DE102020130275A1 - HIGH RESOLUTION MICROSCOPE, MICROOPTIC SYSTEM AND DETECTION ARRANGEMENT - Google Patents

Abstract

The present invention relates to a high-resolution microscope with a micro-optical (1) system, a micro-optical system (1) and a detection arrangement with a micro-optical system (1). The micro-optical system (1) has a lens (2) that can be automatically displaced and/or whose refractive power can be automatically adjusted. At least one position and/or one direction of a light beam can be adjusted by means of the lens (2). For this purpose, the lens (2) can be moved by a miniaturized actuator system (3). Shifts in the lens (2) in the x and/or y direction can be used to compensate for angle errors. The collimation of the light beam can also be influenced by shifting the lens (2) in the z-direction.

Description

The present invention relates to a high-resolution microscope with a micro-optical system, a micro-optical system and a detection arrangement with a micro-optical system.

Complex optical instruments using lasers usually require precise alignment of the different beam paths, e.g. so that the foci of the different beam paths overlap correctly in x, y and z.

In addition, the correct collimation of the beams or the z-position of the foci must be determined very precisely. In some applications it may be necessary to change the collimation state repeatedly, for example to compensate for axial chromatic aberrations in successive exposures for different wavelengths.

An example of a complex optical instrument is a confocal laser scanning microscope. In such a microscope, different beam paths are used for lasers of different wavelengths, and there are also other beam paths in the direction of a pinhole for the detection light, which has to hit the small-area detectors centrally.

Another example are fiber couplers for single-mode fibers that couple laser light into a fiber.

Thermal drifts result in angular changes of the collimated beams and, if focused beams are important, in xy shifts of the focused beams. These affect the application and must be corrected.

Small deviations in the beam direction can have various causes. For example, the output beam of a laser can already be unstable in terms of beam direction due to the laser design, e.g. as a function of temperature. In addition, mechanical components of the beam guidance optics, such as mirror and lens mounts, can drift in angle or in position and impose an angular error on the beam path. A supporting base plate, such as an optical table, a perforated grid plate or a CNC-machined apparatus housing, can also bend when the temperature changes and thus force the beam path at an angle, since the contact surfaces are no longer exactly parallel in different areas.

The beam paths involved often have very small diameters of less than 10 mm. In most applications, lateral beam shifts also play a smaller role than angular deviations. Particularly in the case of well-designed instruments with short beam paths, an angle error cannot be reflected in a significant beam shift due to the short path length.

Angle errors can be actively compensated using actuators and sensors. The sensors can measure the beam position or the beam angle directly. Position-sensitive diodes or 4-quadrant diodes, for example, can be used for this purpose. Alternatively, the sensors can also detect a quantity to be optimized, such as the power transmitted over a fiber.

To compensate for the measured angle errors, motorized mirror mounts are often used for the system's deflection mirrors. These mirror mounts, which typically hold 1 inch or 0.5 inch diameter mirrors, are driven by piezo elements, stepper motors, or piezo stepper motors. However, these solutions are quite large and also expensive. In addition, further opto-mechanical components are required for collimating the beams.

In this context describes WO 2013/044388 A1 describe a scanning mechanism for use in confocal imaging. The scanning mechanism uses an electromagnetic actuator to move elements in an optical system. An objective lens attached to a flexure made of magnetic material is actuated in the axial direction by a solenoid coil through which an optical path extends. Transverse scanning is accomplished using magnetically actuated flexible supports that move the tip of an optical fiber or other pinhole in one or more transverse directions.

WO 2016/007954 A1 describes a control device for an imaging system. The control device comprises a first movable deflection mirror, a second movable deflection mirror and a component connected to the deflection mirrors for independent positioning of the movable deflection mirrors in the xy axes. Positioning along the z-axis is made possible by an electrically adjustable lens.

WO 2019/186143 A1 describes a scanning microscope. The microscope includes an illumination system and an objective lens providing excitation radiation in a focal volume to cause emission of emission radiation from a sample in the focal volume. The objective lens is moved by an objective scanner in the xy-axes transverse to the optical axis of the objective.

WO 2020/102442 A1 describes a method for generating a depth profile of a tissue. An excitation light beam is transmitted from a light source to a surface of the tissue by means of an optical probe. Focusing units in the optical probe are used to simultaneously adjust a depth and a position of a focal point of the excitation light beam along a scanning path. An electrically adjustable lens can be used for this purpose.

It is an object of the invention to provide alternative solutions for the automated adjustment of a light beam in an optical arrangement.

This object is achieved by a high-resolution microscope having the features of claim 1, by a micro-optical system having the features of claim 12 or 14 and by a detection arrangement having the features of claim 15. Preferred developments of the invention are the subject matter of the dependent claims.

According to a first aspect of the invention, a high-resolution microscope has a micro-optical system with an automatically displaceable and/or automatically adjustable lens for adjusting at least one position and/or one direction of a light beam used in the high-resolution microscope.

In the solution according to the invention, a micro-optical system is used to adjust a light beam in a high-resolution microscope. The micro-optical system can be, for example, a miniaturized actuator system with a lens. Such systems were developed for the optical image stabilization of smartphone cameras. Such a miniaturized actuator system has the advantage that it is very compact with dimensions of typically less than 2 cm×2 cm×1 cm and at the same time offers a sufficiently large clear aperture of around 5 mm to 10 mm and a large stroke of more than 100 μm. In addition, it is very inexpensive when produced in large quantities. Further advantages are that closed loop control is provided, i.e. the movements are precise and repeatable, and the displacements can occur very quickly, typically within less than 50 ms.

Displacements of a lens that is required anyway in the x and/or y direction can be used to compensate for angle errors. This has the additional advantage that fewer mirror mounts are required, since fewer beam deflections are required, or alternatively, deflection mirrors can be firmly positioned and therefore do not require expensive kinematic mounts. Z-direction shifts can be used to easily achieve and maintain collimation. The system therefore requires fewer additional opto-mechanical components.

The actuators often provide further degrees of freedom with the option of tilting the lens around two mutually perpendicular axes. These can be used, for example, to compensate for coma by tilting the lens. If a large lateral shift is required to compensate for an angular error in the system, the shifted lens may in turn cause some coma. This can be compensated for by additionally tilting the lens.

As an alternative or in addition to adjusting the lens by moving the lens mechanically, there is also the possibility of adjusting the lens by changing the refractive power, e.g. by deforming the lens. For example, a liquid lens can be used, i.e. a liquid lens or a liquid-filled lens which can be altered in its refractive power electronically, e.g., by mechanical deformation or electrowetting. Other options for displaceable lenses are electro-optical and acousto-optical lenses.

In particular, the high-resolution microscope can be a laser-scanning microscope, for example a STED microscope (STED: Stimulated Emission Depletion; stimulated fluorescence quenching). With STED microscopes it is important to make different beams collinear, e.g. to superimpose the light from the excitation laser and the STED laser very precisely. If individual beams are superimposed, this has typically been solved with motorized mirror holders up to now. The setting of the beam angle according to the invention by means of a displaceable lens allows the realization of a significantly more compact STED microscope with individual beams.

Another way to use a micro-optical system to adjust a light beam in a high-resolution microscope is to build such a micro-optical system into a diode laser module. The diode laser module then includes a laser diode with associated electronics and a collimation lens to collimate the light from the laser diode. This collimation The lens can be shifted automatically and/or its refractive power can be adjusted automatically. For this purpose, it can be arranged in particular on a miniaturized actuator system, for example an actuator system that uses a shape memory alloy. The diode laser module is then able to adjust beam direction and collimation during operation. Tilt and focus can also be optimized automatically. The function of a conventional adjustment device in a high-resolution microscope is thus shifted to the laser module, which saves space and reduces costs. The adjustable beam position can then be used to align the light beam of the diode laser module in relation to other light beams in the STED microscope or in a STED attachment of a microscope. An xyz overlap of the foci in a sample can thus be achieved without additional opto-mechanical components. In addition, coma caused by an objective lens can be reduced by tilting the collimating lens.

The integration of a micro-optical system in a laser is also advantageous if the light emitted by the laser is to be coupled into a fiber. The fiber coupler can be arranged at a distance from the laser, as is the case, for example, with beam combiners in which several lasers are combined by dichroic optical components and coupled into a fiber by means of a common fixed fiber coupler. In this case, the dichroic optical components can be permanently mounted. The laser beam is then aligned in relation to the fiber tip by means of the collimation lens, which can be displaced and/or whose refractive power can be adjusted. Alternatively, a fiber port can also be mounted directly on the front surface of the laser, which does not require adjustment options for different degrees of freedom. The required adjustment of the laser beam in relation to the fiber tip is then in turn effected by the collimation lens, which can be displaced and/or whose refractive power can be adjusted.

With a STED attachment for a camera port of any microscope, there is often exactly one fiber port for excitation light and STED light. Accordingly, lasers of different wavelengths emerge from the common fiber facet and are imaged by the usually well color-corrected microscope optics in a common area of the sample, where they overlap well in x, y, and z. As a result, these lasers are automatically aligned with each other by design because they share a common origin and beam path. This methodology reaches its limits when a deep blue or UV excitation laser is to be used (typically e.g. 405 nm for excitation of DAPI or HOECHST staining of cell nuclei). Due to the characteristic dispersion of all common glasses, where the refractive indices increase sharply in the deep blue, the microscope optics are usually not well color corrected and the corrections of the different manufacturers also differ significantly. Accordingly, it is desirable here to combine a separate deep blue beam path with the common multi-wavelength beam path and to prefocus and tilt the deep blue beam path according to the invention in such a way that the deep blue focus in the sample is aligned with the other laser foci in x, y and z direction overlapped.

A micro-optical system with a lens that can be displaced automatically and/or whose refractive power can be adjusted automatically can also be integrated into a fiber coupler. For example, the coupling lens of such a fiber coupler can be held by miniaturized actuators. If only one laser beam has to be coupled in, tilting and focus can be optimized by means of the coupling lens in such a way that the coupling is optimized. If, on the other hand, several laser beams have to be coupled in, the collimation can be set to the best possible compromise for all laser beams.

A micro-optical system with a lens that can be displaced automatically and/or whose refractive power can be adjusted automatically can also be integrated into a fiber collimator. For example, the collimation lens of such a fiber collimator can be held by miniaturized actuators. This allows the collimator's output beam to be steered using tilt and focus. Multiple laser beams can also be made to overlap in a confocal microscope. An xyz overlap of the foci in a sample can thus be achieved without additional opto-mechanical components. In addition, coma caused by an objective lens can be reduced by tilting the collimating lens.

According to one aspect of the invention, the micro-optical system is part of an autofocus unit of the microscope. In this case, for example, the collimation lens of a laser of the autofocus unit can be held by a miniaturized actuator system. For example, such an autofocus unit can couple an auxiliary light beam into the microscope in such a way that the auxiliary light beam is inclined at an angle in relation to a normal to an object plane of the microscope. In this case, the auxiliary light beam preferably runs in a plane which is spanned outside a main imaging region of the microscope by a straight line running in the object plane and the normal to the object plane. Changes in position of a stepping surface are used to monitor a focusing state of the microscope a part of the auxiliary light beam reflected by a reference surface is detected. In this context, the automatically relocatable and/or automatically adjustable lens can be used to prefocus the auxiliary light beam by shifting it in the z-direction, e.g. to adapt the system to a non-4f microscope or to switch between a collimated and switch to a focused autofocus scenario. The tilting of the auxiliary light beam can also be adjusted in order to precisely set the angle of the auxiliary light beam in the intermediate image and thus adapt it to the microscope stand used. This eliminates the need for a manual and time-consuming adjustment of an actuator for tilting. Such an autofocus unit can be usefully used not only in a laser-scanning microscope, but also in other microscopes. The micro-optical system preferably has two lenses for use in an autofocus unit. In a first embodiment, the refractive power of the first lens can be adjusted and the second lens can be displaced. In a second embodiment, both lenses are adjustable in their refractive power and are arranged off-axis. Both embodiments are particularly advantageous for the autofocus unit described above, in which an angle adjustment is only required in one plane.

According to one aspect of the invention, the micro-optical system is part of a detection unit of the microscope. In this case, the micro-optical system can in particular be set up to position a measuring beam on a detector. An integrated system consisting of a micro-optical system and a small SPAD array (SPAD: Single-Photon Avalanche Diode; single-photon avalanche diode) is particularly advantageous. In this case, the SPAD array can have an expansion in the order of an Airy diameter. When detecting with a SPAD array, the focus on the SPAD array wanders a little when the wavelength band that is directed onto the SPAD array is changed. This then corrupts the evaluation and reduces the resolution. This can easily be compensated for by the solution according to the invention.

According to one aspect of the invention, the micro-optical system is part of a pinhole assembly of the microscope. This can, for example, be placed in front of an adjustable spectral filter in the beam path. The micro-optical system is preferably set up to set a lateral focal position of fluorescent light with respect to an aperture or to set an axial focal position of a laser beam with respect to the aperture. The lens, which can be displaced automatically and/or whose refractive power can be adjusted automatically, can be arranged, for example, in front of a pinhole of a confocal microscope and can be used to optimize the xy position of a fluorescence spot on the pinhole. It is also possible to automatically optimize the z-position for maximum transmission efficiency for a selected wavelength range or to change the z-position between consecutive recordings.

According to one aspect of the invention, the micro-optical system used in the microscope has a lens that can be displaced automatically and a lens whose refractive power can be automatically adjusted. In this case, the micro-optical system is preferably set up to set a tilting and collimation of the light beam by means of a combination of the two lenses. The lens, which can be automatically adjusted in its refractive power, can be arranged off-axis in relation to an optical axis. Likewise, the automatically displaceable lens can have a zero position that is off-axis with respect to the optical axis.

In this embodiment of a solution according to the invention, the microscope has a combination of two lenses, one of which can be displaced automatically and the other whose refractive power can be adjusted automatically. The collimation of a light beam can be adjusted with a first lens. The second lens tilts the light beam when it is adjusted and changes the collimation if necessary. In combination, tilting and collimation of the light beam can be adjusted using the two lenses. For example, a look-up table can be used for the adjustment of the second lens, in which the required values of the lens shift for each setting of the first lens are stored.

The lens whose refractive power can be adjusted can in particular be a liquid lens. Liquid lenses can produce relatively large powers, greater than is possible by z-movement of a lens on an actuator because the actuator's travel is limited. However, when the power of a liquid lens is changed, a deviation in the tilt of the wavefront is often also caused. So far, this has been difficult to eliminate. The combination of a collimating lens on an actuator capable of xy translation with a liquid lens eliminates this problem. The combination offers the large refractive power range of the liquid lens. Tilt deviations caused by the liquid lens can be corrected by shifting the collimating lens. An alternative is to connect a lens whose refractive power can be adjusted, preferably a liquid lens, to an actuator. Parasitic tilting associated with the change in the focus position can then be compensated for by a lateral displacement of the liquid lens.

In an alternative embodiment of the invention, the micro-optical system used in the microscope has two lenses whose refractive power can be automatically adjusted, of which at least one is arranged off-axis in relation to an optical axis. In this case, the micro-optical system is preferably set up to set a tilting and collimation of a light beam by means of the two lenses whose refractive power can be automatically adjusted.

According to a further aspect of the invention, a micro-optical system has two lenses whose refractive power can be automatically adjusted, at least one of which is arranged off-axis in relation to an optical axis. The micro-optical system is set up to adjust a tilting and collimation of a light beam by means of a combination of the two lenses whose refractive power can be automatically adjusted.

In this embodiment, the two lenses can be used to set a tilt in a plane in which the optical axes of the two lenses that are offset relative to one another lie, and to set a collimation of the light beam. To set the second lens, for example, a look-up table can be used, in which the required values of the refractive power for each setting of the first lens are stored. The combination of the two lenses, which can be automatically adjusted in their refractive power, enables a very flexible adjustment of tilting and collimation with a very compact opto-mechanical component.

At least one of the two lenses, whose refractive power can be automatically adjusted, is arranged off-axis. Preferably none of the lenses lies exactly on the optical axis. Rather, both lenses can be oppositely offset with respect to the optical axis. If both lenses have a positive refractive power, there is no angle in this case, only defocusing. If, on the other hand, they assume opposite powers, there is a pure lateral displacement. In principle, all arrangements are possible in which two lenses with parallel axes are offset from one another. The beam angle, which can be adjusted, then lies in the plane spanned by the two parallel axes. The second lens, possibly in conjunction with an associated offset lens, can have a diverging negative as well as a focusing or neutral effect. In order to be able to tilt a beam independently along two directions and also to be able to prefocus it, at least three lenses whose refractive power can be automatically adjusted are required, the three axes of which are preferably parallel, do not coincide, but do not lie in a common plane.

According to a further aspect of the invention, a micro-optical system has a lens that can be displaced automatically and a lens whose refractive power can be automatically adjusted. The micro-optical system is set up to adjust a tilting and collimation of a light beam by means of a combination of the automatically displaceable lens and the automatically adjustable lens in terms of its refractive power. The lens, which can be automatically adjusted in its refractive power, can be arranged off-axis in relation to an optical axis. Likewise, the automatically displaceable lens can have a zero position that is off-axis with respect to the optical axis.

In this embodiment of the invention, a lens whose refractive power can be adjusted, preferably a liquid lens, is combined with a displaceable lens. This combination offers, if the displaceable lens is displaceable in two directions perpendicular to the optical axis, the possibility of being able to tilt a beam independently along two directions and also to be able to prefocus

Applications in a microscope come into consideration, for example, for a lens of a pinhole assembly that requires a relatively large stroke in the z-direction, for a fiber coupler, or for defocusing and adjusting the beam angle of a laser in an autofocus unit. An embodiment with exactly two lenses that can be adjusted in terms of their refractive power can be used particularly advantageously for an autofocus device as described above, in which adjustment to another tripod or another objective only requires the adjustability of the tilting within a plane parallel to the optical axis of the microscope will. Another application concerns the adjustment of the xyz position of individual excitation spots in a laser scanning microscope. For example, it can happen that light of certain wavelengths is not coupled in via a common optical fiber, but rather separately. In this case, it may be necessary to adjust the xyz position of the corresponding excitation spot when changing the objective.

According to a further aspect of the invention, a detection arrangement has a detector array and a micro-optical system with an automatically displaceable and/or automatically adjustable lens for adjusting at least one position of a light beam in relation to the detector array.

In this embodiment of a solution according to the invention, the micro-optical system is set up to position a measuring beam on a detector. This makes it possible to always optimally position the measuring beam on the detector array kidneys In particular, the detector array can be an array of miniaturized single-photon avalanche diodes.

According to one aspect of the invention, the micro-optical system for moving the lens or lenses comprises a voice coil motor, a piezoelectric motor or a shape memory alloy actuator. Such drives have the advantage that they only require a very small amount of space and can be easily implemented.

• 1 zeigt schematisch ein mikrooptisches System zum Einstellen eines Lichtstrahls;
• 2 zeigt die Erzeugung eines kollimierten Lichtstrahls durch ein mikrooptisches System;
• 3 zeigt eine Verkippung des Lichtstrahls durch eine x-oder y-Verschiebung einer Linse des mikrooptischen Systems;
• 4 zeigt eine Änderung der Kollimation des Lichtstrahls durch eine z-Verschiebung der Linse;
• 5 zeigt schematisch ein mikrooptisches System zum Einstellen eines Lichtstrahls mit einer in ihrer Brechkraft anpassbaren Linse und einer verlagerbaren Linse,
• 6 zeigt schematisch ein mikrooptisches System zum Einstellen eines Lichtstrahls mit zwei zueinander versetzt angeordneten, in ihrer Brechkraft anpassbaren Linsen;
• 7 zeigt einen prinzipiellen Aufbau eines Mikroskops, in dem eine erfindungsgemäße Lösung realisiert ist; und
• 8 zeigt schematisch eine Autofokuseinheit in einem Mikroskop.

Further features of the present invention will become apparent from the following description and the appended claims in conjunction with the figures.

• 1 shows schematically a micro-optical system for adjusting a light beam;
• 2 shows the generation of a collimated light beam by a micro-optical system;
• 3 shows a tilting of the light beam due to an x or y displacement of a lens of the micro-optical system;
• 4 Figure 12 shows a change in collimation of the light beam by a z-shift of the lens;
• 5 shows schematically a micro-optical system for adjusting a light beam with a lens that can be adjusted in terms of its refractive power and a displaceable lens,
• 6 shows schematically a micro-optical system for adjusting a light beam with two lenses which are offset relative to one another and whose refractive power can be adjusted;
• 7 shows a basic structure of a microscope in which a solution according to the invention is implemented; and
• 8th shows schematically an autofocus unit in a microscope.

For a better understanding of the principles of the present invention, embodiments of the invention are explained in more detail below with reference to the figures. It goes without saying that the invention is not limited to these embodiments and that the features described can also be combined or modified without departing from the scope of protection of the invention as defined in the appended claims.

1 shows schematically a micro-optical system 1 for adjusting a light beam. The micro-optical system 1 has a lens 2 that can be automatically displaced and/or whose refractive power can be automatically adjusted. At least one position and/or one direction of a light beam can be adjusted by means of the lens 2 . In the example shown, the lens 2 can be moved by a miniaturized actuator system 3 for this purpose. Displacements of the lens 2 in the x and/or y direction can be used to compensate for angle errors. The collimation of the light beam can also be influenced by shifting the lens 2 in the z-direction. The actuator system 3 can also provide further degrees of freedom and, for example, allow the lens 2 to be tilted about two axes perpendicular to one another. These degrees of freedom can be used to compensate for coma by tilting the lens 2, for example. In turn, if a large lateral displacement is required to accommodate an angular error in a system, the displaced lens 2 may cause some coma. This can be compensated for by additionally tilting the lens 2. The actuator system 3 can use, for example, a plunger coil motor, a piezoelectric motor or an actuator made from a shape memory alloy.

As an alternative or in addition to adjusting the lens 2 by a mechanical movement of the lens 2 by an actuator 3, there is also the possibility of adjusting the lens 2 by changing the refractive power, e.g. by deforming the lens 2. For example, a liquid lens can be used i.e. a liquid lens 2 or a liquid-filled lens 2 which can be altered in its refractive power electronically, e.g., by mechanical deformation or electrowetting. Further possibilities for lenses 2 whose refractive power can be changed are electro-optical and acousto-optical lenses.

2 shows the generation of a collimated light beam 4 by a micro-optical system 1. A of a in 2 not shown light source outgoing light beam 4 strikes the lens 2 of the micro-optical system 1. The lens 2 is arranged on the optical axis 8 of the light beam 4, ie the lens 2 is of the actuator 3 of the micro-optical system 1 in a neutral position with respect to a Base 9 held. The distance between the lens 2 and the light source is chosen so that the light beam 4 is collimated.

3 shows a tilting of the light beam 4 by an x or y displacement of the lens 2 of the micro-optical system 1 relative to the base 9 by the actuator 3. In this example, the lens 2 was displaced by the actuator 3 in the x direction from its neutral position. This is indicated by the arrow. The distance between the lens 2 and the light source is unchanged, so the light beam 4 continues to be collimated. Due to the displacement of the lens 2 in the x-direction However, light beam 4 is now deflected relative to the optical axis 8, ie the direction of light beam 4 has changed.

4 shows a change in the collimation of the light beam 4 due to a z-displacement of the lens 2 of the micro-optical system 1. In this example, the lens 2 was displaced by the actuator 3 in the z-direction from its neutral position. This is indicated by the arrow. The distance between the lens 2 and the light source has thus changed so that the light beam 4 is no longer collimated. However, since the lens 2 is not shifted relative to the base 9 either in the x-direction or in the y-direction, the light beam 4 is not deflected, ie the direction of the light beam 4 relative to the optical axis 8 is unchanged.

5 shows schematically a micro-optical system 1 for adjusting a light beam 4 with a lens 5 whose refractive power can be adjusted and a displaceable lens 2 in connection with a light source 40, which is designed as a laser diode, and a fixed lens 41, which captures the light emerging from the laser diode collimated. The collimation of the light beam 4 can be adjusted with the first lens 5 . The second lens 2 can be displaced automatically and tilts the light beam 4 when it is displaced perpendicularly to the optical axis 8 and changes the collimation. In combination, tilting and collimation of the light beam 4 can be adjusted by means of the two lenses 2, 5. For the displacement of the second lens 2, a look-up table can be used, for example, in which the required values of the lens displacement for each setting of the first lens 5 are stored. The lens 5 can in particular be a liquid lens.

6 shows schematically a micro-optical system 1 for adjusting a light beam 4 with two mutually offset arranged, automatically adjustable in their refractive power adjustable lenses 5, eg liquid lenses, in connection with a light source 40, which is designed as a laser diode, and a fixed lens 41, which consists of The light emitted by the laser diode is collimated. At least one of the two lenses 5 is arranged off-axis in relation to an optical axis 8 , neither of the lenses 5 can lie exactly on the optical axis 8 . Rather, the two lenses 5 can be offset opposite each other in relation to the optical axis 8, as is the case in the example in 6 the case is. If both lenses 5 assume the same positive refractive power, there is no angle in this case, only defocusing. If, on the other hand, they assume opposite refractive powers that are equal in magnitude, there is a pure lateral offset in this case. In principle, all arrangements are possible in which two lenses 5 with parallel axes are offset from one another. The beam angle, which can be adjusted, then lies in the plane spanned by the two parallel axes. The lenses 5, in each case optionally in conjunction with an associated offset lens, can have a diverging negative effect as well as a focusing or neutral effect.

7 shows a basic structure of a microscope 10 in which a solution according to the invention is implemented. In this example it is a STED microscope. The setup is based on a laser scanning fluorescence microscope as is known in the prior art. This has an excitation light source 11 for excitation light 12 . The excitation light 12 is reflected from a first beam coupler 13 to a second beam coupler 14 . Both beam couplers 13, 14 can be dichroic mirrors, for example. The second beam coupler 14 serves to superimpose the excitation light 12 with fluorescence prevention light 15 coming from a fluorescence prevention light source 16 . Both beam couplers 13, 14 also serve to separate the detection beam path, ie the beam path for the fluorescent light 17, from the illumination beam paths. The beam coupler 14 separates the detection beam path from the beam path common to the fluorescence light 17 , fluorescence prevention light 15 and excitation light 12 . Finally, the beam coupler 13 separates the detection beam path from the beam path common to the fluorescent light 17 and the excitation light 12 . A wavefront modulator 18 is placed in the optical path of the fluorescence prevention light 15 between the fluorescence prevention light source 16 and the beam coupler 14 . Fluorescence prevention light 15 and excitation light 12 are directed into a sample space 22 through a focusing objective 21 via a lens-comprising scanner 19 and a tube lens 20 . A sample 23 into which the excitation light 12 and the fluorescence prevention light 15 are focused is arranged in the sample space 22 . The wavefront modulator 18 modulates the fluorescence prevention light 15 in the beam path in such a way that, after focusing through the lens 21, a focus with a central intensity minimum is formed in the sample 23. Fluorescent light 17 emitted from the sample 23 passes through the objective 21, the tube lens 20, the scanner 19 and the beam couplers 14, 13 via a mirror 25 and through a filter 26, a lens 27 and a pinhole 28, the lens 27 absorbing the fluorescent light 17 focused on the aperture of the pinhole 28, on a detector 29, which can be part of a detection unit 7. The lens 27 and the pinhole 28 can be part of a pinhole assembly 32 . The wave front modulator 18 is indicated only schematically. Other optical elements for imaging the rear aperture 24 of the lens 21 in the pupils level 30 or in pupil levels 30 are needed in the 6 not shown. The laser scanning microscope shown can also be operated as a confocal laser scanning fluorescence microscope without using the fluorescence prevention light 15 . The fluorescence prevention light 15 may be depletion light. In this case, when the fluorescence preventing light 15, that is, the depletion light in this case, is used, the laser scanning microscope is used as the STED microscope. A use of a micro-optical system according to the invention is possible in the illustrated microscope 10 for various purposes. For example, the micro-optical system can be part of the detection unit 7 or the pinhole assembly 32 .

Furthermore, a micro-optical system 1 according to the invention can be a component of an autofocus unit 6 of a microscope 10 . This is schematic in 8th shown. The microscope 10 comprises an imaging system with an objective lens 33 and a tube lens 20. The imaging system images an object plane 34 in an intermediate image plane 35. A main imaging area 36 is defined in the intermediate image plane 35 and extends over a partial area of a field of view 37 . An auxiliary light beam 31 is provided by means of a light source 40, eg a laser diode, and a fixed lens 41 which collimates the light emerging from the laser diode. This passes through a micro-optical system 1 according to the invention and is coupled into the beam path of the microscope 10 through the intermediate image plane 35 . In the plane shown, the auxiliary light beam 31 is inclined relative to the normal to the object plane 34 and relative to the normal to the intermediate image plane 35, so that the portion 39 of the auxiliary light beam 31 reflected by the object plane 34 runs at the respective corresponding angle of inclination to the respective normal. A beam splitter 38 directs the reflected portion 39 of the auxiliary light beam 31 in the direction of a detection device 42. The detection device 42 can be used to detect changes in the position of the auxiliary light beam 31 in the object plane 34 and the focusing state of the microscope 10 can thus be monitored.

Reference List

1

micro-optical system

2

lens

3

actuators

4

beam of light

5

lens

6

autofocus unit

7

detection unit

8th

optical axis

9

Base

10

microscope

11

excitation light source

12

excitation light

13

beam launcher

14

beam launcher

15

fluorescence prevention light

16

Fluorescence Prevention Light Source

17

fluorescent light

18

wavefront modulator

19

scanner

20

tube lens

21

lens

22

rehearsal room

23

sample

24

rear aperture

25

mirror

26

filter

27

lens

28

pinhole

29

detector

30

pupil level

31

auxiliary beam

32

pinhole assembly

33

objective lens

34

object level

35

intermediate image level

36

main imaging area

37

field of view

38

beam splitter

39

reflected portion

40

light source

41

lens

42

detection device

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was 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.

Patent Literature Cited

• WO 2013/044388 A1 [0011]
• WO 2016/007954 A1 [0012]
• WO 2019/186143 A1 [0013]
• WO 2020/102442 A1 [0014]

Claims (16)

High-resolution microscope (10), with a micro-optical system (1) with a lens (2) that can be automatically displaced and/or automatically adjusted in terms of its refractive power, for adjusting at least one position and/or one direction of a light beam (4 ). High resolution microscope (10) according to claim 1 , wherein the micro-optical system (1) is part of an autofocus unit (6) of the microscope (10). High resolution microscope (10) according to claim 1 , wherein the micro-optical system (1) is part of a detection unit (7) of the microscope (10). High resolution microscope (10) according to claim 3 , wherein the micro-optical system (1) is set up to position a measuring beam (29) on a detector (31, 32). High resolution microscope (10) according to claim 1 , wherein the micro-optical system (1) is part of a pinhole assembly (32) of the microscope (10). High resolution microscope (10) according to claim 3 , wherein the micro-optical system (1) is set up to adjust a lateral focus position of fluorescent light with respect to an aperture (30) or to adjust an axial focus position of a laser beam with respect to the aperture. High-resolution microscope (10) according to one of Claims 1 until 6 , wherein the micro-optical system (1) has a lens (2) that can be displaced automatically and a lens (5) that can be automatically adjusted in terms of its refractive power. High-resolution microscope (10) according to one of Claims 1 until 6 wherein the micro-optical system (1) has two lenses (5) whose refractive power can be automatically adjusted, at least one of which is arranged off-axis in relation to an optical axis (8). High resolution microscope (10) according to claim 7 or 8th , wherein the micro-optical system (1) is set up to set a tilting and collimation of the light beam (4) by means of a combination of the lenses (2, 5). High-resolution microscope (10) according to one of Claims 1 until 7 , wherein the micro-optical system (1) for adjusting the lens (2) has a voice coil motor, a piezoelectric motor or an actuator made of a shape memory alloy. High-resolution microscope (10) according to one of Claims 1 until 10 , wherein the high-resolution microscope (10) is a laser-scanning microscope. Micro-optical system (1) with an automatically displaceable lens (2) and an automated refractive power adjustable lens (5), wherein the micro-optical system (1) is set up by means of a combination of the automatically displaceable lens (2) and the automated in its Refractive power adjustable lens (5) to set a tilt and collimation of a light beam (4). Micro-optical system (1) according to claim 12 , wherein the micro-optical system (1) for adjusting the lenses (2) has a voice coil motor, a piezoelectric motor or an actuator made of a shape memory alloy. Micro-optical system (1) with two lenses (5) whose refractive power can be automatically adjusted, at least one of which is arranged off-axis in relation to an optical axis (8), the micro-optical system (1) being set up automated by means of a combination of the two lenses (5) whose refractive power can be adjusted to tilt and collimate a light beam (4). Detection arrangement (7), with a detector array (31, 32) and with a micro-optical system (1) with an automatically displaceable and/or automatically adjustable lens (2) in terms of its refractive power for adjusting at least one position of a light beam (4) with respect to the detector array (32, 32). Detection arrangement (7) according to claim 15 , wherein the detector array (31, 32) is an array of miniaturized single-photon avalanche diodes.

Images