EP3271694A1

EP3271694A1 - Light emission measuring device and method for measuring light emission

Info

Publication number: EP3271694A1
Application number: EP15720693.9A
Authority: EP
Inventors: Alexander Michael Gigler; Harry Hedler; Remigiusz PASTUSIAK; Anton Schick
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2015-04-30
Filing date: 2015-04-30
Publication date: 2018-01-24
Also published as: JP2018521304A; WO2016173662A1; KR20170141784A; CN107567578A; US20180113074A1

Abstract

An emission measuring device comprising a sample region, an illumination unit for irradiating a sample which is positionable in the sample region and a detection unit for detecting the radiation emitted by the sample by means of a radiation detector is disclosed. The illumination unit comprises a radiation source, a first dispersive element, disposed downstream of the radiation source in the beam direction, for decomposing the radiation into the spectral components thereof, a first micromirror field, disposed downstream of the first dispersive element in the beam direction, for selecting spectral components and a second dispersive element, disposed downstream of the first micromirror field in the beam direction, for unifying the selected spectral components in a common excitation beam. Furthermore, a method for measuring light emission using such an emission measuring device is disclosed, in which the spectral composition of the excitation light beam is selected by activating and/or deactivating the individual micromirrors of the first micromirror field.

Description

description

LIGHT EMISSION METER AND METHOD FOR MEASURING LIGHT EMISSION

The present invention relates to an emission measuring device having a sample area, a lighting unit for irradiating a sample which can be positioned in the sample area, and a detection unit for detecting the radiation emitted by the sample with a radiation detector. Furthermore, the invention relates to a method for measuring the light emission of a sample with such an emission measuring device.

According to the state of the art, emission measuring devices are frequently used either as emission spectrometers or emission microscopes. In known emission spectrometers, a broadband light source is typically used to irradiate a sample, wherein the radiation spectrum of the light source overlaps with at least one absorption band of the sample. By the absorption of light, a compared to the absorption wavelength spectrally verschobe ^¬ ne emission is excited in the sample, which can then be detected in a wavelength depending on a detection unit under decomposition into their spectral components. Such an emission may, for example, be fluorescence emission, photoluminescence emission or phosphorescence emission. In the abovementioned emission mechanisms, part of the energy absorbed by the sample during light absorption is dissipated without radiation, so that the emitted radiation is spectrally changed in the direction of longer-wave radiation. Alternatively, an emission spectrometer can similarly analyze the Raman scattering of a sample. Here, too, there is a spectral change between excitatory and emitted radiation.

In order to stimulate light emission to be measured of the sample ge possible ^¬ aims, it is advantageous if the ANRE ^¬ constricting radiation as much as possible with the absorption band which overlaps the sample. Additional spectral components in the excitation light beam have a disturbing effect on the measurement since, in particular, the longer-wavelength components of the excitation beam can cover the emission to be measured. To prevent this, the art for various samples are used in each different spectrally be selected from ^¬ sorption filter to filter out the unwanted, in particular the longer-wave spectral components of the exciting light according to the state.

For the most accurate detection and spectral analysis of the emitted light, it is also advantageous to filter out the wavelengths of the radiation used for the excitation of the emission, since otherwise the sometimes very weak emission bands can be covered by a strong background signal. In order to achieve a good signal-to-noise ratio of the measurement and a high spectral resolution, therefore, the shorter-wavelength portions of the exciting radiation relative to the emission bands are also filtered out by optical absorption filters.

In a similar manner as in the above-described emission spectrometers, a sample having a short-wave illumination unit for the emission is excited reasonable at the emission microscopy, and the light emitted from the sample radiation is it ^¬ out so imaged on an image plane that a spatial distribution of emission in the different areas of the sample is visualized. Instead of a wavelength-dependent measurement of the emission spectrum, as in the case of an emission spectrometer, an emission microscope thus achieves spatial imaging of the emission centers. Particularly widespread here is the imaging of fluorescent areas by a fluorescence microscope. The two methods of emission spectroscopy and emission microscopy can in principle also be combined with one another.

A disadvantage of the emission spectrometers and emission micro ^¬ microscopes according to the prior art that for the For the sample to be measured adapted filtering of the excitation ^{beam ¬} ment and for the then adapted to the excitation spectrum filtering the radiation to be detected macroscopic optical components (in the form of spectrally selective filters) must be moved and replaced with each other. The replacement of these optical components requires a constant, relatively complicated conversion of the measuring device depending on the sample to be analyzed. On the one hand, this can entail a readjustment of the remaining optical components after each conversion, in order nevertheless to achieve a high measuring quality. On the other hand, the space required in the measuring device for the different, for the different configurations, alternatively or combined in the beam path to be introduced optical filter is a total of relatively high.

The object of the invention is therefore to provide an emission measuring device which overcomes the disadvantages mentioned. In particular ^¬ sondere is to be made available, which is based in terms of apparatus easier listed space saving, easily adaptable and / or universally applicable is an emission measuring device. Another object is to provide a method of measuring light emission with these advantages.

These objects are achieved by the method described in claim 1 emission measuring device and the method described in claim 8 ^¬ measurement process.

The emissivity measuring device according to the invention has a Probenbe ^¬ rich, an illumination unit for irradiating a benbereich positionable in the product sample, and a detection unit for detecting the emitted radiation from the sample with a radiation detector. The lighting unit in this case comprises a radiation source, a valve disposed in the beam direction of the radiation source first dispersive element for separation of the radiation into its spectral components, a valve disposed in the beam direction, after the first dispersive element first micromirror array for selecting spektra ^¬ len components and in the beam direction according to the first Micro-mirror array arranged second dispersive element for combining the selected spectral components in a common excitation beam. In each case the local optical beam direction in the emission measuring device should be understood as meaning the beam direction mentioned, regardless of whether the spatial orientation of the beam path changes during the beam path. The described spatial arrangement of the individual optical components, which are arranged in the beam direction "before" or "after" other components, so no position along a continuous, uniform direction to be specified, but only an order of passage of optical rays on an optical beam path in other words, an optical "before" or "after" in the beam path, which in total leads from the radiation source via the sample to the radiation detector.

An essential advantage of the emission measuring device according to the invention is that the selection of the spectral

Components by means of the first micromirror field Anpas ^¬ sung the spectral properties of the excitation beam on the optical properties of the sample to be measured can be done without spectrally selecting absorption filter in the beam path are needed. Rather, the spectral adaptation of the excitation spectrum to the sample and / or to the predetermined measurement task can take place without macroscopic optical components having to be moved for this purpose. Instead of pushing in and pushing out the optical filters known in the prior art, a spectral selection can be carried out much simpler, more space-saving, more automated and also more precise over the first micromirror field.

The radiation emitted by the radiation source first reaches the first dispersive element, by which it is spatially separated into its various spectral components. The first dispersive element thus changes the ^direction and / or spatial position of the individual to the individual spectral Components associated partial beams and thus fan out the radiation spatially. After the first dispersive element, the radiation reaches the first micromirror field, which makes it possible to select the various spectral components as a result of the position of the individual mirrors. The dispersive elements of the present invention may be generally configured, for example, as an optical prism or as an optical grating. The first micromirror array, for example, a PERIODIC ^¬ ge arranging a plurality of small optical mirrors. These micromirrors can be automatically controlled by a digital control unit, wherein the mirrors are tilted between two predetermined orientations which respectively correspond to an "ON" and an "OFF" state, ie an activated and a non-activated state. Such Mikrospiegelfeider are commercially available from the company Texas Instru ^¬ ment and (Digital Light Processing) under the brand name "DLP" are offered. They are so far mainly used for digital image and video projection.

The core idea of the present invention is to use such a micromirror field for the spectral shaping of the excitation light beam in an emission spectrometer. Due to the spatial fanning of the excitation light after the first dispersive element, in each case a spectral component, that is to say a small subregion of the wavelength spectrum of the excitation light, is assigned to a group of micromirrors. Depending on the orientation of the micromirror field in the

Beam path can then cause either the activated or non-activated state of a micromirror that the incident thereon sub-beam is selected. The sub-beams selected in this way are then bundled again into a common excitation beam by the second dispersive element subsequently arranged in the beam path in such a way that substantially no further fanning out into individual spectral components occurs thereafter. The spectral fanning The first dispersive element is thus introduced only as an ^interim step in order to enable a spectral selection by the micromirror field, and is then reversed by the second dispersive element. The non-selected partial beams of the remaining micromirrors (in the respectively reverse circuit state) are deflected in a different direction, so that they are coupled out of the excitation light beam. Due to the selection and spectral composition of the excitation light beam thus achieved, a very precise adaptation to the optical properties of the

Sample and to the given measurement task. In particular, it is also particularly easy to switch between different excitation spectra for different measurements.

In the method according to the invention for measuring light emission, an emission measuring device ^{according to the} invention is used. The method is characterized by the selection of the spectral composition of the excitation light beam by activating and / or deactivating the individual micromirrors of the first micromirror field. The advantages of the OF INVENTION ^¬ to the invention method are analogous to the above described advantages of the inventive measuring device emission.

Advantageous embodiments and further developments of the invention will become apparent from the dependent claims 1 and 8 claims and the following description. The described embodiments of the emission measuring device and of the measuring method can advantageously be combined with one another.

The lighting unit of the emission measuring device can have little ^¬ least a focusing unit which is in the beam direction between the radiation source and the first dispersive element at ^¬ sorted. Alternatively or additionally, such a focusing unit may be arranged in the beam path between the second dispersive element and the sample area. Such focus Sizing units may include, for example, optical lenses, lens systems and / or concave mirrors. They can thus have at ^¬ play, at least a focusing lens or a focus sierspiegel. By means of a focusing unit arranged between the radiation source and the first dispersive element, a bundling of the individual partial beams corresponding to the spectral components on the different associated areas of the micromirror field can be achieved. This focusing allows a more precise spectral selection. An additionally arranged between the second dispersive element and sample area focusing unit advantageously allows bundling of the typically divergent leaving the second dispersive element beam in a defined, collimated excitation light beam.

In addition to the mentioned focusing units, it is advantageously possible for optical shutters to be arranged adjacent thereto, in each case either in the beam path before or afterwards. For example, an entrance slit may be arranged after the radiation-source side FOCUSSING purity to allow a precise ^¬ re mapping of the beam to the micromirror array and thus a more accurate assignment of individual columns or rows of the micro mirror array to the respective spectral components.

The detection unit of the emission measuring device may advantageously comprise a ^¬ way arranged in the beam path after the sample region third dispersive element for separation of the emitted radiation into its spectral components. It may subsequently have a second micromirror field in the beam path for selecting individual spectral components and in turn following the radiation detector in the beam path. In this embodiment, therefore, the light emitted from the specimen emission light can spectrally dispersed within the detection unit with the aid of the third dispersive element and then be spectrally selec ^¬ advantage with the aid of the second micro mirror array. Similar to the first micromirror field, this selection can be achieved by using the micromirrors, the are associated with a particular spectral component, acti ^¬ viert and / or disabled. The further beam path between the second micromirror field and the detector can then be aligned such that, for example, either the partial beams are deflected by the deactivated micromirrors or the partial beams are deflected by the activated micromirrors onto the detector. The partial beams of the respectively reverse activation state of the mirrors can then be decoupled correspondingly from the detection beam path. In principle, the partial beams selected by the second micromirror field can be directed onto the radiation detector either simultaneously or individually or in groups. The main advantage of the embodiments with a two ^¬ th micromirror array in the detection unit is the fact that the shorter wavelength spectral components of the excitation ^¬ beam can be filtered out prior to the detection of the incident in the detection unit radiation by deselection of the corresponding micro mirror. The secondary radiation emitted by the sample, for example by fluorescence or phosphorescence, is typically shifted towards longer wavelengths of light relative to the excitation light beam. However, depending pass from the arrangement of the detection unit relative to the sample and to the beam path of the excitation beam also additionally reflected and / or scattered and thus not spectrally shifted radiation components of Anre ^¬ supply light beam in the detection unit. To avoid overlay ^¬ tion of the longer wavelength emitted radiation with the short-wave excitation radiation Geren during the actual measurement in the detector, therefore, spectral filtering within the detection unit is appropriate. By USAGE ^¬ dung a second micro mirror array, the use of the replaceable Absorptionsfil- used in the prior art is avoided ter. In this case, similar advantages come into play as they were described in advance for the lighting unit for the replacement of Ab ^¬ sorption filter by the combination of dispersive element and micromirror field. Due to the combination of a first micromirror element in the illumination unit and a second Mikrospiegelele ^¬ ments in the detection unit, the adjustment of the entire measuring device on the spectral characteristics of the test sample in a particularly simple and accurate manner, it ^¬ follow. In particular, such adaptation of the spectral filtering illumination and detection side total oh ^¬ ne movement of macroscopic optical components and / or without the use of spectrally selective absorption filters is possible.

The further development of the detection unit may fail under ^¬ differently, depending on whether it is in the emission measuring an emission spectrometer or a device for mapping emission patterns, that is, for example, an emission microscope. In an emission spectrometer, the detection unit is designed for the spectrally resolved measurement of the emission intensity. To this end, the can already be ^¬ by the third dispersive element dissected ^¬ beams of the emission radiation after its selection by the micromirror array in their spectral components remain aufgefä ^¬ chert and are thus directed to the image plane of a Strah ^¬ lung detector. The radiation detector can be, for example, a one-dimensional or two-dimensional detector field with which the partial ^{beams of} the different spectral components can be measured simultaneously. Thus, the intensities for the entire emission spectrum or just a portion of it can be determined simultaneously.

Alternatively, it is also possible that the radiation detector has only a single detection channel and that the partial beams of the different spectral components selected by the micromirror field are directed successively onto the detection surface of this individual detection channel. So then the intensities for the different wavelength ranges can be measured one after the other. In the last mentioned variant, the mode of action of the second micromirror field for the spectral decomposition of the radiation to be measured is similar to the spectrometer described in EP0548830B1. What is new is the additional benefit of de-selection, ie, the filtering of an unwanted portion of the spectrum, especially the short-wave and with the supply Anre ^¬ spectrum overlapping portion of the detection beam.

In the case of an emission imager, that is to say an emission measuring device for imaging a spatial emission distribution, a further, ie fourth dispersive element can be arranged in the detection unit in the beam path between the second micro mirror field and the radiation detector. This fourth dispersive element then serves to combine the selected spectral components in a common filtered emission beam. This filtered emission beam can then be directed onto the radiation detector so that a spatial image of the emitting sample is generated. By way of example, the radiation detector can have a one-dimensional or two-dimensional pixelated sensor field on the image plane of which the sample is imaged. Alternatively, the image of the sample can also be sequentially imaged by scanning on a single detector channel. The detection unit may be provided to additionally ^¬ with a magnifying optical system, whereby the emission measuring device can be used as the emission microscope, in particular a fluorescence microscope.

In general, the emission measuring device can also be configured both as an emission spectrometer and as an emission imager. This is possible, for example, by the second

Micro-field leaving partial beams remain fanned out in one spatial direction according to their wavelength, but in the other spatial direction are directed to an image plane of the detector that in this direction information about the starting point of the emission radiation is maintained. For this purpose, the radiation detector may expediently have a two-dimensional sensor field. Similar to the embodiments of the illumination unit with a focusing unit, the detection unit can also have one or more focusing units. Here too, these focusing units can each comprise at least one focusing lens and / or one concave mirror. In ^¬ play, such a focusing optical Zvi ^¬'s sample region and the third dispersive element may be arranged to erzie ^¬ len a bundling of the individual corresponding to the spectral components on the different sub-beams corresponding regions of the second micro mirror array. This focus allows a more precise spectral Se ^¬ lesson. An additionally arranged between the second micromirror field and radiation detector focusing ^¬ light advantageously bundling the typically divergent leaving the second micromirror field beam in the direction of an image plane of the radiation detector. Such a focus ^¬ tion allows either a more precise wavelength resolution in an emission spectrometer or a more precise spatial resolution in an emission imager.

To improve the spectral resolution and / or the imaging quality, the detection unit can additionally be provided with one or more optical stops, similar to the screens in certain embodiments of the illumination unit. For example, the detection unit may have an optical stop, preferably a gap, in the beam path in front of the third dispersive element.

The radiation detector may generally advantageously have only a single sensor channel. For example, this sensor channel may have a planar photodiode or a photomultiplier.

Alternatively, the radiation detector may generally have a one- or two-dimensional pixelated sensor array.

This can be, for example, a CCD field, a pin diode field, a CMOS sensor or a focal plane array. In addition to silicon-based sensor materials, For example, InGaAs (indium gallium arsenide) and MCT (mercury-cadmium telluride) are advantageous materials for the photosensor. The illumination unit and / or the detection unit can advantageously be free from spectrally selecting optical ^absorption filters.

The emission measuring device can be designed for measurement with the aid of visible light, ultraviolet radiation and / or infrared radiation. The radiation source can thus be a light source, an ultraviolet radiation source and / or an infrared source. Advantageously may be in the radiation source is a broadband emittieren- de radiation source, such as a broadband light ^¬ diode or a broadband laser, in particular a QCL or a halogen lamp.

The emission measuring device can generally be designed such that radiation emitted by the sample can be coupled into the detection unit with a direction component which opposes the direction of incidence of the excitation beam. The emission measurement can thus be configured as a measurement of the reverse-directed secondary radiation. This can be as examples game achieved by the arrangement of a beam splitter in the vicinity of the sample region, which separates the optical path of the excitation beam and detection beam from ^¬ today. Alternatively, the emission measuring device may be generally so out ^¬ staltet that emitted by the sample radiation with a direction of incidence of the excitation beam direction corresponding component is coupled into the detection unit. For this purpose, the sample can be arranged geometrically between the excitation beam impinging thereon and the part of the emission beam which can be coupled into the detection unit. It may therefore be an arrangement for measuring the forward emission. Or the emission meter can be designed for coupling emission radiation with a main direction perpendicular to the direction of incidence of the excitation beam. In the method for measuring light emission, a single coherent subset of spectral components of the radiation can be selected by the first micromirror field and the remaining radiation can be coupled out of the further beam path. In other words, the first micromirror field in combination with the first and second dispersive elements can act as a bandpass filter with which a predefined coherent wavelength range, that is to say a wavelength band, is selected. Such bandpass filtering of the excitation spectrum may be useful, for example, to select a spectral band for the excitation, which has an overlap with one or more absorption bands of the sample to be examined. The spectral components not required for the excitation of this sample are masked out in this way and thus do not contribute to disturbing optical effects in the further beam path. Alternatively, a group of multiple spectral bands may similarly be selected by the first micromirror field in a similar manner.

Alternatively, a single contiguous subset of spectral components can be generated by the first micromirror field

Radiation from the beam path are coupled out and the remaining radiation can be selected. In other words, the first micromirror field, in combination with the first and second dispersive elements, can act as a bandstop filter with which a predefined coherent wavelength range, that is to say a wavelength band, is masked out. This may be ^{advantageous in} order to hide a specific subarea of the excitation spectrum, which would be particularly disturbing in the further course of the beam path.

Alternatively, all short- ^wave spectral components of the radiation can be selected up to a defined threshold value of the wavelength by the first micromirror field and the remaining, longer-wave radiation from the beam path are coupled out. In other words, the first micromirror field in combination with the first and second disperse elements can act as a short-pass filter, which only allows the short wavelengths below a defined threshold to pass into the further beam path. This embodiment may be advantageous for example to direct short-wave Strah ^¬ development up to the longest-wavelength absorption band to be excited of a sample in the sample region.

Alternatively, all long-wave spectral components above a defined threshold value of the wavelength can be selected by the first micromirror field and the remaining radiation can be coupled out of the beam path. In other words, the first micromirror array in combi nation ^¬ can interact with the first and second dispersive element as a long pass filter that allows only the long wavelengths above a defined threshold in the further beam path.

In the measuring method, the radiation emitted by the sample can advantageously be spectrally selected by means of a second micromirror field arranged in the detection unit by activating and / or deactivating the individual micromirrors. In other words, spectral filtering means micromirror field can also be performed in the detection unit, for example, spectral components of the excitation radiation Comp ^¬ hide from the further beam path of the detection unit. The advantages of these embodiments of the method are analogous to the advantages of the corresponding embodiments of the emission measuring device described above.

Also in such spectral filtering within the detection unit, the profile of the set by the mirrors Posi ^¬ tions filter as previously described for the lighting ^¬ unit can a band pass filter, multi-pass filter, a band elimination filter, a short-pass filter, a longpass filter as well as a combination of the mentioned filter types. Particularly advantageously, the second micromirror field can be controlled or adjusted in such a way that bandpass filtering or long-pass filtering results for the radiation reaching the detection unit, so that the short-wave spectral components overlapping the excitation spectrum from the further course of the beam path, especially from the field of radiation detector, from fade.

In the measuring method, the functions of the illumination unit and the detection unit, a selection pattern of the selected by the first micromirror array spectral components complement especially before ^¬ geous when at least in a partial region of the wavelength spectrum of the radiation to a selection pattern of the se ^¬ lected by the second micromirror array spectral components complementarily is. Such a configuration can be used to use the illumination unit to form a short-wave portion of the radiation emitted by the radiation source for the excitation of the radiation source

Select sample and then filter out exactly this spectral portion before the radiation detector in order to avoid a disturbing superposition of the long wavelength shifted emission ^¬ radiation during the measurement. Furthermore, as an alternative or in addition, the long-wave spectral components in the region of the emission bands of the sample in the illumination unit can be filtered out of the wavelength spectrum of the exciting radiation, since these typically do not contribute to the excitation of the emission. This long-wave components can be then directed within the detection unit se ^¬ lected and the radiation detector, as they provide the main contribution to the wanted signal. Particularly advantageously, the selection patterns of the first micro ^¬ mirror field and the second micromirror field may even be substantially complementary to each other. In many cases, however, it suffices if such a complementary selection pattern is present in a subregion of the wavelength spectrum of the radiation, for example in a spectral region len absorption bands of the sample and / or the emission bands of the sample corresponding area.

In general, the measuring method can be designed such that a conversion of the emission measuring device for a different wavelength range of the emission-exciting radiation and / or another wavelength range of the emitted radiation without the movement of macroscopic optical components. This can be achieved in particular by virtue of the fact that the spectral spectral values to be respectively adapted to the specimen

Filtering is not done by spectrally selective absorption filters, but by digitally controlled Mikrospiegelfeider. The described filtering of the spectral component by the first and / or second micromirror field generally does not have to be binary, as a complete selection or deselection of a given spectral component. On the contrary, grayscale can also advantageously be set during the filtering, so that a specific spectral component can also be proportionally selected. Such grayscale in Fil ^¬ esterification can be realized in different ways:

Particularly advantageous may be a proportionate selection of predetermined spectral components by selecting a predetermined fraction of the micromirrors in one of the respec ^¬ spectral component associated row or column of a two-dimensional first and / or second micromirror field. In other words, the spectral components can be so on a two-dimensional micromirror array ge ^¬ deflected by means of the respective upstream dispersive element, that the respective rows or columns of the Spie ^¬ gelfeldes one spectral component, that correspond to a particular wavelength range. The respective micromirrors of such an approximately monochrome illuminated line or

However, gaps do not necessarily have the same activa ^¬ status when. In order to implement a proportional selection, a predetermined subset of the microspots may also be used. gel in such a spectral subgroup (ie line or column) contribute to a selection of the corresponding spectral component. The different micro mirror connected with such a subgroup can be grouped in principle either after activation state or be mixed cavities ^¬ Lich.

In an alternative embodiment, a proportionate selection of a spectral component can also be effected by a rapidly repeated temporal change of the activation state of the individual micromirrors. This time change can take place, and for example, periodically simultaneously for Mik ^¬ rospiegel a spectral subgroup. The exact proportion of spectral selection is then determined by the ratio between the duration of the activated and deactivated states.

As an alternative or in addition to the two previously described methods of a proportional selection for a specific spectral component, a softening of the selection of the component by the blurring in the fanning out of the respective optical beam into the different spectral components can also take place. Also, this results in the practical implementation usually a not quite completeness digestive selection or de-selection of a particular spectral component, for example for the configuration of a Kan ^¬ tenfilters near the edge, even if the associated to a specific spectral component subset fully ^¬ constantly selected or deselected.

The measuring method can advantageously be a method for the spectrally resolved measurement of the light emission. Alternatively or additionally, it can be a method for imaging a spatial distribution of the light emission. For example, it may be a method for emission microscopy. In the following, the invention will be described by means of some preferred embodiments with reference to the appended drawings, in which:

FIG. 1 shows a schematic representation of the beam path in an emission measuring device according to a first exemplary embodiment,

FIG. 2 shows a schematic representation of the beam path in an emission measuring device according to a second exemplary embodiment,

FIG. 3 shows a schematic representation of an optical filter unit according to a third ^exemplary embodiment,

FIG. 4 shows a schematic illustration of an optical filter unit according to a fourth ^exemplary embodiment,

Figure 5 is a schematic representation of an optical filter unit according to a fifth embodiment represents ^¬ and

Figure 6 is a schematic representation of an optical filter unit according to a sixth embodiment represents ^¬ .

1 shows a schematic block diagram of an emission onsmessgeräts 1 is the He ^¬ invention shown according to a first embodiment. The emissivity measuring device 1 is designed here as a fluorescence reszenzspektrometer with which the spectral can be measured to ^¬ composition of the light emitted from a sample 5 fluorescent light. The emission measuring device 1 has a lighting unit 7 and a detection unit 35, the components of which are each shown in the associated blocks. Further 1, the emission measuring on a sample region 3 in which the sample can be measured 5 posi ^¬ tioniert. The optical components of the emission measuring device 1 are described below essentially along the optical beam path. The lighting unit 7 serves ^¬ total to a STEL required for the irradiation of the sample 5 excitation beam 25 provided len. For this purpose, radiation 11 emitted by a radiation source 9 is used, whereby this radiation is visible light, infrared light or else ultraviolet

Radiation can act. The emitted radiation 11 is now filtered spectrally via various optical components. For this purpose, it is directed to a first dispersive element 15 via a focusing unit 13. The focusing unit 13 serves to concentrate the radiation onto the first dispersive element 15. As shown schematically in FIG. 1, this focusing unit 13 may, for example, comprise a plurality of focusing elements

Lenses 13a exist. Hereby, the radiation 11 is thus directed to the first dispersive element 15, and the light is fanned out by the dispersive element 15 into its spectral Components ^¬ th. By way of example, FIG. 1 shows the beam paths for six different spectral components λι to λβ. After the first dispersive element 15, a first micromirror field 17 is arranged in the beam path of the illumination unit 7. This first micromirror field 17 is a two-dimensional array of digitally controllable micromirrors that can be switched between two defined states. The mirrors can therefore be activated or deactivated, in other words they can be set to ON or OFF. The radiation is spectrally fanned out by the first dispersive element 15 so that individual spectral components are essentially focused on columns of the micro mirror field 17. As shown in FIG. 1, these columns of the micromirror field 17 can be combined to form individual deselected regions 17a and selected regions 17b. In this case, a selected region corresponds to a mutually uniform cleavage state of the micromirrors. The deselected area 17a then corresponds to the other state of the micromirrors. The incident on the selektier ^¬ th portion 17b partial beams are deflected in the further beam path to a second dispersive element 21st In the figure 1 of this beam having a% 2 terized ^¬. However, these are not a fixed wavelength, but a part of the input Wel ^¬ lenlängenspektrums the emitted radiation 11. The other spectral components λι and λ ₃ to λβ are coupled out of the further beam path and, for example, directed to absorbers not shown here or other radiation ^¬ lower. A beam blocker 19 ensures that as little scattered radiation as possible reaches the second dispersive element 21 on other than the intended radiation paths. In interaction with the first dispersive element 15, the micromirror field 17 thus acts here as a bandpass filter, by means of which only the partial region of the spectrum% 2 is selected.

By means of the second dispersive element 21, the slightly different wavelengths also present in this partial area% 2 are bundled again into a common excitation beam 25. A second focusing unit 23 provides a spatially well-defined beam profile of this excitation beam 25. The lighting unit 7 has a total of opti ^¬ cal filter unit set with the digitally controlled the spectral characteristics of the excitation beam 25 ^¬ to. For this purpose, no moving optical absorption filters are needed.

The decoupled from the illumination unit 7 excitation ^¬ beam is designated in the further course with 25a. This now essentially has the second spectral component% 2. Via a mirror 27 and a beam splitter 33, this excitation beam reaches the sample 5 to be measured, which can be positioned in a sample area 3 of the measuring device. In a defined measuring range 29, this sample 5 is therefore irradiated with the comparatively short-wave spectral component% 2. Thereafter, the sample 5 emits by fluorescence long-wave radiation, for example, with the components λ ₃ to λ. ₅ These components is also scattered radiation with the original wavelength% 2 Überla ^¬ device. This emission beam is collectively indicated by the reference numbers Be ^¬ 31st It is coupled through the beam splitter 33 and through an entrance slit 37 into the detection unit 35. The detection unit 35 has a radiation detector 47 and some other optical components, which together also for spectral filtering serve the coupled emission beam 31a. First be ^¬ acts a third focusing unit 39, a bundling of a ^¬ coupled emission beam 31a to a third dispersive element 41. By this third dispersive element 41, the radiation according to their various spectral components 2% is also fanned out to λ. ₅ Thus, the so fanned radiation passes according to their spectral components divided into different columns of a second micro mirror array 43. Again, there 7. is a two-dimensional digital to be driven micromirror array, similar to the ers ^¬ te micromirror array 17 of the illumination unit in gezeig ^¬ th embodiment For example, the second micromirror field 43 is configured such that a partial area illuminated by the second spectral component% 2 is a deselected partial area 43 a. The remaining spectral components λ ₃ to λ ₅ strike the second micromirror field 43 in a selected subarea 43 b. This causes the deflected in relation to the spectral component% 2-wave components of the Fluo ^¬ reszenzlichts λ ₃ to λ ₅ in the further beam path in the direction of the radiation detector 47th For better focusing on this radiation detector 47 in turn serves a fourth focusing unit 45, for example, a focusing lens. The short wavelength spectral component 2%, however, is decoupled from the white ^¬ direct beam path and, for example, directed to a not shown here radiation sink. Again, a beam blocker 49 is used to avoid the incidence of unwanted scattered light in the area of the radiation detector 47. Within the detection unit 35. Thus, the second micromirror array 43 acts here along with the dispersive element 41 as a spectral filter to the spectral components of the excitation light beam can be 2% herausge ^¬ filters. Thus, at least in the partial region of the spectral component% 2 and of the longer-wavelength components λ ₃ to λ ₅ , the first micromirror field 17 and the second micromirror field 43 are configured complementary to one another. The spectral filtering within the detection unit 35 ensures that the short-wave spectral component% 2 the measurement of the long-wavelength components λ ₃ to λ ₅ with the radiation detector 47 does not radiate.

In the exemplary embodiment of FIG. 1, the spectral components λ ₃ to λ ₅ to be measured are simultaneously directed onto the radiation detector 47. This is expediently a pixelated detector with which these individual spectral components can be measured in a spatially resolved manner. Thus, the measuring device of this first embodiment is suitable as an emission spectrometer. As an alternative to the embodiment shown, in which the individual spectral components% 2 to λ ₅ are measured simultaneously, these spectral components can also be selected one after the other by the second micromirror field 43 and thus directed in succession to the radiation detector 47. Further, it may be in the radiation detector 47 also appropriate to a single detector channel that does not spatially resolved, son ^¬ countries offset in time measures the different spectral components. For this purpose, the second micromirror field 43 is then operated as a bandpass filter with temporally variable wavelength adjustment.

2 shows a schematic block diagram of a TERMS ^¬ onsmessgerätes 1 is shown according to a second embodiment of the invention. Similar or equivalent components are in this case provided with the same reference numerals as in FIG. Again, an excitation beam 25 is coupled out of a lighting unit 7 and directed to a sample 5 to be measured. From there, the radiation emitted by the sample is coupled through the entrance slit 37 into a detection unit 35, in which it is measured by a radiation detector 47. The essential differences from the first embodiment lie in the configuration of the two micromirror apertures 17 and 43. The first micromirror field 17 acts here together with the first dispersive element 15 as a multipass filter. There are three individual selected Teilbe ^¬ rich 17b, within which the micromirror auftref ^¬ fende radiation further in the direction of the second dispersive Distract element 21. From the relatively broad spectrum of the radiation 11 emitted by the radiation source 9, three different wavelength bands corresponding to the three spectral components X _ir X3 and λ ₅ are thus selected. By contrast, the other components λ ₂ , λ ₄ and Χβ shown schematically here are coupled out of the beam path. By the second dispersive element 21, the three selektier ^¬ th wavelength components X _ir X3 and λ ₅ bundled again at a mutually extending excitation beam 25 here. The coupled out of the illumination unit 7 excitation beam 25a is directed onto the sample 5, in which different TERMS ^¬ mecha- nisms can be excited by the three spektra ^¬ len components of the excitation beam. For example, are stimulated to emission by the various spectral components X _ir X 3, and λ ₅ different chemical components of the sample 5 in the manner of a multi-channel stimulation. The spectral components can be specifically adapted to be investi ^¬-reaching chemical compounds on the digitally controllable first Mikrospie- gelfeld. Beispielswei- se, the sample 5, three different components contained ^¬ th, which can be excited by the three spectral components of the excitation beam 25a respectively to a slightly long wavelength shifted fluorescence. This leads to a light emission with three new spectral component λ _2, λ ₄ and Χβ · The emission beam 31 thus formed may then re ^¬ around the beam splitter 33 and the entrance slit 37 tektionseinheit in the de- be coupled 35th The spectral components of compo ^¬ emission λ _2, λ ₄ and Χβ the spectral components of the exciting X _ir are superimposed as overall scattered radiation components X3 and λ ₅ also in this example. However, these components are not shown in the emission beam 31 for clarity.

Here, too, the detection unit 35 has a third dispersive element 41 and a second micromirror field 43, which together effect a spectral filtering of the injected emission beam 31a. The three spectral components λ ₂ , λ ₄ and Χβ of the emitted radiation can be, for example be successively selected by the second micromirror field 43. The configuration shown in FIG. 2 corresponds to a selection of the spectral component λ ₄ , the remaining components λ ₂ and λ β being selected from non-selected regions 43 a of the second micromirror field 43

Beam path are coupled out. The clarity hal ^¬ over 35 are shown in the figure 2, the spectral components X _ir λ and λ ₅ of the excitation light beam no longer tion unit within the Detek-. However, parts of the excitation light beam can pass, for example by light scattering in the detecting unit 35. Here, too, and can ^¬ so that not reach the these components of the excitation light beam to the radiation detector 47 by adapting the configuration of the second micro mirror array 43 is also also coupled to the further beam path. The spectral components λ ₂ , λ ₄ and λβ to be measured by the radiation detector 47 can in principle also be directed onto the radiation detector 47 either simultaneously or one after the other. As an alternative to the exemplary embodiments illustrated here, such emission measuring devices 1 can also be used as imaging devices

Measuring devices are operated. For this purpose, a further dispersive element, which in turn concentrates the selected spectral components of the emission beam into common partial beams within the detection unit 35, can be connected downstream of the second micromirror field 43, whereby on the

Radiation detector 47, a spatial image of a surface of the sample 5 can be generated.

The following four figures show four more examples, but they are not complete

Emission ^measuring devices show, but individual optical filter ^¬ units 51, which can be used as optical filter units in the lighting unit and / or the detection unit similar to the already described embodiments. In this case, Figures 3 to 6 each have similar optical components, the control of the micro ^¬ mirror array 17 is designed differently. Thus, FIG. 3 shows an optical filter unit 51, in which the radiation of an input beam 53 is spectrally selected. Thus, an output beam 55 can be generated with an adjustable spectral composition. The input beam is directed by a focusing unit 13 onto a first dispersive element 15. By this dispersive element 15, the radiation in its individual spectral components, here exemplified by λι to λβ, fanned out. The partial beams of these individual spectral components strike a micromirror field 17, the micromirrors of which have a majority of a selecting circuit state. Flanked by two selected partial regions 17b, a single deselected partial region 17a is set, in which the associated micromirrors decouple the incident radiation from the further optical path and thus also from the output beam 55. This deselected portion 17a will affect from the radiation according to the fifth spectral component λ. ₅ The remaining spectral components λι to λ ₄ and λβ are then bundled by the second dispersive element 21 again to form a common output beam 55 whose spectral composition is now reduced by the dese ^¬ selected spectral component λ ₅ . In sum, the configuration shown is a band-stop filter. With the use of the optical filter unit 51 in a detection unit, the second dispersive Ele ^¬ element 21 can also be omitted when the various spectral components prior to the detection must not be bundled in a common optical beam. This also applies to the following embodiment of the optical filter units 51.

FIG. 4 shows a further optical filter unit 51 according to a fourth exemplary embodiment of the invention. This filter unit 51 differs from the preceding exemplary embodiment in the configuration of the micromirror field 17. Here, the micromirror field 17 is connected so that only a single selected subarea 17b flanks of two large-area deselected subregions 17a results. Thus, only a relatively small section of the spectrum of the input beam 53 is filtered through to the output beam 55. In the schematically shown example of FIG. 4, this is the exemplary spectral component% 2 from the set of the original spectral components λι to λβ. The remaining spectral components λι and λ ₃ to λβ are selected by the deselected subregions 17a of the micromirror field 17 here Radiation ^sink , not shown, deflects and thus is no longer available for the output beam 55. This makes it easy to configure a bandpass filter.

FIG. 5 shows a similar optical filter element 51 in another exemplary configuration. Here, the micromirror field 17 cooperates with the dispersive elements 15 and 21 as edge filters, whereby radiation with wavelengths below a spectral edge 17c is transmitted. The micromirror field 17 thus has only a selected subregion 17b and a deselected subregion 17a, the selected subregion 17b being assigned to the shorter-wave spectral components λι to λ ₃ . Accordingly, these shorter-wave components λι to λ ₃ are mixed together to the output beam 55. Figure 6 shows a further embodiment of an optical rule ^¬ filter unit 51, which in turn is configured as an optical cut-off filter. Here, too, an edge 17c forms the dividing line between a deselected partial region 17a and a selected partial region 17b of the micromirror field. In this example, the selected portion 17b the longer-wavelength components λ ₄ to λβ of the input beam 53 corresponds, so that the optical filter element acts as a long total ^¬ pass filter.

Claims

claims

1. Emission measuring device (1) with

a sample area (3),

a lighting unit (7) for irradiating a sample (5) which can be positioned in the sample area (3) and

- a detection unit (35) for detecting the light emitted from the Pro ^¬ be (5) radiation (31) having a Strahlungsde ^¬ Tektor (47)

the lighting unit (7)

a radiation source (9),

a first dispersive element (15) arranged in the beam direction after the radiation source (9) for breaking the radiation into its spectral components (λχ-λδ),

- One in the beam direction after the first dispersive element

(15) arranged first micromirror field (17) for select ^¬ on of spectral components (λ ₂ ) and

a second dispersive element (21) arranged in the beam direction after the first micromirror field (17) for combining the selected spectral components (λ ₂ ) in a common excitation beam (25)

having .

2. emission measuring device (1) according to claim 1, wherein the lighting unit (7) at least one focusing unit (13,

23) which is arranged in the beam direction between the radiation source (9) and the first dispersive element (15) and / or which is arranged in the beam direction between the second dispersive element (21) and the sample region (3).

3. Emission measuring device (1) according to one of claims 1 or 2, in which the detection unit (35)

a third dispersive element (41) arranged downstream of the sample area (3) in the beam direction for breaking up the emitted radiation (31) into its spectral components

(λ ₂ -λ ₅ ), - a in the beam direction according to the third dispersive element (41) disposed second array of micromirrors (43) for Selek ^¬ tion of individual spectral components (λ ₃ ~ λ ₅₎ and

- Having in the beam direction after the second micromirror field (43) arranged radiation detector (47).

4. emission measuring device (1) according to claim 3, wherein the detection unit (35) at least one focusing unit (39, 45), which is arranged in the beam direction between the sample area (3) and third dispersive element (41) and / or in the beam direction between the second micromirror field (43) and radiation detector (47) is arranged.

5. Emission measuring device (1) according to one of the preceding claims, in which the radiation detector (47) has only a single sensor channel.

6. Emission measuring device (1) according to one of claims 1 to 4, wherein the radiation detector (47) has a one- or two-dimensional pixelated sensor field.

7. emission measuring device (1) according to any one of the preceding claims, wherein the illumination unit (7) and / or the detection unit (35) is free of spectrally selecting optical see absorption filters.

8. A method for measuring light emission with an emission measuring device (1) according to one of claims 1 to 7,

characterized by the selection of the spectral composition of the excitation beam (25) by means of activation

and / or deactivating the individual micromirrors of the first micromirror field (17).

9. The method according to claim 8, wherein a single contiguous subset of spectral components of the radiation is selected by the first micromirror field (17) and the remaining radiation is coupled out of the beam path or in which a single contiguous subset of spectral components of the radiation is coupled out of the beam path through the first micromirror field (17) and the remaining radiation is selected.

10. The method according to claim 8, wherein all the short-wave spectral components of the radiation are selected up to a fixed threshold value of the wavelength and the remaining radiation is coupled out of the beam path by the first micromirror field (17)

or

wherein by the first micromirror array (17) all the spectral component ^¬ long wavelength above a predetermined threshold value of the wavelength to be selected and the remaining radiation is coupled out of the beam path.

11. Method according to claim 8, wherein the radiation emitted by the sample is spectrally selected by means of a second micromirror field arranged in the detection unit by means of activation and / or deactivation of the individual micromirrors.

12. The method of claim 11, wherein the at least one selection pattern by the first micro mirror array (17) selected in a partial region of the wavelength spectrum of the radiation spectral components to a selection pattern by the second micro mirror array (43) selected spektra ^¬ len components is complementary ,

13. The method according to any one of claims 8 to 12, wherein a conversion of the emission measuring device (1) for another Wel ^¬ lenlängenbereich the emission-exciting radiation and / or another wavelength range of the emitted radiation takes place without the movement of macroscopic optical components.

14. The method according to any one of claims 8 to 13, wherein a proportionate selection of predetermined spectral components by a repeated switching between an activated and a deactivated state of mirrors of the first and / or second micromirror field (17, 43).

15. The method according to claim 8, wherein a proportional selection of predetermined spectral components by selection of a predetermined fraction of the micromirrors in a row or column of a two-dimensional first and / or second micromirror field associated with the respective spectral component (17, 43).