223 results about "Bessel beam" patented technology

An apparatus includes a light source configured for generating a coherent light beam having a wavelength, λ, a light detector, and beam-forming optics configured for receiving the generated light beam and for generating a plurality of substantially parallel Bessel-like beams directed into a sample in a first direction. Each of the Bessel-like beams has a fixed phase relative to the other Bessel-like beams. Imaging optics are configured for receiving light from a position within the sample that is illuminated by the Bessel-like beams and for imaging the received light onto the detector. The imaging optics include a detection objective having an axis oriented in a second direction that is non-parallel to the first direction, where the detector is configured for detecting light received by the imaging optics. A processor configured to generate an image of the sample based on the detected light.

A method for manufacturing a microstructure, includes: dividing an incident laser beam into a plurality of diffracted beams by means of a diffractive optical element; concentrating said divided plurality of diffracted beams into mutually parallel diffracted beams by means of a telecentric lens; causing each of said mutually parallel diffracted beams to enter perpendicularly to the plane into a collection of axicons comprised of a plurality of axicons arranged into an array in such a manner that the center of each diffracted beam and the center of each axicon coincide, thereby forming a plurality of arrayed Bessel beams; and irradiating said plurality of arrayed Bessel beams onto a machined body.

A microscope including an imaging objective for imaging a sample on a detector and means for illuminating the sample with a light sheet in the focus plane of the imaging objective. The illumination means includes an illumination source which emits coherent light, and Bessel optics which generate at least two plane waves from the light beam and give propagation directions for the plane waves. The propagation direction of each of the plane waves encloses an acute angle with the focus plane in each instance, the magnitude of the acute angle being identical for each of the plane waves, so that the plane waves undergo constructive interference in the focus plane so that a light sheet is generated. Similarly, the illumination means can also include an optical element by which a rotationally symmetric Bessel beam is generated from the light beam for dynamic generation of a light sheet.

A technique is described for generating a Bessel beam. An input optical fiber is provided that supports propagation in the fundamental mode. The input fiber is connected to a fiber mode converting device that provides phase matching, at a predetermined excitation wavelength, between the fundamental mode and a selected azimuthally symmetric higher-order mode. As an input to the fiber mode converting device, a coherent light beam is fed through the input optical fiber to provide a fundamental mode input at the excitation wavelength. The fiber mode converting device resonantly excites the selected azimuthally symmetric mode. The azimuthally symmetric mode is provided as a beam output from an endface of the fiber mode converting device to approximate a Bessel beam.

A measurement method and apparatus rely upon the coherent optical interference between a reference beam and a diffractionless sensing beam having an optical path length that has been disturbed. The interference pattern can be analyzed to determine a measurement parameter of the disturbance. The diffractionless beam is particularly a Bessel beam. Exemplary optical interferometer types including Mach-Zehnder, Michelson, Sagnac and Fabry-Perot include a Bessel beam generator to generate a diffractionless beam as the sensing optical beam and in some aspects the reference optical beam of the interferometer. The sensing optical beam propagates along a sensing optical beam path in free-space. The reference optical beam path may be a free-space medium or a material medium such as an optical fiber. The sensing optical beam path is subject to a disturbance manifested by the optical interference pattern between the sensing optical beam and the reference optical beam. Parameters of the disturbance, such as motion, acoustics, environmental conditions and others can be determined by analysis of the interference pattern.

The invention discloses a laser processing method. The method includes the following steps that a laser device is started through a computer control system, so that the laser device emits laser beams; the light beams pass a small-hole diaphragm, so that the functions of mode selection and radius control over the laser beams are achieved; the laser beams passing the small-hole diaphragm are collimated and expanded through a lens set; the collimated and expanded laser beams are converted into Bessel beams through an axicon optical element; and the Bessel beams are emitted to the surface of a processed material through a galvanometer system. The invention further discloses a laser processing device. The position of a focus does not need to be determined during processing, and the laser processing method has the characteristics of being large in depth-diameter ratio, high in precision and the like. The implementation method is simple, an optical path is easy to adjust, and the laser processing method and device have good application prospects in the laser processing field.

The invention relates to a method and a device for producing diffraction-free Bessel beam array in random order based on phase hologram, which overcomes the technical defects that the existing method is complex and the service efficiency of light energy is low; the method has the following schemes: a beam of monochromatic plane light waves is used for irradiating a group of phase hologram with the same characteristic value arranged according to the design requirement in a space light modulator; a unique bright ring with centralized energy is produced after the hologram is performed with Fourier transform; the bright ring is filtered through an annular space filter; and Fourier transform is performed again so as to generate diffraction-free Bessel beam array. The device comprises a light wave beam expanding alignment lens group, a space light modulator, a Fourier lens I, an annular space filter and a Fourier lens II that are arranged in sequence along the transmitting direction of the light path. The method and the device have the following advantages: the use efficiency of energy is high; according to the need, the phase hologram in the space light modulator is changed and written so that the diffraction-free Bessel beam array in random order and at random position can be obtained.

A three-dimensional imaging system in a deep scattering medium includes a light source, a Bessel light beam generating and scanning device, a fluorescence collection system, a signal detection component, and an image acquisition system which are arranged in order along the optical path propagation direction, wherein the Bessel light beam generating and scanning device includes a translation stage, a cone mirror, a first lens, a galvanometer and a 4f system which are arranged along the optical path. The system and method help to solve the technical problems of inefficiency that conventional three-dimensional imaging technology uses point by point scanning to obtain a three-dimensional image and the phosphor in the scattering medium can not be imaged, use standard Bessel light beam which can generate a line focusing along light propagation direction as excitation light to replace conventional Gaussian beam which produces point focusing in the two-photon excitation fluorescence scanning microtechnic, and change original flat scaning into volume scanning to achieve quick acquisition the internal fluorescence distribution images in the scattering medium.

The invention provides laser cutting equipment and method. The laser cutting equipment comprises a feeding assembly, a first dual-linkage mechanical arm, a cutter wheel cutting assembly, a front laser cutting assembly, a turning-over assembly, a reverse laser cutting assembly, a second dual-linkage mechanical arm, a laser broken piece assembly and a sorting assembly. The front laser cutting assembly and the reverse laser cutting assembly perform laser cutting on a sample through bessel beams, and the focused bessel beams are focused light beams with a large focal depth, so that compared with gauss beams, the thick sample to be cut can be cut effectively, and thus the application range of the laser cutting equipment is broadened. Besides, the laser cutting assemblies and the laser broken piece assembly are adopted to cut the sample twice correspondingly, a finished product can be separated from waste, and cutting efficiency is high. In addition, the laser cutting equipment has the advantages that the cutting path is narrow, edge breakage of the surface of the cut product is small, the conical degree is small, the static pressure strength is high, an abnormally-shaped product can be cut, and the like.

The invention discloses an optical system generating screw type Bessel beams and a generating method. The optical system is composed of a He-Ne laser device, a polarizer, a first beam expander, a binary amplitude grating, a second beam expander, an aperture diaphragm, a liquid crystal spatial light modulator, an axicon and a CCD camera. Gauss beams emitted from the He-Ne laser device are converted into 0-degree linearly polarized light after passing through the polarizer with a 0-degree polarizing direction, beam expanding is carried out on the 0-degree linearly polarized light through the first beam expander, the 0-degree linearly polarized light is vertically emitted into the binary amplitude grating, generated diffracted light passes through the second beam expander, the diffraction angles of all diffraction orders of the diffracted light are enlarged, single-ring Laguerre-Guss beams are obtained through the aperture diaphragm and are sent to the liquid crystal spatial light modulator, the Bessel beams which are off an axis and are transmitted around the axis in a screw mode are generated by passing through the axicon, and the Bessel beams are irradiated to the CCD camera to obtain light distribution. The optical system generating the screw type Bessel beams and the generating method achieve generation of the Bessel beams which are off the optical axis and are transmitted around the optical axis in the screw mode.

The invention provides a laser cutting device and a cutting method. The laser cutting device comprises a laser, a light beam shaping system and a first collecting lens; the laser is a picosecond laser; the laser is used for emitting laser; the laser is a Gaussian beam; the light beam shaping system is used for converting the Gaussian beam to a Bessel beam; and the first collecting lens is used for focusing the Bessel beam to an area to be cut of samples to be cut, so that the area to be cut is precut by the Bessel beam. As the focused Bessel beam is the focused beam with longer focal depth, compared with the Gaussian beam, the Bessel beam can effectively cut the samples to be cut with greater thicknesses to widen the application range of the laser cutting device.

Disclosed in the invention is a generating device of an auto-acceleration type Bessel light beam. The generating device comprises a light source, a receiving fiber, a field type transformation fiber and a phase modulation fiber. Light emitted by the light source is received by the receiving fiber; the field type transformation fiber converts a light field transmitted by the receiving fiber into a high-order Bessel light beam; and the phase modulation fiber carried out phase adjustment on the high-order Bessel light beam to obtain an auto-acceleration type Bessel light beam. According to the invention, the novel auto-acceleration type Bessel light beam has the characteristic of transverse acceleration, so that operation like particle capturing and transport along a bending track and the like can be carried out. With the control mechanism, a specific particle can be transported to a target position around an obstacle. The provided generating device has the great application prospects in the biological, chemical, and medical fields.

The invention discloses a bessel light beam generating device with adjustable parameters and a production method of the bessel light beam generating device. The bessel light beam generating device comprises a continuous wave laser device, wherein a light beam emitted from the continuous wave laser device is reflected by a total reflective mirror, enters a filter, and then is collimated by a convex lens; the collimated light beam passes through a polarizer, becomes into a linearly polarized light and irradiates on a beam-splitting cube; a reflected light which passes through the cube irradiates on a reflected spatial light modulator, is reflected by the reflected spatial light modulator and then generates a vortex light beam; the vortex light beam passes through the beam-splitting cube and a polarization analyzer, and then irradiates on the diaphragm; the vortex light beam which passes through the light diaphragm vertically irradiates on a transmission-type spatial light modulator, passes through the transmission-type spatial light modulator and then generates a bessel light beam; the bessel light beam is imaged in a CCD (charge coupled device) camera, and is stored in a computer, so as to be analyzed. The device disclosed by the invention has the advantages of concise principle and low cost; the parameters can be subjected to real-time online adjustment; the device can be widely applied to the fields such as particle light control and optical test.

The invention provides a laser cutting device and a cutting method. The laser cutting device comprises a first laser unit, a light beam shaping system and a first collecting lens, wherein the light beam shaping system and the first collecting lens are sequentially arranged on the light emitting path of the first laser unit, and the first laser unit is a picosecond laser unit. The first laser unit is used for emitting first lasers which are Gauss beams. The light beam shaping system is used for converting the Gauss beams into Bessel beams. The first collecting lens is used for focusing the Bessel beams to a to-be-cut area of a to-be-cut sample so that the Bessel beams can precut the to-be-cut area. Due to the fact that focused beams of the Bessel beams are the focused beams which are small in diameter, long in focal depth and high in alignment accuracy instead of V-shaped light beams, compared with the Gauss beams, the edge taper of the to-be-cut sample cut by the Bessel beams is small, and application of the to-be-cut sample after cutting is more facilitated.

A bessel beam generator based on an annular Dammann gratings is sequentially formed by the annular Dammam gratings sharing the same optical axis, a first lens, an amplitude type spatial filter, a second lens and a focusing objective lens. The first lens and the second lens are a confocal lens group, each annular Dammam grating is first-ordered and multi-cycle and has the two-value phase difference of pi, and the amplitude type spatial filter is located on a confocal plane of the first lens and the second lens. Diffraction-free light beams with micron dimension or submicron dimension crosswise facula and 10-102 wavelength of axial focal depth can be generated in a focusing backfield of the focusing objective lens. Switch efficiency is as high as 80%. By means of a spatial filtering mode, quality of generated bessel beams is further improved. The micron or submicron diffraction-free bessel beam can be widely used in the fields of optical micro-machining, optical storage, large focus depth imaging, laser grain capture and quickening, a self-focusing servo-system and the like.

Embodiments of the invention are directed to a free-space communications system, a signal transmission platform for a free-space communications system, and a method for free-space communications, that advantageously provide or have the potential to provide measurable improvements in free-space communications over a turbulent atmospheric transmission path. A principal feature of all of the embodiments disclosed herein is the generation of a pseudo-non-diffracting communications signal transmission beam, referred to herein as a ‘non-diffracting signal transmission beam’. A realizable embodiment of such a non-diffracting signal transmission beam known in the art is a Bessel beam. A free-space communications system includes a communications signal transmitter platform that ultimately can generate a particularly specified transmission signal waveform, which is a non-diffracting signal transmission beam. The free-space communications system also includes a communications signal receiver platform that is located along a free-space communications signal transmission path. By modifying the signal light source from Gaussian to Bessel or other non-diffracting type beams, intensity stability under turbulence is improved. This passive technique, by virtue of increased intensity stability, may help to maintain bit error rate performance under turbulence.

The invention discloses a three-dimensional vector beam and a generation method and apparatus thereof. According to the provided three-dimensional vector beam, the optical field distribution is similar to the Bessel beam; and the cross section polarization-state distribution of the light beam changes with the change of the transmission distance and changes periodically. Within one spatial period, the polarization state of the beam changes from radial polarization to angular polarization alternately. Generated light beams can have various polarization-state distribution modes; and thus compared with the existing vector beam in single polarization-state distribution, the provided vector beam has the greater application value. According to the generation apparatus for the three-dimensional vector beam, generation of three-dimensional vector beams with different orders can be realized only by changing holographic grating loaded on a liquid crystal space light modulator without the need to adjust any other optical element again, so that the operation becomes simple and convenient.

The invention provides a laser cutting method and system for frosted glass. Transparent liquid is applied to the two sides of the frosted glass, then transparent glass is attached to the two sides ofthe frosted glass, to-be-processed glass is obtained, the to-be-processed glass is cut and lobed, and a finished product is obtained. The laser cutting method and system have the beneficial effects that according to the method, a layer of transparent liquid is applied to the upper and lower surfaces of the to-be-processed glass, then the two pieces of transparent glass are used for pressing, internal bubbles are removed, and therefore the frosted glass with poor translucency becomes transparent, and laser is very easy to penetrate; then the glass is cut by Bessel beams, holes having certain distances and having the diameter being about 2 microns are formed in the surface of the glass, and cracks are formed between the holes; and CO2 laser is injected to the cutting position through a scanning galvanometer to make the cracks between the holes be heated and cracked, and the needed product is finally obtained. The method can solve the problem that an existing laser cutting method has surface scattering and poor cutting quality; and meanwhile the high processing efficiency is achieved.

The invention discloses a combined cone lens for generating a long-distance diffraction-free Bessel beam. The combined cone lens has a structure formed by tightly gluing two conical surfaces of a positive-axis pyramid and a negative-axis pyramid. Base angles of the conical surfaces of the positive-axis pyramid and the negative-axis pyramid are equal, and a refractive index of the positive-axis pyramid is slightly more than that of the negative-axis pyramid. In the invention, the positive-axis pyramid and the negative-axis pyramid can be manufactured by using two kinds of common optical glass having slightly-different refractive indexes and combined, and the long-distance diffraction-free Bessel beam can be obtained by a combined single element, so the problems that the conventional pyramid cone has a small cone angle and is difficult to process are solved. The combined cone lens for generating the long-distance diffraction-free Bessel beam has the advantages of easiness of element processing, simple structure, high conversion efficiency and high light damage threshold and provides a new simple and effective way to acquire the long-distance diffraction-free Bessel beam. Moreover, a diffraction-free distance of the diffraction-free Bessel beam can be adjusted by adjusting the radius of an incident beam and a difference value between the refractive indexes of the positive-axis pyramid and the negative-axis pyramid. The combined cone lens for generating the long-distance diffraction-free Bessel beam has a great practical value in the fields of high-precision collimation, large-scale linear measurement, equipment manufacturing industry and laser communication.

The invention provides a cutting device and method for a composite substrate. The composite substrate comprises a transparent base and a printing ink coating. The cutting device comprises a first laser device, a first scanning galvanometer, a first field lens, a second laser device, a beam shaping system and a first condenser lens; first laser is emitted from the first laser device, reflected by the first scanning galvanometer and focused by the first field lens, so that the first laser erodes the printing ink coating along preset cutting lines and light transmitting lines are formed; second laser is emitted from the second laser device, and is a gauss beam; the beam shaping system converts the gauss beam into a bessel beam; the bessel beam is focused by the first condenser lens, so that the bessel beam pre-cuts the transparent base along the light transmitting lines; and the erosion width of the printing ink coating and the edge conicity of the composite substrate can be reduced.

The invention provides zero-taper laser cutting equipment and a cutting method based on the same. The zero-taper laser cutting equipment comprises a material feeding component, an indexed material conveying component, multiple receiving tables, a first laser cutting component, a second laser cutting component, a third laser cutting component, a turn-over component and a material discharging component. After a material is fed by the material feeding component and is conveyed by the indexed material conveying component, the first laser cutting component adopts laser to erode an ink layer on the front surface of a sample to form light-transmitting bars; the second laser cutting component adopts a Bessel beam to cut the rear surface of the sample for the first time; the third laser cutting component adopts laser to cut the rear surface of the sample for the second time to cut off and separate the sample; and then the cut sample is conveyed to a material storage box by the material discharging component. The focus beam of the Bessel beam is not a V-shaped beam, but a small-diameter, long-focal-depth and high-alignment-accuracy focus beam, so that the edge taper of the sample which is cut by adopting the Bessel beam is small or even zero, and application of the cut sample is more facilitated.

The invention discloses a tunable semiconductor laser optical tweezers system, including an edge-emitting semiconductor laser, and a plano-convex cylindrical lens, a gradient index lens, an axicon, afocusing lens arranged in sequence according to a laser optical path of a laser. The plano-convex cylindrical lens is placed on the position where circular distribution shows in a light outgoing propagation law process of the edge-emitting semiconductor laser. The distance between the focusing lens and the vertex of the axicon should be larger than the focal length of the focusing lens, and be smaller than a maximum non-diffraction distance that emergent light of the edge-emitting semiconductor laser passes through a light beam shaping system and generates Bessel beams through the axicon. Theoptical tweezers system can obtain bottle beams in different sizes as long as moving the distance between the gradient index lens (GRIN) and the plano-convex cylindrical lens, so as to capture and operate particles. The optical tweezers system is convenient for miniature integration, an optical damage problem of particles is not needed to be worried, and a new effective approach is provided for the semiconductor laser optical tweezers system.

The invention discloses an adjustable Bessel beam generating device and the design method of a high-end ring Dammam grating thereof. The adjustable Bessel beam generating device orderly comprises an optical fiber coupling output laser, a coupling output optical fiber, an optical fiber coupling output mirror, a collimator lens, the high-end ring Dammam grating, a first lens, an annular amplitude filter sheet, a circular turntable and a second lens 9. The annular amplitude filter sheet is arranged on the circular turntable. The circular turntable can freely rotate about the central axis. According to the invention, the lateral resolution and the axial focus depth of a generated Bessel beam can be adjusted to some extent, and the adjustable Bessel beam generating device can be widely used for large depth imaging, laser particle capturing, a self-focusing servo system and other occasions.

The invention belongs to the technical field of light beam conversion, in particular to a method for generating a bezier-like light beam through an optical fiber end face growth microcone. The methodcomprises the following steps of: depositing a photopolymer liquid reagent on the end face of a single-mode optical fiber, coupling green laser into the single-mode optical fiber through a lens, and reacting with the photopolymer liquid reagent deposited on the end face of the single-mode optical fiber to form a polymer microcone; wherein the light beam is converted into a bezier-like light beam after passing through the polymer microcone formed by the end face of the optical fiber. The shape of the microcone is controlled by light polymerization parameters such as green laser power, laser exposure time and oxygen diffusion concentration. The working bandwidth of the microcone covers the whole visible light region and even the near infrared band, and can have more than 30 concentric ringsat most, and the generated Bezier-like beam has self-recovery property. The method has the advantages of high efficiency, low cost and convenience, and can be widely applied to the fields of particlecontrol, optical imaging, nonlinear optics, photoetching, micro-manufacturing and the like.

The invention relates to a second harmonic microscopic imaging system based on Bessel beam pulse shaping. A femtosecond pulse laser transmits femtosecond pulse lasers with energy in Gaussian distribution to a space light isolator by virtue of a half wave plate and a Glan prism sequentially, lights emergent from the space light isolator are transmitted to a first adjustable diaphragm, lights emergent from the first adjustable diaphragm are transmitted to a cone lens to be converted into Bessel lights, the Bessel lights emergent from the cone lens are transmitted to a second adjustable diaphragm, lights emergent from the second adjustable diaphragm are transmitted to a third adjustable diaphragm by virtue of a achromatic lens assembly, lights emergent from the third adjustable diaphragm arescanned and transmitted to a telecentric conjugated system by virtue of a scanning galvanometer assembly, lights emergent from the telecentric conjugated system are transmitted to another half wave plate, light emergent from another half wave plate are transmitted to a dichroscope by virtue of the telecentric conjugated system, lights emergent from the dichroscope are focused on a sample on an objective table by virtue of a microscope objective, the sample produces a second harmonic signal, and then the second harmonic signal is collected by virtue of the microscope objective and then is acquired by an EMCCD by virtue of the dichroscope and a light filter.

A scanning module including first path shifting unit changing a path of an incident electromagnetic wave from a light source; a first driving unit adjusting the path of the electromagnetic wave by moving the first path shifting unit; and a Bessel beam generating unit making a Bessel beam on a portion of an object, using the electromagnetic wave with the path changed by the path shifting unit. A detection probe which includes a light source generating an electromagnetic wave; a path shifting unit changing a path of an electromagnetic wave from a light source; a Bessel beam generating unit making a Bessel beam on a portion of an object, using the electromagnetic wave with the path changed by the path shifting unit; a detecting unit detecting intensity of a wave from the object, and a housing accommodating the light source, path shifting unit, Bessel beam generating unit, and detecting unit.

The invention belongs to the field of laser cutting, specifically relates to a laser processing method for cutting a frosted brittle material by using a Bessel beam. The method comprises the followingsteps of: adding light-transmitting liquid which is not easy to volatilize on the upper surface of an area to be cut of the frosted brittle materials; covering a light glass cover to eliminate bubbles between the light glass and the frosted brittle materials; and then placing the frosted brittle materials on a processing platform; adjusting an optical focusing system to enable the Bessel beam toform a focusing spot and a focal depth required for cutting the frosted brittle material after passing through a 4f system, and moving the Z axis of the axis where the optical focusing system is located to enable the focus of the Bessel beam to fall on the frosted brittle material; setting a cutting path, moving the X axis and Y axis of the processing platform to process the frosted brittle material. The laser processing method provided by the invention ensures the perfection of the Bessel beam focusing system by adding light-transmitting liquid which is not easy to volatilize on the area to be cut, realizes cutting the frosted brittle materials, so the method is suitable for double-side frosted brittle materials.

A method and apparatus for forming and controlling a microwave Bessel beam which may be utilized for examining microstructure including very early stage tumors.