74 results about "Reference mirror" patented technology

The invention discloses a coherent interference-based coaxial transceiving line scanning three-dimensional profile measurement system and method. The system comprises a low-coherence light source; the beam splitter is used for collimating light emitted by the low-coherence light source and then dividing the light into two paths; the measuring light is focused into a linear light beam through the cylindrical lens and is emitted to the surface of the to-be-measured sample, and the measuring light reflected by the surface of the to-be-measured sample returns to the beam splitter along the original path; the reference light is emitted to a reference mirror with a certain inclination angle and is reflected back to the beam splitter through the reference mirror; the measuring light reflected by the surface of the sample to be measured and the reference light reflected by the reference mirror are subjected to beam combination interference through a beam splitter and are imaged to enter a camera for interference pattern acquisition; the signal processing system is used for processing the interference patterns to obtain height distribution of the to-be-measured sample on a line field, and three-dimensional profile measurement of the to-be-measured sample is realized by transversely moving or transversely scanning the to-be-measured sample and overlapping the interference patterns measured at different positions. Therefore, high-efficiency measurement can be realized while the micro-nano precision is kept.

In order to solve the technical problems that a conventional reflector antenna electrical axis direction calibration method is relatively complex and the error is relatively large when the conventional reflector antenna electrical axis direction calibration method is applied to a reflector antenna of which a mechanical axis is not easy to determine, the invention provides a reflector antenna electrical axis direction calibration method. A reference point tool coordinate system measured by a laser tracker and a reference point tool coordinate system tested by a photogrammetry camera are used as transfer, an incidence relation between an antenna coordinate system and a plane scanning frame coordinate system is established, and finally, the plane scanning frame coordinate system is obtained by combining the measured electric axis direction under the plane scanning frame coordinate system. And the electric axis direction under the antenna coordinate system can be obtained. The mechanical axis of the antenna does not need to be tested, a reference mirror is not needed, only one laser tracker and one photogrammetry camera are needed for testing, the testing method is simpler, the testing efficiency is higher, for the antenna of which the mechanical axis is not easy to determine, errors caused by fitting of the mechanical axis are avoided, and the testing precision is improved. The electric axis obtained by the method is more accurate in pointing.

This invention relates to an interferometric measurement method and apparatus for large warp wafers, belonging to the field of optical detection and semiconductor measurement technology. The detection light is polarized and birefringently split to form P-beams and S-beams, which are then further divided into P-reference beams, S-silicon beams, S-reference beams, and P-silicon beams, respectively. By adjusting the spatial orientation of the reference mirror and the wafer under test, and using an aperture for spatial filtering, the P-reference beam and S-silicon beam are allowed to enter the subsequent optical path, while the S-reference beam and P-silicon beam are blocked. The S-silicon beam forms a measurement wavefront carrying information about the surface shape of the wafer under test. The P-reference beam is modulated by a deformable mirror to form a modulated reference wavefront similar to the measurement wavefront. The two form a resolvable interference fringe pattern at the camera. A wavefront sensor measures the surface shape information of the deformable mirror, and a calculation system obtains the surface shape information of the wafer under test based on the deformable mirror surface shape information and the relative surface shape change. This invention can reduce the interference fringe density in the detection of large warp wafers, reduce splicing measurement errors, and improve detection efficiency and accuracy.

The invention discloses a device and a method for synchronously detecting the focal length and the surface topography of a micro-lens array, which can realize synchronous detection on the focal length and the surface topography of the micro-lens array through a set of system, realize mutual matching between two parts of results and greatly shorten the detection time. The device comprises a first monochromatic laser light source (1), a first collimating lens (2), an attenuation sheet (3), a reflector (4), a microlens array sample (5), a microscope objective (6), a barrel lens (7), a first quarter-wave plate (8), an area array detector (9), a first monochromatic optical filter (10), a second monochromatic laser light source (11), a second collimating lens (12), a linear polarizer (13), a beam splitter prism (14), a polarization beam splitter prism (15), a second quarter-wave plate (16) and a reference lens (17). A third quarter-wave plate (18), a second monochromatic optical filter (19) and a polarization camera (20).

The application discloses a multi-axis laser interferometer optical axis space position positioning system and a positioning method, which comprises XYZ three-axis laser interferometer optical axis perpendicular adjustment and XYZ three-axis laser interferometer optical axis space intersection adjustment; wherein the optical axis perpendicular adjustment is to move a turntable independent measurement frame into a space coordinate system vertical reference mirror, to adjust the Z, Y and X axis laser interferometers of the turntable independent measurement frame in sequence according to displacement information and energy signals displayed on a display terminal until the displacement information is the minimum and the energy signal is the maximum; and the optical axis space intersection adjustment is to move a standard reference sphere above the turntable independent measurement frame, to adjust the Z, Y and X axis laser interferometers of the turntable independent measurement frame in sequence until the displacement information is the minimum and the energy information is the maximum. The application is simple in operation, fast in laser interferometer space position adjustment, and can realize high-precision positioning of multi-axis laser interferometer optical axes in space positions.

Provided are an optical inspection device capable of accurately obtaining the film thickness of a film covering a sample even when there is a difference in spatial intensity distribution between irradiation light to the sample and irradiation light to a reference mirror, and a control method therefor. The optical inspection device includes: a light source that emits light; a beam splitter that splits the light emitted from the light source into first irradiation light directed toward a sample and second irradiation light directed toward a reference mirror; an interference light measurement unit that measures interference light due to object light which is reflected light of the first irradiation light from the sample and reference light which is reflected light of the second irradiation light from the reference mirror; and a control unit that controls each unit. The optical inspection device is characterized by further including: an object light measurement unit that measures the intensity of only the object light; and a storage unit that stores the intensity of the object light of a reference sample measured in advance by the object light measurement unit. The control unit is characterized by obtaining the film thickness of a film covering an observation sample on the basis of the intensity of the object light of the reference sample and the intensity of the object light of the observation sample measured by the object light measurement unit.

This invention relates to a lightweight, miniaturized 3S configuration triaxial integrated fiber-MEMS inertial measurement unit, belonging to the field of measurement devices. It includes a base cover, a power supply and detection board assembly located on the top of the base cover, a light source assembly located above the power supply and detection board assembly, a MEMS assembly mounted above the light source assembly, a base fixed to the base cover, fiber optic ring assemblies fixed to the base, and a reference mirror fixed to the top of the base. The power supply and detection board assembly, the light source assembly, and the MEMS assembly are all arranged inside the base. The three fiber optic ring assemblies are evenly distributed on a conical surface with an outer half-cone angle of 54.74° and a bottom projection of 120°. The light source assembly shares a light source with the three fiber optic ring assemblies via a 1*3 coupler. This invention eliminates the unnecessary space occupied by the traditional three independent light source configuration, reduces the overall volume, and improves optical path consistency and system stability. It can meet the engineering requirements of commercial satellite platforms for the miniaturization and mass production of inertial measurement components.

The invention discloses an antenna reference mirror coordinate system measurement calibration method and an antenna assembly precision measurement method, and the calibration method comprises the steps: 1, determining the normal direction of the mirror surface of each reference mirror through employing the optical imaging principles of reflection and plane mirrors; step 2, carrying out point position measurement on the three orthogonal surfaces of the reference mirror through a laser tracker to obtain a three-dimensional coordinate of the geometric center of the reference mirror; step 3, determining a third axial direction of the reference mirror coordinate system, establishing the reference mirror coordinate system, and establishing conversion parameters of the reference mirror coordinate system; step 4, establishing an antenna coordinate system on the basis of the measurement coordinate system of the laser tracker; determining conversion parameters of an antenna coordinate system relative to a laser tracker measurement coordinate system; and step 5, obtaining calibration parameters of the reference mirror coordinate system relative to the antenna part assembly mechanical structure coordinate system according to the results of the step 3 and the step 4. According to the invention, the precision and reliability of the measurement process are improved on the basis of improving the calibration efficiency and saving resources.

The invention relates to the technical field of optical detection, and discloses a self-calibration method, system and equipment for a high-precision spliced interferometer, and the method comprises the steps: obtaining a plurality of sub-aperture measurement data obtained by testing a detected mirror through an interferometer in a random stepping mode; performing first-step calibration according to the measurement data of the plurality of sub-apertures to obtain a first reconstructed surface shape of a reference mirror and a first reconstructed full-aperture surface shape of a measured mirror in the interferometer; and performing second-step calibration according to the first reconstructed surface shape and the first reconstructed full-aperture surface shape to obtain a second reconstructed surface shape of the reference mirror and a second reconstructed full-aperture surface shape of the measured mirror. On the premise that extra hardware is not introduced, absolute surface shape reconstruction of the reference mirror and the measured mirror in splicing interference measurement is achieved only through algorithm innovation, high-precision calibration and elimination of second-order out-of-focus item errors in the meridional direction are achieved, namely absolute calibration can be achieved only through data processing, key second-order errors are calibrated, and the accuracy of calibration is improved. And the detection accuracy of the optical element is improved.

The present application relates to the technical field of semiconductor detection, and particularly relates to a metrology device and a control method thereof, the metrology device comprising: a detection module and a shell connected with each other, one end of the detection module facing the shell is a reference mirror, and the reference mirror and the shell enclose a detection cavity; a carrier and an air floating table, the carrier and the air floating table are both arranged in the detection cavity, and the carrier is located between the air floating table and the reference mirror, and the carrier is used for carrying a wafer; when the wafer is measured, the carrier clamps the edge of the wafer to fix the wafer in a detection station, one side surface of the wafer faces the reference mirror, another side surface of the wafer faces the air floating table, and the part of the detection cavity between the wafer and the reference mirror forms an air-tight cavity. The present application is at least beneficial to reduce the measurement error.

An OCT system includes a broadband light source, and a beam splitter that splits the broadband light into a reference beam and an illumination beam. A reference mirror reflects the reference beam. Illumination optics passes the illumination beam and has a reflective surface with an optical power. Collection optics has a transparent region and a reflective surface with an optical power. The collection optics is configured so that the illumination beam is reflected from the reflective surface of the collection optics to the reflective surface of the illumination optics such that the illumination beam is redirected to a surface of a sample at an angle that results in scattering from within the sample that forms a sample beam propagating normal to a surface of the sample and through the transparent region of collection optics and through the transparent region of the illumination optics. An interferometric combiner is configured to interferometrically combine light from the sample beam and the reference beam. A spectrometer is configured to receive the interferometrically combined light from the sample beam and the reference beam and to generate spectral interferometric information. A processor processes the spectral interferometric information to determine information about the sample.

The present application belongs to the technical field of natural gas hydrocarbon dew point measurement, and particularly relates to a natural gas hydrocarbon dew point measurement system and method based on double-region reference interferometric distance measurement. The system and method pre-process the sample to be detected, divide the sample into two paths, pass the measurement gas and the remaining reference gas into the measurement mirror surface and the reference mirror surface of the dew point measurement device respectively, and synchronously collect the interference signals of the reflected light of the two regions. The system and method extract the direct current component through low-pass filtering of the cutoff frequency, calculate the phases of the measurement region and the reference region respectively, introduce a temperature-pressure cross compensation model and a quadratic baseline drift compensation model, calculate the dynamic differential phase, calculate the mean value, standard deviation and change rate of the thickness, and determine whether the hydrocarbon dew point is reached by using a multi-condition judgment threshold. The system and method realize the anti-mirror surface pollution and aging in the actual process of hydrocarbon dew point measurement, accurately determine the condensation dew point, and improve the detection sensitivity and precision.

The invention relates to a system (1) for digital holographic imaging, comprising at least the following components: - a beam splitter (2), - a retroreflector array (3) comprising a plurality of retroreflector elements (30), - a reference mirror (4), wherein the system (1) is configured to superimpose the object light (100) reflected off the reference mirror (4) and off the retroreflector array (3) such that a plurality of interference patterns that can be assigned to the respective retroreflector elements (30) are produced, wherein the system (1) has a phase-adapting optical structural component (5) for predefined phase adaptation of the object light (100), characterized in that the phase-adapting optical structural component has an assigned angle-of-incidence / phase relation (1000) for each of a predefined plurality of incidence directions (e) of the object light (100), wherein the phase-adapting optical structural component (5) is configured to impress phases (Φ) on the object light (100) in accordance with the assigned angle-of-incidence / phase relation (1000) for each of said plurality of incidence directions such that the interference patterns comprise information with which a hologram correspondingly reconstructed from said interference patterns has an improved resolution with respect to a system (1) without the predefined phase adaptation.

The present application relates to the technical field of spacecraft attitude control, and particularly relates to a load attitude determination method and device based on an included angle monitoring star sensor, wherein the method comprises: obtaining angle conversion relationships between a reference mirror coordinate system and a star sensor measurement coordinate system, between a central prism coordinate system and the reference mirror coordinate system, and between the central prism coordinate system and a star sensor monitoring coordinate system in a ground phase; obtaining angle conversion relationships between the central prism coordinate system and the star sensor monitoring coordinate system, and between the star sensor measurement coordinate system and a J2000 coordinate system in an on-orbit phase; and combining a corresponding relationship between the star sensor measurement coordinate system and the star sensor monitoring coordinate system to determine an angle conversion relationship between the central prism coordinate system and the J2000 coordinate system in the on-orbit phase. The present application can obtain high-precision load pointing.

The application discloses a kind of patch mirror translation error correction methods for extended target, belong to optical imaging technical field.The method for realizing of the present application is: for the optical system of the block type primary mirror of having one piece reference mirror and one piece mirror to be adjusted, to any extended target imaging;Establish the relationship between the reciprocal of the power spectral density of image at the secondary peak position of optical transfer function under wideband spectrum illumination and the translation error of mirror to be adjusted, solve the translation error of mirror to be adjusted using the relationship;Adjust the translation of mirror to be adjusted;Repeat the process of calculating the translation error of mirror to be adjusted until the translation of mirror to be adjusted meets the threshold requirement;For the block type primary mirror optical system containing multiple mirrors, adjust the translation of mirror one by one in turn until all mirrors are adjusted, and the translation error correction is complete.The present application has the advantages of large dynamic range, few iteration times and fast convergence speed, and is suitable for on-orbit translation error correction of telescope with block type primary mirror.

An eye-examining apparatus for diagnosing myopia capable of simultaneously measuring the corneal curvature, refractive power, and axial length of the eye to be examined includes a keratometer; a refractometer including an infrared measurement light source, a lens array, and a refractor sensor; an axial length measurement unit including a beam splitter, a reference mirror, and a light detector; and a computation unit configured to calculate the corneal curvature, refractive power, and axial length of the eye to be examined.

The invention discloses a beam expanding type dynamic interferometer for adaptively correcting emergent collimated wavefront and a measuring method. The beam expanding type dynamic interferometer comprises a dynamic interferometer module, a beam expander module and a standard reference mirror, the dynamic interferometer and the Fizeau interference cavity are integrated in the same beam expanding system, switching between a calibration stage and a test stage is achieved by adjusting the pose of the standard reference mirror, wavefront information of the standard reference mirror and a tested piece is collected through the dynamic interferometer, and finally system errors are eliminated through wavefront subtraction operation of an algorithm. And a high-precision detection result can be obtained.

The interference optical module includes: a housing having a first wall portion provided with a mounting structure; a beam splitter that outputs first light and second light by splitting the light, and outputs interference light by combining the first light and the second light; a first objective lens located on a first optical path of the first light; and a reference mirror and a second objective lens located on a second optical path of the second light. The beam splitter, the first objective lens, the reference mirror, and the second objective lens are supported by the first wall section within the housing such that the first optical path and the second optical path extend along a plane that is biased toward the first wall section side with respect to the center of the width of the housing in the thickness direction of the first wall section.

This invention provides an optical phase-shifting interferometry detection device and method, relating to the field of optical detection technology. The optical phase-shifting interferometry detection device includes a phase-shifting interferometry system and a spectral domain interferometry system. A moving platform is used to induce a small random displacement in a reference mirror or sample, introducing a randomly varying phase shift into the reference light and sample light. Simultaneously, the spectral domain interferometry system detects the overall vibration and random phase shift of the reference mirror or sample in the phase-shifting interferometry system. The obtained phase shift is used to calculate the optical path difference on the sample surface, thus obtaining the surface morphology of the sample.

The present application relates to a kind of big warping wafer interference measurement method and device, belong to optical detection and semiconductor measurement technical field.Detection light is converted and diffracted after birefringence, and P light and S light are formed, and P reference light, S silicon light, S reference light and P silicon light are formed respectively;By adjusting the spatial posture of reference mirror and the wafer to be measured, and cooperating with spatial screening of diaphragm, P reference light and S silicon light enter subsequent optical path, while S reference light and P silicon light are blocked;S silicon light forms the measurement wave front carrying the wafer to be measured surface shape information, P reference light is modulated as the modulation reference wave front similar to the measurement wave front by deformable mirror, and the two form analytical interference fringe pattern at camera;Wave front sensor measures deformable mirror surface shape information, and the computing system obtains the surface shape information of the wafer to be measured according to deformable mirror surface shape information and relative surface shape variation amount.The present application can reduce the interference fringe density in the detection of big warping wafer, reduce splicing measurement error, improve detection efficiency and accuracy.

An active focusing method is applied to a panoramic image acquisition device. The active focusing method comprises the following steps: receiving a plurality of sound signals in a space from a microphone array; obtaining at least one sound source orientation according to the plurality of sound signals; obtaining at least one image picture close to the sound source orientation; analyzing and comparing the sound signal and the image frame to select one of the plurality of lens modules as a reference lens module, the corresponding field of view of which covers the main speaker; obtaining an automatic focusing value of the reference lens module to the main speaker; the processor adjusts the plurality of lens modules according to the automatic focusing value, so that the plurality of lens modules have the same focal length; and the processor respectively obtains the adjusted image pictures from the plurality of lens modules and splices the adjusted image pictures into a panoramic image picture.

The application provides a full-field OCT system based on orthogonal double liquid crystal phase compensation, an imaging method, equipment and a medium, and comprises the following steps: a broadband light source module is used to provide broadband illumination light with a low coherence length; a light splitting module is used to make the broadband illumination light enter a reference arm and a sample arm according to a predetermined proportion; the reference arm is sequentially provided with a first liquid crystal phase modulation component, a first wave plate, a first microscope objective and a fixed reference mirror; the sample arm is sequentially provided with a second liquid crystal phase modulation component, a second wave plate, a second microscope objective and a sample to be measured; a detection module is used to receive an interference signal of the reference arm reflected light and the sample arm backscattered light and to perform photoelectric conversion; and a control module is used to apply a differential driving voltage to the first liquid crystal phase modulation component and the second liquid crystal phase modulation component and to synchronously control a face array camera to collect, so as to solve the problems of stability and defocusing caused by mechanical phase shifting in the FFOCT system and low light energy utilization and dispersion mismatch caused by liquid crystal polarization dependence.

This invention provides an optical path adjustment system and method for a focusless optical system with steering capability. The system includes a self-collimating collimator, a horizontal reference assembly, and a vertical reference assembly. The adjustment method includes correction of the main lens barrel connection positioning surface, correction of the reference mirror, and adjustment of the main lens barrel mirror. This device first adjusts the horizontal reference of the mounting positioning surface of the focusless optical system (optical path product) to be adjusted using the horizontal reference mirror, and then adjusts the vertical reference using the vertical reference mirror. The adjustment method can adjust both the incident and exit light angles of the focusless optical system with steering capability, as well as the collimation of the system. The device is simple to operate, highly effective, and ensures excellent incident and exit light angles and collimation performance of the product.

This invention relates to the field of optical measurement and calibration technology, and in particular to a method, medium, and apparatus for calibrating a plane reference mirror in a vertical interferometer. The method involves placing a calibration plate as a temporary mirror under test in the measurement optical path of a vertical Fizeau interferometer. At at least one measurement point, the calibration plate is continuously rotated around its own rotation center. The rotation centers at each measurement point are offset from the central optical axis of the plane reference mirror and equidistant. Multiple frames of surface shape measurement data are collected at each measurement point, and the absolute surface shape error of the plane reference mirror is obtained by arithmetic averaging of all measurement point data. This method, through the specific offset measurement point settings, systematically changes the spatial orientation of the calibration plate at different points, offsetting central symmetry errors and suppressing asymmetric errors and random noise. It achieves high-precision and robust absolute calibration without the need for complex algorithms. Compared with traditional methods, it combines accuracy, efficiency, and practicality, is suitable for various application scenarios, and provides a framework for subsequent efficiency optimization.

The application discloses a kind of automatic measuring device and detection method of lens center thickness, including spectral confocal system and Fizeau interference system, spectral confocal system includes light source, confocal pinhole and optical system, and optical system includes first half reflection half permeation lens, chromatic focus lens and spectroscope;Fizeau interference system includes Fizeau interferometer and computer, and Fizeau interferometer includes laser emission component and first imaging mirror, reference mirror, second beam expander, second half reflection half permeation lens, second imaging mirror and CCD camera.The lens center thickness with error component is measured using spectral confocal system, the physical translation error component, tilt error component of the lens to be measured are detected in real time using field calibration and Zernike wave surface fitting in Fizeau interference system, and the measured lens center thickness is automatically corrected using error correction formula, and then the lens center thickness is accurately measured, which can greatly save labor and time cost, and improve detection efficiency.

The application discloses a typical laser communication system Kude optical path installation and adjustment method based on a fast reflecting mirror, and comprises the following steps: reflecting a parallel light pipe light beam to a parallel light pipe camera center position through a reference mirror; a fiber collimator emits laser, an optical antenna azimuth direction is rotated through a control coarse tracking turntable, and a transmission light spot position information is acquired through the parallel light pipe camera; the fast reflecting mirror position is adjusted, a Kude optical path pointing rotation error reduction trend is determined, and an accurate reference is provided for Kude optical path installation and adjustment. The method has the characteristics of controllability and rapidity of the fast reflecting mirror in the typical laser communication system, avoids the shortcomings of uncertain direction and low controllability caused by manual control during the existing Kude optical path installation and adjustment, effectively improves the Kude optical path installation and adjustment effect and efficiency, and can be widely applied to the typical laser communication system.

An interference observation device comprises a light source; an optical interference system comprising a reference mirror that splits the light emitted by the light source into a first light and a second light, and emits interference light between the first light reflected from an object under observation and the second light reflected from the reference mirror; an image sensor that detects the interference light; and a processing unit that acquires an interference image. The optical interference system includes a device configured to change the focus of the second light's beam path.The processing unit separates observation surface information and non-observation surface information based on a multitude of interference images obtained when the focusing of the beam path of the second light is changed in a state where the focal point of the first light is aligned with an observation surface of the observed object.

The invention relates to a system (1) for digital holographic imaging, comprising at least the following components: - a beam splitter (2) - a retroreflector array (3) comprising a large number of retroreflector elements (30), - a reference mirror (4), wherein the system (1) is configured to superimpose the object light (100) reflected by the reference mirror (4) and by the retroreflector array (3) so that a multitude of interference patterns attributable to the respective retroreflector elements (30) are created, wherein the system (1) has a phase-adapting optical structural component (5) for predefined phase adaptation of the object light (100), characterized in that the phase-adapting optical structural component has an associated angle-of-incident phase relation (1000) for each of a predefined plurality of incidence directions (e) of the object light (100), wherein the phase-adapting optical structural component (5) is configured to imprint phases (Φ) on the object light (100) for each of these plurality of incidence directions according to the associated angle-of-incident phase relation (1000), so that the interference patterns contain information with which a hologram reconstructed accordingly from these interference patterns has an improved resolution with respect to a system (1) without the predefined phase matching.

The present application relates to a kind of dot auxiliary focusing digital holographic microscope system and holographic reconstruction method, the system includes digital holographic microscopic optical path part and dot auxiliary focusing optical path part, digital holographic microscopic optical path part is irradiated after the object sample of polarization modulation narrowband laser to be measured with reference mirror reflected polarization orthogonal reference light in polarization camera interference imaging, different phase shift acquisition of single image is realized;Dot auxiliary focusing optical path part utilizes the definition of image to calculate the focus position of the object sample to be measured, can directly obtain the best inverse diffraction distance required in digital holographic reconstruction process.Compared with prior art, the present application has improved the autofocusing efficiency of digital holographic microscope, greatly speed up the speed of digital holographic three-dimensional surface reconstruction, on the premise of guaranteeing the reconstruction measurement precision, improves the efficiency and real-time of reconstruction and the like advantages.

Device for the relative coarse adjustment of a measuring head of a fiber optic laser interferometer and a reflective object to be measured, comprising: a beam splitter designed to split at least one light beam into a reference beam directed towards a reference mirror and an object beam directed towards the object to be measured, a detection surface that enables detection a) an object reflection beam reflected from the object to the beam splitter and b) of a reference reflective beam and / or the reference beam reflected from the reference mirror to the beam splitter, wherein the detection surface is arranged so that it is opposite either a reference mirror or an object to be measured, but not the measuring head where A) the beam splitter is part of a beam splitter cube and one surface of the beam splitter cube is provided with the detection surface, and / or B) the detection surface is designed to be photoluminescent, in particular fluorescent, and can be excited by the reference reflection beam and the object reference beam to emit light with at least one wavelength in the range of 380 nm to 780 nm from the respective point of impact.