154 results about "Bessel beam" patented technology

This system and method of for providing a tunable orbital angular momentum system for providing higher order Bessel beams comprising: an acousto-optical deflector configured to receive an input beam, deflect a first portion of the input beam a first deflection angle relative to an axis of propagation and along an optical axis and deflect a second portion of the input beam a second deflection angle relative to the optical axis; a line generator disposed along the optical angle for receiving the first portion and the second portion of the input beam and provide an elliptical Gaussian mean; a log-polar optics assembly disposed along the optical angle for receiving the elliptical Gaussian beam and wrapping the elliptical Gaussian beam with an asymmetric ring; and, a Fourier lens configured to receive the wrapped elliptical Gaussian beam.

The invention relates to the technical field of laser micromachining, in particular to a TGV drilling machining system and method based on a space-time modulation Bessel beam, an initial laser beam is output through a laser device, the initial laser beam is modulated into a dynamic pulse sequence through a pulse chirp regulation and control module, axial energy attenuation is compensated, a machining subsystem generates the Bessel beam, and the TGV drilling machining system and method based on the space-time modulation Bessel beam are obtained. The angle is finely adjusted in real time through piezoelectric driving, and a dynamic spatial light modulator loads an exponential decay type phase mask, so that light beam airspace shaping, non-diffraction light beam generation, pulse time sequence and phase parameter synchronous control and high-peak power pulse array are realized, and finally, integrated micro-perforation and channel modification of the glass substrate are realized; and the machining efficiency and precision are obviously improved.

The invention discloses a sapphire substrate through hole, a superconducting quantum chip manufacturing method and a superconducting quantum chip. The sapphire substrate through hole manufacturing method comprises the following steps: cleaning and drying a sapphire substrate; the cleaned and dried sapphire substrate is fixed to a three-dimensional positioning platform, and the three-dimensional positioning platform is used for moving the sapphire substrate according to a preset machining position so as to achieve relative machining Bessel beam nanoscale displacement; a femtosecond laser light source system emits a Bessel beam according to preset laser process parameters, the Bessel beam is focused to at least one position of a to-be-machined through hole of a sapphire substrate according to a preset laser scanning path, and through hole machining is conducted on the at least one position. According to the invention, the problem that the through hole is difficult to be formed in the sapphire substrate is solved, the high-quality requirement of the through hole in the sapphire substrate in the superconducting quantum chip is met, and a solution is provided for the realization of large-scale expansion of superconducting quantum bits in the future.

The invention provides a space target attitude optical detection device and method, and relates to the field of photoelectric detection and imaging, and the device comprises a Bessel polarization beam emission subsystem, a polarization characteristic and optical signal receiving subsystem, a polarization imaging subsystem, a timing subsystem and a control subsystem. The detection stability and accuracy are further improved through the self-healing property of the Bessel beam; through fusion of the visible light image and the polarization image, the target detection and identification capability can be enhanced, and the detection precision of the space target attitude is further improved.

The invention belongs to the technical field of radiation effect and radiation hardening of semiconductor devices and integrated circuits, and particularly relates to a single event effect laser simulation system based on Bessel beam shaping. A Bessel beam shaping and focusing module based on an axon lens is introduced and composed of the axon lens and two lenses, namely a single lens and a focusing lens, a Gaussian beam of an incident beam is shaped into a quasi-Bessel beam, and the quasi-Bessel beam is utilized to irradiate a semiconductor device to be detected. The axial distribution of the light beam is kept unchanged in a range of hundreds of microns, and the focusing breaking through the diffraction limit is realized in the radial distribution, so that the effect closer to the heavy ion charge deposition track is generated. The technology can solve the problem that a multilayer structure device, a thick sensitive region device and a wide forbidden band device are difficult to test through traditional laser simulation, and has important practical value for promoting laser simulation of the single event effect.

The invention discloses a non-diffraction laser communication terminal based on Bessel beams. The terminal comprises a beacon transmitting module, an optical antenna module, a beacon receiving module, a signal transmitting module, a signal receiving module and a light splitting module. The beacon transmitting module and the signal transmitting module respectively convert the Gaussian beam into a Bessel beam through an axicon, and the Bessel beam is output through a collimating lens; a primary mirror and a secondary mirror of the optical antenna module are mounted in an off-axis manner, so that light beams are shrunk and expanded; the light splitting module completes light path switching and light splitting through a fast reflecting mirror, a 1 / 4 wave plate, a dichroscope and a polarizing beam splitter; the beacon receiving module obtains beacon light position information through a CMOS detector, and the signal receiving module receives signal light through an APD detector. The non-diffraction characteristic of the Bessel beam is utilized, and the off-axis optical antenna and the polarization beam splitting design are combined, so that high-precision and low-loss laser communication is realized.

The invention relates to the field of electromagnetic calculation, in particular to a petal-shaped Bessel light-based distance measurement method in hypersonic plasma turbulence, which comprises the following steps of: simulating plasma sheath turbulence by establishing a multi-layer random phase screen, calculating diffraction transmission of petal-shaped Bessel light after the petal-shaped Bessel light passes through the turbulence, and capturing intensity distribution of reflected light beams; the rotation angle is determined based on the correlation with the ideal intensity distribution, and high-precision distance measurement is realized by using the linear relation between the rotation angle and the propagation distance. The petal-shaped Bessel light is formed by superposing two Bessel mode light beams with different orbital angular momentum orders, has a spatial structure strongly related to the propagation distance, and can keep higher stability and anti-interference capability in a turbulent environment. By combining the self-focusing and approximately non-diffraction characteristics of the Bessel beam, the target detection and distance measurement precision in hypersonic plasma turbulence is remarkably improved, and reliable technical support is provided for communication and target detection of hypersonic aircrafts.

The invention discloses a rapid high-resolution laser differential confocal Raman-LIBS (laser-induced breakdown spectroscopy) spectral microscopic imaging method and device, which are used for solving the problems of low multispectral focus matching efficiency, limited spatial resolution and the like in the prior art. The method comprises the following steps: establishing a height-position mapping model through a linear sensing interval of a differential confocal axial strength curve, calculating focus offset in real time in a spectrum scanning stage, and driving a sample table to carry out closed-loop fixed-focus compensation; and a Bessel beam modulation technology is combined to compress an excitation light spot to a submicron transverse size and expand the focal depth, so that the spatial resolution and the signal intensity are synchronously improved. The device adopts a common-path structure to integrate a light beam modulation system, a differential confocal detection system, a Raman spectrum detection system, an LIBS spectrum detection system and the like, realizes rapid and high-spatial-resolution imaging of geometrical morphology, Raman molecular information and LIBS elemental components, and is widely applicable to the fields of chemical analysis, biomedical detection, material research, trace substance detection and the like.

The invention discloses a uniform Bessel beam drilling device, and relates to the technical field of optical devices, the uniform Bessel beam drilling device mainly comprises a light generation device, a liquid crystal optical element and a regulation and control device, the light generation device is used for generating circularly polarized light and transmitting the circularly polarized light to the liquid crystal optical element; the arrangement mode of liquid crystal molecules in the liquid crystal optical element can be changed through the light-operated orientation technology, the liquid crystal optical element modulated through the light-operated orientation technology can receive circularly polarized light and form uniform Bessel light, and the liquid crystal optical element can have the function of a lens after being modulated through the light-operated orientation technology. Uniform Bessel light can be converged; the regulation and control device comprises a focusing optical element, and the focusing optical element can converge the uniform Bessel light emitted by the liquid crystal optical element again. The invention further discloses a uniform Bessel light drilling method which is implemented by adopting the uniform Bessel light beam drilling device, the energy utilization rate can be improved, the drilling effect is good, and the light path is simple.

The invention discloses a gallium oxide substrate surface grinding morphology prediction method and system, and relates to the technical field of nondestructive testing, and the method comprises the steps: collecting a surface fluorescence distribution image, matching the surface fluorescence distribution image with a pre-constructed fluorescence-crack mapping database, and generating a two-dimensional crack depth distribution cloud picture; marking a risk area coordinate set in the two-dimensional crack depth distribution cloud picture based on a preset crack depth threshold value; inputting the risk area coordinate set into a Bessel beam chromatography scanner for multi-angle transmission type scanning, synchronously collecting scattering images generated by scanning, and fusing the scattering images to generate a subsurface damage three-dimensional model; and performing data registration and weight superposition on the two-dimensional crack depth distribution cloud picture and the subsurface damage three-dimensional model, and outputting a morphology prediction report and grinding process optimization parameters. The subsurface damage three-dimensional model is constructed through the Bessel beam tomography scanning and multi-angle scattering image fusion technology, and high-resolution visual reconstruction of microcracks and damage distribution in the gallium oxide substrate is achieved.

The present invention discloses a laser hole repair system for narrow cavity structural parts without back wall damage, including an ultrafast laser, a beam transmission system, a beam shaping system, a beam focusing system, a coaxial vision system, a three-dimensional motion platform and a computer controller; the ultrafast laser provides a femtosecond laser beam for the entire system, and after the laser beam is transmitted through the beam transmission system, the beam is transmitted to the beam shaping system to obtain a Bessel beam after shaping optimization, and the beam is then focused and contracted by the beam focusing system to the micropores on the surface of the target material of the narrow cavity structural part on the high-precision three-dimensional mobile platform for hole repair, and the whole hole repair process is observed through the coaxial vision system. The present invention obtains the required complete cylindrical micropores and the back wall of the narrow cavity structural part after processing is not damaged. Only the beam process control means are used to achieve the narrow cavity without back wall damage during hole repair, and the operation is simple and convenient.

Disclosed in the present invention is a method for forming a precise through-hole at high speed by using an infrared laser, wherein the method irradiates in turn single modulated Bessel beam onto a workpiece in a scanning fashion by means of a mirror structure with at least one driving unit coupled to form a laser scanning processing pattern that changes the characteristics of the workpiece by precisely micromachining the workpiece into various shapes or sizes at high speed, and then wet-etching the workpiece, such that the method not only enables laser-machining the workpiece at high speed by significantly reducing laser-machining time compared to conventional methods, but also improves productivity by reducing etching time.

The utility model discloses a cutting device utilizing a Bezier beam, which comprises at least two laser processing units, a control unit and a clamping and moving unit, the clamping and moving unit is used for clamping a material to be cut and providing translation in X-Y-Z directions and rotation of the material to be cut, and the cutting device is characterized in that at least two laser processing units are arranged; the laser processing units output non-diffraction Bessel beams, the spot diameter of filiform light spots formed by focusing the Bessel beams is 20-100 micrometers, the non-diffraction distance of the Bessel beams is 15-300 millimeters, and the Bessel beams output by the laser processing units are located in different circumferential directions of the cutting plane respectively. The Bessel beam is adopted, thick materials can be directly ablated and cut, meanwhile, at least two laser processing units are arranged, a plurality of cutting planes can be synchronously cut, or the position of one cutting plane can be simultaneously cut, and the cutting speed is greatly improved.

The invention provides a method for machining a straight micro through hole in glass through ultrafast laser and a machining system. The method comprises the following steps that three glass workpieces are bonded into a sandwich type workpiece through an optical cement technology; the Bessel beam is focused on the sandwich type workpiece by adjusting the length of the Bessel beam; ultrafast laser irradiates the sandwich type workpiece, so that the material structure of the inner area of the glass is converted into a silicon-oxygen three-membered ring or a silicon-oxygen four-membered ring from a silicon-oxygen six-membered ring, and the sandwich type workpiece with a vertically-through modified microarray area inside is obtained after processing; the sandwich type workpiece after laser processing is separated through the optical cement removing technology, and only the target workpiece in the middle is reserved; putting a target workpiece into an etching solution, introducing ultrasonic oscillation for etching, and corroding a silicon-oxygen three-membered ring or a silicon-oxygen four-membered ring in an internal modified microarray region by an etching agent to form a micro through hole; and cleaning the etched target workpiece. The appearance of a horn mouth can be avoided.

The invention provides a long-focal-depth Bessel beam volume microscopic imaging system, and belongs to the technical field of optical microscopic imaging. The system comprises a non-diffraction light beam generation module, a scanning and focusing module, a sample control module, a fluorescence signal detection module and a microscopic imaging processing terminal. According to the invention, laser is used as an excitation light source, the non-diffraction beam generation module generates a long-focal-depth Bessel beam with a non-diffraction distance n times that of a traditional Bessel beam, the transmission distance is controllable, the limitation of an effective numerical aperture can be broken through, and under the condition of a certain transverse resolution, an ultra-large imaging depth of field is provided. Volume imaging is realized by using the characteristic of long focal depth and no diffraction, more axial information stacks are obtained, and the imaging speed and the imaging resolution are relatively high.

The modified Bessel beam generating device that achieves design flexibility is provided. The present invention provides a Bessel beam generating device that splits a laser beam emitted from a single light source and causes diverging light in a donut shape from optical fibers arranged on the same circle to be emitted toward the inside, thereby emitting a disk illumination beam that is focused in the vicinity of the center. This makes it possible to generate a disk illumination beam without blocking the high-intensity central portion and without reducing the light intensity.

This invention relates to the field of semiconductor lasers, and more particularly to a multi-chip ring array vertical cavity surface-emitting laser (VCSEL), comprising: a gain chip array, a beam-splitting axial conical lens group, a beam-combining axial conical lens group, and an output coupling mirror arranged coaxially. The gain chip array includes N (N>1) VECSEL gain chips arranged in M ​​concentric rings (M>1). The beam-splitting axial conical lens group includes M beam-splitting axial conical lenses. The beam-combining axial conical lens group includes M beam-combining axial conical lenses. The N laser beams first pass through the beam-splitting axial conical lens group to generate M-order Bessel beams, and then pass through the beam-combining axial conical lens group to combine into a resonant beam. This resonant beam resonates within the coaxial resonant cavity formed by the output coupling mirror and the gain chip array, resulting in the output laser beam. This invention employs a modular cascaded structure of axial conical lenses, realizing the parallel superposition of multiple rings of chips, fully utilizing the radial spatial dimension, and improving chip integration density.

The application discloses a three-piece Bessel beam shaping system with a diffraction ring, and belongs to the technical field of laser processing, comprising: a beam shaping mirror, a first collimating mirror and a focusing mirror; the incident surface and the exit surface of the beam shaping mirror are annular planes and annular aspheric surfaces respectively, and are used for shaping a collimated Gaussian beam into a point annular beam with energy gradually decreasing from inside to outside; the incident surface and the exit surface of the first collimating mirror are annular aspheric surfaces and annular planes respectively, and are used for collimating the point annular beam; the incident surface of the focusing mirror is a combination of an axicon surface and a spherical surface, and the exit surface is a plane; the focusing mirror is used for focusing the collimated point annular beam into a Bessel beam with a diffraction ring. The application can significantly improve the focal depth of the Bessel beam in laser processing, and can also effectively remove processing materials such as ink. In addition, the focal depth of the Bessel beam in the application is adjustable, and the adjustment mode is more, the flexibility is higher, and is suitable for different laser processing scenes.

The application relates to a large-diameter high-power pseudo-Bessel beam generation method and a generation device, and belongs to the technical field of communication. The method comprises the following steps: S100, an electromagnetic beam output by a feed horn is propagated to a first reflecting surface, and a target pseudo-Bessel beam is reversely propagated to a second reflecting surface; S200, the electromagnetic beam is propagated to the second reflecting surface through the first reflecting surface, a phase difference on the second reflecting surface is obtained, and a deformation variable of the second reflecting surface is updated; S300, the target pseudo-Bessel beam is propagated to the first reflecting surface through the second reflecting surface, a phase difference on the first reflecting surface is obtained, and a deformation variable of the first reflecting surface is updated; and S400, steps S100 to S300 are repeated until the relative field distribution of the output electromagnetic beam and the target pseudo-Bessel beam reaches a stable state, and a large-diameter high-power pseudo-Bessel beam is obtained. The application can solve the technical problems of existing media loss and limited power capacity.

This application relates to the field of electromagnetic waves, specifically providing a polarization state detection method and apparatus. The method utilizes a polarization state detection device for detection and includes: inputting the beam to be detected into the polarization state detection device to obtain orthogonal first and second Bessel beams; using a polarizer to obtain the azimuth angles corresponding to the interference weakening or enhancement regions in the interference patterns of the first and second Bessel beams, and determining the phase difference between the first and second Bessel beams based on the azimuth angles; using the polarizer to obtain the first amplitude of the first Bessel beam and the second amplitude of the second Bessel beam, respectively, and obtaining the amplitude ratio based on the first and second amplitudes; and calculating the polarization state of the wave to be detected based on the phase difference and amplitude ratio. This polarization state detection method simplifies the polarization state detection process for terahertz and millimeter waves, promoting the miniaturization and integration of detection equipment.

The application discloses a method for generating an ultralong focal depth array beam, and belongs to the technical field of grating manufacturing. The method comprises the following steps: constructing a Bessel beam excitation phase and a circular Airy beam excitation phase, constructing a composite phase distribution according to the array Bessel beam excitation phase and the array circular Airy beam excitation phase, and encoding the composite phase distribution to a metasurface; irradiating the metasurface with a linear polarization state plane wave, so that a left-handed circular polarization component excites an array Bessel beam, and a right-handed circular polarization component excites an array circular Airy beam; the array circular Airy beam is converted into a Bessel propagation mode after self-focusing, is spliced with the array Bessel beam in an axial direction to form a continuous light field distribution, and an ultralong focal depth array beam is obtained. The method can be applied to the fields of parallel laser processing, three-dimensional microscopic imaging and microparticle manipulation, and can extend the focal depth of the array Bessel beam while keeping the transverse resolution close to the diffraction limit.

The invention provides a method for realizing ultra-high-speed translation of a Bessel beam by using double acousto-optic modulation elements, which is characterized in that the displacement in the x-axis direction and the displacement in the y-axis direction are changed at a high speed by quickly switching radio frequencies f1 and f2, so that ultra-high-speed punching on the surface of a workpiece is realized; meanwhile, each hole has excellent morphology consistency due to vertical incidence, so that the problem of hole shape distortion caused by inclined incidence at the scanning edge of a traditional galvanometer is avoided; that is to say, the all-solid-state diffractive optical element is adopted, no mechanical moving part exists, the limitation of mechanical inertia is completely eliminated, the response time of light beam displacement only depends on the change speed of a driving signal and the establishment time of the diffraction effect, the MHz-level control effect can be easily achieved, and the speed is several orders of magnitude faster than that of a traditional galvanometer. The method is especially suitable for application scenes such as laser processing, optical tweezers, confocal microscopic imaging and high-speed optical switches.

The invention relates to the technical field of filter membrane processing, and discloses a preparation method and a preparation system for preparing a through-hole filter membrane by using reflective Bessel laser. The preparation system for preparing the through hole filter membrane by using the reflection type Bessel laser comprises a light beam shaping assembly and a transmission assembly, the beam shaping assembly is used for reflecting and converting the incident laser into a Bessel beam; the transmission assembly is arranged on a light path of the Bessel beam and used for transmitting a non-diffraction area of the Bessel beam to a machining station. By arranging the beam shaping assembly, the incident laser can be reflected and converted into the Bessel beam instead of being transmitted to form the Bessel beam. The reflective design can avoid energy absorption of a transmission element, and is suitable for long-time high-power processing; the reflection type design does not need to consider the transmissivity of the material, and can support the incident laser from the ultraviolet band to the infrared band; the reflective design has no thermal lens effect, and the focal depth stability of a Bessel beam diffraction-free area is high.

Method and system for breaking an internal shape in a sheet of glass in the flat state. The invention relates to a method for breaking an internal shape (10_INT) in a sheet of glass (10) in the flat state, said method comprising the steps of: - making (E10) a cutting line (T_D) in the sheet of glass using a Bessel beam pulsed laser or laser filamentation, said cutting line delimiting the internal shape with respect to a peripheral shape (10_EXT) complementary to the internal shape, - generating (E20) a temperature gradient between the internal shape and the peripheral shape to break said internal shape. Figure for the abstract: Fig. 2

The invention discloses a laser double-beam interference micropore machining phase modulation method which comprises the following steps: respectively emitting two Gaussian beams, and respectively modulating and compounding phases to obtain vortex Bessel beams; respectively adjusting the pulse sequences of the two Gaussian beams into a pre-pulse and a main pulse which are connected into a whole and have different energy; respectively carrying out polarization treatment on the two Gaussian beams to obtain two energy brushes which reversely rotate around the outer surface of the circumference of the vortex Bessel beam to clean chips; s2, monitoring the difference between the micropore depth and the target hole depth in real time, and continuously adding additional phase offset to the composite phase in S1; the long focal depth characteristic of the Bessel beam and the annular energy distribution of the vortex beam are combined, the focal depth range is expanded, meanwhile, laser energy is dispersed to the circumferential area from the center point, the peak power density is reduced, the heat dissipation condition is improved, the problem of insufficient focal depth is effectively solved, and feature offset caused by heat accumulation is synchronously restrained.

The invention discloses an achromatic metamaterial lens based on a long focal depth light beam and an imaging method, and the method comprises the steps: generating a zero-order Bessel light beam and a high-order Bessel light beam through a polarization multiplexing metamaterial lens, carrying out the imaging of an object, obtaining a zero-order image and a high-order image, subtracting the high-order image from the zero-order image, and obtaining a high-order image; and obtaining an achromatic image of the to-be-measured object. According to the invention, a large focusing depth of field is obtained through a conical phase, and then broadband imaging is obtained by using a focal depth overlapping region in a broadband, so that achromatic imaging of a visible light waveband is realized; the lens size is not limited, the area can reach the centimeter level or above, meanwhile, image blurring caused by side lobes is effectively eliminated through image subtraction, and the imaging quality is remarkably improved.

The present invention relates to the field of electromagnetic calculations, and specifically relates to a method for ranging based on petal-shaped Bessel light in hypersonic plasma turbulence. This method simulates plasma sheath turbulence by establishing a multi-layer random phase screen, calculates the diffraction transmission of petal-shaped Bessel light through the turbulence, captures the intensity distribution of the reflected light beam, and determines the rotation angle based on its correlation with the ideal intensity distribution. The high-precision ranging is achieved by using the linear relationship between the rotation angle and the propagation distance. The petal-shaped Bessel light is formed by superimposing two Bessel mode beams with different orbital angular momentum orders, and has a spatial structure strongly correlated with the propagation distance, capable of maintaining high stability and anti-interference ability in a turbulent environment. By combining the self-focusing and approximately non-diffracting characteristics of the Bessel beam, the present invention significantly improves the target detection and ranging accuracy in hypersonic plasma turbulence, providing reliable technical support for the communication and target detection of hypersonic vehicles.

The application discloses an optical element subsurface defect detection method and system based on phase contrast digital holography, and belongs to the field of precision measurement technology; the system adopts annular Bessel beam Kohler illumination, utilizes polarization modulation technology and a specially-made polarization contrast ring to realize synchronous four-step phase shift high-speed quantitative phase measurement in a U-shaped light path; the method acquires complex amplitude through a polarization camera, compensates for resolution loss by using a self-supervision super-resolution reconstruction algorithm fused with a physical model; full-field and local inverse diffraction reconstruction is carried out based on angular spectrum diffraction theory, high-precision depth positioning is realized based on the diffraction light complex amplitude distribution characteristics as a focusing criterion; three-dimensional information representation of defects is realized in combination with an optical field scattering and diffraction model and a machine learning algorithm; the application can realize high-sensitivity, high-signal-to-noise ratio, real-time in-situ quantitative detection and three-dimensional reconstruction of submicron defects without significantly increasing the cost.

The invention provides an optical system and laser processing equipment, and the optical system is used for modulating laser and comprises a first optical element and a second optical element which are sequentially arranged in the laser propagation direction; the first optical element is provided with a first surface which allows laser to enter and is vertical to the laser, and a conical second surface of which the axis coincides with the axis of the laser, so as to obtain an annular light beam; the second optical element comprises a correction unit used for correcting aberration of the annular light beam and a focusing unit used for focusing the annular light beam. The laser is modulated through the arranged optical element, the long-focal-depth Bessel beam is obtained, and the quality of glass through hole modification is better.

The invention relates to the technical field of biological fluorescence microscopic imaging, and particularly discloses a Bessel two-photon light sheet microscope illumination beam expansion method and system, and the method comprises the steps: providing a beam of near-infrared femtosecond laser, and modulating the near-infrared femtosecond laser into a Bessel beam; a piezoelectric ceramic displacement device is used for driving an illumination objective lens, so that the illumination objective lens moves in the direction of an illumination optical axis and stays at a plurality of preset positions in sequence; when the piezoelectric ceramic shifter moves to a preset position, increasing the power of the Bessel beam to two-photon excitation power through an electro-optical modulator, and maintaining for time T; in the process that the piezoelectric ceramic shifter moves from one preset position to the next preset position, the power of the Bessel beam is reduced to the level where two-photon fluorescence cannot be excited through an electro-optical modulator; a plurality of relatively short and thin Bessel illumination beams are spliced together to form a long and thin Bessel illumination beam, thereby expanding the high resolution illumination field of view.