
CN108572487A (en) * 2017-09-22 2018-09-25 北京航空航天大学 A kind of round Darman raster photo orientated based on ferroelectric liquid crystals

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10154253B2 (en) * 2016-08-29 2018-12-11 Disney Enterprises, Inc. Multi-view displays using images encoded with orbital angular momentum (OAM) on a pixel or image basis

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102681063A (en) * 2012-04-12 2012-09-19 中国科学院上海光学精密机械研究所 Spiral Dammam zone plate and device for producing three-dimensional dipole vortex Dammam arrays
CN104144025A (en) * 2014-05-29 2014-11-12 深圳大学 Multiplexing and demultiplexing method and system utilizing optical vortex Dammann gratings
CN108572487A (en) * 2017-09-22 2018-09-25 北京航空航天大学 A kind of round Darman raster photo orientated based on ferroelectric liquid crystals

Also Published As

Publication number Publication date
CN113267899A (en) 2021-08-17

Similar Documents

Publication Publication Date Title
US11440136B2 (en) Method and device for shaping radiation for laser processing
WO2020140392A1 (en) Linearly polarized light conversion element, manufacturing method and linearly polarized light conversion system
US5574597A (en) Light scanner and multi-beam generator using the same
US20080239420A1 (en) Agile holographic optical phased array device and applications
CN109870890B (en) Integer order vortex light beam phase mask plate with fractional order vortex contour and light path system
CN109709683B (en) Device and method for generating space diffraction invariant square array vector light beam by using two-dimensional grating
CN111220965B (en) Multi-beam surface emitting waveguide phased array
Braverman et al. Fast generation and detection of spatial modes of light using an acousto-optic modulator
WO2022258075A1 (en) Dmd-based method, apparatus, and system for generating multi-parameter adjustable light field
CN113267899B (en) Method for generating multiple coaxial orbit orbital angular momentum states at one time
CN112859534A (en) Parallel direct-writing device and method based on edge light suppression array
US11625001B1 (en) Optical system for generating arbitrary-order optical vortex arrays and finite optical lattices with defects
CN109343320A (en) A kind of light control device
CN109283805A (en) Laser direct-writing device based on Darman raster
CN108919499B (en) Method for generating multiple focusing light spots with independently controllable positions and intensities
Ashida et al. Conjugated mems phased arrays for large field of view random access scanning
CN113534475A (en) Method for generating Bessel space-time wave packet and Bessel space-time vortex wave packet
CN113059807A (en) High axial resolution three-dimensional printing method and device based on uniform active light sheet
CN109683339B (en) Phase mask plate for realizing bright nuclear vortex light beam and light path system
CN116224606A (en) Space-time combined regulation and control device and method for super-strong ultrashort laser
CN114019763B (en) Parallel direct writing device based on ten thousand independently controllable laser dot matrixes
Wang et al. Design and implementation of a linear array laser emitting optical system based on diffractive principles
CN110568618B (en) Device and method for generating spatial spiral beam array by using periodic binary phase plate
CN116880080B (en) Super-resolution light field modulation method
CN113568194B (en) Zero-order diffraction-free optical complex amplitude regulation and control system and method based on digital lens

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant