262 results about "Laser beam quality" patented technology

A laser (126) and an AOM (10) are pulsed at substantially regular and substantially similar constant high repetition rates to provide working laser outputs (40) with variable nonimpingement intervals (50) without sacrificing laser pulse-to-pulse energy stability. When a working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in coincidence with the laser output (24) to transmit it to a target. When no working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in noncoincidence with the laser output (24) so it gets blocked. So the average thermal loading on the AOM (10) remains substantially constant regardless of how randomly the working laser outputs (40) are demanded. The AOM (10) can also be used to control the energy of the working laser output (40) by controlling the power of the RF pulse (38) applied. When the RF power is changed, the RF duration (44) of the RF pulse (38) is modified to maintain the constant average RF power. Consistent loading on the AOM (10) eliminates deterioration of laser beam quality and laser beam pointing accuracy associated with thermal loading variation on the AOM (10) and is advantageous for applications such as IC chip link processing where stable working laser outputs (40) with variable output intervals (50) are needed.

A laser beam machining method for a wafer, wherein an operation of irradiating the inside of a wafer with a laser beam L along each of planned dividing lines is repeated a plural number of times from a position proximate to a back-side surface of the wafer toward a face-side surface of the wafer so that a plurality of composite layers each including a denatured layer and a cracked layer extending from the denatured layer toward the face-side surface are formed stepwise at intervals (first laser beam irradiation step). Subsequently, each of some of non-cracked layers between the composite layers is irradiated with the laser beam L so as to extend the cracked layer of a given one of the composite layers and to cause the cracked layer to reach the denatured layer of the composite layer which is adjacent to the given one composite layer. The denatured layers and the cracked layers which are sufficient for enabling the wafer to be split are formed by a reduced number of laser beam irradiation operations.

Methods and systems process a semiconductor substrate having a plurality of structures to be selectively irradiated with multiple laser beams. The structures are arranged in a plurality of substantially parallel rows extending in a generally lengthwise direction. The method generates a first laser beam that propagates along a first laser beam axis that intersects a first target location on or within the semiconductor substrate. The method also generates a second laser beam that propagates along a second laser beam axis that intersects a second target location on or within the semiconductor substrate. The second target location is offset from the first target location in a direction perpendicular to the lengthwise direction of the rows by some amount such that, when the first target location is a structure on a first row of structures, the second target location is a structure or between two adjacent structures on a second row distinct from the first row. The method moves the semiconductor substrate relative to the first and second laser axes in a direction approximately parallel to the rows of structures, so as to pass the first target location along the first row to irradiate for a first time selected structures in the first row, and so as to simultaneously pass the second target location along the second row to irradiate for a second time structures previously irradiated by the first laser beam during a previous pass of the first target location along the second row.

A device for an atomic clock, including: a laser source (102) that generates a laser beam; a splitter (101) that makes it possible to divert and allow a portion of the laser beam to pass therethrough in accordance with a predefined percentage; a quarter-wave plate (105) that modifies the linear polarization of the laser beam into circular polarization and vice versa; a gas cell arranged on the circular polarization laser beam; a mirror (107) sending the laser beam back toward the gas cell (106); a first photodetector (108a), and a polarizer (103) arranged between the laser beam outlet and the splitter in order to protect the laser source from the retroreflections emitted by different optical elements constituting the device.

The invention relates to a device for using intracavity self-adaptive optical technique to improve the solid laser beam quality which is formed by a He-Ne laser, a variable density fading disk, a beam-amplifying system, a distorting lens, a solid laser yield medium, a matching beam-amplifying concave mirror, a beam splitter, an output coupling mirror, a Hageman wave front sensor, a power meter, a high pressure amplifier, a high speed processor and a host computer, wherein the He-Ne laser sent light beacon is leaded into the solid laser yield medium by the concave mirror and is divided into two paths of signal by the beam splitter, one path uses the output coupling mirror to output the laser beam of the solid laser beam; the other path uses the Hageman wave front sensor to real-time probe the intracavity image differential information and uses the high speed processor to process it and obtains the corresponding voltage control signal; it adds the voltage to the deformation driver so that it can compensate the intracavity image difference of the solid laser.

The invention provides a high beam quality signal light fiber beam combiner and a manufacture method thereof. The beam combiner comprises at least one signal optical fiber which forms one group and output optical fibers. The signal optical fiber comprises an optical fiber cladding and a fiber core, the fiber core comprises a fiber core body and a fiber core through connection portion, one end of the fiber core through connection portion is connected with one end of the fiber core body, and the cross sectional area of the fiber core through connection portion gradually increases from one end to the other end to enable the fiber core through connection portion to approximately be conical, the refractive index of the fiber core through connection portion gradually reduces from one end to the other end, and a V parameter is invariant. One ends of the output optical fibers are connected with the other end of the fiber core through connection portion of the group of the signal optical fiber. The high beam quality signal light fiber beam combiner adopts the fiber core through connection portion to enable the duty ratio of signal light at a welding position of a plurality of optical fibers and the output optical fibers to achieve 1, enables combined output laser angle relative packing ratio (angles of 1) to be greatly reduced, and effectively promotes output laser beam quality.

The present disclosure describes systems and methods for beam wavelength stabilization and output beam combining in dense wavelength multiplexing (DWM) systems. Systems and methods are described for performing beam wavelength stabilization and output beam combining in DWM systems while achieving increased wall-plug efficiency and enhanced beam quality. Interferometric external resonator configurations can be used to greatly increase the brightness of DWM system output beams by stabilizing the wavelengths of the beams emitted by the emitters of the DWM laser source. The resonant cavities described by the present disclosure provide advantages over the prior art in the form of decreased cost, increased wall plug efficiency and increased output beam quality. Particular implementations of the disclosure achieve increased wall plug efficiency and increased output beam quality through a combination of innovative cavity designs and the utilization of reflection diffraction elements for beam combining.

The invention relates to a fiber laser beam quality measurement method base on a photoelectric detector and a CCD camera. The method comprises: an optical axis of a measured light beam is adjusted to be in a horizontal state, and a beam splitter is arranged at an optical path and thus the measured light beam is divided into two parts that are used for measuring a near field and a far field of the light beam. On the basis of measurement of the near field and the far field of the measured light beam as well as a related data analysis, a near field width and a far field width of the light beam are calculated, so that light beam quality M <2> x and light beam quality M <2>y at a corresponding direction are obtained by calculation. An M<2> factor expression based on near field and far field light intensity distribution of a beam is deduced in theory, so that a defect that the existing M<2> factor measuring instrument can not evaluate the large-size fiber laser beam quality easily can be overcome. The provided fiber laser beam quality measurement method is suitable for fiber laser beam quality measurement including a few of high order modes and some cut fiber laser beam quality measurement.

The invention provides a laser beam light balancing and shaping and speckle eliminating integrated device, which belongs to the field of laser displaying and illuminating and particularly relates to the fields of laser projection displaying and infrared laser night viewing. In the device, laser beam light balancing and shaping and speckle eliminating are considered uniformly, speckles are eliminated by adopting a rotary holographic scattering device, light balancing and shaping are realized by adopting a pure phase diffusion apparatus, and a holographic scattering apparatus, a micro direct current motor, the pure phase diffusion apparatus and a Fourier transform lens are connected and fixed into an entire body with a compact structure, so that the aims of balancing and shaping laser beam light and eliminating speckles are fulfilled simultaneously. The holographic scattering apparatus and the pure phase diffusion apparatus are thin-sheet diffusion optical apparatuses, have small sizes and are thin and light, so that optical-mechanical-electrical integration and miniaturization are easy to realize; moreover, the integrated device is made of a double refraction material, so that the integrated device has polarization maintaining performance, makes full use of the inherit linear polarization property of laser light and further increases the utilization ratio of light energy.

An improved illuminator with an adjustable beam pattern to be worn by medical and dental professionals includes a housing, a light-emitting diode (LED) disposed in the housing outputting light through a distal opening in the housing, an achromatic doublet lens mounted in the opening in the housing, and a singlet lens disposed between the LED and the achromatic lens. The distance between the singlet lens and the doublet lens may be adjustable, and/or distance between the LED and the singlet lens may be adjustable, through a threaded connections, for example.

The invention relates to a laser marking machine, which comprises a laser (13), an embedded industrial control system (12) and a galvanometer system (4), wherein the embedded industrial control system (12) and the laser (13) form a loop with a power supply through conducting wires, and the galvanometer system (4) is arranged on a marking working head (23). The laser marking machine is characterized in that the laser (13) is an optical fiber laser, and the laser (13) and the embedded industrial control system (12) can be positioned in a movable moving box (1); the laser (13) is connected with a focusing device through an optical fiber (14); and the focusing device is adapted together with the galvanometer system (4). Adopting a semiconductor pump fiber laser as a light source, the laser marking machine has the advantages of simple structure, small volume, high conversion efficiency, good laser beam quality, long service life and no maintenance so that a bulky cooling device is not needed in the marking process for the convenience of movable marking. Besides, the movable optical fiber laser marking machine not only requires a simple environment without constant temperature, constant humidity and a water-cooling facility, but also is applicable to a severe environment, thereby having the advantages of least material consumption, international common software, easy learning and understanding, small volume, light weight, small occupied area, and long service life.

A tapered optical fiber based high-power optical fiber end cap comprises a tapered optical fiber, a quartz block and an end cap housing, wherein a big end of the tapered optical fiber passes through one end of the end cap housing into the end cap housing and then is fixed to the end cap housing; a chamber in which the quartz block extends is formed in the other end of the end cap housing; the end, extending into the end cap housing, of the quartz block is a tapered table shaped end head; the end, extending out of the end cap housing, of the quartz block is cylindrical; an anti-reflection film coats the surface of the cylindrical end, extending out of the end cap housing, of the quartz block; the tapered table shaped end head of the quartz block is fused with the big end of the tapered optical fiber; an output end cap protecting window is arranged on the end cap housing section at the end, extending out of the end cap housing, of the quartz block; the cylindrical end, extending out of the end cap housing, of the quartz block is closed through the output end cap protecting window. The tapered optical fiber based high-power optical fiber end cap is simple in structure, and capable of improving the laser power bearing capacity of the optical fibers, and remains high laser beam quality while effectively inhibiting nonlinear effect.

The utility model discloses a wavelength tunable coherent laser beam system based on double gratings and belongs to the field of laser combined beams. The system comprises a semiconductor laser array, a first lens, a dammam grating, a second lens, a diaphragm, a third lens, a blazed grating and a grating rotary device. The second lens, the diaphragm and the third lens form a space filter. The blazed grating is fixed on the grating rotary device. A group of parallel laser beams emitted by the semiconductor laser array converge to reach the dammam grating, and the dammam grating combines the laser beams. The space filter filters zero order light in the combined laser beams, and the filtered zero order light is used as first grade incident light to form a Littrow structure with the blazed grating. First grade direction reflection light is fed back to the dammam grating along an original light path. The beams are divided after reaching the damman grating, are injected into various light-emitting units of the semiconductor laser array and jointly lock the wavelength and phase positions so as to realize coherent combined beams. The wavelength tunable coherent laser beam system combines a plurality of laser beams into a beam of high-power laser, and has the advantages of being high in reliability and good in laser beam quality, working in a single wavelength mode, and the like.

The invention provides a technical scheme of a fast-slow axis beam quality homogenizing device of a semiconductor laser. Based on the beam total reflection principle, the scheme comprises the following steps: using a rectangular prism spatial combination as a beam rotating component, using a cylindrical lens assembly as Y-direction collimation, and using two-pieces type cylindrical beam-shrinking mirror as an X-direction beam-shrinking component so as to shape the fast-slow axis light beam quality of the semiconductor laser in a homogenizing manner. Through the adoption of the device provided by the invention, the beam rotation is aberration-free, the beam forward direction cannot be changed, and a shaping system is simple in adjustment and easy to operate. A semiconductor laser high-brightness optical fiber coupling output light source researched based on the device can be applied to various fields such as pumping optical fiber lasers, medical treatment and industry processing.

The invention relates to a device capable of automatically diagnosing and correcting divergence angle and beam quality of a laser beam. The device is used for extracting an erosion image formed by a laser beam to a refractory material or a processing mark image formed by the laser on a processed material, automatically diagnosing the divergence angle and the beam quality of the laser beam, in particular a laser beam for processing, and correcting the divergence angle and the beam quality of the laser beam by utilizing an optical deformation device, such as a deformable mirror, so that the laser equipment can be assisted to keep the excellent and stable working state, and the processing capacity and efficiency can be furthest improved.

The invention provides a mechanical-electrical compound dimming system for a laser beam quality analyzer. The mechanical-electrical compound dimming system comprises a single-wheel variable optical attenuator, a CCD (charge coupled device) camera, a stepping motor, an electrical control system and a PC (personal computer). For an acquired image, an incident laser beam passes the single-wheel variable optical attenuator and is attenuated after shutter time is preset by the CCD camera, a new acquired spot image is processed by the PC, the electronic shutter time slot of the CCD camera is adjusted by the electrical control system according to a gray value, incident laser intensity is continuously attenuated by the aid of the single-wheel variable optical attenuator, linearity is fine, the dynamic range is wide, and a laser beam quality analyzer attenuation module is small in size and convenient to use. The dimming range of traditional optical wedge continuous attenuation of light intensity in the laser beam quality analyzer is narrow and is about 20-300 times, and the dimming system obtains the wide dynamic dimming range of 5000 times.

The invention discloses a fast laser scanning imaging simulation method based on light beam and triangular patch interaction. The method comprises steps as follows: a target space triangular mesh model is drawn firstly; a laser beam equation, angle resolution and a view field are deduced according to a laser scanning structure; a target model is imported, and target geometry is transformed in the view field range of an imaging system; finally, on the basis of a light beam and triangular patch interaction algorithm, a local search technology is introduced, a traverse range is reduced, the solving process of intersection conditions of laser beams and the target space triangular mesh model is accelerated, the distance between each intersection point and a laser emergent point is solved, and a target distance image is simulated rapidly. The simulation method is simple and high in speed and can be applied to design verification of a laser scanning imaging prototype and algorithm testing such as three-dimensional imaging, recognition, tracing and the like of a target, and the system development cycle is shortened.

The invention relates to an evaluation method of laser beam quality of a low-numerical aperture large-mode field area fiber. According to the invention, effects on an M2 factor imposed by inter-mode relative phases can be eliminated, so the M2 factor which is only related to inter-mode power proportion but not related to the inter-mode relative phases can be obtained. The M2 factor modified with the method can precisely reflect mode components and laser beam quality of the low-numerical aperture large-mode field area fiber. The closer to 1 the numerical value of the M2 factor is, the better the laser beam quality is. In this way, effects on laser beam quality imposed by the inter-mode relative phases are eliminated, and a disadvantage is overcome that it is hard to evaluate the laser beam quality of the low-numerical aperture large-mode field area fiber via an M2 factor.

The invention relates to the technical field of additive manufacturing and processing equipment and especially relates to an integrated array electron gun and an electron beam selective melting rapid formation system. A plurality of electron beam emission units are arranged orderly in an array manner, and each electron beam emission unit is responsible for one region; the electron beam emission units in different array positions are controlled to carry out accurate scanning and forming on different positions of a powder bed, and thus electron beam quality of each electron beam emission unit is ensured; and through effective connection of the regions, under the condition of ensuring part forming precision and quality, the problem that an existing powder bed electron beam selective melting rapid formation device cannot produce large parts due to overlarge electron beam deflection angle is solved, and powder bed electron beam selective melting rapid manufacturing of the large-size parts is realized.

A simple and compact laser resonator is proposed which makes it possible to symmetrically operate a gain medium, preferably a semiconductor, which possesses more than one channel of emission. As a result higher output powers and/or better beam qualities and/or better spectral characteristics can be achieved. The resonator is very compact and ideally comprises only three optical elements: a laseractive gain medium (1), a cylindrical collimation lens (5), and a prism (6) which is adapted to the angle between the two emissions (4) and which carries a beam splitter (7) and a feedback mirror (9) on its faces. Preferably the gain medium (1) possesses a feedback element (2) and an antireflective coating (3) on its faces. If no antireflective coating (11) is desired the same effect can be achieved by arranging the angle of incidence to fulfill the Brewster-condition. In a preferred embodiment the gain medium (1) is a high-power diode laser chip with an internal stripe-array and/or the laser resonator is unstable along the direction parallel to the epitaxial layers. In alternative embodiments the feedback element (9) is wavelength selective like a grating, a dielectric filter, a holographic element or a volume Bragg grating.

An improved illuminator with an adjustable beam pattern to be worn by medical and dental professionals includes a housing, a light-emitting diode (LED) disposed in the housing outputting light through a distal opening in the housing, an achromatic doublet lens mounted in the opening in the housing, and a singlet lens disposed between the LED and the achromatic lens. The distance between the singlet lens and the doublet lens may be adjustable, and/or distance between the LED and the singlet lens may be adjustable, through a threaded connections, for example. In the preferred embodiment, the achromatic doublet lens, the singlet lens, or both the singlet and the doublet lens have a planar surface. A conical mirror may be disposed between the LED and the singlet lens to increase the light collection efficiency of the LED.

A solid-state laser generating a green continuous laser and a method thereof are disclosed. The laser comprises a pumping source used for generating 798-801nm pumping light, a light splitting unit, an optical path conversion unit, an Er3+:YAlO3 crystal, a resonant cavity and two Fabry-Perot etalons. The light splitting unit is used for splitting the pumping light into a first light beam and a second light beam. The first light beam is entered into a first end surface of a laser crystal. The second light beam is entered into a second end surface of the laser crystal through the optical path conversion unit. The laser crystal is used for generating up-conversion fluorescence under excitation of the first light beam and the second light beam. The resonant cavity is used for outputting a laser of a green light wave band. The two Fabry-Perot etalons are located in the resonant cavity and are used for compressing a line width of an output laser. The structure of the laser is simple, cost is low and green-light continuous output of a narrow line width is realized. The invention also provides a method of generating the green-light continuous laser. Advantages that output laser beam quality is good; the line width is narrow; optical to optical conversion efficiency is high and so on are possessed.