265 results about "Divergence angle" patented technology

The invention relates to the technical field of optical communication equipment testing, in particular to an integrated optical module multi-parameter testing system and method.The method comprises the steps that a multi-channel parallel testing unit synchronously collects light spot morphology, divergence angles, insertion loss and return loss space and transmission characteristic parameters through a transmission light path and a reflection light path; the parameter collaborative analysis module performs nonlinear correlation analysis and dynamic performance threshold evaluation based on a cross-dimension correlation model; the intelligent calibration engine dynamically adjusts the test benchmark and compensation parameters according to the environment temperature and the equipment aging attenuation model; the fault diagnosis and prediction unit identifies potential defect types of the collimator, constructs a performance degradation prediction model in combination with a working state and environmental stress, and predicts a performance evolution trend according to test data; and the test report generation module automatically generates a standardized and customized dual-mode test report, a quality grade label and a performance optimization suggestion according to the prediction result and the diagnosis conclusion. Therefore, the problems of poor test precision, low test efficiency and the like in the prior art are solved.

The invention discloses a non-contact measurement system and method for the longitudinal distance between objects, and the method comprises the steps: measuring the position distance between an object and an adjacent object in a size-limited space: placing a light source on the surface of a workpiece, projecting an electromagnetic beam with a set divergence angle to a reference object, and forming an amplified light spot; image information, especially light intensity information, of the light spot and a part of reference object where the light spot is located at the projection position is received through a light receiver; and then the processor processes the image information to obtain geometric data of the light spots, including the positions of the light spots on the reference object, the lengths of the obtained light spots or the distances between different light spots, namely the projection lengths, the projection height from the light source to the reference object is calculated in combination with the divergence angle, and the longitudinal distance between the workpiece and the reference object is obtained in combination with the height of the light source. As long as the size of the light source is small enough and the light source can be placed into the chamber for processing the wafer, the longitudinal distance between the wafer and the top of the chamber can be accurately measured at any time, and the measurement accuracy related to wafer manufacturing is greatly guaranteed.

The invention relates to the technical field of projection modules, and particularly discloses an LCOS laser projection module, which comprises a laser light source module, a laser speckle eliminator, a reflector, a diffuser, a collimating lens, a fly-eye lens, a relay lens, a first linear polarizer, a polarizing beam splitter, an LCOS chip, a second linear polarizer and a projection lens which are sequentially arranged along a light transmission path, the laser light source module is provided with a light source optical axis and is used for emitting light, and the light is projected by the projection lens after being modulated along a light transmission path to form a projection image. The light emitted by the laser light source has the advantages of narrow divergence angle, small light-emitting area and good light concentration and collimation, the resolution of a projected image can be improved, the projected image is bright in color and high in definition, and the requirements of simple structure and small size are met. Meanwhile, the laser speckle can be eliminated through the matching of the laser speckle eliminator and the diffusion sheet, and the projection image can meet the high contrast through the existence of the first linear polarizer and the second linear polarizer.

The invention discloses a light spot beam divergence angle calculation method and device based on adaptive threshold correction and a medium, and relates to the technical field of laser communication. The method comprises the following steps: continuously acquiring a debugging light spot picture output by image acquisition equipment, and calculating the maximum gray value of the debugging light spot picture; based on the maximum gray value, the exposure of the image acquisition equipment is adjusted until an initial light spot picture with the maximum gray value and the number of pixels reaching a preset threshold value is output; based on a preset initial pixel threshold value, calculating a pixel value variance of the initial light spot picture, and updating the initial pixel threshold value until a target pixel threshold value enabling the pixel value variance to reach a maximum value is obtained; setting a pixel value lower than a target pixel threshold value in the initial light spot picture to zero to obtain a target light spot picture; and calculating a first moment and a second moment of the target light spot picture to obtain a light spot beam divergence angle of the target light spot picture. According to the method, the calculation precision of the beam divergence angle of the light spot is improved by adjusting a threshold selection mechanism for maximizing the exposure degree and the variance.

The invention discloses an underwater optical communication routing method based on a three-dimensional dynamic conical sector, belongs to the technical field of underwater wireless communication, and is used for solving the problems of poor routing stability, low communication success rate, high energy consumption, non-adaptive path and the like in the existing underwater optical communication network. The method comprises the following steps: constructing an underwater optical communication network model in a three-dimensional space, and defining a dynamic cone communication sector based on a divergence angle and a direction angle between nodes; discovering neighbor nodes through a conical scanning mechanism, and performing multi-index optimization on candidate forwarding nodes based on distance progress, expected progress, energy efficiency indexes and time delay indexes; selecting an optimal path according to an evaluation result; performing competition coordination among candidate nodes by using a fast time slot response mechanism, and selecting a next hop node; and completing path construction through hop-by-hop transmission, dynamically adjusting a divergence angle, and executing path maintenance and updating. The method does not need global topological information, and is suitable for an underwater communication scene with uncertain node distribution in a dynamic environment.

The invention relates to the technical field of lasers, and discloses a parameter design method of an optical system, the optical system, a device and electronic equipment, the optical system comprises a laser, an optical fiber and a collimating lens, the optical fiber is a rectangular optical fiber with a rectangular core layer or a barrel-shaped optical fiber with a barrel-shaped core layer, and the method comprises the following steps: according to the size and imaging distance of a first light spot, determining the size of the first light spot; determining the residual divergence angle of the laser after passing through the collimating lens; determining the focal length of the collimating lens according to the residual divergence angle and the side length of the core layer; according to the ratio of the focal length to the side length of a core layer, whether the optical fiber is determined to be a barrel-shaped optical fiber is determined, and the core layer of the barrel-shaped optical fiber is composed of a plurality of arcs; and under the condition that the optical fiber is a barrel-shaped optical fiber, determining the curvature radius corresponding to each arc in the plurality of arcs according to the focal length and the side length of the core layer. According to the invention, distortionless rectangular homogenized light spots can be obtained under a large divergence angle.

The invention discloses a three-dimensional asymmetric photonic crystal laser and a preparation method thereof. An epitaxial structure of the three-dimensional asymmetric photonic crystal laser comprises an N-type electrode, an N-type InP substrate, an N-type Al < x > < 1 > In < 1-x > < 1 > As upper limiting layer, a quantum well active region, a P-type Al < y > < 1 > In < 1-y > < 1 > As electron barrier layer, a P-type Ga < z > < 1 > In < 1-z > < 1 > Asz < 2 > P < 1-z > 2 functional layer, a P-type Al < x > < 2 > In < 1-x > < 2 > As lower limiting layer, a P-type InP connecting layer, a bottom insulating layer and a P-type electrode, wherein a three-dimensional asymmetric photonic crystal is etched on the P-type GaInAsP functional layer, and a chiral characteristic is introduced by destroying the symmetry of the photonic crystal, so that the P-type GaInAsP functional layer vertically emits a single-mode light beam with left-handed or right-handed circular polarization. By designing an asymmetric photonic crystal structure, efficient output of circularly polarized light beams is achieved, polarization selectivity and light beam quality are remarkably improved, and the advantages of low divergence angle and high light beam stability are achieved.

The light transmission structure comprises a light transmission piece and a plurality of light source sets, the wavelengths of light emitted by the light source sets are different, the light transmission piece is provided with a plurality of independent light inlet channels, each light inlet channel is provided with a light inlet and a light outlet, the light inlets correspond to the light source sets in a one-to-one mode, and the light source sets are arranged on the light inlet channels in a one-to-one mode. The light outlets correspond to the light inlet side of a prism of the refractometer, and the light inlet channels are arranged at intervals and are crossed with one another, so that divergence angles of light beams emitted by the light outlets are adjusted, the light beams are ensured not to be overlapped after being imaged, namely a bright-dark interface is relatively clear during imaging, the measurement accuracy of the refractive index of liquid is ensured, and the measurement accuracy of the refractive index of the liquid is improved. And the calculation deviation of the liquid concentration is ensured to be within a reasonable range.

The invention provides a laser communication device for rapid link establishment and networking and a satellite internet constellation. The device utilizes the wavelength division multiplexing unit and the pre-aiming unit to realize beam combination of receiving and transmitting optical path signals so as to improve the coaxiality of receiving and transmitting branches; an optical fiber displacement device arranged on the transmitting-receiving lens is used for adjusting the relative position of the beam combining optical fiber and the focal point of the transmitting-receiving lens, and continuous beam changing of a transmitted light path signal within the divergence angle range of 55-1000 microrad is achieved; and a position sensing unit is matched to focus a receiving light path signal, so that a 0.2-1-degree receiving light path continuous field of view is realized. Through 10000 times of offset error estimation simulation, the coverage rate of an uncertain area to a target light spot reaches 99.32%, and about 1mrad beam change can be realized, so that minute-level capture efficiency is realized under the condition of the continuous field of view.

The utility model provides a small-divergence-angle anti-reflection laser. The small-divergence-angle anti-reflection laser comprises a substrate; the active region is formed on the substrate; the etching region is positioned on the light emitting end surface of the active region and comprises a divergence angle improving layer; the cladding extends along the light emitting direction of the active region; the metal contact layer covers the cladding layer above the active region; the isolation layer covers the cladding layer above the etching region; and an N-metal layer and a P-metal layer, the N-metal layer covers the back surface of the substrate, and the P-metal layer covers the metal contact layer and the isolation layer. Through the arrangement of the isolation layer, current injection into the end face can be limited, the light emitting power density of the end face can be reduced, the non-radiative recombination process can be inhibited, the temperature of the end face is reduced in the area, optical catastrophe damage can be reduced, and the service life of the laser can be prolonged.

The invention discloses a device and method for tracking the angle of a long-distance target object, and the device comprises a laser transmitting and receiving end and a target object, and the laser transmitting and receiving end is disposed on a precise adjustment mechanism. The precise adjusting mechanism is used for bearing the laser transmitting and receiving end and adjusting a laser incident angle to realize continuous tracking of a target; the laser transmitting and receiving end comprises a transmitting module and a receiving module; the transmitting module is used for transmitting a beam of wide-spectrum detection laser with a small divergence angle to a long-distance target object; the transmitting module comprises a wide-spectrum laser and a light beam expanding system, the wide-spectrum laser is electrically connected with the high-stability temperature control and current driving system, and the receiving module comprises an optical receiving module and a data processing and control module. The initial wavelength lambda is taken as the reference in each measurement, no accumulative error exists, and the method is very suitable for long-term and continuous monitoring tasks.

The application provides a gallium nitride-based semiconductor laser with a divergence angle modulation layer, which comprises, from bottom to top, a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, an upper limiting layer and a contact layer, wherein the lower limiting layer comprises, from bottom to top, a first lower limiting layer, a second lower limiting layer and a third lower limiting layer, a first divergence angle modulation layer is arranged between the substrate and the first lower limiting layer, and a second divergence angle modulation layer is arranged between the second lower limiting layer and the third lower limiting layer. The normalized Al atomic concentration curves of the SIMS tests of the first divergence angle modulation layer and the second divergence angle modulation layer both satisfy Lorentz function distribution, so that a carrier transverse expansion region is formed in the first divergence angle modulation layer and the second divergence angle modulation layer, the transverse expansion and mobility of carriers are enhanced, the active layer recombination width in the horizontal divergence angle direction of the laser is increased, and the horizontal divergence angle is enlarged.

The invention relates to a rapid scanning type laser active detection system based on laser angle on-line control, and the system comprises an adjustable beam expanding optical unit which can continuously adjust the beam expanding multiplying power on line through position closed-loop control; the scanning detection execution unit can perform large-range search and can compensate image motion caused by carrier motion and continuous scanning, and a variable-speed spiral scanning mode with high probability of finding a target is adopted as a scanning mode; the off-axis beam expanding unit is used for further compressing a laser divergence angle; the photoelectric imaging system can splice scanned images on line, so that the scanning process is clearer and more visual; and the time sequence control unit assists in image motion compensation control. The scanning process can be rapidly completed, imaging is clear in the scanning process, and the scanning result can be directly presented.

The invention relates to a semiconductor laser with a light field expansion layer and a preparation method thereof, and the semiconductor laser sequentially comprises a substrate, a buffer layer, an N-type limiting layer, an N-type waveguide layer, an active layer, a P-type waveguide layer, a P-type limiting layer, and an ohmic contact layer along the epitaxial growth direction. Wherein an N-type light field expansion layer with gradually-changed components is inserted between an N-type limiting layer and an N-type waveguide layer, and a P-type light field expansion layer with gradually-changed components is inserted between a P-type waveguide layer and a P-type limiting layer, so that the distribution of a light field in a device is regulated and controlled, and the light field distribution range in the laser is enlarged; therefore, the semiconductor laser can obtain a lower fast-axis far-field divergence angle on the basis of using a thinner waveguide layer.

The invention provides a distributed photonic crystal semiconductor laser and a design method thereof, and is applied to the field of semiconductor lasers. The semiconductor laser comprises a substrate, an N-type limiting layer, a distributed photonic crystal layer, an N-type waveguide layer, an active layer, a P-type waveguide layer and a P-type limiting layer which are sequentially stacked from bottom to top, wherein the distributed photonic crystal layer comprises high-refractive-index layers and low-refractive-index layers which are alternately stacked, the thickness distribution of the photonic crystal layer is completely non-periodic, and the thickness of each refractive-index layer can be any value and does not follow a fixed period or uniform thickness constraint any more. Through the structure and the design method thereof, the far-field energy divergence angle of the semiconductor laser can be effectively reduced.

The application provides a system for adjusting a light beam, which can be applied to an optical system with high requirements for a reflected wave front. The system comprises a mirror, a surface shape detection device, a calculation and analysis device, and a compensation light generating device. The mirror is used to receive incident light from a first light source and emit reflected light. The surface shape detection device is used to obtain information about an initial surface shape of the mirror after the incident light is incident. The calculation and analysis device is used to generate first indication information according to the information about the initial surface shape, the first indication information indicating that the compensation light generating device emits first compensation light to the mirror. The compensation light generating device is used to emit the first compensation light to the mirror according to the first indication information, the first compensation light being used to change the initial surface shape of the mirror into a first surface shape. The system of the application not only can maintain the wave front of the reflected light, but also can improve the accuracy of regulating and controlling the direction and divergence angle of the reflected light.

An optical interconnect system comprising: at least one light source for emitting light, the light comprising a distribution pattern having a predefined divergence angle; at least one communication medium for transmitting the light, wherein the at least one communication medium comprises a numerical aperture, and wherein at least one of the numerical aperture, the at least one light source, the predefined divergence angle, and the at least one communication medium, is dimensioned to minimize loss of optical power coupling of the light into the at least one communication medium; at least one light detector for receiving the light from the at least one communication medium; at least one optomechanical alignment system configured to optimize collection of the light at the least one light detector.

This invention discloses a high signal-to-noise ratio modulation transfer frequency stabilization optical path device, including a light source and a frequency stabilization optical path. The light source adopts an internally adjustable fiber collimator, with a 45° reflector behind it. The frequency stabilization optical path behind the 45° reflector includes a half-wave plate and a polarizing beam splitter (PBS). An atomic gas cell and two pyramidal reflectors are sequentially arranged on the probe light path of the PBS. A half-wave plate, a 45° reflector, an electro-optic modulator, another 45° reflector, and a half-wave plate are sequentially arranged on the pump light path. The polarizing beam splitter (PBS) is located at the convergence point of the two optical paths, and a 45° reflector, a frequency stabilization optical path lens, and a photodetector are sequentially arranged behind it. This invention cleverly utilizes a folded optical path design and fine-tunes the beam divergence angle to increase the length and area of ​​the laser-atomic interaction without increasing the system volume. At the same time, it actively controls the splitting ratio of the two frequency-stabilized beams, improving the stability of the frequency stabilization.

The embodiment of the invention discloses a display system, and the system comprises an optical fiber scanning array which comprises a plurality of optical fiber scanning units, the optical fiber scanning units are densely arranged in the transverse direction of the optical fiber scanning array, the number of the optical fiber scanning units arranged in the transverse direction is far greater than the number of the optical fiber scanning units arranged in the longitudinal direction, and the number of the optical fiber scanning units arranged in the longitudinal direction is greater than the number of the optical fiber scanning units arranged in the longitudinal direction. The included angle between the adjacent optical fiber scanning units in the transverse direction and the display center is related to the divergence angle of the emitted light. The directional scattering screen is configured to perform directional scattering in the longitudinal direction; light emitted by the optical fiber scanning array forms a display space range for imaging on the other side of the directional scattering screen through the directional scattering effect of the directional scattering screen.

The application discloses a laser and target debugging device with self-reference light and a debugging method thereof. The application comprises a seed source, a stretcher, a first amplifier, a first pump source, a menu system, a second amplifier, a second pump source, a compressor, a reference light loop, a reference light switch and a three-phase switch. The application does not need to place reference light externally, is more economical, and has the same quality of the main laser beam, including the same spot size, divergence angle and wavelength, which can accurately replace the original laser for subsequent target system debugging, and the debugging result is equivalent to that of the main laser. The addition of the reference light switch increases the use safety and avoids accidents caused by misoperation. The mKHz laser has high frequency, is beneficial to the observation of the human eye, and is very convenient for subsequent adjustment as the self-reference light.

Disclosed in the present invention is an optical system, consisting of an image surface, a fourth lens, a third lens, a second lens, and a first lens, which are sequentially arranged from a front side to a rear side. A polarizing reflective film is provided between the first lens and the second lens, a quarter-wave plate is provided between the second lens and the third lens, and the first lens, the second lens and the third lens are sequentially cemented to form a composite lens. In the optical system of the present invention, by rationally setting the radius of curvature of a lens on the side close to a screen, it is possible to better match the divergence angle of light emitted from the image surface, thereby improving energy utilization and the uniformity of display brightness in the optical system. In addition, by rationally designing the focal lengths of the composite lens and the fourth lens, the field of view angle of the optical system can be increased, and by rationally allocating the axial thickness of each lens, the thickness of the optical system can be reduced, resulting in a compact structure and achieving a lightweight and thin design for the optical system, thus effectively reducing the sensitivity and improving the imaging performance of the optical system.

The invention belongs to the technical field of measurement, and relates to a real-time in-situ measurement system and method for a far-field divergence angle of a laser. The system comprises a laser emitting unit, a detection imaging unit, a detection control unit, a data processing unit and a light beam monitoring unit. According to the system and the method provided by the invention, the short-wave infrared camera integrated with a range gating function is adopted, so that the range information and spatial distribution of laser spots can be acquired in real time and the divergence angle of laser can be solved in real time under the condition that a cooperative target or a complex laboratory device is not needed. The method is especially suitable for laser performance monitoring and evaluation under external field, mobile platform and dynamic change conditions.

An example distance sensor includes a light projection system for projecting a pattern of points of light onto an object. The light projection system includes a laser light source for projecting coherent light and a diffractive optical element having a plurality of layers etched to form a binary step pattern, where the plurality of layers are configured to split the coherent light into a plurality of light beams, where each light beam forms one point of the pattern, and where the plurality of layers are further configured to control a divergence angle of the light beams. The example distance sensor also includes a light receiving system for capturing an image of the pattern projected onto the object, and a processor for calculating a distance to the object based on an appearance of the pattern in the image and knowledge of a trajectory of the light points.

The invention discloses a high-precision full-polarization angle resolution microscopic system excitation device. The device comprises an excitation light source module, a collimation light source optimization module, an imaging module, a switchable reflector, a spectrometer path and a detector path. The excitation light source module is used for exciting full polarized light; the collimation light source optimization module inhibits the divergence angle of the laser through the converging lens group and transmits the laser to the imaging module; the imaging module irradiates the parallel light beams subjected to divergence angle suppression to the surface of a sample to be detected through a microscope objective, so that angle resolution excitation is realized; and the switchable reflector is used for selecting a path of a signal generated by the to-be-tested sample returned from the beam splitter. The converging lens group is additionally arranged on the periphery of the thin film beam splitter, the focal length of the lens group is accurately calculated and optimized, and the divergence angle of exciting light is inhibited. Through experimental data calculation, after passing through the light path designed by the invention, the drop amplitude of the divergence angle exceeds 75%, and the light path can be cascaded and is compatible with a traditional angle resolution scheme.

The invention discloses a laser output optical device, a laser, equipment and a method. The laser output optical device comprises an output optical fiber, an optical waveguide and an optical output head which are connected in sequence, the output optical fiber is used for outputting point ring light beams, a cladding layer, wrapping the second fiber core, of at least partial area, close to the output optical fiber, of the optical waveguide comprises a second conical structure, and the cross section of the second conical structure is annular. The outer diameter of the second conical structure is gradually increased in the light beam transmission direction, and the second conical structure is used for adjusting the light path of the point ring light beam so as to adjust the divergence angle of inner and outer ring light beams. And the optical output head is used for outputting the light beam adjusted by the optical waveguide. The pre-modulated light from the output optical fiber is accurately regulated and controlled, the divergence angle of the output light is adjusted, the light beam quality is improved, and meanwhile the device has the advantages of being simple in structure, low in cost and high in stability.

The application discloses a kind of self-adapting threshold correction spot beam divergence angle calculation method, equipment and medium, it is related to laser communication technical field.The method includes: continuously obtaining the debugging spot picture of image acquisition equipment output, and the maximum gray value of debugging spot picture is calculated;Maximum gray value is based, and the exposure of image acquisition equipment is adjusted, until the initial spot picture of maximum gray value and pixel number reaches preset threshold value is output;Based on preset initial pixel threshold value, the pixel value variance of initial spot picture is calculated, and initial pixel threshold value is updated, until the target pixel threshold value that makes pixel value variance reach maximum value is obtained;Zero is placed in the pixel value lower than target pixel threshold value in initial spot picture, to obtain target spot picture;The first moment and second moment of target spot picture are calculated, to obtain the spot beam divergence angle of target spot picture.The application is by adjusting exposure and variance maximization threshold selection mechanism, to improve the calculation precision of spot beam divergence angle.

The invention relates to the technical field of laser communication, particularly provides a laser communication terminal with a variable beam divergence angle, and aims to solve the problems of low link establishment efficiency, high cost and poor adaptability caused by dependence on beacon light or a small beam divergence angle of an existing laser communication terminal. The terminal comprises an optical antenna, a fine tracking fast reflecting mirror, a divergence angle adjusting assembly, a signal light emitting assembly, a receiving aiming link and the like. The signal light emitting assembly outputs different mode field signal light, after the signal light is shaped by the collimating lens group, the beam divergence angle is continuously adjusted by the divergence angle adjusting assembly, and then the signal light is emitted to the outside through a preset light path. And the receiving aiming link realizes signal receiving and light spot positioning feedback through light splitting and branching, and is matched with a fine tracking fast reflecting mirror to correct deviation and a solar optical filter to improve the strong light adaptability. Beacon light is not needed, the beam divergence angle can be flexibly switched to complete coarse and fine alignment, the structure is simplified, the power consumption cost is reduced, the link building efficiency, the aiming precision and the environmental adaptability are greatly improved, and the method is suitable for multi-scene laser communication of satellites, emergencies and the like.

The invention discloses a high-power low-divergence-angle near-infrared semiconductor laser, belongs to the technical field of semiconductor lasers, and particularly relates to a high-power low-divergence-angle near-infrared band semiconductor laser. The problems that in the prior art, a low divergence angle and high light beam quality cannot be obtained at the same time under high-power output, and optical catastrophe damage (COD) and reliability reduction are caused by cavity surface heat accumulation are solved. The laser comprises a laser gain area, a conical waveguide area, a segmented waveguide area and a V-shaped groove structure optical fiber coupling area which are sequentially integrated in a monolithic mode in the laser propagation direction. The high-power low-divergence-angle near-infrared semiconductor laser is suitable for application scenes with high requirements on output power, light beam quality and system integration level, such as the fields of fiber laser pumping sources, laser processing, laser radars, space optical communication and the like.

The utility model discloses a semiconductor laser device which comprises a pump light module and a shaping assembly. The pump light module is used for outputting a collimated light beam; the shaping assembly is arranged on an output light path of the collimated light beam and comprises a deformation prism and a focus lens which are arranged in sequence. The deformation prism is used for correcting the collimated light beam, so that the sizes of light spots of the collimated light beam in the slow axis direction and the fast axis direction are consistent; and the focusing lens is used for focusing the collimated light beam corrected by the deformation prism and reducing a light beam divergence angle. According to the semiconductor laser device, shaping of the collimated light beam in the fast axis direction or the slow axis direction is achieved by arranging the deformation prism in the light path, the production cost is reduced, and the overall integration degree of the device is improved.

An imaging-based non-contact gloss measurement device, includes: a housing having a top cover provided with a measurement window, a measurement zone being located above the measurement window; an illumination light source mounted inside the housing and on one side of the measurement window and configured to illuminate the measurement zone at an incident angle θ1; and a grayscale camera mounted inside the housing and on the other side of the measurement window and configured to receive light reflected from the measurement zone at a reflection angle θ2 for grayscale imaging, and obtaining gloss values from the grayscale values. The illumination light source has an incident divergence angleα1′in the measurement plane and an incident divergence angleβ1′perpendicular to the measurement plane; the grayscale camera has a reflection divergence angleα2′in the measurement plane and a reflection divergence angleβ2′perpendicular to the measurement plane, θ1=θ2,a1′>α2′⁢ and⁢ β1′>β2′.