DE102010046907B4 - Robust one-shot interferometer and method, especially as a scout sensor for multi-sensor material measurement or tumor cell detection - Google Patents

Abstract

A method of robust one-shot interferometry or high-aperture short-coherence interference microscopy for distance, depth, profile, shape, waviness, microform, micro-profile and / or roughness measurement or for measuring the optical path length of an object or an object detail or its spatial or temporal change and / or optical coherence tomography (OCT) or optical coherence microscopy (OCM), in particular as an optically measuring scout sensor in a multi-sensorial material measurement and material processing system or in a multi-sensorial system Detection of tumor cells and their optical treatment - with at least a two-beam interferometer, also in the form of a high-aperture short-coherence interference microscope, - with at least one monochromatic and / or polychromatic source (1, 100, 110) of electromagnetic radiation at the entrance of the two-beam interferometer , - with a beam part he area (4) in each two-beam interferometer for generating object and reference light, ie in the form of object and reference beams or object and reference wavefronts, by division of the wave amplitude - and with one of these beam splitter surface (4 ) each at least approximately parallel opposite and from ...

Description

State of the art

The use of a triple reflector in the beam path X of a Michelson interferometer can already be found in F. Twyman and A. Green, sa U.S. Patent 1,565,533 . 8th , from 1923 [1]. This approach allows the compensation of wavefront inversion, which is given in the beam path U by the combination lens with reflective plane mirror in the focal plane.

As the state of the art here are the classic Linnik interferometer, which already as an optical arrangement in 6 in [1], as well as the already mentioned arrangement according to 8th in [1] with a triple reflector in the beam path of a Michelson interferometer viewed.

The state of the art here is also the interferometer, proposed in 1988 by K. Körner and H. Fritz, according to the patents DD 282 371 A7 [2] or also US 4,983,042 [3]. The application of this interferometer was presented in the following technical article: G. Spur, K. Körner, H. Fritz, L. Nyársik and E. Uhlmann: "Optical Measurement of Micro-Topography of Ultra Precision Manufactured Surfaces", conference papers: 7th International Conference on Production / Precision Engineering (7 th ICPE), Chiba / Tokyo, Japan, 15.-17. September 1994, pp. 639-643, Advancement of Intelligent Production: Eiji Usui (Editor), ^© 1994 Elsevier Science BV / The Japan Society for Precision Engineering, [4].

Here are - in contrast to the arrangement according to F. Twyman and A. Green - the beam splitting and beam combination surface in the interferometer clearly separated from each other and arranged parallel to each other. The object arm has a measuring objective for object illumination and for microscopic object imaging, and a triple reflector for beam guidance with wavefront inversion and beam guidance with a predetermined parallel offset is arranged in the reference arm so that the lateral shear of the two interfering wavefronts can be completely eliminated after recombination. This interferometer arrangement, with qualified use for interferometric, areal roughness or profile measurement on nano-precision machined surfaces, achieves a deep measurement uncertainty deep in the sub-nanometer range, since the interferometric reference mirror is of a virtual nature, thus physically conditionally, free of residual roughness and particles. The corner point and the edges of the triple reflector can be located in this interferometer advantageously outside of the used beam path, which greatly reduces the unwanted scattered radiation, in particular from the corner point in the reference beam path.

These interferometers mentioned above avoid the wave front inversion of object and reference radiation at the output of the interferometer, that is to say in the case of interference. This avoidance of the wavefront inversion from one another is an absolutely necessary prerequisite for the interference evaluation of measurement points in the measurement field outside the optical axis of the measurement objective when using spatially incoherent or partially incoherent light sources.

In an interference microscope with the lens in the object arm or an interferometer with measuring lens in the object arm and only one plane mirror in the reference, however, there is a very harmful wavefront inversion of the interfering waves to each other, as in contrast to the object arm on the plane mirror - ie in the reference arm - no wavefront Inversion is generated. This can lead to the complete disappearance of the interference phenomenon when using spatially incoherent or spatially partially incoherent light sources. The introduction of wavefront inversion also in the reference arm is therefore an essential prerequisite for interferometric microscopy imaging in the object arm for a linear and area-like interference-microscopic one-shot measurement of an object without a mechanical scan.

This is in an arrangement according to the disclosure DE 10 2006 015 387 A1 [5] by M. Hering, W. Happold, S. Herrmann, C. Knoll, W. Osten and K. Körner. Here in [5] an interferometric measuring device based on white-light interferometry, also known as short-coherence interferometry, is described, in which the wavefronts of the reflected object beam and that of the reflected reference beam are tilted by a certain angle 2 × delta-alpha are inclined to each other, so that a spatial interferogram can arise as a one-shot data set on a screened detector. For example, this angle is realized here in a modified Linnik-interferometer arrangement by a tilting mirror, which is only once passed by the light on the way to detection. With this measurement method, one or more spatial interferograms, even as a line stack on a Matrix camera, as one-shot data sets in the period of an image recording are made completely available. The introduction of a wavefront inversion in the reference arm is given here.

Of particular advantage in this approach with the tilting mirror in the collimated beam path, that the spatial frequency for the centroid wavelength, or the center of gravity wave number, in the spatial interferogram at the output of the interferometer in a first approximation is not affected by the inclination of the object surface in relation to the interferometer. This invariance of the spatial frequency represents a major advantage for the evaluation of spatial interferograms.

However, this subordinate tilt device described in [5] is generally quite susceptible to undesired misalignments and thus the interferometer is usually not long-term stable. Thus, the waveform of a short-coherent spatial interferogram can change in a largely unknown manner, which can represent a significant disadvantage for the evaluation.

A targeted change in the angle between the interfering wavefronts by tilting device, for example, to change the spatial frequency for the centroid wavelength in the spatial interferogram predetermined, this can lead to an undesirable lateral displacement of the object wavefront and reference wavefront during detection, which is complicated or by an adjustment in some If necessary, it can not be compensated for. Thus, in this arrangement, the ability to change the spatial frequency for the center wavelength in the spatial interferogram in a simple manner, severely limited. Furthermore, a suboptimal adjustment of the rather complex interferometer can permanently lead to only partial lateral coverage of the object wavefront and reference wavefront, which can be a source of measurement errors or severely limit the depth measurement range since the interference effect disappears in the absence of superimposition.

In the publication by M. Hering, K. Körner and B. Jähne in Applied Optics, Vol. 48, Number 3, pages 525 to 538 of January 20, 2009 [6], the measured spatial interferograms in the potential of this approach according to [5]. The in the presented interferometric one-shot measurement arrangement is an experimental setup for study purposes and is for the economic implementation rather too complex and too voluminous and also adjustment-consuming. The optical principle requires that in this case the technical and constructive measures to achieve a high mechanical stability and temperature stability, quite expensive. Typical measurement results based on this approach were reported by M. Hering, S. Herrmann, M. Banyay, K. Körner and B. Jähne in the Proceedings of SPIE, Vol. 6188, 61880E-1 to 61880E-11 in 2006 of the 7 represented [7].

The gaining of spatial interferograms for the one-shot measurement technique by inclination device in the form of a plane tilting mirror in the interferometer, but this is always outside of the object-imaging and outside of the focused reference beam path, ie in a collimated beam path, as given here Prior art considered.

In this principle, the inclination of an object surface with respect to the interferometer advantageously does not lead to a change of the spatial frequency for the centroid wavelength, or the centroid wave number, in a spatial interferogram. However, the interference contrast may approach zero even at a relatively small tilt or tilt of the object surface. A comparatively high interference contrast in the detected spatial interferogram can only be achieved over a comparatively large tilting or tilting angle range of the object surface if this object surface is illuminated by means of high numerical aperture optics and laterally almost diffraction-limited focus points or focused line images.

By contrast, Michelson-type interferometer interference microscopes are those in which the spatial frequency for the centroid wavelength in a spatial interferogram at the output of the interferometer by tilting the plane reference mirror or by tilting the object with respect to the interferometer or the interferometer with respect to the object to change is not of interest at all. For measuring objects with varying and unknown surface inclination, this approach may pose considerable problems in the evaluation of spatial interferograms. Therefore, such approaches are not considered as relevant prior art and are therefore not listed here.

The acquisition of spatial interferograms for the one-shot measurement technique by means of lateral shear between object and reference wavefronts at the output of a two-beam interferometer fundamentally represents a further possibility of generating spatial interferograms for the one-shot measurement technique. For example, for detecting the distance. For a predetermined set lateral shear in an interferometric arrangement can be used as a basis for generating interference of mutually inclined wavefronts in an excellent plane of the optical imaging system at the output of the interferometer with advantage.

The at German Patent and Trademark Office with the file number 10 2010 006 239 [8] on January 22, 2010 by K. Körner, R. Berger and W. East submitted font for a method and a device for robust interferometry (ROSI) based on the use of predetermined set lateral shear in the interferometric reference beam through a special mirror group is generated. However, this approach is well-suited for object imaging in particular for the low or medium numerical aperture range, but rather less or only to a limited extent for interferometric measurement with a high numerical aperture.

It should also be pointed out at this point that the generation of spatially displayed interferograms, spatial interferograms, with mutually inclined wave fronts for static Fourier transform spectroscopy as a single-shot approach already goes back to GW Stroke and AT Funkhouser in 1965, s. a. G.W. Stroke, A.T. Funkhouser, "Fourier-Transform Spectroscopy using imaging without Computing and stationary interferometers", Physics Letters, Vol. 16, pp. 272-274, 1965 [9]. The detection of a spatial interferogram happens here within the image integration time of a camera.

Description of the invention

The object of the invention is, firstly, robust one-shot measurement technology (ROSI) with a comparatively high lateral resolution for detecting distance, depth, profile, shape, waviness and / or roughness or the optical path length in or on technical or biological objects, also in a layered form or also for optical coherence tomography (OCT), in particular also with one-shot multi-point probing, in which the signals generally arise in wavelet form, in a comparatively short measuring time , Furthermore, the tilting and / or inclination of the object surface or its shape, or microform, should have little or no influence on the signal shape, in particular the frequency of the wavelet.

Thus, the object to be solved when optically probing the object surface, an object point or an object volume with an interferometer optical signals in bestgeeigneter, so the best possible evaluable waveform for a punctiform, a line-like field or even for a two-dimensional measuring field with many individual measuring points without provide a mechanical, time-serial depth scan. Due to the requirement for a high lateral resolution, there is also the task of designing the measuring system with a comparatively high numerical aperture up to the limit of the technically feasible. By a large and possibly also very large numerical aperture, a comparatively high proportion of the light irradiated to the object to be detected so that the measurement time can be selected comparatively short according to the task and measurements even in a vibration environment, on moving components or in vivo diagnostics are possible on living humans. In particular, tumor cells should be able to be reliably detected. By means of the femtosecond laser provided, tumor cells should be able to be destroyed in a highly precise localized manner on the basis of data obtained from the inspection area by means of optical sensors. The treatment methods in particular or even the special destruction methods of living tissue are outside the scope of this invention, as these on the scout sensor technology for two- and three-dimensional representation of tumor cells, the inspection of living tissue, or on the two- and three-dimensional Focus material measurement.

In doing so, many laterally adjacent object elements or object points should be able to be appropriate at the same time. That is, there is the task, in the state of available evaluation algorithms well evaluable and relatively robust optical signals in the optical probing of objects by the inventive method and the inventive arrangement by means of an object interferometer measuring, also in the form of a high-aperture interference microscope with measuring objective in the object arm to provide as quickly as possible.

The spatial frequency for the centroid wavelength of the signals in wavelet form, or the center of gravity wavenumber kS in a spatial interferogram should be highly constant or predetermined adjustable and be highly independent of the tilt and tilt of the object surface.

In this case, the amount of inclination of interfering wavefronts, which form a spatial interferogram on a detector, with simple means, cost, as long-term stable and largely invariable by environmental influences, so also very robust, can be realized. The misalignments typically occurring when using an optical system by changing the position of components, also by temperature changes in the environment as well as by varying mechanical stresses, eg. B. in the holding elements of the components in the measuring system, should have no or only a relatively small effect on the amount of inclination of the interfering wavefronts in the detection. As is known, this can only be achieved if the spectrum of the interfering light remains invariable.

The influence of the dispersion in the application of refractive components, in particular in the interferometric beam path, should be kept negligibly small in order to achieve a substantially constant center frequency in the resulting interference wavelet. This in turn greatly facilitates comparatively simple and reliable signal processing. Of course, the influence of the dispersion of the object is always given and must also be taken into account during signal processing and, if necessary, processed by suitable algorithms.

Fields of application of the inventive solution should be: The microform and the micro-profile measurement, the measurement of roughness and the mini-form measurement, the shape measurement on not or little cooperative surfaces, as well as z. B. human liver tissue. An example of the application of the invention is also the detection of the microform of cells, in particular tumor cells on the living organism. In this case, the tendency is rather the near-surface optical probing.

In this case, the interferometer according to the invention can also be used as a scout sensor system for exploring the three-dimensional environment and the three-dimensional fine structure of an operating area already in the surgical operation phase in a human. In this case, the interferometer according to the invention is located within a highly complex and multi-sensor spectroscopic diagnostic system, which may include, for example, a Raman spectrometer. Thereby, additional information about human tissue in conspicuous organ areas should be obtained in order to identify, for example, malignant cells and tumors comparatively reliably by parallelized detected multisensory data sets already in the surgical operation phase. The highly complex, multi-sensor spectroscopic diagnostic system may also include a near infrared spectrometer, especially in the form of a differential spectrometer, and / or a multiphoton microscope.

The optical data should be parallelized for all sensors of the overall system and simultaneously obtained from the same inspection area or object area, so for all sensors of the multi-sensorial system, the same and shared optical inspection channel to the object should exist. The individual sensors can work simultaneously in different spectral ranges.

For the parallelized acquisition of multi-sensor data sets, an interferometric arrangement with more than one interferometer output is to be provided in order to be able to connect further sensor systems, such as a high-resolution near-infrared difference spectrometer, which makes accurate measurements in the operating area. For example, in order to be able to reliably refute or confirm suspicions on tumor cells in the patient. So topographic as well as spectroscopic data should be parallelized and obtained in real time.

Another field of application is the measurement of polished and non-polished optical aspheres and free-form surfaces.

The measuring arrangement and the method should also be used for optical coherence tomography (OCT), in particular with multi-point probing, for technical or biological objects.

A particular field of application may be biological and medical basic research, for example, the inventive methods and arrangements by the coupling, in particular spectrally super-resolution, sensor systems for the detection of formation and growth, including the metabolic processes in vivo of tumor cells, can be used.

Here, the term light is always used as a synonym for electromagnetic radiation from the terahertz, over the infrared to the deep UV range.

Method for solving the tasks:

It is a robust one-shot interferometry (ROSI) technique, also known as high-kimed short-coherence interference microscopy (HA KIM), for distance, depth, profile, shape, ripple, microform, microprofile and / or roughness measurement or for measuring the optical path length of an object or an object detail or its spatial or temporal change and / or for Optical Coherence Tomography (OCT) or Optical Coherence Microscopy (OCM), in particular also as optically measuring Scout Sensor in a multi-sensorial material measurement and material processing system or in a multi-sensorial detection system for tumor cells, living tissues and especially optical treatment thereof. The multi-sensorial system can be designed, in particular, with maximum spectral resolution in a plurality of spectral ranges from the deep UV range through the visible and the near infrared range to the medium, long-wave infrared range and the terahertz range.

For this purpose, at least one two-beam interferometer, also in the form of a high-aperture short-coherence interference microscope, or a plurality of two-beam interferometers is arranged.

In this case, at least one monochromatic and / or polychromatic source of electromagnetic radiation is associated with the two-beam interferometer or the plurality of two-beam interferometers. This can be laterally finely structured as a multi-point light source, also in line or surface form or even in three dimensions.

This two-beam interferometer or a plurality of two-beam interferometers is each with a beam splitter surface in each two-beam interferometer for generating object and reference light, ie in the form of object or reference beams or object or reference wavefronts depending on geometric or wave optical view, formed by dividing the wave amplitude of the light entering the two-beam interferometer. This beam splitter surface is in each case associated with an at least approximately parallel opposed and spatially separated beam combiner surface for the reunification of object and reference light for the purpose of interference.

The reference beam path in the two-beam interferometer is each formed with a retro-reflector for retro-reflection of the reference light. The retro-reflector has in each case at least two partial apertures (TAT-E, TAT-A or TAF-E, TAF-A), of which a partial aperture (TAT-E, TAF-E) in each case alone for entering into the retro-reflector Light and a sub-aperture each alone (TAT-A, TAF-A) is used for outgoing from the retro-reflector light

The two-beam interferometer or a plurality of two-beam interferometers further has an object beam path with a measuring objective illuminating and imaging the object or at least one element of the object.

For the illumination and imaging of an object of a biological or technical nature by means of a measuring objective, the term optical probing is also used synonymously here.

The two-beam interferometer or a plurality of two-beam interferometers is further associated with at least one screened detector or a plurality of screened detectors for electromagnetic radiation, with which at least one spatial interferogram is registered.

• • Geometrische Separierung von hinlaufendem und zurücklaufendem Strahlenbündel im Referenzstrahlengang zumindest näherungsweise in der Größe des Referenz-Strahlenbündel-Durchmessers mittels Retro-Reflexion mittels der lateralen Positionierung und/oder der geometrischen Ausbildung des Retro-Reflektors im Zweistrahl-Interferometer. Dadurch wird eine Separierung von in den Retro-Reflektor einfallendem Licht und von nach der Retro-Reflexion austretendem Licht durchgeführt. Der Betrag dieser Separierung liegt mindestens in der Größe des Referenz-Strahlenbündel-Durchmessers, so dass sich die entgegenlaufenden Strahlenbündel nicht überdecken.
• • Erzeugen einer vorbestimmten Neigung eines Referenzstrahlenbündels zu je einem Objektstrahlenbündel am Ausgang des Zweistrahl-Interferometers durch Mittel zur zumindest näherungsweise achromatischen Strahlablenkung im Referenzstrahlengang auf der Basis von Reflexion und/oder Diffraktion und/oder Refraktion, einschließlich von Maßnahmen zur vorbestimmten geometrischen Ausbildung des Retro-Reflektors oder von Komponenten desselben,
• • und/oder Erzeugen der vorbestimmten Neigung eines Referenzstrahlenbündels zu je einem Objektstrahlenbündel am Ausgang des Zweistrahl-Interferometers mittels Reflexion von Referenzstrahlenbündel oder Objektstrahlenbündel bei deren Wiedervereinigung an der separierten Strahlvereiniger-Fläche, so dass als Resultat der Summe der Mittel und Maßnahmen zur achromatischen Strahlablenkung des Referenzstrahlenbündels und der Wiedervereinigung an der Strahlvereiniger-Fläche eine vorbestimmte Neigung des Referenzstrahlenbündels zu je einem Objektstrahlenbündel mit dem Winkel alpha am Ausgang des Zweistrahl-Interferometers besteht,
• • Erzeugen von räumlichen Kurzkohärenz-Interferenzen zueinander geneigter Objekt- und Referenzstrahlenbündel auf einem gerasterten Detektor elektromagnetischer Strahlung, wobei der Neigungswinkel alpha am Ausgang des Zweistrahl-Interferometers zumindest näherungsweise unabhängig von der Wellenlänge gemacht ist, und diese vorbestimmte Neigung im Überdeckungsbereich von Objekt- und Referenzwellenfronten auf dem gerasterten Detektor – also im räumlichen Interferogramm – eine Änderung des optischen Gangunterschieds zwischen den interferierenden Wellenfronten über der lateralen Ausdehnung des räumlichen Interferogramms bewirkt, der zu einer Modulation der Intensität im räumlichen Interferogramm führt,
• • Bildung mindestens eines Signalmaximums oder mindestens eines Signalminimums im räumlichen Interferogramm auf dem gerasterten Detektor,
• • Detektion mindestens eines räumlichen Interferogramms auf dem gerasterten Detektor und
• • Auswertung eines räumlichen Interferogramms zur Bestimmung von Abstand, Tiefe, Profil, Form, Mikroform, Welligkeit und/oder Rauheit oder der optischen Weglänge in oder an einem biologischen oder technischen Objekt oder Objektdetail.

According to the invention, the following process steps are carried out:

• Geometric separation of traveling and returning beam in the reference beam path at least approximately in the size of the reference beam diameter by means of retro-reflection by means of the lateral positioning and / or the geometric design of the retro-reflector in the two-beam interferometer. As a result, a separation of light incident in the retro-reflector and of light emerging after the retro-reflection is carried out. The amount of this separation is at least the size of the reference beam diameter, so that the counter-rotating beams do not overlap.
• Generating a predetermined inclination of a reference beam to an object beam at the output of the two-beam interferometer by means for at least approximately achromatic beam deflection in the reference beam on the basis of reflection and / or diffraction and / or refraction, including measures for the predetermined geometric formation of the retrospective Reflector or components thereof,
• • and / or generating the predetermined inclination of a reference beam to each object beam at the output of the two-beam interferometer by reflection of reference beam or object beam at their reunification at the separated Strahlereiniger surface, so that as a result of the sum and measures for achromatic beam deflection of the Reference beam and the reunification at the Strahlvereiniger surface is a predetermined inclination of the reference beam to each object beam with the angle alpha at the output of the two-beam interferometer,
• • Generating spatial short-coherence interference of mutually inclined object and reference beams on a rasterized detector of electromagnetic radiation, wherein the inclination angle alpha at the output of the two-beam interferometer is at least approximately independent of the wavelength, and this predetermined tilt in the coverage area of object and reference wavefronts on the screened detector - ie in the spatial interferogram - causes a change in the optical path difference between the interfering wavefronts over the lateral extent of the spatial interferogram, which leads to a modulation of the intensity in the spatial interferogram,
• Formation of at least one signal maximum or at least one signal minimum in the spatial interferogram on the screened detector,
• Detection of at least one spatial interferogram on the screened detector and
• Evaluation of a spatial interferogram for determining distance, depth, profile, shape, microform, waviness and / or roughness or the optical path length in or on a biological or technical object or object detail.

It is advantageous for the operation of a high-aperture short-coherence interference microscope (HA KIM) if at least the half-width of the envelope of the spatial interferogram fits into the middle of the depth-measuring range on the rastered detector.

• • des Betrags und des Vorzeichens der lateralen Bündelseparierung bei der Retro-Reflexion im Referenzstrahlengang,
• • des Betrags und des Vorzeichens der vorbestimmten geometrischen Separierung der Strahlteilungsfläche und Strahlvereinigungsfläche unter Berücksichtigung der Brechungsindizes der optischen Materialien, die zwischen Strahlteilungsfläche und Strahlvereinigungsfläche angeordnet sind,
• • sowie des Winkelbetrags und des Vorzeichens des Neigungswinkels alpha des Referenzstrahlenbündels R zum Objektstrahlenbündel O

durchgeführt.Furthermore, in the method for robust one-shot interferometry, at least approximately, an elimination of the lateral shear of object and reference beams on the rastered detector of electromagnetic radiation is achieved by the simultaneous tuning

• The amount and the sign of the lateral bundle separation in the retro reflection in the reference beam path,
• The magnitude and sign of the predetermined geometric separation of the beam splitting surface and beam combining surface taking into account the refractive indices of the optical materials disposed between the beam splitting surface and the beam combining surface,
• • and the angle and the sign of the inclination angle alpha of the reference beam R to the object beam O

carried out.

Furthermore, in the method for robust one-shot interferometry, wave front shaping of object and reference waves at the output of the two-beam interferometer is preferably carried out by means of cylinder optics or anamorphotically acting prisms, so that predetermined wavefront shaping introduces astigmatism for object and reference waves. In the detection of each spatial interferogram by astigmatic focusing - each of an object and a reference cylindrical wave forming a spatial interferogram - this spatial interferogram is formed at least approximately in linear form on the rasterized detector.

Furthermore, in the method for robust one-shot interferometry, confocal discrimination by means of a gap or pinhole aperture is preferably carried out for the returning object light. As a result, scattered light from the object can be reduced.

Furthermore, in the method for robust one-shot interferometry, confocal discrimination by means of a gap or pinhole aperture is preferably carried out for the returning reference light. This results in a low-pass filtered reference wavefront, which may reduce the influence of coherent perturbations in the spatial interferogram.

In the method for robust one-shot interferometry is preferably also the second output A3 of the two-beam interferometer, which is geometrically decoupled by the arrangement with separate locations for beam splitting and association from the input, together with the output A2 for the dual-balanced Technology used. This is done to the DC component - due to the antiphase of the signal of the second output - in the detected interferogram electronically and / or numerically at least approximately eliminate.

Furthermore, in the method for robust one-shot interferometry, at least one output of the two-beam interferometer is preferably used for NIR spectroscopy. This allows additional information about the object to be obtained so that multi-sensor data can be obtained to increase safety, for example in the detection of tumor cells.

Furthermore, in the method for robust one-shot interferometry, at least one output of the two-beam interferometer is preferably used for Raman spectroscopy. This allows additional information about the object to be obtained so that multi-sensor data is available to increase safety, for example in the detection of tumor cells.

Furthermore, in the method for robust one-shot interferometry, at least one output of the two-beam interferometer is preferably used for fluorescence spectroscopy. This allows additional information about the object to be obtained so that multi-sensor data is available to increase safety, for example in the detection of tumor cells.

Furthermore, preferably in the method for robust one-shot interferometry, at least one output of the two-beam interferometer is used for multiphoton microscopy. This allows additional information about the object to be obtained so that multi-sensor data is available to increase safety, for example in the detection of tumor cells.

Furthermore, in the method for robust one-shot interferometry, at least one output of the two-beam interferometer is preferably used simultaneously for differential spectroscopy. This can be done in the near-infrared area. This allows additional information about the object to be obtained so that multi-sensor data is available to increase safety, for example in the detection of tumor cells.

Due to the inclination angle alpha of the reference beam R to the object beam O, a clear separation possibility of object and reference light is given in the detection, so that, for example, for NIR difference spectroscopy is a very precise reference in real time available. Thus, even the smallest fluctuations in the intensity of one or more light sources can be kept away from the measurement result, for example by a subtraction operation. Other differential methods with the goal of highest sensitivity are applicable here. Wherever a reference to the object light is needed, this approach can be applied with the possibility of separating object and reference light by introducing the angle of inclination alpha between the reference beam R and the object beam O.

The details of these methods, such as NIR spectroscopy, Raman spectroscopy, multiphoton microscopy, fluorescence spectroscopy and the meaningful coupling of the same within a multisensorial system, in particular for the diagnosis of tumor cells, are not in the focus of this invention. The details of the application, the parameterization as well as the sensible selection of couplings of these procedures are to be addressed here by the skilled person. In this case, it is particularly important to provide multimodal and multi-sensorially generated measurement data - in particular topographical and multiple spectroscopic - with comparatively low measurement uncertainty, from which meaningful indicators are derived. Using computer-aided and model-based linking of these indicators to complex indicator matrices, it should be possible to make statements with high reliability regarding the presence of tumor cells - that is, in early cancer detection - in real-time operations.

Furthermore, in the method for robust one-shot interferometry over a partial aperture of the measuring objective, suitable laser radiation is preferably supplied for the laser treatment of living tissue or biological dead material or laser radiation for processing non-biological material. The information gathered through multisensor measurements can be used in process real time for in-process machining of material. On the other hand, for example, carcinogenic skin cells can be removed very quickly and the patient gently and completely by appropriate laser treatment after their multi-sensorially assisted detection. In this case, a partial aperture of the measuring system, which is preferably designed as a Schwarzschild mirror objective with suitable mirroring for the laser radiation, can be used.

Furthermore, in the method for robust one-shot interferometry in the measuring objective and / or in the object beam path, means for chromatic longitudinal splitting are preferably arranged in order to perform a depth separation of focus points for implementing the chromatic-confocal technique. This serves to considerably increase the wave-optical depth of field.

Furthermore, in the method for robust one-shot interferometry, the two-beam interferometer is preferably optically fed with a multiplicity of input beams, so that a multiplicity of object bundles and reference bundles are formed in parallel. Each reference bundle formed is a retro-reflector and each measuring object bundle is associated with a measuring objective and thus a parallelized optical scanning of the object can be carried out. The term optical scanning is used here synonymously for the optical measurement of the object.

• – Nach- bzw. Durchfokussieren des Sensors in Relation zum Messobjekt, so dass sich der optische Gangunterschied zumindest für den Hauptstrahl im Objektstrahlengang im Zweistrahl-Interferometer sich zumindest näherungsweise nicht ändert und
• – gleichzeitiges Durchstimmen der Quelle elektromagnetischer Strahlung im Frequenzraum mittels durchstimmbarer Frequenzkamm-Laserlichtquelle oder mittels durchstimmbarem Vielstrahl-Interferometer hinsichtlich optischer Weglänge 2L – also des „einfachen” optischen Gangunterschieds x_zu im Vielstrahl-Interferometer. Dabei wird die aktuelle Fokusebene, speziell der Fokuspunkt auf der optischen Achse des Objektstrahlenganges des hochaperturigen Kurzkohärenz-Interferenzmikroskops (HA KIM) stets zumindest näherungsweise dort lokalisiert, wo eine Kompensation des optischen Gangunterschieds x des Kurzkohärenz-Interferenzmikroskops durch die einfache optische Verzögerungslänge 2L der Frequenzkamm-Laserlichtquelle oder des Vielstrahl-Interferometers auf der optischen Achse des Objektstrahlenganges besteht.

Furthermore, the following method steps are preferably carried out in the method for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM):

• - Refocusing or focussing of the sensor in relation to the measurement object, so that the optical path difference, at least approximately does not change at least for the main beam in the object beam path in the two-beam interferometer, and
• - Simultaneous tuning of the source of electromagnetic radiation in the frequency space by means of tunable frequency comb laser light source or by means of tunable multi-beam interferometer in terms of optical path length 2L - ie the "simple" optical path difference x_zu in the multi-beam interferometer. In this case, the current focus plane, especially the focal point on the optical axis of the object beam path of the high-aperture short-coherence interference microscope (HA KIM) is always at least approximately localized where a compensation of the optical path difference x of the short-coherence interference microscope by the simple optical delay length 2L of the frequency comb. Laser light source or the multi-beam interferometer on the optical axis of the object beam path consists.

Thus, the pitches of the intensity maxima of the frequency comb laser light source in the frequency comb, or the transmission maxima of the multi-beam interferometer in the frequency domain change when tuning. At this time, the optical retardation length 2L of the frequency-comb laser light source or the multi-beam interferometer is made equal at least approximately once to the optical retardation x in the high-aperture short-coherence interference microscope (HA KIM) at a time of temporal tuning. In this case, a detection - preferably a short-term detection - in a time window in the time of tuning by rasterized detector. The rasterized detector can be capable of short-time detection. However, it can also be assigned to the optical beam path, a fast shutter system or the light source can also be designed as a short pulse light source. Preferably, in the frequency comb laser light source or in the multi-beam interferometer fast countermovement by means of piezoelectric adjustment can be generated in a predetermined manner, so that practically does not change the spatial interferogram in the time window of image acquisition by rasterized detector, because the optical path difference does not change in this time window , It may be advantageous if the optical scanning in the object space is preferably carried out in steps of approximately half the coherence length, which results from the global spectrum of the light source. It is assumed that the wave-optical depth of field exceeds the coherence length. The optical path difference in the object arm of the high-aperture short-coherence interference microscope (HA KIM) is thus not changed when tuning the frequency comb laser light source in the frequency comb or the multi-beam interferometer.

• – Nach- bzw. Durchfokussieren des Sensors in Relation zum Messobjekt, so dass der optische Gangunterschied – zumindest für den Hauptstrahl im Objektstrahlengang im Zweistrahl-Interferometer – sich zumindest näherungsweise nicht ändert und
• – gleichzeitiges Durchstimmen eines dem hochaperturigen Kurzkohärenz-Interferenzmikroskop (HA KIM) zugeordneten Zweistrahl-Interferometers hinsichtlich seines optischen Gangunterschieds x_zu. Dabei wird die aktuelle Fokusebene, speziell der Fokuspunkt auf der optischen Achse des Objektstrahlenganges des hochaperturigen Kurzkohärenz-Interferenzmikroskops (HA KIM) stets zumindest näherungsweise dort lokalisiert, wo eine Kompensation des optischen Gangunterschieds x des hochaperturigen Kurzkohärenz-Interferenzmikroskops (HA KIM) durch den optischen Gangunterschied x_zu des zugeordneten Zweistrahl-Interferometers auf der optischen Achse des Objektstrahlenganges besteht.

Furthermore, the following method steps are preferably carried out in the method for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM):

• - Refocusing or focussing of the sensor in relation to the measurement object, so that the optical path difference - at least approximately does not change - at least for the main beam in the object beam path in the two-beam interferometer - and
• - Simultaneous tuning of a two-beam interferometer associated with the high-aperture short-coherence interference microscope (HA KIM) with respect to its optical path difference x_zu. In this case, the current focus plane, especially the focal point on the optical axis of the object beam path of the high-aperture short-coherence interference microscope (HA KIM) is always at least approximately localized where a compensation of the optical path difference x of the high-aperture short-coherence interference microscope (HA KIM) by the optical path difference x_zu the associated two-beam interferometer on the optical axis of the object beam path consists.

In this case, the optical path difference x_zu of the associated two-beam interferometer is made equal at least approximately once to the optical path difference x in the high-aperture short-coherence interference microscope (HA KIM) at a time of the temporal tuning. Thus, there is a path difference compensation and there is a detection - preferably a short-term detection - in a time window in the time of tuning by rasterized detector. The rasterized detector can be capable of short-time detection. However, it can also be assigned to the optical beam path, a fast shutter system or the light source can also be designed as a short pulse light source. Preferably, in the associated two-beam interferometer, a fast countermovement by means of piezoelectric technology can be generated in a predetermined manner, so that practically does not change the spatial interferogram in the time window of image acquisition by means of rasterized detector, because even the optical path difference does not change in this time window. It may be advantageous if the optical scanning in the object space is preferably carried out in steps of approximately half the coherence length, which results from the spectrum of the detected interfering light. It is assumed that the wave-optical depth of field exceeds the coherence length. The optical path difference in the object arm of the high-aperture short-coherence interference microscope (HA KIM) is thus not changed in this case when tuning the associated two-beam interferometer.

The short-term temporal freezing of the spatial interferograms in the scan during the time of image recording by rasterized detector, ie the simultaneous tuning and refocusing or focussing, but preferably by means of a fast "logistic countermovement" by means of highly dynamic piezoelectric technology can be carried out predetermined on the reflector in the reference arm. The optical path difference in the object arm is also not changed here in the measurement. This is a well-practicable approach, especially in non-endoscopic applications.

With these measuring methods, it is possible to generate and detect evaluable spatial interferograms from the volume of the object or objects to be measured, even in the case of strong vibrations and strong air turbulences. By means of vibrations and / or strong air turbulences in different focus positions "in one shot" detected wavelets and wavelet groups can be detected in conjunction with sensors which additionally also detect measurement results on vibration movements and vibration frequencies of the measurement object as a rigid body and possibly also of air turbulence Consistent three-dimensional data sets, so point clouds are charged. This can also be done on the basis of model-based approaches with a priori information about the measurement object. If necessary, elastic deformations of the measurement object can also be measured time-resolved and three-dimensionally.

This allows the use of interferometry in particular in endoscopic applications in which a focus by means of a predeterminable controllable liquid lens, controllable membrane mirror as a spatial light modulator is well possible, but no depth scanning or a change in the optical path difference in the reference, for example, for reasons of available Volume prohibits. These approaches thus also allow the successful operation of interferometric in-line metrology in areas and industrial environments, especially in metal-working manufacturing technology, which remained largely closed to interferometry because of uncontrollable interference.

Arrangements for the solution of the tasks:

This is an arrangement for robust one-shot interferometry (ROSI), also in the form of high-aperture short-coherence interference microscopy (HA KIM), for distance, depth, profile, shape, waviness, microform, microprofile and / or roughness measurement or for measuring the optical path length of an object or an object detail or its spatial or temporal change and / or for Optical Coherence Tomography (OCT) or Optical Coherence Microscopy (OCM), in particular also as optically measuring Scout Sensor in a multi-sensorial material measurement and material processing system or in a system for detecting and optically treating tumor cells with the features of the preamble.

• • entweder als kompakter Tripelspiegelreflektor mit drei Planspiegelflächen,
• • oder als Tripelspiegel-Anordnung, bestehend aus einer Dachkantspiegel-Anordnung und einer einzelnen, dieser Dachkantspiegel-Anordnung zugeordneten Planspiegelfläche,
• • oder als Tripelspiegel-Anordnung, bestehend aus drei einzelnen Planspiegelflächen, die jeweils zumindest näherungsweise eine Raumecke darstellen,
• • oder der Retro-Reflektor ist mit mindestens einem fokussierendem Referenzobjektiv und einem Referenz-Endreflektor ausgebildet, welcher jemals zumindest näherungsweise in der Fokusposition dieses Referenzobjektivs angeordnet,
• • und der Retro-Reflektor weist dabei stets jeweils mindestens zwei Teilaperturen (TAT-E, TAT-A oder TAF-E, TAF-A) auf, von denen eine Teilapertur (TAT-E, TAF-E) jeweils allein für in den Retro-Reflektor hineingehendes Licht und eine Teilapertur jeweils allein (TAT-A, TAF-A) für aus dem Retro-Reflektor herausgehendes Licht genutzt wird.

The retro-reflector is included in the reference beam path

• Either as a compact triple mirror reflector with three plane mirror surfaces,
• Or as a triple mirror arrangement, consisting of a roof-edge mirror arrangement and a single planar mirror surface associated with this roof-edge mirror arrangement,
• • or as a triple mirror arrangement, consisting of three individual plane mirror surfaces, each representing at least approximately a corner of the room,
• • or the retro-reflector is formed with at least one focusing reference lens and a reference end reflector, which ever at least approximately arranged in the focus position of this reference lens,
• • And the retro-reflector always has at least two sub-apertures (TAT-E, TAT-A or TAF-E, TAF-A), of which a sub-aperture (TAT-E, TAF-E) each alone in the Retro-reflector entering light and a sub-aperture each alone (TAT-A, TAF-A) is used for outgoing from the retro-reflector light.

• • des kompakten Tripelspiegelreflektors,
• • oder der Tripelspiegel-Anordnung, bestehend aus einer Dachkantspiegel-Anordnung und einer einzelnen, dieser Dachkantspiegel-Anordnung zugeordneten Planspiegelfläche
• • oder der Tripelspiegel-Anordnung im Referenzstrahlengang.
• • Oder, es sind erfindungsgemäß mindestens einer der beiden Teilaperturen (TAT-E, TAT-A) Mittel zur Durchführung einer zumindest näherungsweise achromatischen Strahlablenkung zum Einführen einer vorbestimmten Strahlablenkung delta_rho zugeordnet.
• • Oder, der Retro-Reflektor mit fokussierendem Referenzobjektiv und Referenz-Endreflektor weist in dessen kollimierten Strahlengang mindestens zwei Teilaperturen (TAF-E, TAF-A) auf, von denen eine Teilapertur (TAF-E) allein für in den Retro-Reflektor hineingehendes Licht und eine Teilapertur (TAF-A) allein für aus dem Endreflektor herausgehendes Licht genutzt wird. So wird eine Separierung von in den Retro-Reflektor einfallendem und austretendem Licht durchgeführt und im kollimierten Strahlengang sind mindestens einer dieser beiden Teilaperturen (TAF-E, TAF-A) Mittel zur Durchführung einer zumindest näherungsweise achromatischen Strahlablenkung zum Einführen einer vorbestimmten Neigung delta_rho des Referenzstrahlenbündels zugeordnet
• • und/oder mittels vorbestimmter Rest-Winkelabweichung delta_gamma von der Parallelität von Strahlteiler-Fläche und dieser gegenüberliegenden, separierten Strahlvereiniger-Fläche besteht nach der Strahlvereinigung am Ausgang des Zweistrahl-Interferometers jeweils eine vorbestimmte Neigung einer Referenzwellenfront zu je einer Objektwellenfront.

According to the invention, there is either a predetermined angular deviation delta_beta from the ideal room corner of at least one planar mirror surface

• • the compact triple mirror reflector,
• • or the triple mirror arrangement, consisting of a roof edge mirror assembly and a single, this roof edge mirror assembly associated planar mirror surface
• • or the triple mirror arrangement in the reference beam path.
• Or, according to the invention, at least one of the two sub-apertures (TAT-E, TAT-A) is associated with means for performing an at least approximately achromatic beam deflection for introducing a predetermined beam deflection delta_rho.
• • Or, the retro-reflector with focusing reference lens and reference end reflector has in its collimated beam path at least two sub-apertures (TAF-E, TAF-A), of which a sub-aperture (TAF-E) alone for entering the retro-reflector Light and a sub-aperture (TAF-A) is used solely for outgoing light from the end reflector. Thus, a separation of incident and emerging in the retro-reflector light is performed and in the collimated beam path at least one of these two sub-apertures (TAF-E, TAF-A) means for performing an at least approximately achromatic beam deflection for introducing a predetermined inclination delta_rho of the reference beam associated
• • and / or by means of a predetermined residual angular deviation delta_gamma from the parallelism of the beam splitter surface and this opposite, separated beam combiner surface there is a predetermined inclination of a reference wavefront to an object wavefront after the beam combination at the output of the two-beam interferometer.

Furthermore, preferably in the arrangement for robust one-shot interferometry (ROSI), also in the form of high-aperture short-coherence interference microscopy (HA KIM), the reference end reflector of the retro-reflector with focusing reference lens is designed as a plane mirror for single reflection of the focused reference beam.

Furthermore, preferably in the arrangement for robust one-shot interferometry (ROSI), also in the form of high-aperture short-coherence interference microscopy (HA KIM), the reference end reflector of the retro-reflector with focusing reference lens as a triple plane mirror group for the triple reflection of is formed focused reference beam, wherein the three plane mirrors are each arranged perpendicular to a common reference plane. The resulting transverse offset of the returning reference beam leads to a beam deflection, so that there is an inclination of the reference beam to the object beam at the output of the interferometer.

Furthermore, in the case of the arrangement for robust one-shot interferometry, the means for at least approximately achromatic beam deflection are preferably in the form of an achromatized deflection wedge or a mirrored staircase or an achromatic prism mirrored staircase.

Furthermore, in the case of the arrangement for robust one-shot interferometry, the whipstock is preferably designed as a combination of refractive prism wedge and at least one diffractive optical element (DOE).

Furthermore, in the arrangement for robust one-shot interferometry, both the arrangement of beam splitter surface and beam combiner surface and the plane mirror of the triple mirror arrangement are preferably designed as a rigid body arrangement, so that the predetermined angular deviation delta_beta is predetermined by the ideal room corner fixed and permanent.

Furthermore, in the case of the arrangement for robust one-shot interferometry, at least one light source is preferably laterally finely structured, also in line or surface form or else in three dimensions.

Furthermore, refractive and / or diffractive means for chromatic longitudinal splitting are preferably arranged in the arrangement for robust one-shot interferometry in the measuring objective and / or in the object beam path.

Furthermore, in the arrangement for robust one-shot interferometry in the measuring objective and / or in the object beam path, the means for chromatic longitudinal splitting with diffractive-optical elements are preferably formed.

Furthermore, in the arrangement for robust one-shot interferometry, many miniaturized measuring objectives are preferably arranged in a row or matrix arrangement and geometrically aligned accordingly, triple reflectors in row or matrix arrangement, the triple reflectors having at least approximately each a predetermined angular deviation delta_beta ,

Furthermore, in the arrangement for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM), preferably miniaturized measuring objectives are arranged in the form of a microlens array.

Furthermore, in the arrangement for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM), the retro-reflector is preferably an arrangement of two halved, at least approximately identical reference half-objectives with the focal lengths f'_1 and f'_2 = f 'formed. These two reference half lenses form a retro reflector system. In this case, their optical axes are at a small predetermined distance delta_e parallel to each other and the focal planes of the two halved, identical reference half lenses coincide at least approximately. These two reference half lenses are highly stable and rigidly combined. Such a retro-reflector system produces a constant achromatic tilt of the output beam to its input beam from delta_rho = (delta_e) / f and can thus be used in the reference beam path of the robust one-shot interferometer to achieve a proportion of the predetermined inclination alpha of object to the reference beam at the output of the two-beam interferometer. As a rule, this will be the main part of alpha. The inclination angle delta_rho thus represents the predetermined deviation from the parallelism of output beams to the input beam of the thus modified retro-reflector system.

It is possible that, for example, by single-point diamond processing, the two mirrors of a Schwarzschild lens are made as reference half lenses that these correspond to at least approximately identical Schwarzschild half systems whose optical axes arranged parallel to each other and delta_e by a small amount are offset. In the simplest case, the two mirrors each have two spherical shells whose center points are offset slightly, that is, by delta_e. These two Schwarzschild half systems have the same focal length f'_1 and f'_2 = f 'and the focal planes of the two half systems coincide. The two Schwarzschild half-system mirrors are preferably each on the same base body. However, when assembling such a modified Schwarzschild system, care must be taken with respect to the azimuthal position of the two modified mirror halves to minimize aberrations. Furthermore, in the arrangement for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM), the object-imaging measuring objective is preferably formed with a comparatively high numerical aperture. This numerical aperture can be significantly more than 0.1.

Furthermore, in the arrangement for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM), preferably the source of electromagnetic radiation in the frequency domain as over time tunable frequency comb laser light source, or as - in terms of optical path length 2L on the time - tunable multi-beam interferometer formed. Thus, the distances of the intensity maxima of the frequency comb laser light source in the frequency comb, or the transmission maxima of the multi-beam interferometer in the frequency space change. At this time, the optical path length or the optical retardation length 2L is made equal at least approximately once to the optical retardation x in the high-aperture short-coherence interference microscope (HA KIM) at a time of temporal tuning. This approach has already been described in the German Offenlegungsschrift DE 2008 062 879 A1 by K. Körner and W. Osten for a frequency comb laser light source and in the German patent specification DE 2008 020 902 B4 by K. Körner, W. Lyda and W. Osten for a multi-beam interferometer.

Furthermore, in the arrangement for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM), preferably means for simultaneous through- or Nachfokussierung arranged in the object beam path in addition to the means of tuning, which means with the synchronization of the tunable frequency comb light source or combined with means for synchronizing a time tunable multi-beam interferometer. Thus, the pitches of the intensity maxima of the FC laser in the frequency comb, or the transmission maxima of the multi-beam interferometer change when tuning.

Furthermore, in the case of the arrangement for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM), the means for simultaneous through- or post-focussing in the object beam path may be a predetermined controllable liquid lens, a predetermined controllable membrane mirror or a spatial, predetermined controllable light modulator formed. Preferably, the means for simultaneous through- or refocusing in the object beam path are in the Fourier plane of the object beam path, so that the magnification of the image does not change, at least approximately.

Furthermore, in the arrangement for robust one-shot interferometry, also in the form of high-aperture short-coherence interference microscopy (HA KIM), means for wave front shaping are preferably arranged in the object space. This makes it possible to measure aspheres. These may be static or may be designed to be variable over time.

Description of the figures

The invention is exemplified by the 1 to 10 and additionally described with reference to six embodiments of the interferometer or of a component of the interferometer AB1 to AB6 without figures.

Here, the term light is always used as a synonym for electromagnetic radiation from the terahertz, over the infrared to the deep UV spectrum.

The 1 represents a sensor based on an interferometer, which was proposed in basic type in 1988 by K. Körner and H. Fritz [2] - [4]. The sensor according to 1 , designed here as a point sensor, can also be used to test polished aspheres. The light from a spectrally comparatively broadband light source 1 in the near-infrared range occurs via a single-mode fiber 2 whose fiber end is a light source point, and is passed through a collimator 3 mapped to infinity. The collimated bundle reaches a beam splitter surface 4 a plane parallel plate 5 where the light is split into a reference beam R and an object beam O. The course of two beams A and B can until detection on the rasterized receiver 131 be tracked. The beam splitter surface 4 on the plan parallel plate 5 opposite and slightly offset is a beam merging surface 6 arranged, which then serves the beam association.

The light which is at the beam splitter surface 4 is reflected in the object beam path, enters a half-Schwarzschild measuring objective 7 which consists of a central mirror 8th and an exterior mirror 9 exists, which is shown symbolically in detail A in the plan view. In a further embodiment (AB1), the Schwarzschild measuring objective is also designed as a full system, which is then used only halfway here. The half-Schwarzschild measuring objective has an average numerical aperture of 0.14. The marginal beam angle of the measuring lens varies here azimuthally due to the half system.

The object light beam strikes after passing the half-Schwarzschild measuring objective 7 Focuses on the specular object surface of the object at the measuring point MP 101 , This object 101 here represents an aspherical optic to be measured for the measurement of form. The object surface thereof in the scanned annular region should be located within the wave-optical depth of field of the focused light. The object 101 returning light becomes after passing the half-Schwarzschild measuring objective 7 , the transmission at the beam splitter surface 4 and after transmission of the beam combiner surface 6 via the interferometer output in the direction of the screened detector 131 directed. That at the beam splitting of the input beam, the beam splitter surface 4 rectilinearly passing reference light bundle R reaches the triple reflector 11 , In this triple mirror reflector 11 is the plane mirror 12 around the angle delta_beta from the ideal room corner tilted out. The reference light bundle R undergoes reflection of the first two plane mirrors of the triple mirror reflector 11 and finally, after reflection on the plane mirror 12 a beam tilt to the input beam of delta_rho hits the beam combiner surface 6 and after reflection, arrives at the screened detector in the form of a matrix camera 131 where there is interference with the object from the beam splitter surface 4 and the beam combiner area 6 coming object beam O comes. The angle between reference and object beams, or between the normals of the two interfering wavefronts is alpha. This creates two-beam interference. TAT-E is the sub-aperture of the triple reflector in its input area. TAT-A represents the sub-aperture of the triple reflector in its output region. The lateral shear between the interfering wavefronts - ie on the matrix camera 131 - is at least approximately made to zero, even by the collimator 3 resulting wavefront aberrations are largely ineffective. That on the matrix camera 131 resulting areal short-coherence interferogram that in each illuminated by the interference light line of the matrix camera 131 an intensity wavelet 140 is evaluated to evaluate the shape errors of the asphere, the asphere being for optical scanning on a rotating but not shown ultra-precision turntable. Before the evaluation, an averaging of the intensity values of the spatial interferograms is performed. On the matrix camera, at least the half-width of the envelope of the spatial interferogram, which consists of the spectrum of the interfering light and the data of the geometrical-optical image on the matrix camera, should be accommodated 131 results. It is advantageous if at least the full width of the envelope of the spatial interferogram of the length of the detected interferogram on the matrix camera 131 equivalent. The measuring arrangement is to be dimensioned in connection with the wave-optical depth of focus of the object image.

The 2 represents a point sensor following the arrangement 1 Here, the detail B the detail A in 1 equivalent. This point sensor can also be used to test polished aspheres. To increase the wavelength of the optical depth of field, there is additionally a weakly focusing, diffractive-optical element 15 , a DOE, here a Fresnel lens with positive refractive power, arranged. This diffractive-optical element 15 leads to a chromatic depth splitting of foci in the range delta_z, ie from MPmin to MPmax, in the object space, so that the depth measuring range of the point sensor compared to the simple optical depth of field given by the numerical aperture and the respective acting wavelength - increased here several times. To compensate for the optical path difference and to eliminate path difference variations in the interferometer in the reference beam path is a plane parallel plate 16 arranged to compensate for the optical path difference and for adjusting the dispersion, which by the substrate of the diffractive optical element 15 is introduced. At the output of the interferometer is a cylinder optics 17 which focuses the collimated beams from the object and reference arms into a line of light representing the spatial interferogram, wherein in the focal plane the cylinder optics 17 a slit diaphragm 18 , see also detail C, which also gives partial confocal discrimination. This spatial interferogram is transmitted through a telescope to a line camera 132 displayed. The telescope consists of the first telescope objective 19 , the second telescope lens 21 as well as a double slit panel 20 , see also detail D, in the common focal plane of the telescope lenses 19 and 21 which also serves the low pass filtering of the object light beam and another partial confocal discrimination. Thus, object and reference wavefronts overlap on the line scan camera 132 to a spatial interferogram whose intensity distribution is a wavelet 140 is shown.

The 3 represents a multipoint line sensor, which in the basic optical concept also on the optical arrangement according to 1 is based, here the detail E the detail A in 1 equivalent. The spectrally broadband light source 100 is designed as an arrangement with a plurality of single-mode fibers in a straight line. The individual light source points at the fiber ends are each controlled by a collimator 3 mapped to infinity. The thus collimated bundles reach a beam splitter surface 4 a plane parallel plate 5 where each incident light beam is split into a reference beam by transmission and an object beam by reflection. The beam splitter surface 4 on the plan parallel plate 5 opposite and slightly offset is a beam merging surface 6 arranged, which then serves the beam association. In the reference beam path is a Schwarzschild reference lens 22 with reference mirror 23 arranged in its focus position. TAF-E, see also detail F, is the partial aperture of the Schwarzschild reference lens 22 in its entrance area and TAF-A represents the sub-aperture of the Schwarzschild reference lens 22 in the output region. The beam deflection is by means of achromatic optical wedge 24 consisting of a prism wedge with an applied diffractive optical element generated. As a result, there is an at least approximately the same angle alpha between the reference beam and the object beam, or between the normals of the two interfering wavefronts at the output of the interferometer, for all wavelengths. In the object beam path is a plane parallel plate 16 to balance the optical Path difference arranged in the interferometer, so that the effect of the substrate in terms of optical path length and dispersion of the achromatic optical wedge 24 is at least approximately compensated. The measurement object here represents a metallic, micromachined measurement object 102 whereby a confocal discrimination of the object light is not absolutely necessary, since, due to physical reasons, no stray light emerges from the interior of the metallic object, which would make optical data acquisition more difficult. At the output of the interferometer is a cylinder optics 17 which focuses the plurality of collimated bundles from the object and reference arms into a plurality of separated and parallel light lines, each light line each having a spatial interferogram on a matrix camera 131 represents, so that a plurality of spatially separated interferogram simultaneously by means of matrix camera 131 is detected in a camera frame in the form of a stack, which is shown symbolically in detail G. The intensity distributions of two interferograms 141 and 142 are shown. Thus, with appropriate design of the sensor, a linear profile measurement on the measurement object 102 in the time of a single camera frame possible, since for profiling each spatial interferogram provides a depth measurement point.

The 4 also represents a line sensor and is partly based on the arrangement 3 where detail H is detail A in FIG 1 corresponds and the detail J the detail F in 3 , To increase the wave-optical depth of field is also here - as in 2 A weakly focusing diffractive-optical element 15 , a DOE, here a Fresnel lens with positive refractive power, arranged. This diffractive-optical element 15 performs chromatic depth splitting of foci in the range delta_z, ie from MPmin to MPmax, in the object space, so that the depth measuring range of this line sensor compared to the simple optical depth of field - given by the numerical aperture and the respective acting wavelength - increased here several times , The biological object of measurement 103 is optically scanned simultaneously in a cut surface by a plurality of foci both laterally and in depth. To compensate for the effect of the substrate diffractive-optical element 15 on the optical path difference in the interferometer is the substrate of the achromatic optical wedge 24 in the reference beam path with at least approximately the same optical path length as the substrate of the diffractive-optical element 15 educated. The dispersion of the substrates is at least approximately equalized. At the output of the interferometer is a cylinder optics 17 which focuses the plurality of collimated beams from the object and reference arms into a plurality of lines of light, each spatial interferograms in the focal plane of the cylinder optics 17 form. Here, in the focal plane of the cylinder optics 17 a multi-pane panel 25 , see also detail K, which also gives partial confocal discrimination. The spatial interferograms are transmitted through a telescope to a matrix camera 131 displayed. This telescope consists of the first telescope lens 19 , the second telescope lens 21 as well as a double slit panel 20 , see also detail L, which is located in the common focal plane of the telescope, which also serves the low-pass filtering of the object light beam and another partial confocal discrimination. Thus, low pass filtered object and reference wavefronts overlap on the matrix camera 131 , represented in detail M, to spatial interferograms whose intensity distributions are exemplified in the form of two wavelets 141 and 142 are shown.

The 5 shows a mirrored staircase 26 coming from a first plane mirror 261 and a second plane mirror 262 is constructed. This mirrored staircase 26 generates a beam direction change of delta_rho for the reference beam R and becomes a cusp reflector 11 or a Schwarzschild reference lens 22 with reference plane mirror 23 , which together form a retro-reflector system, added or arranged in order to produce a slope with the angle alpha between the reference and object beams at the output of the interferometer.

The 6 represents a three-plane mirror reflector group 270 where the first plane mirror 271 , the second plane mirror 272 and the third plane mirror 273 each perpendicular to a common reference plane E stand. This three-plane mirror reflector group 270 creates a lateral shear. When placed in the focus area of a reference Schwarzschild lens 22 - Instead of a single plane mirror - creates a beam direction change for the reference beam R to produce the angle alpha between the reference and object beams.

The 7 represents a reference retro reflector 280 which has two sub-apertures TAF-E and TAF-A, of which the sub-aperture TAF-E each alone for in the reference retro-reflector 280 incoming light and a sub-aperture TAF-A each alone for from the reference retro-reflector 280 Outgoing light is used. The reference retro reflector 280 is an arrangement of two halved, at least approximately identical reference half lenses 281 and 282 formed with the focal lengths f'_1 = f'_2 = f '. These two reference half lenses 281 and 282 form together with the reference plan mirror 23 the reference retro reflector 28 , Here are the optical axes of the two reference half lenses 281 and 282 in a small predetermined distance delta_e parallel to each other and the focal planes of the two halved, identical reference half lenses 281 and 282 coincide. These two reference half lenses 281 and 282 are highly stable and mechanically rigidly combined. Such a reference retro-reflector 280 produces a constant achromatic slope delta_rho of the output beam to its input beam from delta_rho = (delta_e) / f ' and can thus be used in the reference beam path of a robust one-shot interferometer in order to realize at least a portion of the predetermined inclination alpha of the object to the reference beam at the output of the two-beam interferometer. In general, this will be the major part of alpha. The inclination angle delta_rho thus represents the predetermined deviation from the parallelism of output beams to the input beam of the reference retro-reflector 280 represents.

Another embodiment of the reference retro-reflector (AB2) - here without representation in a figure - is constructed as a Schwarzschild lens. In this case, the two mirrors of the Schwarzschild objective are manufactured as reference half-objectives by single-point diamond machining such that they correspond at least approximately to two identical Schwarzschild half systems whose optical axes are arranged parallel to one another and offset by a small amount delta_e. In the simplest case, the two mirrors each have two spherical shells whose center points are offset slightly, that is, by delta_e. These two Schwarzschild half systems have the same focal length f'_1 and f'_2 = f 'and the focal planes of the two half systems coincide. The two Schwarzschild half-system mirrors are preferably each on the same base body. However, when assembling such a modified Schwarzschild system, care must be taken with respect to the azimuthal position of the two modified mirror halves to minimize aberrations.

Another embodiment of the interferometer (AB3) - here without representation in a figure - is constructed with a multi-point light source whose light points cover a measuring field area after imaging, for microforming on rough surfaces. This is a matrix camera 131 arranged slightly twisted for detecting a variety of spatial interferograms. Such an approach, which comes here to avert, was already for the areal spectral interferometry already in the Scriptures DE 10 2006 007 172 A1 in paragraph 0056 and the 8th to 10 revealed.

The 8th represents a line sensor on the optical retardation zero with full-screen observation. This embodiment is particularly well suited for objects that ensure a rather good pupil illumination in the returning object light and in which Speckling does not occur or only to a negligible extent. This is usually given in the micro-material processing, when the machined surfaces reflect.

The light from a spectrally broadband light source 110 in the near-infrared area for linear lighting meets one unit 111 , consisting of a microlens array with a downstream pinhole line, which is not shown here in detail. This creates a line of microscopic point light sources whose light is highly spatial coherent with a mirror objective 112 mapped without infinity to infinity. After passing a beam splitter 113 , the only one of the coupling and decoupling of light from the light source 170 For simultaneous illumination and detection of the processing area in the visible spectral range, the collimated light of the point light sources enters the interferometer block 114 one. There it meets the beam splitter and beam combiner unit 115 coming from the plane parallel plate 5 consists of several 90 ° prisms 116a . 116b and 116c are attached with optical contact to allow each vertical beam input and failure. After the beam splitting at the beam splitter surface 4 arise the object beam O and the reference beam R. The object beam O enters a Schwarzschild lens 117 which is from the central mirror 118 and the outside mirror 119 consists. A section of the central mirror 118 and a portion S1 of the outside mirror 119 are each reserved for measuring radiation. The Schwarzschild lens 117 has a numerical aperture of 0.14 for the measuring radiation incident on the metallic workpiece 102 is focused. For machining the metal workpiece 102 is a femtosecond laser 120 arranged, whose short-pulsed light, the metallic workpiece 102 via a deflection mirror and over a partial area of the central mirror 118 and the portion S2 for machining radiation of the outside mirror 119 reached. The parameterization of the femtosecond laser 120 is not the subject of this embodiment.

That of the metallic workpiece 102 For interferometric measurement and for inspection returning light passes over parts of the Schwarzschild lens 117 in the beam splitter and Beam combiner unit 115 where at the beam splitter surface 4 a new splitting takes place. Part of the light from the inspection area, from the light source 170 in the visible range for object room illumination with rectangular field of view diaphragm 171 and collimator 172 comes after leaving the Strahlvereiniger unit 115 via the output A, then via the beam splitter 113 in reflection, the deflection mirror 173 , the blocking filter 174 , which serves to block the near-infrared sensor measuring light and the laser radiation from the machining process, and the camera lens 175 on a CCD camera 176 brought. This becomes the inspection area of the metallic workpiece 102 imaged in high resolution and areal. The light source 170 is made switchable, so that in the interferometric measurement process whose light does not lead to measurement errors. The possibility of inspection of the processing area by means of a light source 170 and CCD camera 176 also serves to set up the interferometric line sensor before and during the machining process by means of microscopic image processing. The measuring light from the light source 110 happens the beam splitter surface 4 , passes through the plane parallel plate 5 made of refractive material and strikes the Strahlereinigerfläche 6 where it comes to the superposition with the reference beam R from the reference beam path. For reference beam R: The reference beam R transmits upon entry of the light from the spectrally broadband light source 110 at the beam splitter surface 4 and enters the triple mirror reflector 11 , There it also happens the plane mirror 12 of the triple mirror reflector 11 , which by the angle delta_beta from the ideal corner of the room, or ideal cube corner, tilted out. Depending on the position of the triple mirror reflector 11 to the incident reference beam R results - as a result of the angular deviation delta_beta of the plane mirror 12 - At the exit of the triple mirror reflector 11 a deviation from the parallelism of the individual beams of the reference beam R from the angle delta_rho. The distance of the triple mirror reflector 11 from the beam splitter and beam combiner unit 15 is chosen so that the optical paths of the reference beam R correspond to those of the object beam O after the beam combination at least approximately. The reference beam R strikes after passing through the triple mirror reflector 11 on the Strahlereinigerfläche 6 , So where it comes to the superposition with the reference beam R from the reference beam path. This results in two pairs of pairs of interference beams IB1 and IB2, the pair of pairs of interference signals IB1 being output at the output IA1 via the prism 116c and the interference bunch IB2 at the output IA2 over the polished plane surface 116d the plane parallel plate 5 exit. The interferograms which supply the pairs of pairs of interference beams IB1 and IB2 are due to the dielectric and thus lossless stack of layers of the beam unit surface 6 at the outputs IA1 and IA2 of the interferometer block 114 at least approximately out of phase. Thus, the dual-balanced technique is applicable, which eliminates the DC component of interferograms by difference operations. Thus, useful measurement results are delivered even in the case of non-cooperative measurement objects. At the prism 116b if this in the manufacturing process of the sensor as the last prism in the interferometer block 114 to the plane parallel plate 5 is attached, can during optical contacting to this plane parallel plate 5 - By means of special computer-aided interferogram analysis for dispersion analysis - by a micrometer fine lateral displacement a different dispersion between object and reference beam path in the interferometric beam path for a metallic object to be measured 102 be fully compensated. In this case, the optical path difference by means of distance setting on the triple reflector 11 be tracked successively, so that when using the sensor, the detection of a variety of interferograms in the vicinity of the optical path difference can be zero.

The two interference bundle pairs IB1 and IB2 leave the interferometer block 114 and are about the plane mirror 177 and 178 deflected so that they are at least approximately symmetrical to Strahlvereinigerfläche 6 expand, and are made by the cylindrical mirror optics 179 and 180 to a variety of linear spatial interferograms on the CCD matrix camera 131 focused on the two subregions SB IB1 and SB IB2 of the same, after a VIS UV cut filter 181 - for the blocking of radiation from the visible and UV spectral range - from the near-infrared radiation was passed. Detail N shows the CCD matrix camera rotated into the plane of the drawing 131 with the narrow subregions that form a stack and where the line-shaped spatial interferograms are detected individually and separately. This is shown in detail N. The lateral shear is made zero in the two pairs of interference bands IB1 and IB2 during the detection. Each line-shaped spatial interferogram here represents a measuring point along a line on the metallic object to be measured 102 ,

In another embodiment, not shown here to a line sensor (AB4) after 8th The light of the femtosecond laser is used to generate a particularly slim system 120 in 8th via a dichroic beam splitter in the subregion S1 of the outside mirror 119 coupled. The processing and measurement times are interleaved in time so that there is no impairment of the measurement due to the high-energy radiation from the machining process.

The 9 represents a multi-modal system for in vivo detection or in vivo diagnosis, and the in vivo treatment of tumor cells and carcinogenic tissue areas thus a cancer cell detector with an integrated femtosecond laser 121 for treatment. The in vivo diagnosis is based on a multi-sensorial detection in combination with a computer-assisted diagnostic system. The multi-modal system is configured as a spectral wide-area system in order to be able to make informed decisions on the presence of tumor cells and the further course of action with the greatest possible degree of certainty in surgical "real-time surgery".

This multi-modal measuring system is also suitable for an object class, which does not ensure very good pupil illumination in the returning object light due to the object characteristic. Here, too, speckling can occur in the detected object light, ie, bacon is tolerable, even if this increases the measurement uncertainty. A hardware-based confocal filtering on a slit diaphragm produces an at least partially low-pass filtered object cylinder shaft.

The lighting is done, inter alia, with a light source system 301 for linear beamforming, which includes both a spatially coherent spectral narrowband near-infrared source and a suitable laser for Raman spectroscopy. In the 9 Shade covers and light traps are not shown in principle, since their arrangement and use the expert expert is a matter of course. That from the light source system 301 emitted light - light in the sense of electromagnetic radiation - passes the beam splitter 302 , At this beam splitter 302 In addition, spectral broadband light from a near-infrared source is reflected 303 for near-infrared spectral analysis of human tissue 103 coupled. The line-focused light strikes a unity 111 , consisting of a microlens array with a downstream pinhole line, which is not shown here in detail. This creates a line of microscopic point light sources whose light is highly spatial coherent after passing through a beam splitter 303 - For decoupling of returning object light - and a mirror lens 112 mapped without infinity to infinity.

After passing another beam splitter 113 , the only one of the coupling and decoupling of light from the light source 170 in the visible spectral range for simultaneous illumination and inspection of the examination, or the operation area, serving on the human organ, which is the human tissue to be examined 103 contains, the collimated light of the point light sources enters the interferometer block 114 one. There it meets the beam splitter and beam combiner unit 115 coming from the plane parallel plate 5 consists of several 90 ° prisms 116a . 116b and 116c are attached with optical contact to allow each vertical beam input and failure. After the beam splitting at the beam splitter surface 4 arise the object beam O and the reference beam R. The object beam O enters a Schwarzschild lens 117 which is from the central mirror 118 and the outside mirror 119 consists. A section of the central mirror 118 and a subarea 51 the exterior mirror 119 are each reserved for measuring radiation. The Schwarzschild lens 117 has a numerical aperture of 0.14 for the measuring radiation incident on the human tissue 103 is focused on suspected tumor cells, so that creates a variety of focal points in a line. The type of evaluation based on the topographic or depth information obtained from the focus points - ie the optically addressed measurement points on human tissue 103 - can be obtained, as well as the spectroscopic information for the purpose of reliable diagnosis of the nature of the cells or the nature of the human tissue 103 is not part of this invention. For the treatment of human tissue 103 After evaluation of the extensive data situation by the doctor in connection with a computer-supported diagnostic system is a femtosecond laser 121 whose short-pulsed light is the human tissue 103 via a deflection mirror and over a partial area of the central mirror 118 and the portion S2 of the outside mirror 119 reached. The parameterization of the femtosecond laser 121 for the treatment of human tissue 103 suspected tumor is not the subject of this embodiment.

That of human tissue 103 For interferometric measurement and for the return of light comes light over parts of the Schwarzschild lens 117 into the beam splitter and beam combiner unit 115 where at the beam splitter surface 4 a new splitting takes place. Part of the light from the inspection area, from the light source 170 in the visible range for object room illumination with rectangular field of view diaphragm 171 and collimator 172 comes after leaving the Strahlvereiniger unit 115 via the output A, then via the beam splitter 113 in reflection, the deflection mirror 173 , the blocking filter 174 , which serves to block the near-infrared sensor measurement light and the laser radiation from the treatment process, and the camera lens 175 on a CCD camera 176 brought. This becomes the human tissue 103 imaged in high resolution and areal. The light source 170 is made switchable, so that in the interferometric measurement process whose light does not lead to measurement errors. The possibility of Inspection of human tissue 103 by means of light source 170 and CCD camera 176 in full-screen mode also serves the establishment of the interferometric line sensor before and during the treatment process with the means of microscopic image processing. The measuring light from the light source 110 happens the beam splitter surface 4 , passes through the plane parallel plate 5 made of refractive material and strikes the Strahlereinigerfläche 6 where it comes to the superposition with the reference beam R from the reference beam path. For reference beam R: The reference beam R transmits upon entry of the light from the spectrally broadband light source 110 at the beam splitter surface 4 and enters the triple mirror reflector 11 , There it also happens the plane mirror 12 of the triple mirror reflector 11 , which by the angle delta_beta from the ideal corner of the room, or ideal cube corner, tilted out. Depending on the position of the triple mirror reflector 11 to the incident reference beam R results - as a result of the angular deviation delta_beta of the plane mirror 12 - At the exit of the triple mirror reflector 11 a deviation from the parallelism of the individual beams of the reference beam R from the angle delta_rho. The distance of the triple mirror reflector 11 from the beam splitter and beam combiner unit 15 is chosen so that the optical paths of the reference beam R correspond to those of the object beam O after the beam combination at least approximately. The reference beam R strikes after passing through the triple mirror reflector 11 on the Strahlereinigerfläche 6 , So where it comes to the superposition with the reference beam R from the reference beam path. This results in two pairs of pairs of interference beams IB1 and IB2, the pair of pairs of interference signals IB1 being output at the output IA1 via the prism 116c and the interference bunch IB2 at the output IA2 over the polished plane surface 116d the plane parallel plate 5 exit. The interferograms which supply the pairs of pairs of interference beams IB1 and IB2 are due to the dielectric and thus lossless stack of layers of the beam unit surface 6 at the outputs IA1 and IA2 of the interferometer block 114 at least approximately out of phase. Thus, the dual-balanced technique is applicable, which eliminates the DC component of interferograms by difference operations. Thus, even with the usually little cooperative human tissue 103 still usable measurement results delivered. The pair of interference bunches IB2 passes over the deflection plane mirror 183 , the beam splitter 188 in transmission to the cylinder mirror 184 , wherein a further beam splitter, which is required for coupling into the detection beam path, is not shown here. The interference bundle IB1 emerging via the output IA1 passes over the deflection plane mirror 182 on the cylinder mirror 184 , wherein the further, not shown here, beam splitter is passed for coupling into the detection beam path. The two pairs of interference fringes IB1 and IB2 are by the pair of cylinder mirrors 184 and 185 focused to cylindrical waves. Due to the inclination of the reference beam R to the object beam O at the angle alpha at the outputs IA1 and IA2 of the two-beam interferometer, the foci of the beams are at the double slit diaphragm 186 separated. Thus, an adapted low-pass filtering can be carried out, in particular for the object light. The mirror lens 187 without center shading, the object beam O and the reference beam R focus upon passing VIS-UV cut filter 181 on the InGaAs infrared matrix camera 133 , There, parallel to the plane of the drawing, the spatial interferograms are created. It can be very well the recognized dual-balanced technology used. These are the spatial interferograms resulting from the individual points of light of the unit 111 , consisting of a microlens line with downstream pinhole line in focus position, in the beam paths of the out-of-phase outputs of IA1 and IA2 set to "gap". As a result, there are spatial interferograms with antiphase alternating components on the InGaAs infrared matrix camera 133 side by side. This is shown in detail M. The lateral shear is made zero in the two pairs of interference bands IB1 and IB2 during the detection. Each linear spatial interferogram here represents a measurement point for the appropriate human tissue 103 along a line. On the scan movements for global optical scanning of human tissue 103 such as A-scans or B-scans in fine or coarse scales or micro-scans to increase the degree of filling of the measurement is not discussed here, because these possibilities are known to the skilled person of course.

The over the beam splitter system 188 decoupled object O and reference beams R are via a two-stage mirror lens without Mitabschattung 189 each focused on a light point chain, each on the two input column of the optical part of a line difference one-shot spectrometer 190 to meet. Point of light for the point of light of the light entering the column is spectrally analyzed, that is, resolved laterally. The source for near-infrared spectral analysis is a spectrally broadband near-infrared source 303 that's over the beam splitter 302 the entrance to the beam path to the interferometer block 114 place. The line difference one-shot spectrometer, which is indeed a double spectrometer, is either a dispersive or a static Fourier transform spectrometer, the latter optionally also with cyclic optical path, but in any case as a one-shot system, educated. In the signal processing system 191 the difference formation of the signals takes place from each spectrometer of the double system, so that the difference spectrum exists for each light point. Each spectrally analyzed point of light is also assigned its depth information, which from the two associated spatial interferograms by means not shown here Calculator hardware is calculated. The detection is carried out as shown by means of InGaAs infrared matrix camera 133 So, every measuring point along a line can be used for the appropriate human tissue 103 the spectral data are assigned. There are several line cuts of human tissue 103 recorded, so that the spatial coordinates are present in three dimensions. In a further embodiment, ABS for a multi-modal system according to 9 is over the beam splitter system 188 also coupled to a fluorescence spectrometer. In order to operate here also Raman spectroscopy, is in the light source system 301 also integrated a laser for Raman spectroscopy. A Raman spectrometer 192 is the beam splitter 304 for the returning and already at the unit 111 associated with pinhole line strictly confocal discriminated light.

In a further embodiment AB6 for a multi-modal system according to 9 For example, the PPP5 is made of calcium fluoride with no prisms attached, so the multi-sensor line sensor can also be used as a wide-spectrum spectral system from the ultraviolet spectral range to the 2.5 μm wavelength in the infrared range.

The 10 based on the arrangement according to 9 and also provides an arrangement for linear detection of tumor cells with an integrated femtosecond laser 121 for treatment. Instead of the deflecting mirror 182 is a beam splitter system 193 arranged. This output can be used for further sensor technology, also based on Raman spectroscopy, for the generation of further measurement data for the detection of tumor cells. In the object beam path is a refractive power compensated diffractive optical element 194 arranged. Thus, the depth measurement range can be increased by a longitudinal chromatic aberration many times the wave-optical depth of field. The depth splitting here is about three times this wave-optical depth of field. The depth measurement uncertainty may increase somewhat, since the width of the envelope in the spatial interferogram increases due to the masking of spectral components due to the confocal discrimination. On the InGaAs infrared matrix camera 133 At least the half width of the envelope of the spatial interferogram should be placed in the middle of the depth measurement range. This half-value width results from the spectrum of the interfering light, which is substantially cut by the chromatic splitting with subsequent confocal discrimination, and the geometric-optical image data on the InGaAs infrared matrix camera 133 , LIST OF REFERENCE NUMBERS reference numeral description 1 Point light source, spectrally broadband 2 Single-mode fiber 3 collimator 4 Beam splitter surface 5 Plane parallel plate made of refractive material 6 Beam combiner surface 7 Semi-Schwarzschild measurement objective 8th Central mirror of the half-Schwarzschild measuring objective 7 9 Exterior mirrors of the half-Schwarzschild measuring objective 7 11 Corner cube reflector 12 Plan mirror of the triple mirror reflector 15 Low-focusing diffractive-optical element with positive refractive power (Fresnel lens) 16 Plan parallel plate to compensate for the optical path difference in the interferometer 17 cylindrical optics 18 slit 19 first telescope lens 20 Double slit diaphragm 21 second telescopic lens 22 Schwarzschild reference objective 23 Reference plane mirror 24 Achromatic wedge, consisting of prism wedge and applied diffractive-optical element 25 Multi slit 100 Spectral broadband light source with single-mode fiber arrangement in one line 101 object 102 Metallic, micromachined measurement object, workpiece 103 Biological target, Human tissue 110 Spectral broadband light source for linear illumination 111 Unit consisting of a microlens line with a downstream pinhole line in focus position 112 two-stage mirror lens without center shading 113 beamsplitter 114 Interferometerblock 115 Beam splitter and beam combiner unit 116a , b, c 90 ° prisms 117 Schwarzschild lens with a partial pupil for measuring radiation and a partial pupil for processing radiation 118 Central mirror of the Schwarzschild lens 117 119 Exterior mirror of the Schwarzschild lens 117 120 Femtosecond laser for processing 121 Femtosecond laser for treatment 131 matrix camera 132 line camera 133 InGaAs infrared matrix camera 140 Intensity wavelet of short-coherence interferogram 141 Intensity wavelet of short-coherence interferogram from a stack 142 Intensity wavelet of short-coherence interferogram from a stack 170 Light source in the visible area for object room illumination for the purpose of inspection by means of microscopic image processing 171 rectangular field stop for object room lighting 172 collimator 173 the deflection mirror 174 Barrier filter for the line sensor measuring light 175 camera lens 176 CCD camera 177 Plane mirror 1 178 Plane mirror 2 179 Cylindrical mirror optics 180 Cylindrical mirror optics 181 VIS-UV cut filter 182 Umlenkplanspiegel 183 Umlenkplanspiegel 184 cylindrical mirror 185 cylindrical mirror 186 Double slit diaphragm 187 two-stage mirror lens without center shading 188 Beam splitter system 189 two-stage mirror lens without center shading 190 Optical part of a line difference one-shot spectrometer 191 Signal processing system of the Line Difference One-Shot Spectrometer 192 Raman spectrometer 193 Beam splitter system 194 Refractive power compensated diffractive optical element 260 mirror cascade 261 Plane mirror 1 262 Plane mirror 2 270 Three-plane mirror reflector group 271 First plane mirror 272 Second plane mirror 273 Third plane mirror 280 Reflective retro-reflector with achromatic beam deflection 281 first half-lens of the reference retro-reflector 280 with achromatic beam deflection 282 second half-lens of the reference retro-reflector 280 with achromatic beam deflection 301 Light source system with spatially coherent, spectrally narrow-band near-infrared source and laser for Raman spectroscopy 302 Beam splitter in the illumination beam path 303 Spectral broadband near infrared source for near infrared spectral analysis 304 beamsplitter O Object-ray beam R Reference radiation beam IB1 Interference bundle pair 1 IB2 Interference bundle pair 2 TAT E Partial aperture for triple reflector, entrance area TAT-A Sub-aperture for triple reflector, output range TAF-E Partial aperture for half Schwarzschild measuring objective 7 , Entrance area TAF-A Partial aperture for half Schwarzschild measuring objective 7 , Exit area

Claims (32)

A method of robust one-shot interferometry or high-aperture short-coherence interference microscopy for distance, depth, profile, shape, waviness, microform, micro-profile and / or roughness measurement or for measuring the optical path length of an object or an object detail or its spatial or temporal change and / or optical coherence tomography (OCT) or optical coherence microscopy (OCM), in particular as optically measuring scout sensor in a multi-sensorial material measurement and material processing system or in a multi-sensorial system Detection of tumor cells and their optical treatment - with at least one two-beam interferometer, also in the form of a high-aperture short-coherence interference microscope, - with at least one monochromatic and / or polychromatic source ( 1 . 100 . 110 ) electromagnetic radiation at the entrance of the two-beam interferometer, - with a beam splitter surface ( 4 ) in each two-beam interferometer for generating object and reference light, ie in the form of object and reference beams or object and reference wavefronts, by division of the wave amplitude - and with one of these beam splitter surface ( 4 ) each at least approximately parallel opposite and from this spatially separated Strahlereiniger surface ( 6 ) for the reunification of object and reference light for the purpose of interference - with a reference beam path in the two-beam interferometer each with a retro-reflector ( 11 . 22 . 280 ), each of which has at least two partial apertures (TAT-E, TAT-A or TAF-E, TAF-A), of which one half aperture (TAT-E, TAF-E) each alone for in the retro-reflector entering light and one partial aperture each alone (TAT-A, TAF-A) for out of the retro-reflector ( 11 . 22 . 280 ) outgoing light, whereby a separation of in the retro-reflector ( 11 . 22 . 280 ) incident light and from - after the retro-reflection - exiting light is performed, - with an object beam path in the two-beam interferometer with an object ( 101 . 102 . 103 ) or at least one element of the object ( 101 . 102 . 103 ) illuminating and imaging measuring objective ( 7 ), - and with at least one rastered detector ( 131 . 132 . 133 ), with which at least one spatial interferogram is registered, characterized by the method steps: - Geometric separation of incoming and returning beam in the reference beam at least approximately in the size of the reference beam diameter by means of retro-reflection by means of the lateral positioning and / or the geometric Training of the Retro-reflector ( 11 . 22 . 28 ) in the two-beam interferometer, - generating a predetermined inclination alpha of a reference beam R to an object beam O at the output of the two-beam interferometer by means ( 24 ) for at least approximately achromatic beam deflection in the reference beam path on the basis of reflection and / or diffraction and / or refraction, including measures for the predetermined geometric design of the retro-reflector (US Pat. 11 . 22 . 280 ) or of components thereof, and / or generating the predetermined inclination alpha of a reference beam R to an object beam (O) at the output of the two-beam interferometer by reflection of reference beam (R) or object beam (O) in their reunification at the separated beam combiner -Area ( 6 ), so that as a result of the sum of the means and measures for the achromatic beam deflection of the reference beam (R) and the reunification at the Strahlereiniger surface ( 6 ) a predetermined inclination of the reference beam (R) to each object beam (O) at the angle (alpha) at the output of the two-beam interferometer, - generating spatial short-coherence interference of mutually inclined object and reference beams on the at least one rastered detector ( 131 . 132 . 133 ), wherein the inclination angle alpha at the output of the two-beam interferometer is made at least approximately independent of the wavelength, and this predetermined inclination in the coverage area of object and reference wavefronts on the rastered detector ( 131 . 132 . 133 ), in the spatial interferogram, causes a change in the optical path difference between the interfering wavefronts over the lateral extent of the spatial interferogram leading to a modulation of the intensity in the spatial interferogram, - formation of at least one signal maximum or at least one signal minimum in the spatial interferogram on the rasterized Detector ( 131 . 132 . 133 ), - detection of at least one spatial interferogram on the screened detector ( 131 . 132 . 133 ) and - evaluation of a spatial interferogram for determining the distance, depth, profile, shape, microform, waviness and / or roughness or the optical path length in or on a biological ( 103 ) or technical object ( 101 . 102 ) or object detail. Method for robust one-shot interferometry according to claim 1, characterized in that at least approximately an elimination of the lateral shear of object and reference beams on the rasterized detector ( 131 . 132 . 133 electromagnetic radiation by the simultaneous tuning of the amount and the sign of the lateral bundle separation in the retro-reflection in the reference beam path, the magnitude and the sign of the predetermined geometric separation of the beam splitting surface and the beam combination surface, taking into account the refractive indices of the optical materials which exist between the beam splitting surface 4 ) and beam union surface ( 6 ) as well as the angle and the sign of the angle of inclination (alpha) of the reference beam (R) to the object beam (O) is performed. A method for robust one-shot interferometry according to at least one of claims 1 and 2, characterized in that a wave front shaping of object and reference waves at the output of the two-beam interferometer by means of cylinder optics ( 17 ) or anamorphic prisms is performed, so that in wave front shaping predetermined astigmatism for object and reference waves is introduced and in the detection of each spatial interferogram by astigmatic focusing of each one of a spatial interferogram forming object and reference cylindrical wave of this spatial interferogram at least approximately in linear form on the screened detector ( 131 . 132 . 133 ) is formed. Method for robust one-shot interferometry according to at least one of claims 1 to 3, characterized in that a confocal discrimination by means of gap ( 18 . 20 . 25 ) or pinhole aperture for the returning object light is performed. Method for robust one-shot interferometry according to at least one of claims 1 to 3, characterized in that a confocal discrimination by means of gap ( 18 . 20 ) or pinhole aperture for the returning reference light is performed. Method for robust one-shot interferometry according to at least one of claims 1 to 5, characterized in that also the second output (IA2) of the two-beam interferometer, which is characterized by the arrangement with separate locations for beam splitting ( 4 ) and association ( 6 ) is geometrically decoupled from the input, is used together with the first output (IA1) for the dual-balanced technique to numerically at least approximately completely eliminate the DC component in the detected spatial interferogram. Method for robust one-shot interferometry according to at least one of Claims 1 to 5, characterized in that at least one output (A, IA1, IA2) of the two-beam interferometer is used for NIR spectroscopy. Method for robust one-shot interferometry according to at least one of Claims 1 to 5, characterized in that at least one output (A, IA1, IA2) of the two-beam interferometer is used for Raman spectroscopy. Method for robust one-shot interferometry according to at least one of Claims 1 to 5, characterized in that at least one output (A, IA1, IA2) of the two-beam interferometer is used for fluorescence spectroscopy. Method for robust one-shot interferometry according to at least one of Claims 1 to 5, characterized in that at least one output (A, IA1, IA2) of the two-beam interferometer is used for multiphoton microscopy. Method for robust one-shot interferometry according to at least one of Claims 1 to 5, characterized in that at least one output (A, IA1, IA2) of the two-beam interferometer is used for differential spectroscopy. Method for robust one-shot interferometry according to at least one of claims 1 to 11, characterized in that over a partial aperture of the measuring objective ( 7 . 117 ) suitable laser radiation for laser treatment of living tissue or biological dead material or laser radiation for laser processing of non-biological material is supplied. Method for robust one-shot interferometry according to at least one of claims 1 to 12, characterized in that in the measuring objective ( 7 . 117 ) and / or in the object beam path means for chromatic longitudinal splitting ( 15 ) and at least partial confocal discrimination ( 18 . 20 . 25 ) are arranged to perform depth separation of focus points to implement the chromatic confocal technique. Method for robust one-shot interferometry according to at least one of claims 1 to 13, characterized in that the two-beam interferometer is optically fed with a plurality of input beams, so that a plurality of object beams and reference beams is formed in parallel, and each reference beam formed a retro-reflector and each formed object bundle a measuring objective ( 7 . 117 ) and a parallelized optical scan of the object ( 101 . 102 . 103 ) is carried out. Method for robust one-shot interferometry according to at least one of claims 1 to 14, characterized in that the following method steps are carried out: - subsequent or focussing of the sensor in relation to the measurement object ( 102 . 103 ), so that the optical path difference, at least for the main beam in the object beam path in the two-beam interferometer does not change greatly and - simultaneous tuning of the source of electromagnetic radiation in the frequency space by means of tunable frequency comb laser light source or by means of multi-beam interferometer in terms of optical path length (2L) of the "simple "Optical retardation (x_zu), wherein the current focal plane, especially the focal point on the optical axis of the object beam path of the high-aperture short-coherence interference microscope is always at least approximately localized where a compensation of the optical retardation (x) of the short-coherence interference microscope by the simple optical Delay length (2L) of the frequency comb laser light source or the multi-beam interferometer on the optical axis of the object beam path is made. Method for robust one-shot interferometry according to at least one of claims 1 to 14, characterized in that the following method steps are carried out: - subsequent or focussing of the sensor in relation to the measurement object ( 102 . 103 ), so that the optical path difference at least approximately does not change, at least for the main beam in the object beam path in the two-beam interferometer and - simultaneous tuning of a two-beam interferometer associated with the high-aperture short-coherence interference microscope with respect to its optical path difference (x_zu), wherein the current focal plane, in particular the focal point on the optical axis of the object beam path of the high-aperture short-coherence interference microscope is always at least approximately localized where a compensation of the optical path difference (x) of the high-aperture short-coherence interference microscope by the optical path difference (x_zu) of the associated two-beam interferometer on the optical axis of the object beam path, so that thereby the optical path difference (x_zu) of the associated two-beam interferometer in each case at least approximately once the optical path difference (x) is equalized in the high-aperture short-coherence interference microscope at a time of temporal tuning. Method for robust one-shot interferometry according to at least one of claims 1 to 16, characterized in that the short-term temporal freezing of the spatial interferograms in the scan in the time of image acquisition by means of rastered detector ( 131 . 132 . 133 ) is carried out by means of highly dynamic piezoelectric technology predetermined on the reflector in the reference arm. Arrangement for robust one-shot interferometry, or for high-aperture short-coherence interference microscopy, for distance, depth, profile, shape, waviness, microform, microprofile and / or roughness measurement or for measuring the optical path length of an object ( 101 . 102 . 103 ) or an object detail or its spatial or temporal change and / or for optical coherence tomography (OCT) or optical coherence microscopy (OCM), in particular as optically measuring scout sensor in a multi-sensorial system for material measurement and material processing or in a system for the detection of tumor cells and their optical treatment with the features of the preamble and wherein in the reference beam path of the retro-reflector - either as a compact triple mirror reflector ( 11 ) with three plane mirror surfaces, - or as a triple mirror arrangement, consisting of a roof edge mirror arrangement and a single, this roof edge mirror arrangement associated planar mirror surface, - or as a triple mirror arrangement ( 11 ), consisting of three individual plane mirror surfaces, each representing at least approximately a corner of the room - or the retro-reflector with at least one focusing reference lens ( 22 ) and a reference end reflector ( 23 ), which in each case at least approximately in the focus position of this reference lens ( 22 ), and - the retro-reflector ( 11 . 22 . 23 . 280 ) always has at least two partial apertures (TAT-E, TAT-A or TAF-E, TAF-A), of which one partial aperture (TAT-E, TAF-E) is used alone in the retro-reflector ( 11 . 22 . 23 . 280 Incoming light and a subaperture alone (TAT-A, TAF-A) for from the retro-reflector ( 11 . 22 . 23 . 280 ) is used, characterized in that - either a predetermined angular deviation (delta_beta) from the ideal corner of at least one planar mirror surface ( 12 ) - the compact triple mirror reflector ( 11 ), Or the triple mirror arrangement, consisting of a roof-edge mirror arrangement and a single plane mirror surface associated with this roof-edge mirror arrangement, or the triple-mirror arrangement (US Pat. 11 ) in the reference beam path - or at least one of the two sub-apertures (TAT-E, TAT-A) means ( 24 ) for performing an at least approximately achromatic beam deflection for introducing a predetermined beam deflection (delta_rho) are assigned, - or the retro-reflector with focusing reference lens ( 22 . 281 . 282 ) and reference end reflector ( 23 ) in whose collimated beam path at least two partial apertures (TAF-E, TAF-A), of which a partial aperture (TAF-E) alone for light entering the retro-reflector and a sub-aperture (TAF-A) solely for from the end reflector Outgoing light is used, so that a separation of incident and exiting light in the retro-reflector is performed, and in the collimated beam path of at least one of these two sub-apertures (TAF-E, TAF-A) means ( 24 . 260 ) are assigned for performing an at least approximately achromatic beam deflection for introducing the predetermined inclination (delta_rho) - and / or that by means of predetermined residual angular deviation (delta_gamma) from the parallelism of the beam splitter surface ( 4 ) and this opposite, separated beam combiner surface ( 6 ) after the beam combination at the output of the two-beam interferometer in each case a predetermined inclination (alpha) of a reference wavefront to each an object wavefront is predetermined. Arrangement for robust one-shot interferometry according to claim 18, characterized in that the reference end reflector of the retro-reflector ( 280 ) with focusing reference lens ( 22 . 281 . 282 ) as plane mirror ( 23 ) is designed for single reflection of the focused reference beam. Arrangement for robust one-shot interferometry according to claim 18, characterized in that the reference end reflector of the retro-reflector with focusing reference lens ( 22 ) as a triple plane mirror group ( 270 ) is designed for the triple reflection of the focused reference beam, wherein the three plane mirrors ( 271 . 272 . 273 ) are each arranged perpendicular to a common reference plane (E). Arrangement for robust one-shot interferometry according to claim 18, characterized in that the means for at least approximately achromatic beam deflection as an achromatized whipstock ( 24 ) or a mirrored staircase ( 260 ) or an achromatic prism mirror staircase are formed. Arrangement for robust one-shot interferometry according to claim 21, characterized in that the whipstock ( 24 ) is formed as a combination of refractive prism wedge and at least one diffractive optical element (DOE). Arrangement for robust one-shot interferometry according to claim 18, characterized in that both the arrangement of beam splitter surface ( 4 ) and beam combiner surface ( 6 ) as well as the plane mirrors of the triple mirror arrangement ( 11 ) are formed as a rigid body arrangement, so that the predetermined angular deviation (delta_beta) from the ideal room corner is predetermined fixedly and permanently. Arrangement for robust one-shot interferometry according to at least one of claims 18 to 23, characterized in that at least one light source ( 100 . 110 ) is laterally finely structured, or formed in a line or surface shape or three-dimensional. Arrangement for robust one-shot interferometry according to at least one of claims 18 to 24, characterized in that in the measuring objective ( 7 . 117 ) and / or in the object beam path refractive and / or diffractive means ( 15 ) are arranged for chromatic longitudinal splitting. Arrangement for robust one-shot interferometry according to claim 25, characterized in that in the measuring objective ( 7 . 117 ) and / or in the object beam path the means ( 15 ) are designed for chromatic longitudinal splitting with diffractive optical elements. Arrangement for robust one-shot interferometry according to at least one of claims 18 to 26, characterized in that many miniaturized measuring lenses arranged in a row or matrix arrangement and to triple reflectors are aligned in row or matrix arrangement, the triple reflectors at least approximately each have a predetermined angular deviation (delta_beta). Arrangement for robust one-shot interferometry according to claim 27, characterized in that the miniaturized measuring objectives are arranged in the form of a microlens array. Arrangement for robust one-shot interferometry according to at least one of claims 18 to 27, characterized in that the retro-reflector ( 280 ) as an arrangement of two halved, at least approximately identical reference half-objectives ( 281 . 282 ) is formed with the focal lengths f'_1 and f'_2 = f ', and these two reference half lenses form a retro-reflector system and their optical axes are parallel to each other at a small predetermined distance (delta_e) and the focal planes of the two halved, identically constructed reference half-objectives ( 281 . 282 ) at least approximately coincide. Arrangement for robust one-shot interferometry according to at least one of Claims 18 to 29, characterized in that the source of electromagnetic radiation in the frequency domain is tunable as a time-combatable frequency comb laser light source or as a multi-beam tunable over time with respect to optical path length (2L). Interferometer is formed. Arrangement for robust one-shot interferometry according to at least one of claims 18 to 30, characterized in that in addition to the means of tuning and means for simultaneous through or Nachfokussierung are arranged in the object beam path, which with means for synchronizing the tunable frequency comb light source or are combined with means for synchronizing a time-tunable multi-beam interferometer. Arrangement for robust one-shot interferometry according to at least one of claims 18 to 31, characterized in that the means for simultaneous through- or refocusing in the object beam path are designed as a predetermined controllable liquid lens, as a predetermined controllable membrane mirror or as a spatial, predetermined controllable light modulator.

Images