DE102015108383A1 - Multichromator device, lighting device, imaging device and corresponding method - Google Patents

Abstract

A particularly miniaturizable multichromator device, a lighting device and an imaging device and corresponding methods are provided. The multichromator device may include a first dispersive element configured to spectrally split light in a first direction. This spectrally split light is incident on a light modulator (20) with a plurality of light modulator elements (21), for example micromirrors. The light modulator elements (21) are driven in a first direction (22) to select a desired spectral range and in a second direction (23) to determine an intensity for a respective spectral range.

Description

The present application relates to a multichromator device, a lighting device having a multichromator device, an imaging device such as a microscope device having such a multichromator device, and corresponding methods. A multichromator device is to be understood as meaning a device with which a spectral distribution of an incoming light beam can be selectively changed. In particular, the present application relates to such devices and methods in which the multichromator device or the illumination device is miniaturized compared to conventional devices and / or manages without macroscopically moving parts or components.

In various applications, it is desirable to realize a spectrally adjustable illumination, i. to realize a substantially arbitrary spectral distribution in an illumination beam. Such spectrally selective illumination may be desirable, for example, in microscopy, for example in material microscopy or in a laser scanning microscope. Also in surgical microscopy or other medical imaging techniques, including procedures during surgery, such adjustable illumination may be desirable.

From the DE 102 41 472 A1 In this regard, an arrangement for the adjustable change of illumination light is known in which a spectral spatial splitting of at least one radiation component is performed with a dispersive element and a spectral selection is carried out, for example, by means of a strip-shaped light modulator with which certain spectral components can be masked out. The thus spectrally altered light can be brought together again by means of a further dispersive element.

A similar arrangement is from the DE 198 35 072 A1 known. In the device disclosed therein, a switchable micromirror arrangement is used for wavelength selection of dispersively split illumination light. To change the intensity while mirrors can be switched oscillating, with an average intensity then results from a duty cycle of the oscillation. For this purpose, a switching frequency of the mirror is necessary, which is well above a desired modulation frequency of the spectrum in order to provide the desired intensity on average.

It is therefore an object of the present application to provide a preferably miniaturizable multichromator device, a corresponding illumination device, an imaging arrangement as well as a corresponding method, whereby a selection of arbitrary spectral distributions and preferably at the same time an arbitrary intensity selection is made possible. Spectral and intensity modulation can be changed, for example, with video rate or faster.

In this regard, a multichromator device according to claim 1 and a method according to claim 24 are provided. The subclaims define further exemplary embodiments as well as a lighting device with a corresponding multichromator device and an imaging device with a corresponding lighting device.

According to a first aspect, there is provided a multi-chromator device comprising:
a dispersion device configured to spectrally split an incoming light beam in a first direction to produce a split beam,
a light modulator having a multiplicity of light modulator elements, wherein the light modulator elements can be driven in the first direction for selecting one or more spectral ranges,
wherein the dispersion assembly is further configured to spectrally combine light from the light modulator to form an illumination beam.

Preferably, the light modulator is a two-dimensional light modulator in which the plurality of light modulator elements are arranged in the first direction and in a second direction, wherein the light modulator elements in the second direction are controllable for setting an intensity for a respective spectral range.

By means of such a two-dimensional light modulator, a desired intensity can thus be set in a simple manner for different spectral components.

The light modulator may comprise a micromirror arrangement, wherein the light modulator elements may comprise micromirrors.

The dispersion device may spectrally split a first dispersive element configured to spectrally split the incoming light beam in the first direction to produce the split beam, and a second dispersive element configured to transmit the light (FIG. 15 ) from the light modulator spectrally to the illumination beam.

The first dispersive element and the second dispersive element may be integrally formed, in particular monolithically integrated.

An integral implementation of the first dispersive element and the second dispersive element may be i.a. Reduce manufacturing costs, in particular because adjustment specifications are intrinsically fulfilled between the first and the second dispersive element. Furthermore, manufacturing costs are reduced in such embodiments because replication costs for a monolithic double lattice are about half the replication cost for two individual lattices.

The light modulator arrangement may be configured to rotate an incidence plane of the second dispersive element with respect to an incidence plane of the first dispersive element.

The second dispersive element may be twisted relative to the first dispersive element.

The dispersion assembly may also spectrally split a (single) dispersive element configured to spectrally split the incoming light beam in the first direction to produce the split beam and spectrally combine the light from the light modulator with the illumination beam, and a polarization array (Fig. 93 . 94 ) configured to extract the illumination beam.

Such a construction requires only a single dispersive element.

In this case, the polarization arrangement may comprise a lambda / 4 plate arranged between the dispersive element and the light modulator and a polarization beam splitter.

The above-mentioned dispersive elements may include imaging dispersive elements, and / or gratings, in particular holographic gratings such as concave aberration-corrected holographic gratings, e.g. so-called Carl grid, or volume grids include.

By using imaging dispersive elements a compact design is possible. By using concave aberration corrected gratings, e.g. Carl-Gittern is a particularly high light throughput with excellent imaging properties and thus high spectral resolution possible.

The multichromator device may further comprise an entrance slit in front of the dispersion assembly and an exit slit after the dispersion arrangement.

The dispersion arrangement, e.g. The above-mentioned dispersive elements such as gratings may include alignment marks.

For example, high adjustment specifications for one-piece / monolithic grids, in particular for an original grating, which serves as a template for further grids in the production, can be ensured by special alignment marks, which are applied by direct laser beam writing (DWL) on the original grid and a "mix & match "Allow between DWL and holographic technology.

These adjustment marks can be used to align further optical elements of the miniaturized multichromator, in particular the light modulator or the input gap or the output gap or the fiber ends when using optical waveguides.

According to a second aspect, there is provided a lighting device comprising:
a light source, and
a multichromator device as described above configured to receive light from the light source.

The illumination device may further comprise a controller for driving the light modulator of the multichromator device to select a desired spectral component of light of the light source.

The light source may comprise a broadband light source covering, for example, an entire spectral range of interest.

According to a third aspect, there is provided an imaging device comprising:
a lighting device as described above for illuminating a sample, and
an image pickup device for picking up light emitted from the sample in response to the illumination.

The image pickup device may comprise a microscope device.

The image capture device may include a camera device.

According to a fourth aspect, there is provided a method comprising:
Illuminating a light modulator with spectrally split light in the first direction, activating the light modulator in a first direction for selecting spectral ranges and optionally also in a second direction for setting an intensity for respective spectral ranges, and
Merging light from the light modulator into an illumination beam.

The method can be carried out by means of one of the devices described above.

Embodiments are particularly suitable for performing a spectral scanning (staring), in which, for example, a camera consecutively takes spatially two-dimensional images of an area, this area is illuminated in the recordings with different spectra, such as specific spectral distributions or different spectral colors, and scatters accordingly. Specifically, the specific spectral distributions may be adapted (e.g., for a particular sample or sample type) spectral distributions that can be tuned for wavelengths and the intensity associated with the particular wavelengths.

Hereinafter, various embodiments of the present invention will be explained in more detail with reference to the accompanying drawings. Show it:

1 a lighting device according to an embodiment,

2 a schematic representation of a two-dimensional light modulator, which is usable in embodiments,

3 a flowchart for illustrating a method according to an embodiment,

4 a lighting device according to a further embodiment,

5 . 6 . 7A and 7B Illustrations illustrating multichromators according to various embodiments,

8th an imaging device according to an embodiment, and

9 a multichromator according to another embodiment.

Hereinafter, various embodiments of the present invention will be explained with reference to the accompanying drawings. These embodiments are merely illustrative and are not to be construed as limiting. In particular, a description of an embodiment having a plurality of features or elements is not to be construed as requiring all of these features or elements for implementation. Rather, other embodiments may have fewer features or elements and / or alternative features or elements.

In addition, features or elements of various embodiments may be combined with each other unless otherwise specified.

Various embodiments include two-dimensional light modulators. This is to be understood as a spatial light modulator which can spatially modulate light striking it in at least two dimensions (spatial directions), for example by switching individual elements.

In 1 a first embodiment of a lighting device is shown schematically. The lighting device of 1 includes a light source 10 for generating a light beam 11 , The light source 10 may in particular be a broadband light source, ie spectrally broadband light source, for example, a white light source. The spectral range of the light source 10 Depends on a desired application and may for example also be in the infrared range or in the ultraviolet range or comprise such ranges or parts thereof. In other words, the use of embodiments of the present invention is not limited to visible light.

The light beam 11 arrives in the embodiment of the 1 to a multichromator device which is a first dispersive element 12 , a two-dimensional spatial light modulator 14 and a second dispersive element 16 includes. The first dispersive element 12 splits the light beam 11 in a first direction spectrally to a light beam 13 on, so spectrally in the first direction split light on the light modulator 14 falls. The light modulator 14 then selects desired spectral components as well as in some embodiments also their intensity from a spectrally modified light beam 15 to obtain. The second dispersive element 16 combines the spectral components of the light bundle 15 again to an output light beam 17 which can then serve as an illumination light beam for various applications.

The first dispersive element 12 and the second dispersive element 16 For example, imaging dispersive elements, for example imaging holographic elements such as holographic gratings, for example concave aberration-corrected gratings, also referred to below as Carl grids, may be used. In other embodiments, conventional dispersive elements such as other conventional gratings may also be used. In the case of non-imaging dispersive elements 12 . 16 For example, additional elements such as lenses or mirrors may be provided to, for example, light from the dispersive element 12 on the light modulator 14 and from there to the dispersive element 16 map. By using imaging dispersive elements such as holographic imaging elements or curved grids, however, a more compact design of the multichromator is possible because no additional optical elements may be needed. The design of the dispersive elements 12 . 16 For example, gratings such as Carl holographic grids may be theoretically optimized and specified according to a required spectral range to maximize the étendue of the multichromator and / or the lattice efficiencies and / or to minimize stray light and / or stray light.

The light modulator 14 may in particular comprise a micromirror arrangement (for example a DMD arrangement, from the English "Digital Micromirror Device"). For example, in other embodiments, the light modulator may include a liquid crystal panel. In the embodiment of the 1 becomes the light beam 11 through the dispersive element 12 spectrally split in the first direction. By driving the light modulator 14 In the first direction, a spectral selection can thus be made. By driving in the second direction, in some embodiments, the intensity can also be adjusted for respective spectral components.

This will now be with reference to 2 explained in more detail. In 2 is an example of a two-dimensional light modulator 20 shown. The light modulator 20 For example, a micromirror device having a plurality of micromirrors 21 be. In the example shown, the micromirrors are 21 arranged in a field of 13 × 7 micromirrors. However, this is merely illustrative, and there may be other numbers of micromirrors, especially significantly more micromirrors. For example, over 200, over 1000 or even over 4000 micromirrors may be provided in each direction. The individual mirrors 21 can then be switched between, for example, two states. In a first state, for example, light from the first dispersive element 12 then to the second dispersive element 16 forwarded while the light is removed in the second state of the beam path and is passed, for example, to a light trap. An arrow 22 indicates a direction of spectral splitting, for example, by the first dispersive element 12 of the 1 at. For some corrections, in some embodiments, the individual mirrors may be switched between more than two states.

Thus, for example, each column of the micromirror arrangement corresponds to a specific wavelength range. Thus, by variable control of the light modulator 20 in the direction of the arrow 22 a desired spectral range can be selected, and by driving in one direction as indicated by an arrow 23 indicated, a desired intensity for each spectral range can be adjusted by, for example, more or less micromirrors 21 Be "activated", ie switched so that falling on the respective micromirror light contributes to the output beam. Such a control of a light modulator can, for example, by a controller such as a controller 18 in 1 respectively. The various components are preferably coordinated. For example, a height of the light modulator can be tuned to an extent of an input and / or output gap, and a width of the light modulator arrangement can be tuned to a desired or generated by a light source spectral length. In this way, the light modulator arrangement is preferred in the direction of the arrows 22 . 23 as far as possible illuminated.

It should be noted that the directions in 2 (horizontally and vertically for the arrows 22 and 23 ) merely as an example in the drawing of 2 serve, and a corresponding light modulator arrangement such as a micromirror arrangement can be arranged substantially arbitrarily in space.

In some embodiments, light that is not from the light modulator device may be used 14 to the second dispersive element 16 is also routed to another output and / or passed to another detector, which can be used for example for calibration and / or reference purposes. In particular, a reference intensity of the light can thus be determined. Also for calibration such an arrangement can be used. For this purpose, one or more further mirrors can be provided to that of the light modulator 14 not to the second dispersive element 16 directed light to a desired location.

In 3 a flowchart of a method according to an embodiment is shown. The procedure of 3 For example, by referring to FIGS 1 and 2 however, it is not limited thereto and can be implemented, for example, by means of further embodiments to be discussed later.

While the procedure of 3 is described as a sequence of different steps, this sequential order is not to be construed as limiting. In particular, the illustrated steps may also be performed simultaneously and / or repeatedly, for example, in parallel by various components of a lighting device such as the lighting device of 1 ,

In step 30 For example, a two-dimensional light modulator, for example a micromirror arrangement, is illuminated with spectrally split light in the first direction. The spectral splitting can be effected by a dispersive element, in particular an imaging dispersive element, such as a holographically produced grating.

In step 31 For example, the light modulator, in particular elements thereof such as micromirrors, is driven in a first direction for spectral selection and optionally also in a second direction for intensity adjustment for each of a plurality of spectral regions. This can be done, for example, as with reference to 2 explained.

In step 33 the light is brought together by the light modulator back into an illumination beam, which then can serve for example for the optical examination of a sample. This combination can be done by a further dispersive element, in particular an imaging dispersive element.

In 4 is a schematic representation of another lighting device according to an embodiment shown.

The embodiment of 4 has a light source 40 which emits in a desired spectral range. The light source 40 for example, as for the light source 10 of the 1 discussed, be designed.

Light from the light source 40 passes through an entrance gap 41 on a first grid 42 , which spectrally splits the light beam. The light source 40 For example, it may include high pressure lamps, lasers, light emitting diodes, organic light emitting diodes, broadband light sources or other sources. The grid 42 may in particular be an imaging grating, for example an imaging holographic grating. Such imaging gratings can be, for example, Rowland gratings, Offner gratings or concave aberration-corrected gratings. In this case, for example, a compact arrangement can be achieved with a concave-aberration-corrected grating. The spectrally split light, for example in the first diffraction order of the grating 42 , becomes a micromirror arrangement 44 directed. By means of the micromirror arrangement 44 a spectral setting or selection and optionally an adjustment with respect to the intensity in different spectral ranges. This can be done in particular as already described with reference to 2 explained. The thus modified light passes from the micromirror arrangement 44 to a second grid 43 , which in turn serves as an imaging grid, as already for the grid 42 discussed, can be designed. From the second grid 43 then light comes to an output gap 45 , Instead of grids, it is also possible to use prisms for spectral splitting or combination. The grids 42 . 43 can be integrally formed, in particular monolithically integrated, which can reduce manufacturing costs. Also, adjustment and assembly can be achieved through a common monolithic fabrication of the grid 42 . 43 be improved. Different configurations are possible. In particular, a one-piece implementation of the grid 42 . 43 Reduce manufacturing costs, since adjustment specifications are intrinsically fulfilled between the first and the second dispersive element. Furthermore, manufacturing costs are reduced in such embodiments because replication costs for a monolithic double lattice are about half the replication cost for two individual lattices.

The grids 42 . 43 or other dispersive elements may in particular in the case of one-piece training Justagemarken. For example, high adjustment specifications for such a one-piece / monolithic grid, in particular for an original grid, which serves as a template for other grids in the production, be ensured by special Justagemarken which are applied by direct laser writing (DWL) on the original grid and a "mix & match "between DWL and holographic technology.

These adjustment marks can be used to align further optical elements of the multichromator, in particular the light modulator or the input gap or the output gap.

In some embodiments, optionally, in front of the micromirror array 44 next to this one correction plate 46 , eg a phase front correction plate. As a result, a further improvement of the image quality is possible. The correction plate 46 is segmented in the dispersion direction. Each segment can be realized both by a refractive micro-optic element and by a diffractive element. Depending on the specification to be realized (resolution), the width of the individual segments in the dispersion direction can be approximately the width of a micromirror of the micromirror arrangement 44 or the width of several micromirrors correspond. Advantageously, the width of the individual segments of the correction plate 46 slightly larger in the dispersion direction than the real micromirror width - the latter is subject to a finite fill factor, while the correction plate can be realized with a fill factor of almost 100%.

For example, as shown, a dual monochromato configuration with two gratings may be used wherein by means of the micromirror arrangement 44 (For example, DMD) an incidence plane of the second grid 43 with respect to the plane of incidence of the first grid 42 is twisted. In particular, for this purpose, the angles of mirrors of the micromirror arrangement 44 adjusted accordingly. In another embodiment, the position of the output gap 45 by rotation and / or displacement of the second grid 43 so as to separate from the location of the entrance slit 41 to realize. Alternatively, the position of the output gap can also be determined by rotation and / or displacement of the second grid 43 be set. These possibilities will be discussed later with reference to the 5 to 7 illustrated. In other embodiments, instead of mapping grids 42 . 43 It is also possible to use combinations of gratings and mirrors, for example planed gratings with parabolic mirrors, for producing a desired beam path, for example a collimated beam path.

Next, referring to the 5 to 7 the embodiments discussed above are further illustrated. Generally, a grid vector and a normal vector at the apex of the grids (first and second grids) span an incidence plane. If incident and diffracted light lie in this plane of incidence, this is referred to here as in-plane diffraction, otherwise as off-plane diffraction. In a symmetrical arrangement of both grids, the locations of entry and exit slit coincide, which can hardly be realized in a device practically. Therefore, in the 5 - 7 presented some possibilities, by twisting one or both grids, to separate the places of entrance and exit slits.

5 shows an example of the case in which by means of a micromirror arrangement of an incidence plane of a second grating 52 with respect to an incidence plane of a first grid 51 is twisted. The position of a micromirror arrangement is with 50 designated. 53 denotes an entrance slit from which an input beam emanates, and 54 denotes an exit slit. In 5 becomes the first grid 51 in-plane and the second grid 52 illuminated off-plane. For this purpose, the micromirror arrangement is included 50 and the second grid 52 for example, different angles θy (for example, the y-direction shown) twisted.

In 6 is with 61 is a first grid, with 62 a second grid and with 60 denotes a position of a micromirror arrangement. 63 denotes an outlet gap, 64 an entrance slit. The first grid 61 and the second grid 62 are illuminated in-plane by rotation of the second grid 62 by an angle θx (for example, the drawn drawn x-direction), the position of the output gap in the representation of 6 moved to 'down'. The incidence levels of the grid 61 . 62 are identical here.

The 7A and 7B show further variants, wherein 71 a position of a micromirror arrangement, 72 a first grid, 73 a second grid, 70 a position of an entrance slit and 71 shows a position of an exit nip. 7A shows an asymmetric variant, while 7B shows a symmetrical variant.

In 7A is the first grid 72 in-plane and the second grid 73 illuminated off-plane. By rotation of the second grid 73 by an angle θy (for example, the y-direction shown) is the position of the output gap 74 in the presentation of the 7A moved to 'right'.

In 7B are the first grid 82 and the second grid 73 illuminated off-plane. By turning the grid 72 . 73 around θy in opposite directions results in the position of the output gap 74 symmetrical to the micromirror arrangement 71 mirrored to the position of the entrance gap 70 ,

In 9 a lighting device according to another embodiment is shown. In the embodiment of the 9 is compared to the embodiments discussed above only a single dispersive element, for example, a single grid 91 , provided, which the function eg the grid 42 . 43 of the 4 takes over. The grid 91 may again be designed as a Carl grid. The separation between incoming and outgoing beam via the polarization, as will be explained in more detail below.

Light from a source 90 (For example, an entrance slit, which is illuminated by a broadband light source) passes through a polarization beam splitter 94 to the grid 91 , The polarization beam splitter polarizes the light in the illustrated embodiment linearly. The grid 91 splits the light spectrally and forms it on a light modulator 92 from. The light modulator 92 may operate as in the previously described embodiments to perform spectral selection and, optionally, intensity adjustment.

Between the grid 91 and the light modulator 92 is a particular diffractive lambda / 4 plate 93 arranged with chirped zero order grating (CZOG). The light passes from the light modulator 92 back to the grid 91 , making the light the lambda / 4 plate 93 passes twice, causing a polarization rotation of 90 °. The light modulator 92 itself is arranged to leave the polarization of the light essentially unchanged.

The light is then removed from the grid 91 spectrally combined again and to the polarization beam splitter 94 directed there and there due to the rotated by 90 ° polarization to an output 95 (eg output gap) coupled out.

In this way, a structure with only one grid can be realized.

In 8th is an imaging device, in particular a microscope device 85 represented according to an embodiment. The imaging device of 8th For example, it can be a device for medicine / biomedicine or else a device for material analysis and provides an example of a use of a lighting device according to the invention 80 dar. The lighting device 80 can do so with reference to the 1 . 2 and 4 to 7 and 9 explained be configured and can in particular produce light with adjustable spectral distribution. The lighting device 80 may be particularly compact (miniaturized) that they are within the microscope device 85 can be arranged.

A lighting beam 81 , which of the lighting device 80 is generated falls on a sample 82 , From the sample 82 in response to the lighting with the light 81 outgoing light 83 is for example a microscope device 84 (For example, microscope objective and associated detection unit) detected. The detection unit of the microscope device 84 For this purpose, in particular a camera (not shown). In operation, the spectral distribution of the illumination beam 81 by appropriate adjustment of the lighting device 80 change, and the microscope device 84 can take pictures of the sample 82 for different illumination spectra. From the recorded images can then properties of the sample 82 be determined. Such analyzes are also referred to as hyperspectral analyzes. These can, as already explained in medicine / biomedicine, for example, for the perfusion and activity of blood and tissue or tumor diagnosis, in microscopy, agriculture, landscaping, chemical analysis (gas selection, sorting of plastics, hazardous substances) of the food control, the Art (for example analysis of paintings), in physics, geology, mineralogy, biology, and in particular in pharmacy (for example, the effect of molecular information in the infrared, for example, on the development of new pharmaceutical products, automated production control, or contamination monitoring of stored products) for industrial processes (eg material identification on assembly lines, chemical color imaging). Depending on the application, the microscope device can be used 84 be replaced by another suitable image pickup device. Another area of application is the analysis of the fluorescence of biomarkers.

In some applications, a difference image between recorded images with, for example, two different adapted spectral distributions can be used. In other embodiments, e.g. in fluorescence dye detection, more images with more different spectral distributions, e.g. 4 to 6 pictures (or more) can be used. In many applications where conventionally e.g. Color filter wheels have been used, typically e.g. 4 to 6 (rarely more) color filter for the excitation of fluorescent dyes, the replacement of these color filters by a simpler and smaller multichromator as described above without moving macroscopic parts is advantageous. This allows a much faster variation between the different spectral ranges, which is important for all fluorescence analyzes, for example, in all multi-well analyzes. Moreover, in the conventional approach, the detection of different components labeled by different fluorescent dyes is often limited by the fact that the individual excitation spectra of the fluorescent dyes overlap strongly. Already the fast spectral scanning with high resolution, in connection with intelligent eg multivariant data analysis offers the possibility of a signal detection with clearly higher information content.

Finally, the excitation with respectively optimized excitation spectra allows a particularly high signal-to-noise ratio by an optimized cross-correlation between the spectral distribution of the excitation light and the detected emitted light.

• – Ausführungsbeispiele der Erfindung erlauben die Erzeugung einer nahezu beliebigen Spektralverteilung abhängig von dem von einer Lichtquelle bereitgestellten Licht und erlaubt damit beispielsweise in Verbindung mit einem ortsauflösenden Sensorsystem wie einer Kamera für ein bestimmtes Spektrum die Aufnahme eines insbesondere zweidimensionalen Gesamtbildes zu einem einzigen Zeitpunkt. Bei dem bestimmten Spektrum kann es sich hierbei sowohl um einen nahezu monochromatischen Bereich oder um einen Spektralbereich endlicher Breite oder auch um die Kombination einer nahezu beliebigen Anzahl an Spektralbereichen nahezu beliebiger Bandbreite handeln, begrenzt durch die Verteilung der Lichtquelle und der Auflösung der Lichtmodulatoranordnung, beispielsweise Mikrospiegelanordnung. Eine spektrale Vorselektion kann hierbei besonders auf hoch aufgelöste Einzelbereiche erfolgen. Dabei kann jedem örtlich identifizierbaren Flächenelement δ(x, y) auf einer untersuchten Probenoberfläche in den aufgenommenen Daten ein Spektrum mit Intensität pro Wellenlänge λ bzw. δλ oder je Wellenlängenbereich zugeordnet werden.
• – Des Weiteren erlaubt das dargestellte optische Design eine Miniaturisierung des Multichromators insbesondere auch durch die Verwendung abbildender dispersiver Elemente. Eine Größe des Multichromators kann dabei beispielsweise im Bereich 10 × 10 Zentimeter oder 1 × 1 Zentimeter liegen, kann jedoch je nach Anwendung auch darüber oder darunter liegen.
• – Mit einer Multichromatorvorrichtung gemäß den beschriebenen Ausführungsbeispielen, die in einem Beleuchtungsstrahlengang wie z.B. in 8 gezeigt angeordnet sind, können insbesondere Nachteile herkömmlicher Hyperspektralkameras ausgeglichen werden, da bei einer solchen Anordnung lediglich ein ortsaufgelöstes Sensorsystem, beispielsweise eine entsprechende Kamera, bereitgestellt werden muss, während die Auswahl der Spektraleigenschaften durch eine entsprechende Modifikation des Beleuchtungslichts durch die Multichromatorvorrichtung erfolgt.
• – Bei verschiedenen Ausführungsbeispielen können verschiedene Spektralbereiche mit gewünschten Intensitäten innerhalb sehr kurzer Schaltzeiten (im Wesentlichen beschränkt durch die Schaltzeiten der Mikrospiegelanordnung) angesteuert und ausgewertet werden, beispielsweise mit einer üblichen Videorate mit beispielsweise 25 Bildern pro Sekunde (fps, vom Englischen „Frame per Second“), 30 fps, 50 fps oder 60 fps, auch wenn bei anderen Ausführungsbeispielen auch andere Raten verwendet werden können.
• – Je nach verwendeten Lichtquellen, dispersiven Elementen wie beispielsweise Gittern und Detektoren können die dargestellten Ausführungsbeispiele im Wesentlichen für beliebige Spektralbereiche benutzt werden.
• – Die dargestellten Techniken erlauben insbesondere eine zeitlich hoch aufgelöste Hyperspektralanalyse, wobei räumliche, zeitliche und spektrale Auflösung unabhängig voneinander optimiert werden können, da insbesondere für die spektrale Auflösung mit der dargestellten Multichromatorvorrichtung eine separate Einheit bereitgestellt ist, welche von andere Komponenten im Wesentlichen unabhängig arbeitet.
• – Zudem beinhalten Ausführungsbeispiele der Erfindung keine makroskopisch mechanisch bewegten Teile, sondern allenfalls die beweglichen Mikrospiegel, welche beispielsweise als mikroelektromechanisches System (MEMS) implementiert sein können. Somit weisen Ausführungsbeispiele der vorliegenden Erfindung vergleichsweise geringen Verschleiß auf.
• – Bei entsprechender Ansteuerung einer Kamera können auch Messungen mit hohem Dynamikbereich (HDR; vom Englischen „High Dynamic Range“) durchgeführt werden.

By using a lighting device as described here, in particular of the illustrated multichromator, the following advantages may result:

• Embodiments of the invention allow the generation of an almost arbitrary spectral distribution as a function of the light provided by a light source and thus, for example, in conjunction with a spatially resolving sensor system such as a camera for a certain spectrum the inclusion of a particular two-dimensional overall picture at a single time. The particular spectrum may be either an almost monochromatic region or a spectral range of finite width or even the combination of almost any number of spectral regions of virtually any bandwidth, limited by the distribution of the light source and the resolution of the light modulator arrangement, for example micromirror arrangement , A spectral preselection can be done here especially on high-resolution individual areas. In this case, each spatially identifiable surface element δ (x, y) on a sample surface being examined can be assigned a spectrum with intensity per wavelength λ or δλ or per wavelength range in the recorded data.
• Furthermore, the illustrated optical design allows a miniaturization of the multichromator, in particular also by the use of imaging dispersive elements. A size of the multichromator may be, for example, in the range 10 × 10 centimeters or 1 × 1 centimeter, but may also be higher or lower depending on the application.
• With a multichromator device according to the described exemplary embodiments, which in an illumination beam path such as in 8th In particular, disadvantages of conventional hyperspectral cameras can be compensated, since in such an arrangement only a spatially resolved sensor system, for example a corresponding camera, must be provided, while the selection of the spectral properties is effected by a corresponding modification of the illumination light by the multichromator device.
• In various embodiments, different spectral ranges with desired intensities can be controlled and evaluated within very short switching times (essentially limited by the switching times of the micromirror arrangement), for example with a conventional video rate with, for example, 25 frames per second (fps, from the English "frame per second"). ), 30 fps, 50 fps or 60 fps, although other rates may be used in other embodiments.
• Depending on the light sources used, dispersive elements such as gratings and detectors, the illustrated embodiments can be used essentially for arbitrary spectral ranges.
• In particular, the illustrated techniques allow high-resolution hyperspectral analysis, wherein spatial, temporal and spectral resolution can be optimized independently of each other, since in particular for the spectral resolution with the multichromator device shown, a separate unit is provided which operates essentially independently of other components.
• In addition, embodiments of the invention do not include macroscopically mechanically moving parts, but at most the movable micromirrors, which may be implemented, for example, as a microelectromechanical system (MEMS). Thus, embodiments of the present invention have comparatively little wear.
• - With the appropriate control of a camera also measurements with high dynamic range (HDR, from English "High Dynamic Range") can be carried out.

Thus, embodiments of the present invention may provide one or more of the following economic and / or conceptual benefits: low system cost, such as minimal assembly and minimal adjustment effort, a modular combination of various photometric requirements for spectral bandwidths, for example, or resolutions, resulting in short reaction times to changed ones Needs allows a smaller space, which in addition to a smaller volume also means less mass and / or a relatively low energy input into a sample, since the spectral illumination can be adapted to the specific requirements exactly. Thus, embodiments of the present invention offer significant advantages over conventional solutions. However, the scope of the present application is not limited to the specific embodiments shown, but these are merely illustrative.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10241472 A1 [0003]
• DE 19835072 A1 [0004]

Claims (25)

A multichromator device comprising: a dispersion assembly ( 12 ; 42 ; 51 ; 61 ; 72 ; 16 ; 43 ; 52 ; 62 ; 73 ; 91 ), which is set up, an incoming light beam ( 11 spectrally splitting in a first direction to form a split beam ( 13 ), a light modulator ( 14 ; 20 ; 44 ; 50 ; 60 ; 71 ; 92 ) with a multiplicity of light modulator elements ( 21 ), wherein the light modulator elements ( 21 ) are controllable in the first direction for selecting one or more spectral regions, wherein the dispersion arrangement is further configured to emit light ( 15 ) of the light modulator ( 14 ; 20 ; 44 ; 50 ; 60 ; 71 ; 92 ) spectrally to an illumination beam ( 17 ) to unite. A multichromator device according to claim 1, wherein the light modulator is a ( 14 ; 20 ; 44 ; 50 ; 60 ; 71 ; 92 ) two-dimensional light modulator ( 14 ; 20 ; 44 ; 50 ; 60 ; 71 ; 92 ), in which the plurality of light modulator elements ( 21 ) in the first direction ( 22 ) and in a second direction ( 23 ), wherein the light modulator elements ( 21 ) in the second direction for setting an intensity for a respective spectral range are controllable. Multichromator device according to claim 1 or 2, wherein the light modulator ( 14 ; 20 ; 44 ; 50 ; 60 ; 71 ; 92 ) comprises a micromirror arrangement, and wherein the light modulator elements comprise micromirrors ( 21 ). Multichromator device according to one of claims 1-3, wherein the dispersion device comprises a first dispersive element ( 12 ; 42 ; 51 ; 61 ; 72 ), which is set up, the incoming light beam ( 11 ) in the first direction spectrally split to the split beam ( 13 ) and a second dispersive element ( 16 ; 43 ; 52 ; 62 ; 73 ), which is set up the light ( 15 ) of the light modulator ( 14 ; 20 ; 44 ; 50 ; 60 ; 71 ) spectrally to the illumination beam ( 17 ). Multichromator device according to claim 4, wherein the first dispersive element ( 12 ; 42 ; 51 ; 61 ; 72 ) and the second dispersive element ( 16 ; 43 ; 52 ; 62 ; 73 ) are integrally formed. Multichromator device according to claim 5, wherein the first dispersive element ( 12 ; 42 ; 51 ; 61 ; 72 ) and the second dispersive element ( 16 ; 43 ; 52 ; 62 ; 73 ) are monolithically integrated. Multichromator device according to one of claims 4 to 6, wherein the light modulator arrangement relative to the second dispersive element ( 16 ; 43 ; 52 ; 62 ; 73 ) and / or with respect to the first dispersive element ( 12 ; 42 ; 51 ; 61 ; 72 ) is twisted. Multichromator device according to one of claims 4-7, wherein the second dispersive element ( 16 ; 43 ; 52 ; 62 ; 73 ) relative to the first dispersive element ( 12 ; 42 ; 51 ; 61 ; 72 ) is twisted. Multichromator device according to one of claims 1-3, wherein the dispersion device is a dispersive element ( 91 ), which is set up, the incoming light beam ( 11 ) in the first direction spectrally split to the split beam ( 13 ) and the light ( 15 ) of the light modulator ( 14 ; 20 ; 44 ; 50 ; 60 ; 71 ) spectrally to the illumination beam ( 17 ) and a polarization array ( 93 . 94 ) which is arranged to disengage the illumination beam comprises. A multichromator device according to claim 9, wherein the polarization arrangement comprises a signal between the dispersive element (16). 91 ) and the light modulator ( 92 ) arranged λ / 4 plate and a polarization beam splitter ( 94 ). Multichromator device according to one of claims 4-10, wherein the first dispersive element ( 12 ; 42 ; 51 ; 61 ; 72 ), the second dispersive element and / or the dispersive element comprises an imaging dispersive element. Multichromator device according to one of claims 4-11, wherein the first dispersive element ( 12 ; 42 ; 51 ; 61 ; 72 ), the second dispersive element and / or the dispersive element ( 91 ) comprises a holographic grating.  The multichromator device of claim 12, wherein the holographic grating comprises a concave aberration corrected grating. Multichromator device according to one of claims 4-11, wherein the first dispersive element ( 12 ; 42 ; 51 ; 61 ; 72 ), the second dispersive element and / or the dispersive element ( 91 ) comprises a volume grid. Multichromator device according to one of claims 1-14, wherein the dispersion arrangement ( 12 ; 42 ; 51 ; 61 ; 72 ; 16 ; 43 ; 52 ; 62 ; 73 ; 91 ) Has alignment marks. Multichromator device according to one of claims 1-15, further comprising an entrance slit ( 41 ), which is arranged in the beam path before the dispersion arrangement, and an output gap ( 45 ) which is arranged in the beam path after the dispersion arrangement. The multichromator device of any one of claims 1-16, wherein the dispersion device comprises alignment marks. A lighting device, comprising: a light source ( 10 ; 40 ) and a multichromator device according to any one of claims 1-17, which is arranged to emit light from the light source ( 10 ; 40 ) to recieve. Lighting device according to claim 18, further comprising a controller ( 18 ) for driving the light modulator ( 14 ; 20 ; 44 ; 50 ; 60 ; 71 ) of the multichromator device for selecting a desired spectral component of light from the light source ( 10 ; 40 ). Lighting device according to claim 18 or 19, wherein the light source ( 10 ; 40 ) comprises a broadband light source. An imaging device comprising: a lighting device according to any of claims 18-20 for illuminating a sample ( 82 ), and an image pickup device ( 84 ) for picking up light emitted from the sample in response to the illumination ( 83 ). Imaging apparatus according to claim 21, wherein the image acquisition device ( 84 ) comprises a microscope device. Imaging apparatus according to claim 21 or 22, wherein the image capture device ( 84 ) comprises a camera device. Method, comprising: Illuminating a two-dimensional light modulator with spectrally split light in the first direction, Driving the light modulator in a first direction to select spectral ranges, and Merging light from the light modulator into an illumination beam. The method of claim 24, wherein the method is performed by means of a device according to any one of claims 1-23.

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