DE102017129096A1 - Method for the spectral splitting of a light beam and fluorescent light microscope for carrying out such a method - Google Patents

Abstract

For separating a light beam (2) into parts (3 to 7) of different wavelengths, the light beam (2) is directed at a first location (13) for a first time onto a dichroic interface (8) at a first angle such that the dichroic interface (8) transmits a first portion (3) of the light beam (2) having first wavelengths on one side of a first cut-off wavelength and reflecting a first remainder (14) of the light beam (2) having wavelengths on the other side of the first cutoff wavelength. The first remainder (14) reflected by the dichroic boundary surface (8) becomes a second one at a second angle (17) changed from the first angle in one direction of rotation and / or at a second position (17) displaced in a translation direction from the first position (13) Directed to the dichroic interface (8) such that the dichroic interface (8) has a second portion (4) of the second wavelength light beam (2) on one side of a second cutoff wavelength which is on the other side of the first cutoff wavelength; and reflects a second remainder (18) of the light beam (2) at wavelengths on the other side of the second cut-off wavelength. The second remainder (18) reflected by the dichroic interface (8) becomes a third one at a third angle changed from the second angle in the direction of rotation and / or at a third point (20) displaced in the translation direction from the second point (17) Directed to the dichroic interface (8) such that the dichroic interface (8) has a third portion (5) of the third wavelength light beam (2) on one side of a third cutoff wavelength which is on the other side of the second cutoff wavelength; and reflects a third remainder (21) of the light beam (2) at wavelengths on the other side of the third cut-off wavelength.

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a method for separating a light beam into components of different wavelengths. In particular, the invention relates to a method having the features of the preamble of independent claim 1. Furthermore, the invention relates to an apparatus for separating a light beam into portions of different wavelengths. In particular, the invention relates to a device having the features of the preamble of independent claim 7.

The aim of the spectral splitting of the light beam, which is followed by the method or the device, may be the registration of intensities of different spectral components of the light beam or else the separate or joint use of different spectral components of the light beam.

STATE OF THE ART

From the DE 10 2006 034 908 A1 a beam splitter for use in the detection beam path of a laser scanning microscope is known, which consists of a displaceable in the beam path gradient filter for adjustable wavelength-dependent splitting of detection light into a transmitted and a reflected portion. The gradient filter has a continuous spatial change in the cut-off wavelength between the reflected and the transmitted portion of the reflection light and can be embodied as a shortpass, longpass or bandpass. The reflected and transmitted portions of the light beam are measured by two separate detectors.

From the DE 10 2009 012 874 A1 a laser scanning microscope with a detection beam path for the detection of spectral components of excited in a sample light radiation with multiple detection channels is known. The light radiation reaches a variable long or short pass filter. The long or short pass filter is a variable edge filter having a different division into transmitted and reflected wavelength components along its longitudinal extent. Shares of the light radiation reflected and / or transmitted by the long or short pass filter are reflected back in parallel by a reflector onto the long or short pass filter and reflected or transmitted by it again before they then reach one of a total of four detectors. Two of the four detectors then measure portions of the light radiation that were once reflected by the long or short pass filter and transmitted once, thus falling into an up and down limited wavelength range. On the other hand, the other two detectors measure portions of the light radiation which have been transmitted twice or reflected twice and are therefore limited on one side with respect to their wavelength.

From the DE 10 2010 060 747 B4 For example, a confocal laser scanning microscope with at least two detector units is known, which detect detection light passing through a detection pinhole. An optical element which separates the detection light into at least two beam bundles and spectrally splits within the beam bundle is arranged in the beam direction between the detection pinhole and the detector units. The optical element comprises a prism arrangement. A wavelength range of the beam bundles can be limited before detection with the aid of a spectral limiting element, wherein this spectrally limiting element is arranged so as to be displaceable and / or rotatable for varying the detected wavelengths. The optical element can also separate the detection light beam into three or more beams and spectrally split within the beam.

For example, from the DE 20 2016 008 334 U1 It is known to spectrally separate a light beam by successively directed to a plurality of dichroic interfaces formed at different optical elements with different cut-off wavelengths between transmission and reflection.

OBJECT OF THE INVENTION

The invention has for its object to provide a method for and a device for the separation of a light beam in shares of different wavelengths, in which the wavelengths of the various components are easily adjustable and / or many finely graded with respect to their wavelengths shares are available.

SOLUTION

The object of the invention is achieved by a method having the features of independent claim 1 and a device having the features of independent claim 7. Claim 15 relates to a fluorescent light microscope with a device according to the invention.

DESCRIPTION OF THE INVENTION

In the method according to the invention for separating a light beam into components of different wavelengths, the light beam is directed at a first location for a first time onto a dichroic boundary surface at a first angle, so that the dichroic interface transmits a first portion of the light beam having first wavelengths on a first side of a first cutoff wavelength and reflecting a first remainder of the light beam having wavelengths on the other side of the first cutoff wavelength.

Then, the first remainder reflected by the dichroic boundary surface, but at least a part thereof, is exposed a second time to the dichroic under a second angle changed in a direction of rotation relative to the first angle and / or in a second position displaced in a translational direction relative to the first position Directed so that the dichroic interface transmits a second portion of the light beam having second wavelengths on one side of a second cutoff wavelength, which is on the other side of the first cutoff wavelength, and a second remainder of the light beam having wavelengths on the other side of the second cutoff wavelength reflected.

Hereinafter, the second remainder reflected by the dichroic boundary surface, but at least a part thereof, becomes a third time onto the dichroic one under a third angle changed in the direction of rotation relative to the second angle and / or in a third position displaced in the direction of translation relative to the second position Directed so that the dichroic interface transmits a third portion of the third wavelength light beam on one side of a third cut-off wavelength, which is on the other side of the second cutoff wavelength, and a third remainder of the light beam having wavelengths on the other side of the third cutoff wavelength reflected.

In many cases, in the method according to the invention, the third residue reflected by the dichroic boundary surface, but at least a part thereof, becomes a fourth at a fourth angle changed in the direction of rotation relative to the third angle and / or at a fourth position displaced in the direction of translation in relation to the third position Time directed to the dichroic interface so that the dichroic interface transmits a fourth portion of the fourth wavelength light beam on one side of a fourth cutoff wavelength that is on the other side of the third cutoff wavelength and a fourth remainder of the light beam with wavelengths on the other Side of the fourth cutoff wavelength reflected. This may be followed by further similar reflections and transmissions at the dichroic interface, in which further portions of the light beam are transmitted and further remnants of the light beam are reflected at specific wavelengths.

The first, the second, the third and any further angles, under which the light beam or the first, the second, the third, etc. remainder are directed to the dichroic interface are either all the same or they follow one another in the direction of rotation. If the angles are the same, the first position, the second position, the third position, etc. in which the light beam or the first remainder, the second remainder, etc. strike the dichroic interface, follow each other in the direction of translation. On the other hand, if the first angle, the second angle, the third angle, etc. are different, the first digit, the second digit, the third digit, etc. may be the same. Due to the changing angles and / or locations of the impact of the light beam or its residues on the dichroic boundary surface, the dichroic boundary surface acts differently on the light beam or the rest. Accordingly, the dichroic interface successively passes other portions of the light beam in the form of the first component, the second component, the third component, etc., and reflects a spectrally increasingly limited remainder of the light beam. The second portion, the third portion of the light beam, etc., which are thereby transmitted from the dichroic interface correspond to wavelength bands, the first portion on the one hand by the first cutoff wavelength and on the other hand by the second cutoff wavelength, the second portion on the one hand by the second cutoff wavelength and On the other hand, limited by the third cutoff wavelength, etc. The first cutoff wavelength may be shorter than the second cutoff wavelength, the second cutoff wavelength may be shorter than the third cutoff wavelength, and so on. Conversely, it is also possible that the first cutoff wavelength is longer than the second cutoff wavelength, the second cutoff wavelength is longer than the third cutoff wavelength, and so on.

After carrying out the method according to the invention, at least three portions of the light beam which are separated from one another by their angle and / or their location are located behind the dichroic boundary surface and can be measured separately from each other or otherwise used. The number of this share can be easily increased to four or more.

The rear side of the dichroic boundary surface, on which the separate portions of the light beam are present, can nevertheless be kept free of reflectors, which reflect the transmitted portions of the light beam back to the dichroic interface in order to split them further. However, this does not exclude that here reflectors for the transmitted portions of the light beam are arranged in order to redirect them in a desired direction.

In the method according to the invention, at least the part of the first residue and at least the part of the second residue and optionally at least a portion of the third residue reflected from the dichroic interface, or at least a portion of further residues, are directed back to the dichroic interface by further interfacial reflections. These further interfacial reflections can in particular take place at a further optical interface opposite the dichroic boundary surface. In another embodiment of the method according to the invention, these further boundary surface reflections take place not only at one but a plurality of successive further optical interfaces.

If the further interfacial reflections, which direct the remainder of the light beam back to the dichroic interface, take place at a further optical interface opposite the dichroic interface, the dichroic interface and the further optical interface opposite it can be planar. In one embodiment, these planar interfaces are then aligned at a small angle to each other; in another embodiment, they run parallel to each other. Interfaces parallel to one another cause the locations where the various remnants of the light beam strike the dichroic interface to vary, but not the distances of these locations and the angles at which the various residues impinge. By contrast, at a small angle between the interfaces, both the locations and the angles of incidence vary. If the distance and / or the angle between the interfaces are changed, this will change the selection of the different wavelengths of the light beam transmitted through the dichroic interface. So this selection can be adjusted as needed.

If the further interfacial reflections, which direct the remainder of the light beam back to the dichroic interface, occur at several successive further optical interfaces, the residues can always impinge at the same location on the dichroic interface, but at different angles. Regardless of whether each remainder of the light beam strikes the dichroic interface again after reflection at one or more further interfaces, each further optical interface can be a fully reflecting or also a further dichroic interface. If there is another dichroic interface, further portions of the light beam of different wavelengths pass through this further dichroic interface, which can also be separately measured or otherwise used.

In practice, any further optical interface and optionally also the dichroic interface may be formed on a surface of a prism. This results in a defined arrangement of the interfaces formed on the prism to one another.

In the method according to the invention, the dichroic boundary surface is preferably formed by a gradient beam splitter having a spatial progression of at least one cutoff wavelength between transmission and reflection. The gradient beam splitter can be designed either as a longpass or shortpass or as a bandpass. In the first two cases, it has a cut-off wavelength between transmission and reflection with a spatial course. In the latter case of the bandpass, the gradient beam splitter has parallel spatial characteristics of a lower cutoff wavelength limiting down a transmission band and an upper cutoff wavelength bounding the transmit band upwards. With such a gradient beam splitter, the portions of the light beam transmitted by the dichroic interface are directly limited both downwards and upwards with respect to their wavelengths. If, on the other hand, the gradient beam splitter is a long-pass or short-pass, a direct limitation of the transmitted components with respect to their wavelengths takes place only in one direction. However, a limitation in the other direction can be introduced by directing the portions of the light beam transmitted through the dichroic boundary surface onto another gradient beam splitter with spatial progression of its at least one limit wavelength. In particular, in the case of a long pass forming the dichroic boundary surface, the further gradient beam splitter can be a short pass with an opposite course of its at least one limit wavelength (and vice versa).

Alternatively to the formation of the dichroic interface by a gradient beam splitter, the angle at which the respective remainder of the light beam is directed to the dichroic interface may be the critical angle of total reflection at the respective cut-off wavelength. In this embodiment of the method according to the invention, use is made of the wavelength dependence of the critical angle of the total reflection. In this case, where the optically denser medium is arranged, it can be determined whether the critical angle increases or decreases with the wavelength of the rest of the light beam impinging on the dichroic boundary surface.

The portions of the light beam transmitted through the dichroic boundary surface can be registered with light sensors arranged spatially next to one another, with one or more portions of the light beam being measured separately from the other portions with each of the light sensors can. In particular, when the light beam is a pulsed light beam, its passing through the dichroic interface portions can also be registered or measured separately by means of temporal resolution. The various portions of the light beam passing through the dichroic interface have previously been reflected at different frequencies at one or more other interfaces and have accordingly traveled different optical paths until they are registered. Thus, it can be concluded from the time of arrival of the shares of a single light sensor, which shares with what wavelengths.

In order to register them with the light sensor (s), the portions of the light beam transmitted through the dichroic interface can be directed directly at the light sensor (s). However, it is also possible to use one or more converging lenses and / or a microlens array and / or one or more mirrors and / or one or more retroreflectors in order to supply the different components to the light sensor (s).

In order to vary the assignment of the individual light sensors to the portions of the light beam transmitted through the dichroic boundary surface, the individual light sensors and / or the optical element or elements arranged in front of it can be displaced. In this way, the wavelength ranges detected by the light sensors can be adapted to the particular application of the method according to the invention.

In a specific embodiment of the method according to the invention, another light beam is directed through the dichroic boundary surface in the opposite direction to one of the portions of the light beam which is transmitted through the dichroic boundary surface, if present. If this light beam falls in the same wavelength band as the portion of the light beam whose opposite direction it occupies, it runs in the opposite direction to this portion up to the origin of the light beam. This is especially true even if the proportion of the light beam to which the further light beam is coupled in the opposite direction, not the first portion of the light beam, but a higher proportion.

This embodiment of the method according to the invention can be used, for example, to couple fluorescence excitation light or fluorescence prevention light as another light beam in the opposite direction to fluorescent light from a sample which forms the light beam. The fluorescence excitation or prevention light can then be applied to fluorophores in the sample from which the fluorescent light originates. Parts of the fluorescence excitation or prevention light reflected back from the sample then pass through the dichroic interface in the opposite direction to the coupled fluorescence excitation or prevention light and can thus be spectrally separated from the fluorescent light of interest.

An apparatus according to the invention for separating a light beam into components of different wavelengths has a beam path beginning at an entrance window for the light beam. The beam path first hits a dichroic interface at a first location, thereby transmitting a first portion of the first wavelength light beam on one side of a first cutoff wavelength and a first remainder of the light beam having wavelengths on the other side of the first Limit wavelength reflected along a first continuation of the beam path.

At least a portion of the first remainder reflected from the dichroic boundary surface impinges a second time on the first continuation of the beam path at a second angle changed from the first angle in one direction of rotation and / or at a second position displaced from the first position in a translation direction dichroic interface. The dichroic interface thereby transmits a second portion of the second wavelength light beam on one side of a second cutoff wavelength that is on the other side of the first cutoff wavelength and reflects a second remainder of the light beam having wavelengths on the other side of the second cutoff wavelength along a second Continuation of the beam path.

At least a portion of the second residue reflected from the dichroic boundary surface impinges a third time on the second continuation of the beam path at a third angle changed from the second angle in the direction of rotation and / or at a third point shifted from the second position in the translation direction dichroic interface. At this time, the dichroic interface transmits a third portion of the light beam having wavelengths on one side of a third cutoff wavelength which is on the other side of the second cutoff wavelength, and reflects a third remainder of the third wavelength light beam on the other side of the third cutoff wavelength along a third Continuation of the beam path. The third remainder of the light beam may then hit the dichroic interface again and then be split into a fourth portion and a fourth remainder and so on.

Also in the device according to the invention are the first, the second, the third and each other angles at which the light beam or the first, the second, the third, etc. rest impinge on the dichroic interface, either always the same, or they follow each other in the direction of rotation. If the angles are the same, the first position, the second position, the third position, etc. in which the light beam or the first remainder, the second remainder, etc. strike the dichroic interface, follow each other in the direction of translation. On the other hand, if the first angle, the second angle, the third angle, etc. are different, the first digit, the second digit, the third digit, etc. may be the same.

The first continuation of the beam path, the second continuation of the beam path and any further continuation of the beam path can be returned to the dichroic interface by further surface reflections. In this case, a plurality of successive further optical interfaces redirect the first continuation of the beam path, the second continuation of the beam path and optionally also further continuations of the beam path through further interface reflections to the dichroic interface.

Alternatively, the dichroic boundary surface can face a further optical interface which redirects the first continuation of the beam path and the second continuation of the beam path and optionally further continuations of the beam path to the dichroic boundary surface by a respective further surface reflection. The dichroic boundary surface and the other optical interface opposite it can in this case be formed and aligned at a small angle or parallel to one another. The small angle and / or a distance between the two boundary surfaces can be variable in order to set the limit wavelengths applicable for the respective portions of the light beam.

Regardless of whether the first continuation of the beam path, the second continuation of the beam path and further continuations of the beam path return to the dichroic interface by one or more further surface reflections, each further optical interface on which an interface reflection takes place can have a fully reflecting interface or also be another dichroic interface, which transmits further portions of the light beam.

Furthermore, each further optical interface and optionally also the dichroic interface may be formed on a surface of a prism. The formation of dichroic interfaces can be done by appropriate coating of surfaces of the prism.

As already explained in connection with the method according to the invention, the dichroic boundary surface may be a gradient beam splitter having a spatial progression of at least one cutoff wavelength between transmission and reflection. If the gradient beam splitter has only one cut-off wavelength at each location, then another gradient beam splitter with a spatial gradient of its at least one cut-off wavelength can be arranged behind the dichroic boundary surface, which assigns an opposite second cutoff wavelength to the respective location of the first gradient beam splitter. In other words, one gradient beam splitter is designed as a shortpass and the other as a longpass. Thus, each portion of the light beam transmitted by both gradient beam splitters is limited by an upper and a lower cut-off wavelength.

Alternatively, the gradient beam splitter may have parallel spatial characteristics of a lower cutoff wavelength limiting down a transmission band and an upper cutoff wavelength bounding the transmission band upwardly, i. H. be designed as a bandpass.

Another possibility, as has been mentioned above in connection with the method according to the invention, is that the angle at which the respective remainder of the light beam is directed to the dichroic cutoff wavelength is the critical angle of total reflection at the respective cutoff wavelength. It is understood that in this embodiment of the device according to the invention the first angle, the second angle and the third angle are not the same but different.

For the transmitted through the dichroic interface portions of the light beam spatially arranged side by side light sensors may be present. These light sensors can be arranged behind the dichroic interface so that the transmitted light falls directly onto the light sensors. For at least some of the transmitted through the dichroic interface portions of the light beam, a common, time-resolved light sensor may be present. This separates the various components of the light beam transmitted through the dichroic boundary surface on the basis of their different transit times due to different lengths of optical paths before their transmission through the dichroic boundary surface.

A collecting lens and / or a microlens array and / or at least one mirror and / or at least one retroreflector may be arranged in front of the light sensor or the light sensors in order to combine and / or divert the light of the portions of the light beam prior to impinging on the respective light sensor. This optical Elements, as well as the light sensors, can be varied in their position in order to vary the portions of the light transmitted through the dichroic boundary surface registered by the individual light sensors.

In the device according to the invention, a light source may also be present which directs a further light beam through the dichroic boundary surface in the opposite direction to one of the portions of the light beam which is transmitted through the dichroic boundary surface, if it is actually present in the light beam. In this form, the device according to the invention z. B. in a fluorescence light microscope according to the invention for coupling the fluorescence excitation light or fluorescence-preventing light further light beam in the opposite direction in the fluorescent light from a sample-leading beam path can be used. The device then keeps portions of the fluorescence excitation or prevention light reflected from the sample away from the other portions of the light beam by spectral separation. An additional prerequisite for this, however, is that the further light beam is directed not only in the opposite direction to the one of the portions of the light beam through the dichroic interface, but also has a wavelength in the range between the respective lower and upper limit wavelength one of the components of the light beam.

In the previous description of both the method according to the invention and the device according to the invention and of the microscope according to the invention, it has been pointed out that the individual components of different wavelengths into which the light beam is split are transmitted by the dichroic interface, while the respective remainder of the light beam is reflected , However, transmission and reflection may also be reversed such that the portions of different wavelengths are each reflected off the dichroic interface, while the remainder of the light beam is transmitted at the respective angle and location of the dichroic interface. In the claims, the two alternative embodiments of the invention are covered by either-or formulations.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the description are merely exemplary and can take effect alternatively or cumulatively, without the advantages having to be achieved by embodiments according to the invention. Without thereby altering the subject matter of the appended claims, as regards the disclosure of the original application documents and the patent, further features can be found in the drawings, in particular the illustrated geometries and the relative dimensions of several components and their relative arrangement and operative connection. The combination of features of different embodiments of the invention or of features of different claims is also possible deviating from the chosen relationships of the claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different claims. Likewise, in the claims listed features for further embodiments of the invention can be omitted.

The features mentioned in the patent claims and the description are to be understood in terms of their number that exactly this number or a greater number than the said number is present, without requiring an explicit use of the adverb "at least". For example, if we are talking about a convergent lens, this is to be understood that exactly one converging lens, two converging lenses or more converging lenses are present. The features cited in the claims may be supplemented by other features or be the only features exhibited by the particular method or device.

The reference numerals contained in the claims do not limit the scope of the objects protected by the claims. They are for the sole purpose of making the claims easier to understand.

list of figures

• 1 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung für das Auftrennen eines Lichtstrahls in Anteile verschiedener Wellenlängen mit einem als Bandpass ausgebildeten Gradientenstrahlteiler.
• 2 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit einem als Langpass ausgebildeten Gradientenstrahlteiler, dem ein weiterer als Kurzpass ausgebildeter Gradientenstrahlteiler nachgeschaltet ist.
• 3 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit einem als Kerbfilter ausgebildeten Gradientenstrahlteiler.
• 4 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung, bei der nicht nur die Stellen, sondern auch die Winkel unterschiedlich sind, unter denen die Reste des Lichtstrahls auf eine dichroitische Grenzfläche treffen.
• 5 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit zwei einander gegenüberliegenden, als Gradientenstrahlteiler ausgebildeten dichroitischen Grenzflächen, wobei der eine Gradientenstrahlteiler ein Kurzpass und der andere Gradientenstrahlteiler ein Langpass ist.
• 6 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung auf Basis eines Prismas.
• 7 zeigt eine erfindungsgemäße Vorrichtung mit zwei verschiebbaren Spiegeln zur Selektion der Wellenlängenbereiche der Anteile, in die der Lichtstrahl aufgetrennt wird.
• 8 zeigt eine Ausführungsform der Vorrichtung mit zwei dichroitischen Grenzflächen ähnlich wie 5 und zusätzlichen verschiebbaren Spiegeln.
• 9 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit Retroreflektoren für jeweils mehrere Anteile des Lichtstrahls.
• 10 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit einer Sammellinse vor einem Lichtsensor.
• 11 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit mehreren räumlich nebeneinander angeordneten Lichtsensoren.
• 12 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit einem gegenüber der Ausführungsform gemäß 11 zusätzlichen Mikrolinsenarray vor den Lichtsensoren.
• 13 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit einer Sammellinse vor mehreren räumlich nebeneinander angeordneten Lichtsensoren; und
• 14 zeigt eine Ausführungsform der erfindungsgemäßen Vorrichtung mit einer Lichtquelle, um einen weiteren Lichtstrahl in Gegenrichtung zu einem der Anteile des Lichtstrahls einzukoppeln.

In the following the invention will be further explained and described with reference to preferred embodiments shown in the figures.

• 1 shows an embodiment of the device according to the invention for the separation of a light beam into components of different wavelengths with a trained as a bandpass gradient beam splitter.
• 2 shows an embodiment of the device according to the invention with a designed as a long pass gradient beam splitter, which is followed by another formed as a short-pass gradient beam splitter.
• 3 shows an embodiment of the device according to the invention with a trained as a notch gradient beam splitter.
• 4 shows an embodiment of the device according to the invention, in which not only the locations, but also the angles are different, under which the remains of the light beam strike a dichroic interface.
• 5 shows an embodiment of the device according to the invention with two opposite, formed as a gradient beam splitter dichroic interfaces, wherein the one gradient beam splitter is a short-pass and the other gradient beam splitter is a long pass.
• 6 shows an embodiment of the device based on a prism according to the invention.
• 7 shows a device according to the invention with two movable mirrors for selecting the wavelength ranges of the shares, in which the light beam is separated.
• 8th shows an embodiment of the device with two dichroic interfaces similar to 5 and additional sliding mirrors.
• 9 shows an embodiment of the device according to the invention with retroreflectors for a plurality of portions of the light beam.
• 10 shows an embodiment of the device according to the invention with a converging lens in front of a light sensor.
• 11 shows an embodiment of the device according to the invention with a plurality of spatially juxtaposed light sensors.
• 12 shows an embodiment of the device according to the invention with respect to the embodiment according to 11 additional microlens array in front of the light sensors.
• 13 shows an embodiment of the device according to the invention with a converging lens in front of a plurality of spatially juxtaposed light sensors; and
• 14 shows an embodiment of the device according to the invention with a light source to couple another light beam in the opposite direction to one of the components of the light beam.

DESCRIPTION OF THE FIGURES

In the 1 in the form of a first embodiment illustrated device 1 serves to separate a light beam 2 in shares 3 to 7 different wavelengths. The device 1 has a dichroic interface 8th on, this is a band pass 9 trained gradient beam splitter 10 is. The through an entrance window 11 , which does not have to be a physical window, into the device 1 incoming light beam 2 moves along a beam path 12 and meets at an angle φ at a first location 13 on the dichroic interface 8th , This is the first share 3 of the light beam 2 from the dichroic interface 8th having wavelengths in the wavelength band for which the bandpass 9 at the point 13 is permeable. The first rest 14 The light beam is from a parallel to the dichroic interface 8th arranged fully mirrored interface 15 to the dichroic interface 8th reflected back and meets a first sequel 16 of the beam path 12 in a second place 17 again at an angle φ to the dichroic interface. It is characterized by the dichroic interface 8th the second share 4 of the light beam 2 having wavelengths in the wavelength band for which the gradient beam splitter transmits 10 at the point 17 is permeable. One in the place 17 from the dichroic interface 8th reflected second remainder 18 of the light beam 2 arrives at the fully reflecting interface after reflection 15 on a second sequel 19 of the beam path 12 back to the dichroic interface 8th , Here he meets again at the angle φ at a third place 20 on. This is done by the gradient beam splitter 10 the third share 5 of the light beam 2 let through and a third rest 21 reflected on a third sequel 22 of the beam path after renewed reflection at the fully reflecting interface 15 in a fourth place 23 on the dichroic interface 8th meets. At this point 23 will the proportion 6 transmitted by the light beam and so on. In this way, the proportions show 3 to 7 of the light beam 2 separated from each other different wavelengths, by the course of lower and upper limit wavelengths for the wavelength band of the gradient beam splitter 10 trained bandpass 9 depend. By lateral displacement of the gradient beam splitter 10 can the wavelengths of the shares 3 to 7 of the light beam 2 be varied. By changing the distance between the dichroic interface 8th and the fully mirrored interface 15 both the lateral distances of the shares change 3 to 7 as well as the distances of the wavelengths of the shares 3 to 7 ,

In the embodiment of the device 1 according to 2 is the dichroic interface 8th one as a long pass 24 trained gradient beam splitter 10 , The shares occur 3 to 7 then by a short pass 25 formed further gradient beam splitter 26 therethrough. In this way, the two cut-off wavelengths that are the wavelengths of each of the parts 3 to 7 of the light beam 2 limit, by separate gradient beam splitter 10 . 26 established. Basically, the further gradient beam splitter 26 Although not mandatory, because, for example, the second share 4 in principle, only has wavelengths longer than a cutoff wavelength of the longpass 24 at the point 17 are shorter than the cut-off wavelength of the long pass 24 at the point 13 are because the longer wavelengths as a proportion 3 already on the spot 13 through the dichroic interface 8th have passed through. But while the long pass 24 Light with wavelengths below its local cut-off wavelength at the points 13 . 17 . 20 and 23 When it is not completely transmitted but reflected, it also reflects a part of light with wavelengths greater than its local cut-off wavelength. This part of the light is at the proportions 3 to 7 with the help of the shortpass 25 blocked.

The embodiment of the device 1 according to 3 has two opposing and parallel to each other fully reflecting interfaces 15 on. In between is the dichroic interface 8th of here in shape as a notch filter 27 trained gradient beam splitter 10 arranged. The notch filter 27 reflected in the first place 13 selectively the first part 3 , in the second place 17 selectively the second part 4 , in the third place 20 selectively the proportion 5 , in the fourth place 23 selectively the proportion 6 etc. laterally out of the area between the two fully reflecting interfaces 15 out. The rest 14 . 18 . 21 of the light beam 2 run on the sequels 16 . 19 . 22 of the beam path 12 between the fully reflecting interfaces 15 back and forth.

4 shows an embodiment of the device 1 in which the dichroic interface 8th at a small angle α to its opposite fully reflecting interface 15 is arranged. So the beam path hits 12 or meet his sequels 16 . 19 . 22 not only in different places 13 . 17 . 20 . 23 , but also at different angles 90 ° -α, 90 ° -3α, 90 ° -5α, 90 ° -7α, etc. on the dichroic interface 8th , The dichroic interface can be formed 8th for example, as in 1 as a gradient beam splitter 10 in the form of a bandpass. To define the cut-off wavelengths of the components 3 to 7 of the light beam 2 passing through the dichroic interface 8th but can also be the wavelength-dependent critical angle of total reflection at the dichroic interface 8th be exploited.

In the embodiment of the device according to the invention 1 according to 5 lies the dichroic interface 8th that is a gradient beam splitter 10 in the form of a short pass 25 is another dichroic interface 28 in the form of a long pass 24 formed further gradient beam splitter 26 opposite, the dichroic interfaces 8th and 28 are aligned parallel to each other. In addition to the three shares here 3 to 5 of the light beam 2 coming from the dichroic interface 8th be transmitted, here are two more shares 29 and 30 of the light beam in places 31 and 32 the further dichroic interface 28 transmitted, which also have defined wavelength ranges. In 5 are the wavelength ranges of the components 3 to 5 such as 29 and 30 as well as the wavelength ranges of the radicals 14 . 18 and 21 of the light beam 2 as well as on the sequels 16 and 19 of the beam path 12 specified. In these terms, a parenthesis is "exclusive", while an angle bracket means "inclusive." For example, [I1, I2) denotes the interval from I1 to I2 including I1, but excluding I2. The indicated wavelengths λ ₁ to λ ₅ are the cut-off wavelengths λ ₁ , λ ₂ and λ _{3 of} the short-pass 25 in the places 13 . 17 and 20 as well as the cut-off wavelengths λ ₅ and λ _{4 of} the long-pass 24 in the places 31 and 32 ,

6 shows an embodiment of the device 1 based on a prism 33 , It is on a main surface 34 of the prism 33 the dichroic interface 8th as a gradient beam splitter 10 in the form of a bandpass 9 educated. The other two main surfaces 35 and 36 serve as inner fully reflecting interfaces 15 of the prism 33 that the rest 14 . 18 . 21 on the sequel 16 . 19 . 22 of the beam path 12 to the dichroic interface 8th reflect back. 6 lets recognize that in this way a simple education of the entrance window 11 and a splitting of the light beam 2 in a variety of proportions 3 to 7 different wavelengths is possible.

7 illustrates an embodiment of the device 1 that basically 1 corresponds, but at the two laterally movable mirror 37 and 38 in front of the dichroic interface 8th and, depending on their position, one or more of the posts 13 . 17 . 20 . 23 fully reflecting, where the beam path 12 or its continuation 16 . 19 . 22 on the dichroic interface 8th meets. This has the consequence that the otherwise fully mirrored bodies (here 13 and 23 ) through the dichroic interface 8th passing parts (here 3 . 6 . 7 ) can not pass and again with the last rest 61 from the device 1 escape. With the help of the mirror 37 and 38 Thus, it is possible to select the parts that are actually passing through the dichroic interface 8th pass.

8th shows an embodiment of the device 1 similar to the embodiment according to 5 having. Also in the embodiment of the device 1 according to 8th lies the dichroic interface 8th in the form of a short pass 25 trained gradient beam splitter 10 another dichroic interface 28 in shape one as a long pass 24 formed further gradient beam splitter 26 opposite, the dichroic interfaces 8th and 28 are aligned parallel to each other. According to 8th however, are behind the dichroic interfaces 8th and 28 fully reflecting interfaces 15 arranged here orthogonal to those passing through the respective interface 8th or. 28 passing shares 3 to 6 or. 29 and 30 aligned mirrors 39 and 40 form. It is in front of the mirrors 39 and 40 laterally movable panels 41 to 44 arranged. The mirror 39 and 40 cause that in the opposite direction to the light beam 2 from the entrance window 11 again emerging light 45 basically the same spectral composition as the light beam 2 but except for the shares 3 . 29 that with the apertures 41 to 44 hidden and correspondingly not from the mirrors 39 and 40 be reflected. So will with the help of the device 1 the spectral composition of the light 45 Are defined. When the fully reflecting interfaces 15 slightly around the axis of intersection of its mirror surface with the plane of the drawing 8th opposite the dichroic interfaces 8th and 28 are tilted, run from the mirrors 39 and 40 reflected portions 4 - 6 or. 30 at small angles to the plane of the drawing, and they stand at the window 11 as separate parts of the light 45 next to the entering beam 2 out.

For the in 8th given wavelengths λ ₁ to λ ₈ holds that the wavelengths λ ₁ to λ ₄ , the cut-off wavelengths of the short-pass 25 in the places 13 . 17 . 20 and 23 and that the wavelengths λ ₈ to λ ₅ are the cut-off wavelengths of the long-pass 24 in the places 31 . 32 etc. are. The same applies to the meaning of the round and square brackets 5 specified.

In the embodiment of the device 1 according to 9 are instead mirrorless reflecting mirror like in 8th retroreflectors 46 to 49 each provided several of the dichroic interface 8th transmitted shares 3 to 7 of the light beam 2 with different lateral offset to the dichroic interface 8th reflect back. These portions are then removed from the device 1 merged again, as far as they have the same lateral offset, and then with this lateral offset in the opposite direction to the light beam 2 as output beams 50 to 53 output. With sliding panels 41 to 44 in front of the retroreflectors 46 to 49 can in addition to the location of the retroreflectors 46 to 49 Influence on the spectral composition of the output light beams 50 to 53 be taken, with the aperture 41 to 44 certain wavelength ranges are hidden.

10 shows an embodiment of the device 1 which, in addition to those according to 1 a condenser lens 54 which has all the shares 3 to 7 of the light beam 2 behind the dichroic interface 8th on a light sensor 55 focused. The light sensor 55 can still the shares 3 to 7 distinguish if, for example, the light beam 2 a pulsed light beam is because the different spectral components 3 to 7 each pulse different lengths optical paths to the light sensor 55 as they travel differently between the dichroic interface 8th and the fully mirrored interface 15 were reflected back and forth before leaving the dichroic interface 8th were transmitted.

In the embodiment of the device 1 according to 11 are in addition to 1 several spatially juxtaposed light sensors 55 each for one of the dichroic interface 8th transmitted shares 3 to 7 of the light beam 2 intended. According to 12 is in front of the light sensors 55 additionally a microlens array 56 arranged that the respective shares 3 to 7 on the photosensitive area of the respective light sensor 55 focused.

The embodiment of the device 1 according to 13 in addition to the one according to 4 a condenser lens 54 on, at the different angles passing through the dichroic interface shares 3 to 7 of the light beam 2 a plurality of spatially adjacent light sensors 55 supply. In other words, the condenser lens is like 54 here the different exit angles of the shares 3 to 7 and also their different places of passage through the dichroic interface 8th out.

In the embodiment of the device 1 according to 14 is in addition to that according to 1 a light source 57 present, which is another ray of light 58 send out so that he is in place 20 through the dichroic interface 8th passes under the same angle φ, below the portion not present here 5 of the light beam 2 at this point 20 would pass if it existed. The light beam 58 , whose spectral composition of the spectral composition of the proportion 5 corresponds, therefore, occurs in the opposite direction to the light beam 2 from the entrance window 11 the device 1 out. Specifically, the device can 1 according to 14 be used to fluorescence excitation or prevention light in a beam path of a fluorescent light microscope 59 via the fluorescent light from a sample 60 get back and with the help of the device 1 spectrally separated. It is also ensured by means of this spectral separation that of the sample 60 reflected portions of the light beam 58 from the fluorescence light of interest actually from the sample 60 be separated spectrally.

LIST OF REFERENCE NUMBERS

1

device

2

beam of light

3

proportion of

4

proportion of

5

proportion of

6

proportion of

7

proportion of

8th

dichroic interface

9

bandpass

10

Gradientenstrahlteiler

11

entrance window

12

beam path

13

first place

14

first rest

15

fully reflecting interface

16

first continuation of the beam path

17

second place

18

second rest

19

second continuation of the beam path

20

third place

21

third rest

22

third continuation of the beam path

23

fourth place

24

longpass

25

short pass

26

further gradient beam splitter

27

notch filter

28

another dichroic interface

29

another share

30

another share

31

another job

32

another job

33

prism

34

main area

35

main area

36

main area

37

mirror

38

mirror

39

mirror

40

mirror

41

cover

42

cover

43

cover

44

cover

45

light

46

retroreflector

47

retroreflector

48

retroreflector

49

retroreflector

50

Output light beam

51

Output light beam

52

Output light beam

53

Output light beam

54

converging lens

55

light sensor

56

Microlens array

57

light source

58

another light beam

59

Fluorescent light microscope

60

sample

61

Last rest

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 102006034908 A1 [0003]
• DE 102009012874 A1 [0004]
• DE 102010060747 B4 [0005]
• DE 202016008334 U1 [0006]

Claims (15)

Method for separating a light beam (2) into parts (3 to 7) of different wavelengths - the light beam (2) being firstly directed at a first location (13) to a dichroic interface (8) at a first angle, such that the dichroic interface (8) transmits either a first portion (3) of the light beam (2) having first wavelengths on one side of a first cut-off wavelength and a first remainder (14) of the light beam (2) having wavelengths on the other side of the first cutoff wavelength reflected - or a first portion (3) of the light beam (2) with first wavelengths reflected on one side of a first cutoff wavelength and a first remainder (14) of the light beam (2) with wavelengths on the other side of the first cutoff wavelength transmitted, - wherein at least a portion of the first remainder (14) reflected or transmitted by the dichroic interface (8) at one opposite the first angle in A second point (17), which is changed in a direction of rotation, and / or a second point (17) displaced with respect to the first point (13) in a translation direction is directed a second time onto the dichroic boundary surface (8), so that the dichroic boundary surface (8) is either one second portion (4) of the light beam (2) having second wavelengths on one side of a second cut-off wavelength lying on the other side of the first cut-off wavelength, and a second remainder (18) of the light beam (2) having wavelengths on the other side the second cutoff wavelength is reflected - or a second portion (4) of the second wavelength light beam (2) on one side of a second cutoff wavelength lying on the other side of the first cutoff wavelength, and a second remainder (18) of the light beam (2 ) with wavelengths on the other side of the second cutoff wavelength, characterized in that - min at least one part of the second residue (18) reflected or transmitted by the dichroic boundary surface (8) at a third angle changed in the direction of rotation relative to the second angle and / or at a third point displaced in the direction of translation relative to the second location (17) ( 20) is directed a third time at the dichroic interface (8) so that the dichroic interface (8) - either a third portion (5) of the light beam (2) having third wavelengths on the one side of a third cut-off wavelength, on the another side of the second cut-off wavelength, transmits and reflects a third remainder (21) of the light beam (2) with wavelengths on the other side of the third cut-off wavelength - or a third portion (5) of the light beam (2) with third wavelengths on the one side a third cutoff wavelength, which lies on the other side of the second cutoff wavelength, and reflects a dri The remainder (21) of the light beam (2) is transmitted at wavelengths on the other side of the third cut-off wavelength. Method according to Claim 1 , characterized in that at least the part of the first remainder (14) and at least the part of the second remainder (18) and optionally at least a part of the third remainder (21) reflected or transmitted by the dichroic interface (8) are re-opened by further interfacial reflections the dichroic boundary surface (8) are directed, wherein, optionally, the further interfacial reflections - at one of the dichroic interface (8) opposite another optical interface and / or - each at a plurality of successive other optical interfaces. Method according to Claim 2 , characterized in that the dichroic boundary surface (8) and the other optical interface opposite it are flat and aligned at a small angle or parallel to each other, the small angle and / or distance between the dichroic interface (8) and the its opposite further optical interface for selecting the different wavelengths of the transmitted through the dichroic interface (8) portions (3 to 7) of the light beam (2) is changed. Method according to one of the preceding claims, characterized in that the from the dichroic interface (8) transmitted or reflected portions (3 to 7) of the light beam (2) - spatially juxtaposed light sensors (55) and / or - one or more light sensors (55) are registered with a time resolution. Method according to Claim 4 , characterized in that at least some of the dichroic boundary surface (8) transmitted or reflected portions (3 to 7) of the light beam (2) - directly or - with a converging lens (54) and / or a Mikrolinsenarray (56) and / or at least one mirror (37 to 40) and / or at least one retroreflector (46 to 49) are directed to the light sensor (s) (55), wherein - the light sensor (s) (55) and / or - the converging lens (54 ) and / or - the microlens array (56) and / or - the at least one mirror and / or - the at least one retroreflector are / is moved to the assignment of the individual light sensors (55) to the through the dichroic interface (8) transmitted portions (3 to 7) of the light beam (2) to vary. Method according to one of the preceding claims, characterized in that in the direction opposite to one of the portions (3 to 7) of the light beam (2), which is as far as transmitted from the dichroic interface (8) or reflected, another light beam (58) the dichroic interface (8) is directed, wherein, optionally, the further light beam (58) comprises fluorescence excitation light or fluorescence prevention light, the fluorophore in a sample (60) is applied, and the light beam (58) is fluorescent light from the fluorophores. Device for separating a light beam (2) into parts (3 to 7) of different wavelengths with a beam path (12) beginning at an entrance window (11) for the light beam (2), wherein the beam path (12) is at a first angle a first location (13) for a first time encounters a dichroic interface (8) which either - transmits a first portion (3) of the light beam (2) having first wavelengths on one side of a first cutoff wavelength and a first remainder (14) of the light beam (2) with wavelengths on the other side of the first cutoff wavelength along a first continuation of the beam path (16) reflected - or a first portion (3) of the light beam (2) with first wavelengths on one side of a first cutoff wavelength reflected and a first Remainder (14) of the light beam (2) with wavelengths on the other side of the first cut-off wavelength along a first continuation of the beam path (16) transmit - wherein at least a portion of the first remainder (14) reflected by the dichroic interface (8) on the first continuation of the beam path (16) is at a second angle to the first angle in a direction of rotation and / or one opposite to the first Digit (13) in a translation direction shifted second location (17) hits a second time on the dichroic interface (8), thereby - either a second portion (4) of the light beam (2) having second wavelengths on one side of a second cut-off wavelength which is on the other side of the first cutoff wavelength, transmits and reflects a second remainder (18) of the light beam (2) having wavelengths on the other side of the second cutoff wavelength along a second continuation of the beam path (19) - or a second portion (4 ) of the second wavelength light beam (2) on one side of a second cutoff wavelength, on the other side is the first cutoff wavelength, reflected and a second remainder (18) of the light beam (2) having wavelengths on the other side of the second cutoff wavelength along a second continuation of the beam path (19) transmitted, characterized in that at least a portion of the dichroic Boundary surface (8) reflected second remnant (18) on the second continuation of the beam path (19) at a third angle to the second angle in the direction of rotation changed third and / or at a second point (17) in the translated direction third position ( 20) strikes the dichroic interface (8) a third time, thereby transmitting either a third portion (5) of the light beam (2) having wavelengths on one side of a third cutoff wavelength which is on the other side of the second cutoff wavelength and a third remainder (21) of the third wavelength light beam (2) on the other side e of the third cut-off wavelength along a third continuation of the beam path (22) reflected - or a third portion (5) of the light beam (2) with wavelengths on the one side of a third cut-off wavelength, which is on the other side of the second cut-off wavelength, reflected and a third remainder (21) of the light beam (2) having third wavelengths on the other side of the third cut-off wavelength along a third continuation of the beam path (22). Device after Claim 7 , characterized in that - a plurality of successive further optical interfaces the first continuation of the beam path (16) and the second continuation of the beam path (19) and optionally the third continuation of the beam path (22) by further surface reflections back to the dichroic interface (8) deflect and / or - that the dichroic interface (8) opposite to another optical interface, the first continuation of the beam path (16) and the second continuation of the beam path (19) and optionally the third continuation of the beam path (22) by further interfacial reflections again deflected to the dichroic interface (8). Device after Claim 8 , characterized in that the dichroic boundary surface (8) and the other optical interface opposite it are flat and are aligned at a small angle or parallel to each other, wherein, optionally, the small angle and / or a distance between the dichroic interface (8 ) And the other optical interface opposite it is variably adjustable. Device according to one of Claims 7 to 9 , characterized in that each further optical interface is a fully reflecting interface (15) or a further dichroic interface (26) and / or - that each further optical interface and optionally also the dichroic interface (26) is formed on a surface of a prism (33). Device according to one of Claims 7 to 10 Characterized in that - the angle at which the respective remainder of the light beam (2) impinges upon the dichroic interface (8), the critical angle of total reflection at the respective cut-off wavelength and / or that the dichroic interface (8) Gradientenstrahlteiler ( 10) with a spatial profile of at least one cut-off wavelength between transmission and reflection, wherein, optionally, behind the dichroic boundary surface (8) a further gradient beam splitter (26) with spatial progression of its at least one cut-off wavelength is arranged or the gradient beam splitter (10) parallel spatial courses one lower, a transmission band down limiting boundary wavelength and an upper, the transmission band has upwardly limiting cutoff wavelength. Device according to one of Claims 7 to 11 Characterized in that - the transmitted or by the dichroic interface (8) reflected components (3 to 7) of the light beam (2) are spatially adjacently arranged light sensors (55) are present and / or - that at least one common, time-resolution light sensor (55) for at least some of the dichroic interface (8) transmitted or reflected portions (3 to 7) of the light beam (2) is present. Device after Claim 12 , characterized in that a converging lens (54) and / or a microlens array (56) and / or at least one mirror (37 to 40) and / or at least one retroreflector (46 to 49) in front of the juxtaposed light sensors (55) and / or the time-resolved light sensor (55), wherein, optionally, the juxtaposed light sensors (55) and / or the time-resolved light sensor (55) and / or the convergent lens (54) and / or the microlens array (56) and / or or the at least one mirror (37 to 40) and / or the at least one retroreflector (46 to 49) are movably mounted. Device according to one of Claims 7 to 13 , characterized in that a light source (57) is provided which, in the opposite direction to one of the portions (3 to 7) of the light beam (2), which is transmitted or reflected by the dichroic boundary surface (8), forms a further light beam ( 58) to the dichroic interface (8). Fluorescence light microscope (59) with a device according to Claim 14 for coupling the fluorescence excitation light or fluorescence prevention light further light beam (58) in the opposite direction in the fluorescent light from a sample (60) leading beam path (12).

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