61 results about "Infrared laser beam" patented technology

The invention relates to a laser welding method suitable for a manganese-copper diverter, which comprises the following steps of: respectively splicing and tightly attaching two non-ferrous metal strips to two sides of a middle metal strip, and after the to-be-welded surfaces of the non-ferrous metal strips and the middle metal strip are positioned on the same horizontal plane, welding the to-be-welded surfaces of the non-ferrous metal strips and the middle metal strip; a near-infrared laser beam and a blue laser beam which are coaxial form a red-blue composite laser beam, the red-blue composite laser beam is used for conducting laser welding along the splicing gap of the non-ferrous metal strip and the middle metal strip, and during laser welding, the inclination angle between the red-blue composite laser beam and the vertical face of the surface to be welded is larger than or equal to 7 degrees. A light spot formed by the near-infrared laser beam swings in a light spot formed by the blue light laser beam, a welding seam is formed at the splicing position of the non-ferrous metal strip and the middle metal strip and penetrates through the non-ferrous metal strip to form a bonding layer, laser welding can be adopted only, the welding seam quality of laser welding is improved, welding spatter is reduced, and material overheating is avoided; and the consistency of product quality and the high efficiency of production are both considered, the production cost is reduced, and batch production is achieved.

The invention belongs to the technical field of wind measurement laser radars, and particularly relates to a wind measurement laser radar with a self-cleaning function, which comprises a machine body, heat dissipation openings are formed in the two sides of the machine body, a glass window is formed in the top of the machine body, a fixing frame is connected to the top of the machine body, and a mounting cover is connected to one end of the fixing frame. A motor is mounted in the mounting cover, the output end of the motor is connected with a first lead screw, the first lead screw is driven by the motor to rotate in a reciprocating mode, a first connecting block in threaded connection with the outer wall of the first lead screw can move along a sliding groove under the action of a sliding block, and a silica gel scraping strip and a spray head can be driven to move together; meanwhile, a suction pump is started to pump water in a water tank to a water spraying pipe, a spray head sprays water to the surface of the glass window, and a silica gel scraping strip is matched to scrape the surface of the glass window in a reciprocating mode, so that self-cleaning of the surface of the glass window can be achieved, and dust is prevented from affecting infrared laser beam penetration of the laser radar.

The invention relates to a method for data glasses (10) with a virtual retinal display (12) (Retinal Scan Display), comprising at least one optical system (14) which projects an image onto a retina (16) of an eye (18) of a wearer of the data glasses (10), and comprising at least one laser feedback interferometry (LFI) sensor (20) which emits an infrared laser beam (22) which passes through at least part of the optical system (14). It is proposed that the LFI sensor (20) detects reflection signals (24, 24') of the infrared laser beam (22) and detects contaminations of components (26) of the virtual retinal display (12), in particular of the optical system (14), from the reflection signals (24).

An apparatus for rapid gas chromatography measurement of oil field gas includes: an infrared laser configured to emit an infrared laser beam; an infrared sensor configured to receive the infrared laser beam; a Fabry-Perot gas cell disposed in a path between the infrared laser and the infrared sensor such that the infrared laser beam passes through the gas cell, the gas cell configured to receive the gas sample; a gas chromatographic column assembly, the gas chromatographic column assembly comprising an input port, a gas chromatographic column, and an output port, the gas chromatographic column assembly being configured to provide the gas sample to the Fabry-Perot gas cell; and a controller in electronic communication with the infrared sensor and configured to process the received infrared laser beam to estimate a composition of the gas sample.

The invention relates to the technical field of laser welding, in particular to a 6-series aluminum alloy welding method and device with a magnetic field cooperating with time-sharing double-beam scanning, and the method comprises the steps that in the welding process, a blue light laser beam is used for scanning along a to-be-welded path in a spiral path, and a micro molten pool array is formed; after the blue laser beam stops scanning, a near-infrared laser beam concentric with a light spot of the blue laser beam is emitted at a preset time interval, and welding is conducted along a linear path deviating from the center line of the micro-molten pool array by a preset deviation amount; and during emission of the near-infrared laser beam, a constant magnetic field perpendicular to the welding surface is applied to the welding surface. The welding stability and the joint consistency of the 6-series aluminum alloy are improved, and the welding effect is effectively improved.

The invention provides a recovery method of a silicon-based gallium nitride wafer, and relates to the technical field of semiconductor manufacturing, the recovery method aims at the silicon-based gallium nitride wafer comprising a silicon substrate and a gallium nitride-based epitaxial layer arranged on the silicon substrate, and the recovery method comprises the following steps: using an infrared laser beam to scan the silicon-based gallium nitride wafer through a preset laser scanning path strategy; incident light enters the silicon-based gallium nitride wafer from one side of the gallium nitride-based epitaxial layer, so that the gallium nitride-based epitaxial layer is separated from the silicon substrate; and stripping the gallium nitride-based epitaxial layer. And by utilizing the characteristic difference that the gallium nitride-based epitaxial layer is transparent to infrared laser and the silicon substrate strongly absorbs the infrared laser, laser energy accurately acts on the interface of the gallium nitride-based epitaxial layer and the silicon substrate, so that high-efficiency and low-damage separation is realized. The defects that a traditional etching technology is high in cost and heavy in pollution and the substrate is prone to being damaged are overcome, and a brand-new and effective technical path is provided for low-cost and green recovery of the silicon substrate.

Device (102) and method for detecting a pupil, wherein a scanning area is scanned line by line with an infrared laser beam (108), wherein brightnesses of reflections (110) of the infrared laser beam (108) are detected line by line, wherein the brightest reflections in particular are determined, the brightness of which exceeds a predetermined threshold, wherein a Voroni diagram (200) is determined line by line depending on the brightnesses detected line by line, wherein the brightest reflections in particular, the brightness of which exceeds the predetermined threshold, form the origin centers of Voroni cells in the Voroni diagram, and the pupil is detected depending on the positions of the Voroni cells in the Voroni diagram, the device (102) comprising data glasses (100).

The invention relates to a method for preparing a metal powder intended for an additive manufacturing process of the type involving the scanning of a powder bed by a near-infrared laser beam, characterized in that it comprises: an initial step for selecting a powder having an optical reflectance higher than 70% for wavelengths ranging between 800 nm and 1500 nm; then a step for treating said powder, which is different from particle grafting, and which causes a physical and / or chemical surface modification of the particles (4) of said powder, such that it is possible to reduce their optical reflectance at a given wavelength. The invention also relates to the use of such a powder, the particles (4) having a median size d50 between 5 pm and 50 pm after treatment.

A laser-assisted bonding method includes: placing a semiconductor chip on a substrate, the semiconductor chip having an anti-reflection layer for infrared light on a front surface thereof, and a solder bump formed between the substrate and the semiconductor chip; and irradiating an infrared laser beam to the semiconductor chip through the anti-reflection layer to reflow the solder bump by heat generated by energy of the infrared laser beam absorbed by the semiconductor chip, in which the anti-reflection layer is used to reduce reflection of the infrared laser beam by the semiconductor chip.

The invention discloses a light spot detection, adjustment and tracking element based on an intermediate infrared detector array, which comprises a TO-can TO8 base, a detector gasket, 12 independent intermediate infrared detector units and a tube cap, and the detector units are bonded on the detector gasket through elargol according to a specific arrangement mode. The 12 detector units are arranged in a specific geometric layout to form various arrays. When light irradiates the detector unit array, each detector unit can receive different light beam intensities according to different positions of the cross section of a light spot and generate corresponding electric signals, and the electric signals accurately reflect information such as the diameter, the center position, the intensity distribution, the moving direction and the moving speed of the light spot. Therefore, the method can be widely applied to various application scenes needing to accurately measure the size, the position or the motion of the light spot and the like. Therefore, the engineering requirements of light spot analysis, adjustment and tracking during collimation of the intermediate infrared laser beam can be met.

The application discloses a laser-electrolysis-ultrasonic in-situ composite super-precision cutting device for black metal, which comprises a workpiece, a diamond tool head, a tool handle, an ultrasonic vibration unit, a focused infrared laser beam and a metal layer. In the machining process, an electrochemical reaction occurs at the cutting position of the workpiece to generate an oxidation layer with soft and loose quality and weak carbon affinity, thereby avoiding direct contact between the diamond and the black metal matrix material and reducing chemical wear caused by iron-carbon affinity. The application simultaneously introduces inert high-pressure airflow and electrolyte droplet jet flow for continuous heat dissipation and cooling of the machining area, so that the machining process temperature is reduced. On this basis, the focused infrared laser beam introduced in the machining process can accelerate the electrochemical reaction and increase the thickness of the oxidation layer, thereby being beneficial to efficient and low-temperature cutting. The ultrasonic vibration introduced in the machining process can further utilize the ultrasonic cavitation effect to accelerate material removal and removal. Through the ingenious in-situ composite of the laser, the ultrasonic and the electrolysis electric field, high-quality, efficient, super-precision and low-loss machining of the black metal complex component is realized.

This invention relates to the field of laser welding technology, and in particular to a 6-series aluminum alloy welding method and apparatus using magnetic field-coordinated, time-sharing dual-beam scanning. The method comprises: during the welding process, a blue laser beam is used to scan a spiral path along the path to be welded, forming an array of micro-molten pools; after the blue laser beam stops scanning, a preset interval is set, and a near-infrared laser beam concentric with the blue laser beam spot is emitted, welding along a linear path offset by a preset amount from the center line of the micro-molten pool array; during the emission of the near-infrared laser beam, a constant magnetic field perpendicular to the weld surface is applied to the weld surface. This method improves the welding stability and joint consistency of 6-series aluminum alloys, effectively enhancing the welding effect.

A laser apparatus for generating a sub- 190 nanometer laser beam includes a deep-ultraviolet solid-state laser source to generate an initial deep-ultraviolet laser beam, at least one mid-infrared solid-state laser source to generate at least one respective mid-infrared laser beam, and at least one lithium triborate crystal to generate an output deep-ultraviolet laser beam from the initial deep-ultraviolet and mid-infrared laser beams via sum-frequency generation. Each mid-infrared solid- state laser source includes (a) a holmium-, thulium-, or chromium-doped gain crystal or gain fiber or (b) an optically-pumped semiconductor gain material to generate the respective mid-infrared laser beam. The laser apparatus may be configured for continuous-wave and pulsed operation, thus offering versatile solutions for applications requiring DUV laser radiation below 190 nanometers. Advantageously, the present approach relies on lithium triborate. Lithium triborate crystals can be grown with the quality and dimensions needed for industrial applications.

The application discloses an infrared laser beam quality measuring device and method, and the infrared laser beam quality measuring method directly or focuses the infrared laser on an infrared up-conversion thick film material, converts the infrared laser spot which cannot be detected by a CMOS / CCD camera into a spot which can be detected by the CMOS / CCD camera, collects the spot on the infrared up-conversion thick film material by using the CMOS / CCD camera, quantitatively analyzes various parameters of the spot, and realizes quantitative measurement and evaluation of the infrared laser beam quality. The application converts the infrared laser spot which cannot be detected by the CMOS / CCD camera into the spot which can be detected by the CMOS / CCD camera, collects the spot by using the CMOS / CCD camera, realizes low-cost and reliable laser spot imaging, realizes measurement of the beam quality of the infrared laser which cannot be detected by the CMOS / CCD camera, and is easy to be widely popularized in industrial applications; furthermore, the reliability of the measurement is further improved, and the measurement efficiency is improved.

The invention relates to a laser correlation detector which comprises a transmitting end, a receiving end and a mobile terminal. The transmitting end comprises a transmitting module, a first control unit, a first communication module, a first Bluetooth module and a two-dimensional adjusting table; the transmitting module is used for transmitting infrared laser beams, the first control unit is in communication connection with a mobile terminal through the first Bluetooth module, the first control unit is in communication connection with the receiving end through the first communication module, and the two-dimensional adjusting table is used for adjusting the transmitting angle of the transmitting module. And the angle parameter is transmitted to the first control module. According to the invention, the data of the transmitting end and the receiving end are acquired in real time through the mobile terminal, cooperative operation of multiple persons is not needed, debugging personnel can independently complete the focusing process, and manpower and time are greatly saved.

The invention relates to a pupil detection method, in particular for data glasses (10), comprising at least one scanning step (30), in which a laser beam (12), in particular an infrared laser beam, in particular by means of a MEMS micromirror system (16), of at least one laser feedback interferometry (LFI) sensor (14) is scanned over at least a majority of a visible part of a user's eye (18); and at least one detection step (32) in which a portion (20) of the laser beam (12) backscattered by the user's eye (18) is detected by the LFI sensor (14) and converted into an electrical signal. According to the invention, in at least one recording step (34), in order to detect a pupil (22) of a user's eye (18), signal shifts (24, 50, 52), in particular above a settable threshold value, in the electrical signals are recorded together with scanning coordinates (alpha, beta), in particular of the MEMS micromirror system (16), associated with the respective signal shift (24).

The invention provides a stainless steel powder laser printing method which comprises the following steps: laying a stainless steel powder layer with the thickness of 0.05-0.07 mm on a substrate in a forming cavity, controlling an infrared laser beam to selectively scan according to a preset scanning strategy in an inert gas protection atmosphere according to three-dimensional model slicing data, so that the powder layer is molten and solidified to form a cladding layer, and repeating the steps until the three-dimensional component is obtained. The scanning strategy comprises the following steps: (1) the laser power is 200-250W, the scanning interval is 0.08-0.11 mm, and the scanning speed is 700-900mm / s; (2) the laser power ranges from 250 W to 300 W, the scanning distance ranges from 0.08 mm to 0.11 mm, and the scanning speed ranges from 900 mm / s to 1100 mm / s; and (3) the laser power is 300-400 W, the scanning distance is 0.07-0.09 mm, and the scanning speed is 800-1000 mm / s. In addition, the invention further provides a stainless steel three-dimensional component and a heat treatment method thereof.

The utility model discloses a de-bonding device. The de-bonding device comprises a laser source for providing an infrared laser beam for performing de-bonding through a carrier silicon wafer; the galvanometer is used for transmitting the infrared laser to the first surface of the carrier silicon wafer and irradiating a bonding layer through the carrier silicon wafer, and the galvanometer is used for de-bonding the carrier silicon wafer and a device according to a target scanning speed by adjusting the laser frequency, the device is bonded on the second surface of the carrier silicon wafer through the device, and the laser spot generated by the next pulse corresponding to the target scanning speed is next to the laser spot generated by the previous pulse and is not overlapped with the laser spot generated by the previous pulse. Through the above debonding device, nondestructive debonding can be carried out on the permanently bonded silicon wafer, so that the separated silicon wafer can be reused, subsequent processing is facilitated, the efficiency of debonding permanent bonding can be improved, and the size of the whole debonding device is reduced.

The present invention provides a ballistic imaging method and system based on infrared laser. The system comprises: an infrared laser emitting module, a receiving module and a host computer. The infrared laser emitting module comprises a power supply, an infrared laser beam array, a scattering mirror, a collimating mirror and a housing. The receiving module comprises a bandpass filter, a photodiode array, an outer frame and a data interface. In this system, the infrared laser beam array emits multiple infrared laser beams. Through the action of the scattering mirror and the collimating mirror, the multiple independent infrared laser beams form an infrared laser column that can completely cover the photodiode array. The bandpass filter on the receiving module can transmit light waves with wavelengths within the infrared light range. The photodiode array receives infrared signals to form a path, and the host computer records the power supply status of each photodiode on the photodiode array.

An apparatus for non-contact measuring temperature includes a stand, for securing a vapor chamber, wherein the vapor chamber comprises a condenser area and an evaporator area, wherein the evaporator area comprises a heating spot; a continuous-wave laser device, facing the stand, for irradiating the heating spot by providing an infrared laser beam, wherein the infrared laser beam comprises a first infrared wavelength range; a switch device, controlling an irradiating cycle of the infrared laser beam, wherein the irradiating cycle comprises a irradiating time-interval and a non-irradiating time-interval; a first infrared sensor, facing the stand, for collecting a first thermal radiation data of the heating spot in a second infrared wavelength range; a data processing unit, only transferring the first thermal radiation data in the non-irradiating time-interval into a first temperature, wherein the irradiating time-interval is longer than the non-irradiating time-interval.

The utility model relates to the technical field of concentration measurement, in particular to a gas concentration detection device. The gas concentration detection device comprises a detection gas chamber which is internally provided with a light path channel, a gas inlet is formed in the detection gas chamber, the light path channel is communicated with the outside through the gas inlet, and at least one light reflecting piece is fixedly installed in the light path channel; the infrared laser and the infrared sensor are installed at the two ends of the light path channel respectively, infrared laser emitted by the infrared laser irradiates towards the light reflecting pieces, and the infrared laser faces the infrared sensor after being reflected by at least one light reflecting piece. The infrared laser emitted into the detection gas chamber is reflected by the reflecting part, so that the optical path of the infrared laser in a limited space can be prolonged, a longer infrared laser optical path can be obtained in a shorter detection gas chamber, and the calculation accuracy of the concentration of the to-be-detected gas can be greatly improved.

The utility model discloses an infrared laser induction video pile structure, which relates to the technical field of parking lot management equipment and comprises two vertical rods. The two vertical rods are located on the left rear side and the right rear side of the parking space correspondingly. A camera unit is arranged on one vertical rod and is used for collecting an image of one parking space; the two vertical rods are each provided with an infrared laser recognition unit. The infrared laser recognition unit is electrically connected with the camera shooting unit; one infrared laser identification unit corresponds to one infrared laser beam; during working, one end of the infrared laser beam extends to the infrared laser recognition unit, and the other end of the infrared laser beam extends to the front side surface of the parking space. The projections of the two infrared laser beams on the ground form an X-like shape. Compared with the prior art, the video pile structure provided by the utility model can effectively reduce the monitoring power consumption of the video pile and reduce the misjudgment rate of parking space vehicle identification.

The invention relates to a copper and stainless steel composite laser welding process and device and application of the copper and stainless steel composite laser welding process and device. The copper and stainless steel composite laser welding process comprises the steps that after the end faces of a to-be-welded copper part and a to-be-welded stainless steel part are attached and assembled to form an abutted seam, a red-blue composite welding head forms a red-blue composite laser beam through an infrared laser beam and a blue laser beam; firstly, red and blue composite laser beams are used for carrying out pre-laser welding on one or more positions of an abutted seam path, the pre-laser welding comprises spot welding and / or segmented welding, and then the red and blue composite laser beams are used for carrying out laser welding along the abutted seam path to form a welding seam. During pre-laser welding and laser welding, a light spot formed by an infrared laser beam is controlled to swing, the swing center is located on an abutted seam path, and the center of a blue light spot of a blue light laser beam is controlled to deviate to one side, outside the abutted seam path, of the copper part; filling materials such as welding wires and welding rods are not needed, the welding efficiency and quality of copper pieces and stainless steel pieces with the thickness smaller than or equal to 3 mm can be effectively improved, the production cost is remarkably reduced, and a technical path is provided for large-scale mass production of copper and stainless steel vapor chambers and the like.

The invention relates to a double-beam laser nitriding device and method for alloy steel. The double-beam laser nitriding device comprises an integration box, an optical system and an airflow auxiliary system. A movable platform is mounted in the integration box, a heating disc is mounted on the movable platform, and a to-be-nitrided alloy steel substrate is placed on a heater; the optical system comprises a far-infrared laser, a near-infrared laser and a galvanometer, a far-infrared laser beam enters the integration box and is parallel to the surface of the alloy steel substrate to be nitrided, ammonia gas is induced to be subjected to photochemical dissociation to generate nitrogen atoms, and the near-infrared laser beam enters the integration box through the galvanometer and irradiates the surface of the alloy steel substrate to be nitrided, so that the surface temperature of the alloy steel is increased; the ammonia gas is assisted to generate nitrogen atoms on the surface of the alloy steel through photo-thermal dissociation, and the surface nitridation efficiency of the alloy steel substrate is improved through the combined action of the two lasers; the airflow auxiliary system comprises an air pump and a vacuum pump. According to the double-beam laser nitriding method adopted by the invention, the gas nitriding speed of the alloy steel can be greatly increased at a lower environment temperature, and the nitriding efficiency is improved while the nitriding quality is controlled.

To provide a mobile body control system capable of stably performing position estimation of a mobile body.SOLUTION: A processing device of a drone 2 references moving route area position coordinate information, and the drone 2 moves within a moving route area 51 corresponding to the moving route area position coordinate information. Shortly after the drone 2 departs, a distance between the drone 2 and a first fixed base station 31 is calculated on the basis of LPWA radio waves from the first fixed base station 31, and a direction from the drone 2 to the first fixed base station 31 is identified on the basis of an infrared laser beam from the first fixed base station 31. On the basis of the distance, the direction, and position coordinate information of the first fixed base station 31, current position coordinate information of the drone 2 is estimated. The current position coordinate information is compared with the moving route area position coordinate information. If they are determined not to match, control is performed to move the drone 2 from a first current location 55 toward a destination 53 while approaching the moving route area 51.SELECTED DRAWING: Figure 2

An apparatus for separating a coated substrate (120), the apparatus being configured to: Directing an infrared laser beam (212) onto a first surface (123) of the coated substrate (120), wherein: the coated substrate (120) comprises a coating layer (121) disposed on a transparent workpiece (122); a plurality of defects (172) are arranged within the coated substrate (120), which extend into both the coating layer (121) and the transparent workpiece (120) and are arranged along a contour line (142) separating a primary region (124) of the coated substrate (120) from a blind region (126) of the coated substrate (120); and the infrared laser beam (212) projects an infrared beam spot (214) onto the first surface (123) of the coated substrate (120); and Moving at least one of the coated substrate (120) and the infrared laser beam (212) relative to each other so that the infrared beam spot (214) follows an oscillating path (150), wherein: the oscillating path (150) follows an offset line (144) in a translation direction (101) and oscillates between an inner track line (146) and an outer track line (148); the oscillating path (150) is arranged on the blind area (126) of the coated substrate (120); and the infrared laser beam (212) applies thermal energy to the plurality of defects (172) arranged in the coated substrate (120) and induces separation of the coated substrate (120) along the contour line (142).

The invention provides a laser printing method for copper alloy powder. The laser printing method comprises the steps that (a) a copper alloy powder layer with the thickness ranging from 0.05 mm to 0.07 mm is laid on a base plate in a forming cavity or a previous solidification layer; (b) under the protection atmosphere of inert gas, according to preset three-dimensional model slice data, infrared laser beams are controlled to selectively scan and irradiate the copper alloy powder layer according to a preset scanning strategy, the power of the infrared laser is 500-800 W, the scanning speed is 600-900 mm / s, and the scanning interval is selected from 0.07-0.10 mm; (c) completely melting and solidifying the copper alloy powder in the scanned area to form a cladding layer; (d) repeating the steps (a) to (c), and printing layer by layer until the three-dimensional component is completed; wherein in the step (b), the infrared laser power is 500 to 600 W, and the scanning interval is 0.08 to 0.10 mm; or the power of the infrared laser is 700 to 800 W, and the scanning distance is 0.07 to 0.09 mm. In addition, the invention further provides a three-dimensional component and a heat treatment method thereof.

The invention discloses an unmanned aerial vehicle landing guiding device, and relates to the field of unmanned aerial vehicles. Comprising a laser transmitter; the beam expanding system is at least partially arranged above the transmitting end of the laser transmitter; the light splitting system is arranged above the beam expanding system and comprises a plurality of light splitting units which are uniformly arranged along the circumferential direction; the emission window assembly comprises a plurality of first scattering mirrors which at least partially correspond to the light splitting unit and allow laser to pass through. According to the invention, the field of view of the infrared laser beams is spliced, and the signal dead angle is small; a reflective system is used as a collimated beam expansion system, the structure is simple, and the weight is light.

This utility model provides a rapid installation and positioning device for elevator guide rails, relating to the field of elevator guide rail installation technology. It includes a workbench, several laser emitting modules, a laser receiving module, and an infrared transmitter. The laser emitting modules are installed around the bottom of the elevator shaft and positioned close to the elevator guide rail installation location. Mounting seats are fixedly installed on both sides of the workbench's upper surface near the elevator guide rail. The spacing is adjusted by moving two sliders within a horizontal frame at the top, and the sliders are moved by rollers until they abut against the inner wall of the elevator shaft, thus fixing the workbench inside the shaft and preventing it from shaking. The laser emitting and receiving modules are used in combination to quickly adjust the position of the infrared transmitter. The infrared laser beam generated by the transmitter is positioned to fit against the surface of the elevator guide rail, facilitating rapid positioning during installation.

Device and method for detecting scattered light, in particular for determining the position of a pupil (4) of an eye (2), especially for data glasses, comprising: scanning a deflecting device (104) with a laser beam (106) emitted in a variable direction of emission (108), in particular an infrared laser beam, a laser beam source (102) in at least one dimension, in particular in two dimensions;Deflecting the laser beam (106) by means of the deflecting device (104), wherein the laser beam (106) is deflected depending on the emission direction (108) and / or depending on at least one wavelength of the laser beam (106) such that the eye (2) is illuminated from a virtual first point (110) or a virtual second point (112), wherein the virtual first point (110) has a first focal length (f1) and the virtual second point (112) has a second focal length (f2), wherein the first focal length (f1) and the second focal length (f2) are different relative to the eye (2); detecting scattered light (120) of the eye (2) of the deflected laser beam (106) by means of a detection device (118), in particular a photodiode.