Provided are a device for measuring fractional-order optical vortex topology charge values and a measuring method thereof. The measuring method comprises the steps of writing generated calculating holographic images into a spatial light modulator through a computer holographic technique, acquiring wrapped phase images of vortex light beams through Michelson interference light paths and a four-step phase shifting technique, analyzing distribution of real phases theta of the vortex light beams through a phase image unwrapping algorithm, and calculating according to the topology charge definition of m=theta/2pi to obtain topology charge values m of any fractional-order accuracy. The device and method achieve the measurement of any step (0.1 step) of topology charge values of the fractional-order vortex light beams, can correct measurement of topology charge values of vortex light beams from existing half-integer step (0.5 step) to any step and can be widely applied to measurement of topology charge values in the fields of bose-einstein condensation, quantum communication, information coding and transmission, particle confinement, optical tweezers, optical wrenches and the like.

Device for measuring fractional-order optical vortex topology charge values and measuring method thereof

The invention relates to a method and device for generating a perfect Laguerre-Gaussian beam After a Gaussian beam is expanded, a spatial light modulator of a computer-generated hologram is loaded and used for regulating a light field, a first-level diffraction beam emitted by the spatial light modulator is captured, and then a hollow Gaussian beam is obtained; phase modulation is conducted through a spiral phase plate, so that a hollow beam carrying orbital angular momentum is obtained; focusing is conduced through a convex lens, so that the perfect Laguerre-Gaussian beam is obtained According to the method and device for generating the perfect Laguerre-Gaussian beam, the perfect Laguerre-Gaussian beam is generated through the hollow beam carrying the orbital angular momentum, the method is simple and reliable, and the device is simple in structure, easy to adjust and good in stability; the generated beam can be applied to the fields such as the particle capturing field, the free space optical communication and the beam transmission characteristic research field

Method and device for generating perfect Laguerre-Gaussian beam

The invention relates to a laguerre-gaussian beam-based speckle contrast imaging measurement device and a laguerre-gaussian beam-based speckle contrast imaging measurement method The device comprises a continuous wave laser; after being reflected by a total reflective mirror, a light beam emitted by the continuous wave laser irradiates on a collimating beam expander; after that, the light beam becomes linearly polarized light by a polarizer and then irradiates on a beam splitting prism; after passing through the beam splitting prism, the light beam is divided into two beams, wherein one path is reflected light, and the other path is transmission light; the reflected light beam irradiates on a spatial light modulator, and the light beam reflected by the spatial light modulator irradiates on a diaphragm after passing through the beam splitting prism and an analyzer again; after passing through the diaphragm, the light beam irradiates on a sample to be tested; after being scattered by the sample to be tested, the light beam is converged by an imaging lens, and then an image is formed in a charge coupled device (CCD) camera; after that, the image is stored in a computer, and the image contrast value can be calculated; when a light path is difficult to adjust, the speckle size is adjusted by changing the characteristics of the illumination beam, so that the method has the characteristics of being flexible and reliable; the method is widely applied to the fields such as hemorheology monitoring, plant growth condition monitoring, etc

Laguerre-gaussian beam-based speckle contrast imaging measurement device and laguerre-gaussian beam-based speckle contrast imaging measurement method

An optical system for generating an Airy beam light sheet comprising an optical arrangement for generating a Gaussian beam, and an optical element for converting the Gaussian beam into an Airy beam light sheet, wherein a single optical element is provided for converting the Gaussian beam into an Airy beam light sheet.

Airy beam light sheet and airy beam light sheet microscope

Provided are a perfect vortex light beam topological load measurer and method based on light intensity analysis, relating to the particle optical control and optical test field. The measurer comprises a continuous wave (CW) laser; a pin hole filter is provided in the forwarding direction of the light beam emitted by the CW laser; a convex lens I, an aperture diaphragm I, a polarizer and a reflection type spatial light modulator are successively arranged in the forwarding direction of the light beam after the pin hole filter; in the forwarding direction of the light beam generated after reflection of the reflection type spatial light modulator, a polarization analyzer, an aperture diaphragm II, a convex lens II and a CCD camera are successively provided; through phase compensation, the diffraction positive and negative first order generated by black grids in the spatial light modulator interferes imaging in the CCD camera, and interference fringe images are transmitted to the computer for treatment. The measurer and method do not need to perform beam splitting on light, omit external interference optical elements, simplify an optical path, and realize integer order vortex light beam topological load measurement, and have the advantages of concise principle, low cost, real-time on-line parameter adjustment, easy operation, etc.

Perfect vortex light beam topological load measurer and method based on light intensity analysis

The invention discloses a method for measuring partially coherent vortex light beam topological charge number. A measured light beam passes through an imaging convex lens and then passes through a beam splitter to be divided into a transmission light beam and a reflection light beam, optical fiber scanning probes of two single-photon counters are respectively arranged at the centers of the transmission light beam and the reflection light beam, the position of a single-photon counter optical fiber probe is fixed, the position of the other single-photon counter optical fiber probe is regulated to perform point-by-point scanning measurement, correlation function values gamma of the two beams on measuring position points are recorded, a spatial distribution image of a fourth-order correlation function gamma is output through computer processing according to fourth-order correlation function gamma relationship of partially coherent laguerre-gaussian beams, and the topological charge number of the beam to be measured is obtained through the number of dark rings on the image. The method is based on the fourth-order correlation function, a novel method for measuring the partially coherent vortex light beam topological charge number is provided, an adopted measuring device is simple in light path and easy to achieve, measuring method is simple, data processing is convenient, and result is reliable.

Method for measuring partially coherent vortex light beam topological charge number

Method and device for generating radial or angled polarization self-focusing Airy beam

The invention relates to a beam transmission and conversion technology, and discloses a method for producing partially coherent Airy beams. The method comprises the following steps that: a laser device emits a fully coherent gauss beam, and a convex lens and a rotary frosted glass sheet regulate the coherence of the gauss beam to get a partially coherent gauss beam; and after being collimated by a second convex lens, the partially coherent gauss beam is subjected to beam intensity distribution shaping by a gauss amplitude filter, a spatial light modulator to which a phase information graph is loaded modulates the phase of the partially coherent gauss beam, and a first-stage diffracted beam is captured through a circular aperture diaphragm, thus obtaining the partially coherent Airy beam. The method produces the partially coherent Airy beam by directly using the gauss beam, and is scientific in principle and easy to realize; and the device for implementing the method is simple in structure, easy to regulate, excellent in stability and low in production cost. The beam provided by the method can be practically used in the fields of optical particle cleaning, biomedical therapy, particulate trapping, electron acceleration, and the like.

Method for producing partially coherent Airy beams

The invention relates to non-iterative phase recovery apparatus and method under illumination of partially coherent light The non-iterative phase recovery apparatus under illumination of partially coherent light includes a partially coherent light generation unit and an object phase measurement unit, wherein the partially coherent light generation unit includes a laser, a beam expanding lens, a focusing lens, a rotation ground glass plate, a collimating lens and a Gaussian filter plate, and a spiral phase plate can be arranged between the beam expanding lens and the focusing lens; and the object phase measurement unit includes a beam splitter mirror, a spatial light modulator, a reflector, a porous array plate, a Fourier lens, a charge coupled element and a computer Compared with an iteration algorithm, the non-iterative phase recovery and method under illumination of partially coherent light is quicker in the recovery process and can realize real-time object information recovery Compared with a mode expansion method, the non-iterative phase recovery method under illumination of partially coherent light has a wider application range, and can realize object information recovery under unknown partially coherent light, of the associated structure The non-iterative phase recovery method under illumination of partially coherent light can be developed and applied to lensless diffraction imaging of X ray The non-iterative phase recovery method under illumination of partially coherent light has the advantages of being simple in apparatus, being wide in application range, being high in recovery speed, and having an important application prospect

Cai Yangjian

Papers

Method for measuring partially coherent vortex light beam topological charge number

Method and device for generating perfect Laguerre-Gaussian beam

Method and device for generating radial or angled polarization self-focusing Airy beam

Method for producing partially coherent Airy beams

Non-iterative phase recovery apparatus and method under illumination of partially coherent light