XY deflection unit for laser light with two operating modes and their use

Abstract

An XY deflection unit for laser light comprises: a tube, which includes: a first port for attaching a single-mode optical fiber with a core diameter in the range of 3 µm to 5 µm, a lens, and a focus adjustment gear for changing the distance between one end of the optical fiber and the lens; a housing, which includes: a first and a second deflection mirror, wherein the respective mirror surfaces of the deflection mirrors have a diameter of at least 10 mm, and a second port for attaching the XY deflection unit to a microscope; an adjustable connecting element, wherein the tube is connected to the housing by means of the adjustable connecting element, the connecting element being designed to adjust both a tilt and a transverse displacement of the tube relative to the housing;and a drive unit for rotating the deflecting mirrors about an axis each, in order to direct the laser light to a desired location in a sample on the microscope, wherein the lens is designed to direct laser light emerging from the end of the single-mode optical fiber onto the deflecting mirrors and the deflecting mirrors are designed to direct the laser light into the microscope, wherein in a first position of the focus adjustment gear the XY deflection unit is in a first operating mode in which the lens is designed to spread the laser light emerging from the end of the single-mode optical fiber into a parallel beam of at least 7 mm in diameter, and wherein in a second position of the focus adjustment gear the XY deflection unit is in a second operating mode in which the lens is designed to focus the laser light emerging from the end of the single-mode optical fiber into a focused beam.

Description

TECHNICAL AREA

[0001] The present disclosure relates to an XY deflection unit for laser light, in particular an XY deflection unit which can be attached to a microscope to direct the laser light into the microscope, wherein the XY deflection unit can be operated in two different operating modes. The present disclosure further relates to the use of an XY deflection unit on a microscope. BACKGROUND

[0002] A fluorescence research microscope can be connected to an XY deflection unit, which is designed to couple laser light into the microscope's optical beam path. This laser light can be used, for example, to manipulate a sample, such as by selectively bleaching fluorescent dyes, uncaging biomolecules, or cutting cell membranes. If the manipulation light needs to be focused not just on a single point, but on multiple points of the sample (scanning), the XY deflection unit can be used to shift the focus in the X and Y directions. However, conventional XY deflection units have several disadvantages. In particular, they are mounted some distance from the microscope housing on additional supports, which necessitates complex fine-tuning of the beam path.The XY deflection unit disclosed in DE 10 2018 201 490 B3 can overcome these disadvantages. Furthermore, it may be desirable not only to provide the aforementioned diffraction-limited point illumination for bleaching, stimulating, or sectioning cell organelles, but also to perform TIRF microscopy as an additional technique on the microscope. However, this requires a different beam path that enables grazing planar TIRF illumination for imaging. Conventionally, this is achieved using a second XY deflection unit or a single XY deflection unit that provides two separate optical beam paths. This, however, increases both the financial and adjustment costs. For these and other reasons, there is a need for an improved XY deflection unit.DE 10 2018 201 490 B3 discloses an XY deflection unit for laser light, comprising a tube with a first port for attaching an optical fiber, a lens, and a focus adjustment gear for changing the distance between one end of the optical fiber and the lens. The XY deflection unit further comprises a housing with two deflection mirrors and a second port for attaching the XY deflection unit to a microscope, as well as an adjustable connecting element that connects the tube to the housing. DE 10 2016 108 987 A1 discloses an optical scanning microscope, US 2014 / 0 320 958 A1 discloses an illumination system for a microscope in which it is possible to switch between two illumination modes, and US 2013 / 0 321 907 A1 discloses an adjustable illumination apparatus for TIRF microscopy.

[0003] The problem addressed by the invention is solved by the features of the independent claims. Advantageous embodiments and further developments of the invention are specified in the dependent claims. SUMMARY

[0004] Specific examples relate to an XY deflection unit for laser light, comprising: a tube comprising: a first port for attaching a single-mode optical fiber with a core diameter in the range of 3 µm to 5 µm, a lens, and a focus adjustment gear for changing the distance between one end of the optical fiber and the lens; a housing comprising: a first and a second deflection mirror, wherein the respective mirror surfaces of the deflection mirrors have a diameter of at least 10 mm, and a second port for attaching the XY deflection unit to a microscope; an adjustable connecting element, wherein the tube is connected to the housing by means of the adjustable connecting element, the connecting element being designed to adjust both a tilt and a transverse displacement of the tube relative to the housing;and a drive unit for rotating the deflecting mirrors about an axis each, in order to direct the laser light to a desired location in a sample on the microscope, wherein the lens is designed to direct laser light emerging from the end of the single-mode optical fiber onto the deflecting mirrors and the deflecting mirrors are designed to direct the laser light into the microscope, wherein in a first position of the focus adjustment gear the XY deflection unit is in a first operating mode in which the lens is designed to spread the laser light emerging from the end of the single-mode optical fiber into a parallel beam of at least 7 mm in diameter, and wherein in a second position of the focus adjustment gear the XY deflection unit is in a second operating mode in which the lens is designed to focus the laser light emerging from the end of the single-mode optical fiber into a focused beam.

[0005] Specific examples relate to the use of the aforementioned XY deflection unit on a microscope. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The accompanying drawings are examples and, together with the description, serve to explain the basic features of the disclosure. The elements of the drawings are not necessarily to scale with each other. Identical reference numerals may denote corresponding, similar, or identical parts. The Fig. 1A and Fig. Figure 1B schematically shows an exemplary XY deflection unit according to the revelation. Fig. In position 1A, the XY deflection unit is in a first operating mode and in Fig. In position 1B, the XY deflection unit is in a second operating mode. Fig. Figure 2 shows a schematic top view of an adjustable connecting element of the XY deflection unit according to the disclosure. The adjustable connecting element can be used to adjust both a transverse displacement and a tilt of a tube of the XY deflection unit relative to a housing of the XY deflection unit. The Fig. 3A and Fig. Figure 3B shows an example of a transverse shift ( Fig. 3A) as well as a tilting ( Fig. 3B) of the tube relative to the housing of the XY deflection unit. Fig. Figure 4 schematically shows the beam path of laser light which is coupled into a microscope through the XY deflection unit, both for the first operating mode and for the second operating mode of the XY deflection unit. Fig. Figure 5 shows a system which includes a microscope, the XY deflection unit and a controller. DETAILED DESCRIPTION

[0007] The following detailed description refers to the drawings and the examples shown therein. However, it will be apparent to a person skilled in the art that one or more aspects of the disclosure may be carried out with a lesser degree of specific detail. In other cases, known structures and elements are shown schematically to facilitate the description of one or more aspects of the disclosure.

[0008] Although a particular feature or aspect of an example may be disclosed with respect to only one of several implementations, such feature or aspect may also be combined with one or more other features or aspects of the other implementations, provided this may be desirable and advantageous for any given or particular application, unless specifically stated otherwise or a technical limitation applies. Where the terms "contain," "include," "with," or other variations thereof are used, either in the detailed description or in the claims, these terms shall furthermore have an inclusive meaning similar to that of the term "include." The terms "coupled" and "connected," and derivatives thereof, may also be used.It should be obvious that these terms can be used to indicate that two elements work together or interact with each other, regardless of whether they are in direct physical or electrical contact or not; intermediate elements or layers may be provided between the “attached” or “connected” elements. Furthermore, the term “exemplary” is intended to mean an example and not the best or optimal solution.

[0009] The Fig. 1A and Fig. Figure 1B schematically shows an XY deflection unit 100 for laser light, which has a tube 110, a housing 120, an adjustable connecting element 130 and a drive unit 140. Fig. Figure 1A shows the XY deflection unit 100 in a first operating mode and Fig. Figure 1B shows the XY deflection unit 100 in a second operating mode, as will be explained in more detail below.

[0010] The XY deflection unit 100 is designed to be connected to a microscope, allowing laser light from a laser light source to be directed onto a sample on the microscope via the XY deflection unit 100. This laser light is in the Fig. 1A and Fig. 1B is indicated as a beam 100'. In particular, the XY deflection unit 100 can be designed to scan a sample on a microscope, to which the XY deflection unit 100 is coupled, in an xy plane with a focal spot in the first operating mode, and to also allow TIRF operation (TIRF: Total Internal Reflection Microscopy) of the microscope in the second operating mode. The XY deflection unit 100 thus advantageously enables two distinctly different illumination methods on a single microscope, between which a quick switch can be made by moving a single mechanical component, as will be explained in more detail below.

[0011] The tube 110 has a first port 112, which is designed for attaching (e.g., by inserting or screwing in) a single-mode optical fiber to the tube 110. The single-mode optical fiber can, for example, be a polarization-maintaining single-mode optical fiber and can have a core diameter in the range of 3 µm to 5 µm. Furthermore, the numerical aperture of a suitable single-mode optical fiber can, for example, be in the range of approximately 0.2 to approximately 0.3, and in particular be approximately 0.22.

[0012] The tube 110 also includes a lens 114. The lens 114 can be, for example, a plano-convex lens or an achromatic lens. The lens 114 can also have an antireflective coating, for example, an antireflective coating of more than 90% in a wavelength range of 350 nm to 700 nm. The lens 114 can be made of, for example, BK7 material. The diameter of the lens 114 can be in the range of approximately 20 mm to approximately 35 mm, and can be, for example, approximately 25 mm. The lens 114 can have a focal length within a range that covers the maximum adjustable distance range between the lens 114 and the first port 112 via the tube 110. The focal length of lens 114 can, for example, be in a range from about 40mm to about 100mm, e.g. a focal length of equal to or greater than approximately 50mm, 60mm, 70mm, 75mm, 80mm, or 90mm.In the case where the focal length is 75mm, the "back focal length" (distance from the lens surface closer to the focal point to the focal point) can be approximately 70mm.

[0013] During operation, laser light with a Gaussian beam profile emerges from the end of an optical fiber attached to the first port 112. After traversing the distance from the end of the optical fiber at the first port 112 to the lens 114, the laser light is expanded according to the numerical aperture of the optical fiber used, so that the full width at half maximum (FWHM) of the Gaussian beam profile is, for example, 7 mm, 8 mm, or 9 mm.

[0014] The laser light can be pulsed, with pulses having a duration of, for example, 10 ps to 20 ps and a pulse energy of approximately 40 µJ. Alternatively, the laser light can be continuous wave. The wavelength of the laser light can be in the range of approximately 260 nm to 800 nm, particularly 260 nm to 600 nm, or 300 nm to 450 nm, or 350 nm to 400 nm, particularly 355 nm. An Nd:YAG laser, for example, can be used as the light source. The Nd:YAG laser can have a tripled frequency.

[0015] The tube 110 further comprises a focus adjustment gear 116, which is designed to change the distance between one end of the optical fiber (i.e., the first port 112) and the lens 114. The focus adjustment gear 116 can be manually adjustable and can be designed to position the end of the optical fiber precisely at the focal point of the lens 114. The focus adjustment gear 116 can have a fine gear and can have any suitable maximum travel, e.g., a travel in a range of approximately 20 mm to approximately 50 mm, in particular a travel in a range of approximately 22 mm to approximately 30 mm, e.g., approximately 25 mm. In particular, the focus adjustment gear 116 is designed to switch between the first operating mode (which requires a parallel beam path in the XY deflection unit 100, see Figure 112) and the second operating mode (which requires a parallel beam path in the XY deflection unit 100, see Figure 112). Fig. 1A) and the second operating mode (which requires a focused beam path in the XY deflection unit 100, see below). Fig. 1B) to switch. In particular, it may be necessary that the travel of the focus adjustment gear 116 be sufficiently large to allow switching between the two operating modes, e.g., at least 20 mm, at least 22 mm, or at least 25 mm. The required minimum travel may depend on the optical fiber and lens 114 used.

[0016] The housing 120 contains a first deflecting mirror 122 and a second deflecting mirror 124, which are designed to deflect laser light exiting the optical fiber into the microscope. The deflecting mirrors 122 and 124 are comparatively large, with their respective mirror surfaces having a diameter of at least 10 mm.

[0017] The housing 120 further features a second port 126, which is designed for attaching the XY deflection unit 100 to a microscope. The second port 126 can be designed as a flange, which can be attached to a mating flange of a microscope, optionally without requiring adjustment. The XY deflection unit 100 can be configured (in particular, designed to be so compact or have such a low weight) that it can be mounted to the microscope in a cantilevered manner via the second port 126. "Cantilevered" in this context can mean that the XY deflection unit 100 does not need to be placed on additional supports and that its entire weight rests on the second port 126.

[0018] For example, the housing 120 has maximum dimensions of approximately 120 mm x 100 mm x 100 mm. The tube 110 can, for example, have a maximum length measured along the optical axis of approximately 100 mm, 90 mm, 80 mm, or 75 mm. The diameter of the tube 110 can correspond approximately to the diameter of the lens 114. The XY deflection unit 100 can have a maximum mass of 0.8 kg, 0.7 kg, or 0.6 kg. This compactness of the XY deflection unit 100 can be achieved through the use of deflection mirrors 122 and 124 with comparatively large mirror surfaces, as described above.

[0019] The housing 120 can have an interior space, in which the deflecting mirrors 122, 124 are arranged and the drive unit 140 is not arranged in the interior space. The interior space can, for example, be a maximum of approximately 50 mm long when measured along a first side. The interior space can, for example, be a maximum of approximately 60 mm wide when measured along a second side. The interior space can, for example, be a maximum of approximately 40 mm deep when measured along a third side (where in the Fig. 1A and Fig. 1B the first side runs along the z-axis, the second side along the x-axis and the third side along the y-axis).

[0020] The optical path from lens 114 to the first deflecting mirror 122 can be in the range of approximately 1.5 cm to approximately 3 cm. The optical path from the first deflecting mirror 122 to the second deflecting mirror 124 can be approximately 12 mm. The arrangement of the two deflecting mirrors 122 and 124 can cause a beam offset relative to the optical axis of lens 114, for example, a beam offset of 12.4 mm, where the beam offset is in the Fig. 1A and Fig. 1B into the plane of the paper. The arrangement of the two deflecting mirrors 122, 124 can further deflect the path of the beam 100' by approximately 90°. In particular, the first and second ports 112, 126 can be arranged at an angle of approximately 90° to each other. The deflecting mirrors 122, 124, 1212 can also have a reflectivity of approximately 80% over a wavelength range from 180 nm to 800 nm. The distance between the second deflecting mirror 124 and the second port 126 (e.g., measured to an outer surface of the flange forming the second port) can be less than 5 cm, in particular less than 3 cm, or less than 2 cm.

[0021] The lens 114 is designed to direct laser light exiting the end of the single-mode glass fiber onto the deflecting mirrors 122, 124, and the deflecting mirrors 122, 124 are designed to direct the laser light into the microscope.

[0022] According to one example, the XY deflection unit 100, apart from the lens 114 and the deflecting mirrors 122 and 124, has no further optical components (lenses, mirrors, prisms, filters, etc.), in particular no further lenses or mirrors. Due to the comparatively large mirror surfaces of the deflecting mirrors 122 and 124, it is also not necessary to use an F-theta lens in the XY deflection unit 100. The absence of further optical components can also refer only to sections of the optical path in the XY deflection unit, for example, to the path between the deflecting mirrors 122 and 124 and / or behind the second deflecting mirror 124.

[0023] According to one example, the XY deflection unit 100 further comprises a heat sink. The heat sink can be arranged on the housing 120. The second port 126 can be arranged on the heat sink and, in particular, extend through the heat sink. According to one example, the tube 110 can be attached to the heat sink (by means of the adjustable connecting element 130). The heat sink can be made of metal. The heat sink can form part of the housing wall of the housing 120. The placement of the heat sink at the second port 126 can cause a shift in the center of mass of the XY deflection unit 100 towards the second port 126. This can help to mount the XY deflection unit 100 cantilevered over the second port 126 on a microscope.

[0024] The adjustable connecting element 130 is arranged between the tube 110 and the housing 120 such that the tube 110 is connected to the housing 120 by means of the adjustable connecting element 130. The adjustable connecting element 130 is designed to compensate for a tilting of the longitudinal axis of the tube 110 relative to the housing 120 (in the Fig. 1A and Fig. 1B the longitudinal axis of the tube 110 runs along the x-axis). Furthermore, the adjustable connecting element 130 is designed to allow a transverse displacement (i.e. a displacement of the tube 110 in the yz-plane in the Fig. 1A and Fig. 1B) of the tube 110 relative to the housing 120. Thus, the adjustable connecting element 130 allows the beam path to be adjusted in all four required degrees of freedom. Such an adjustment of the orientation of the tube 110 can be carried out to center the beam bundle 100' in the beam path of the XY deflection unit 100. In particular, transverse adjustability may be necessary to avoid readjusting the laser beam position when switching between the operating modes of the XY deflection unit 100.

[0025] The adjustable connecting element 130 can, for example, have a rubber O-ring that is pressed against the housing 120. The adjustable connecting element 130 can further have at least two first screws and at least two second screws, wherein one orientation of the second screws can be perpendicular to one orientation of the first screws. By tightening or loosening the first screws, the tube 110 can be moved transversely, cf. the example of Fig. 3A. By tightening or loosening the second screws, the tilting of the longitudinal axis of tube 110 can be corrected, see the example of Fig. 3B.

[0026] According to an example of the XY deflection unit 100, adjustment of the beam path only takes place in front of the deflection mirrors 122, 124 (in particular at the connecting element 130), but not between or behind the deflection mirrors 122, 124. In particular, no adjustment of the XY deflection unit 100 relative to the microscope takes place at the second port 126, provided that this is designed as an adjustment-free port.

[0027] The drive unit 140 is designed to rotate the deflecting mirrors 122 and 124 about axes 122' and 124', respectively, to direct the laser light to a desired location on a sample within the microscope. The axes 122' and 124' can be arranged, for example, at an angle of approximately 45° relative to each other. The drive unit 140 can, for example, include galvanometric motors, such as a first galvanometric motor for rotating the first deflecting mirror 122 about the axis 122' and a second galvanometric motor for rotating the second deflecting mirror 124 about the axis 124'. The drive unit 140 can have a positioning speed ("dwell time") of the deflecting mirrors 122 and 124 of a maximum of 2 µs. The angular resolution of the drive unit 140 can be equal to or less than 12 µrad, and the repeatability can be equal to or less than 2 µrad. The drive unit 140 can be a commercially available galvanometric drive unit.

[0028] For example, the XY deflection unit 100 can have an (electrical) control terminal 142, which is connected to the drive unit 140. Voltage can be applied to the drive unit 140 via the control terminal 142. The drive unit 140 can, for example, have an operating voltage of 15V. The drive unit 140 can be configured to receive varying voltage values ​​via the control terminal 142, which control the drive unit 140 (i.e., rotate the deflection mirrors 122, 124 about the axes 122' and 124', respectively). The voltage values ​​can be analog, meaning the drive unit 140 is configured to receive analog control signals. The voltage values ​​can be, for example, up to +5V or -5V of the operating voltage. Such voltage values ​​can be supplied, for example, by a digital-to-analog converter card, such as those used in personal computers.

[0029] By rotating the deflecting mirrors 122, 124 by means of the drive unit 140, the beam 100' can be directed to any desired position of a surface perpendicular to the optical axis running through the second port 126 (within the travel range of the drive unit 140).

[0030] As mentioned above, the XY deflection unit 100 is in the first position of the focus adjustment gear 116 in a first operating mode. In the first operating mode, the lens 114 is designed to expand the laser light exiting the end of the single-mode optical fiber into a parallel beam 100' with a diameter of at least 7 mm, cf. Fig. 1A. The parallel beam of light is directed by the deflecting mirrors 122, 124 to the microscope and can be focused in it by means of the microscope objective to a diffraction-limited point, which can be used, for example, for bleaching, stimulating or cutting cell organelles.

[0031] In the second position of the focus adjustment gear 116, the XY deflection unit 100 is in the second operating mode, cf. Fig. 1B. In the second operating mode, the lens 114 is designed to focus the laser light exiting the end of the single-mode optical fiber into a focused beam 100'. In particular, the light path between the fiber exit aperture at the first port 112 and the lens 114 can be longer in the second position of the focus adjustment gear 116 than in the first position. In this way, a focused beam path required for TIRF illumination is generated at the entrance aperture of the microscope objective. The required TIRF angle (condition for total internal reflection at the interface between the sample coverslip and the sample medium) can be set using the deflecting mirrors 122 and 124. The focused laser beam is moved to the outermost edge of the entrance pupil of a microscope objective. For this to work, the microscope objective must have a numerical aperture (NA) of at least 1.4 at a magnification of at least 60x.The same laser source is used for both applications, as the laser radiation is coupled in via a single single-mode optical fiber.

[0032] With TIRF illumination, the following problem can arise: the evanescent light field formed above the sample coverslip during total internal reflection can, due to an inclined position of the cellular sample or inhomogeneities within the sample, produce shading in the image that is undesirable for the user. One method to correct this shading is to rotate the laser beam along the edge of the entrance pupil of the microscope objective. The rotation of the laser beam occurs significantly faster than the exposure time of a camera, thus optically averaging the shading from all directions. The result is virtually shadow-free illumination.This rotation of the laser beam can be achieved using the XY deflection unit 100, for example, by applying a sinusoidal voltage to an analog X-voltage input of the XY deflection unit 100 and a sinusoidal voltage phase-shifted by 90° to an analog Y-voltage input (the voltage inputs can, for example, be part of the control connection 142). In this way, a circular motion of the laser radiation at the rear focal plane of the microscope objective can be generated using a two-channel signal generator. Advantageously, no software or computer control is required for this.

[0033] Fig. Figure 2 shows a top view of the adjustable connecting element 130 according to a specific example. Fig. Figure 2 in particular shows a top view of the adjustable connecting element 130 along the optical axis (the x-axis in the Fig. 1A and Fig. 1B).

[0034] As in Fig. As shown in Figure 2, the adjustable connecting element 130 can have a first ring 132 and a second ring 134. The first ring 132 is designed to be connected to the housing 120, and the second ring 134 is designed to be connected to the tube 110. According to the Fig. In the example shown, the first ring 132 is an outer ring and the second ring 134 is an inner ring of the adjustable connecting element 130. The rings 132 and 134 can be, for example, metal rings or plastic rings.

[0035] The second ring 134 is transversely adjustable relative to the first ring 132 by means of adjustment elements. The adjustment elements can be adjusted, for example, by hand. In the example of Fig. 2 The adjustment elements include at least one spring 136 and at least two first screws 138-1. The spring 136 is designed to press the second ring 134 against the first screws 138-1. The spring 136 can be arranged on the opposite side of the second ring 134 relative to the first screws 138-1. In particular, the spring 136 and the first screws 138-1 can be arranged radially around the second ring 134 such that the spring 136 is at position 0°, one of the first screws 138-1 is at position 120°, and a second of the first screws is at position 240°, cf. Fig. 2. By tightening one or both of the first screws 138-1, the second ring 134 is moved transversely towards the spring 136, and by loosening one or both of the first screws 138-1, the second ring 134 is moved transversely in the opposite direction.

[0036] As in the example of Fig. As shown in Figure 2, the adjustable connecting element 130 can further comprise at least two second screws 138-2, which are arranged on the first ring 132 and are aligned perpendicular to the first screws 138-1 (in Figure 2). Fig. 2. The second screws 138-2 run parallel to the x-axis). The second screws 138-2 are designed for adjusting the tilt of the tube 110 relative to the deflecting mirrors 122, 124. Similar to the spring 136 and the first screws 138-1, the second screws 138-2 can be rotated on a circle around the optical axis (which in Fig. 2 (pointing into the plane of the drawing) should be arranged, e.g., relative to each other at positions 0°, 120° and 240°.

[0037] For the purpose of adjusting the tilt, the adjustable connecting element 130 can further comprise an elastic component, e.g. a rubber ring, which is arranged between the first ring 132 and the housing 110 (this elastic component is shown in the top view of Fig. (2 not visible). The second screws 138-2 are designed to press the first ring 132 against the elastic component. By tightening or loosening individual second screws 138-2, the tilt of the adjustable connecting element 130, and thus also of the attached tube 110, relative to the housing 120 or the deflecting mirrors 122, 124, can be adjusted.

[0038] According to one example, the second ring 134 can have recesses 134' at the position of the second screws 138-2. The recesses 134' prevent the second ring 134 from colliding with the second screws 138-2 if the second screws, as in the example of Fig. 2 shown, partially extending beyond the first ring 132 inwards towards the second ring 134.

[0039] The Fig. 3A and Fig. Figure 3B shows how the adjustable connecting element 130 can be used to adjust the beam path in the XY deflection unit 100.

[0040] Fig. Figure 3A shows the case where a transverse adjustment is necessary. In other words, the optical axis 300 defined by the tube 110 is transversely offset relative to the optical axis 300' defined by the first deflecting mirror 122. The adjustable connecting element 130, in particular the first screws 138-1, can be used to transversely offset the axis 300 so that it is coincident with the axis 300'.

[0041] Fig. Figure 3B shows the case where an adjustment of the tilt of tube 110 is necessary. In other words, axes 300 and 300' enclose an angle α that is greater than zero. Using the second screw 138-2 of the adjustable connecting element 130, the tilt of tube 110 can be corrected so that α equals zero.

[0042] Fig. Figure 4 shows an example of an XY deflection unit 100 connected to a microscope 400 via a microscope port 406. In the case where the XY deflection unit 100 is operated in the first operating mode, the generated beam 100' and the position of the first port 112 are shown with solid lines, and in the case where the XY deflection unit 100 is operated in the second operating mode, the beam 100' and the position of the first port 112 are shown with dashed lines.

[0043] The microscope 400 can have a body 402 and an objective 403, and the microscope 400 can further have a collimator 404. The microscope port 406 can be arranged on the input side of the collimator 404, and the XY deflection unit 100 can be attached to the microscope port 406 by means of the second port 126 (e.g., flanged to a mating flange of the microscope port 406).

[0044] The collimator 404 can have a first collimator lens (relay lens) 408 and a second collimator lens (field lens) 410. The first collimator lens 408 can, for example, have a focal length of approximately 105 mm, and the second collimator lens 410 can, for example, have a focal length of approximately 130 mm.

[0045] The collimator 404 can be an internal microscope collimator and / or a commercial collimator and can, for example, be part of a modular system for the microscope 400. The collimator 404 can widen a parallel beam by a factor of approximately 1.3. As described above, the deflecting mirrors 122 and 124 of the XY deflection unit have 100 large mirror surfaces that circumscribe a diameter of at least 10 mm. Therefore, it is not necessary to connect the XY deflection unit 100 to the microscope 400 via a special collimator with a higher expansion factor, which in particular allows for the short distance between the XY deflection unit 100 and the microscope 400 as well as the cantilevered mounting of the XY deflection unit 100 on the microscope 400 (for example, it may be necessary for the beam 100' in the first operating mode of the XY deflection unit 100 to have a diameter of at least approx. 7 mm or at least approx.8mm, so that a diffraction-limited focal spot of the manipulation light with a diameter of at most 0.6µm is created at the focal point of the lens 403).

[0046] In the event that deflection mirrors with a smaller reflective surface were used, e.g., with a reflective surface circumscribing a diameter of only approximately 3 mm, the XY deflection unit would have to be connected to the microscope 400 via a special collimator with a suitably large magnification factor. This special collimator would have to be attached externally to the microscope 400. This special collimator would protrude considerably from the body 402 of the microscope 400, and it would be necessary to place the XY deflection unit on additional supports. Furthermore, such an XY deflection unit would require significant adjustment relative to the microscope 400.

[0047] According to one example, the collimator 404 can also be dispensed with, i.e. the beam of rays 100' is guided into the objective 403 without passing through a collimator.

[0048] For example, the microscope 400 can also have an adapter, and the XY deflection unit 100 can be connected to the microscope 400 via the adapter. The adapter can, for example, contain the collimator 404. The adapter can have more than one microscope port 406 and can, for example, have a dichroic lens arranged in front of the first collimator lens 408, allowing illumination light to be coupled in through the other microscope port. Alternatively, the dichroic lens can allow light emitted from the sample under investigation to be coupled out to a camera connected to the other microscope port.

[0049] For example, the microscope port 406 may not protrude from the body 402 of the microscope 400, or only by a very small amount, e.g., no more than 10 cm, or no more than 8 cm, or no more than 5 cm. This can help to allow the XY deflection unit 100 to be mounted cantilevered on the microscope 400.

[0050] For example, microscope 400 is a NIKON TiE2 type microscope and microscope port 406 is the "E" port of this microscope.

[0051] Fig.Figure 5 shows a system 500 comprising the microscope 400, a cantilevered XY deflection unit 100 connected to the microscope 400, and a controller 502. The controller 502 can, for example, include a computer such as a PC. The controller 502 can be configured to control the microscope 400 and the controller 502 can be configured to control the XY deflection unit 100, in particular the drive unit 140. For this purpose, the controller 502 can be connected to the XY deflection unit 100 via the control port 142 to transmit (analog) control signals to the drive unit 140.

[0052] Another aspect of the disclosure concerns the use of the XY deflection unit 100 on a microscope, in particular for scanning a sample on the microscope with a focal spot of a manipulation light in the first operating mode of the XY deflection unit 100 or for TIRF illumination of the sample in the second operating mode. EXAMPLES

[0053] The following section explains the XY deflection unit and the aspect of using the XY deflection unit on a microscope in more detail using specific examples.

[0054] Example 1 is an XY deflection unit for laser light, comprising: a tube comprising: a first port for attaching a single-mode optical fiber with a core diameter in the range of 3 µm to 5 µm, a lens, and a focus adjustment gear for changing the distance between one end of the optical fiber and the lens; a housing comprising: a first and a second deflection mirror, wherein the respective mirror surfaces of the deflection mirrors have a diameter of at least 10 mm, and a second port for attaching the XY deflection unit to a microscope; an adjustable connecting element, wherein the tube is connected to the housing by means of the adjustable connecting element, the connecting element being designed to adjust both a tilt and a transverse displacement of the tube relative to the housing;and a drive unit for rotating the deflecting mirrors about an axis each, in order to direct the laser light to a desired location in a sample on the microscope, wherein the lens is designed to direct laser light emerging from the end of the single-mode optical fiber onto the deflecting mirrors and the deflecting mirrors are designed to direct the laser light into the microscope, wherein in a first position of the focus adjustment gear the XY deflection unit is in a first operating mode in which the lens is designed to spread the laser light emerging from the end of the single-mode optical fiber into a parallel beam of at least 7 mm in diameter, and wherein in a second position of the focus adjustment gear the XY deflection unit is in a second operating mode in which the lens is designed to focus the laser light emerging from the end of the single-mode optical fiber into a focused beam.

[0055] Example 2 is the XY deflection unit according to Example 1, wherein the XY deflection unit has no further lenses or mirrors apart from the lens and the two deflection mirrors.

[0056] Example 3 is the XY deflection unit according to Example 1 or 2, wherein the focus adjustment gear has a travel of 20mm or more.

[0057] Example 4 is the XY deflection unit according to one of the preceding examples, wherein the adjustable connecting element has a first ring and a second ring, wherein the first ring is attached to the housing and the tube is attached to the second ring, and wherein the second ring is transversely adjustable relative to the first ring by means of adjustment elements.

[0058] Example 5 is the XY deflection unit according to Example 4, wherein the adjustment elements include at least one spring and at least two first screws, wherein the spring is designed to push the second ring against the first screws.

[0059] Example 6 is the XY deflection unit according to Example 4 or 5, wherein the first ring is an outer ring and the second ring is an inner ring of the adjustable connecting element.

[0060] Example 7 is the XY deflection unit according to any one of Examples 4 to 6, wherein the adjustable connecting element further comprises at least two second screws arranged on the first ring, the second screws being aligned perpendicular to the first screws and designed to adjust the tilt.

[0061] Example 8 is the XY deflection unit according to Example 7, which further comprises: a rubber ring arranged between the first ring and the housing, wherein the second screws are designed to press the first ring against the rubber ring.

[0062] Example 9 is the XY deflection unit according to Example 7 or 8, wherein the second ring has recesses at the position of the second screws to avoid colliding with the second screws.

[0063] Example 10 is the XY deflection unit according to one of the previous examples, wherein the XY deflection unit can be attached to the microscope in a cantilevered manner using the second port.

[0064] Example 11 is the XY deflection unit according to Example 10, wherein the second port is designed as a flange which can be attached to a counter flange of the microscope without adjustment.

[0065] Example 12 is the XY deflection unit according to any of the preceding examples, further comprising: an electrical connection for applying analogous first and second control voltages to the drive unit, wherein the first control voltage causes the drive unit to rotate the first deflection mirror about a first axis and the second control voltage causes the drive unit to rotate the second deflection mirror about a second axis.

[0066] Example 13 is the XY deflection unit according to Example 12, wherein by applying first and second control voltages that are phase-shifted by 90° the laser light in the sample describes a circle on the microscope.

[0067] Example 14 is the XY deflection unit according to one of the previous examples, wherein the housing has maximum dimensions of approximately 120mm * 100mm * 100mm and / or the XY deflection unit has a maximum mass of approximately 0.6kg.

[0068] Example 15 is the XY deflection unit according to one of the preceding examples, wherein the XY deflection unit is designed to enable TIRF illumination in the sample on the microscope in the second operating mode, provided that an objective of the microscope, into which the laser light is directed by means of the XY deflection unit, has a numerical aperture of at least 1.4 and a magnification of at least 60x.

[0069] Example 16 is the use of the XY deflection unit from one of the previous examples on a microscope. LIST OF REFERENCE MARKS 100 XY deflection unit 100' beam 110 Tube 114 lens 116 Focus adjustment gear 112 first port 120 cases 122 first deflecting mirror 122' first axle 124 second deflecting mirror 124' second axle 130 adjustable connecting element 132 first ring 134 second ring 134' recess 136 spring 138-1 first screw 138-2 second screw 140 drive unit 142 Control connection 300 optical axis of the tube 300' optical axis of the first deflecting mirror 400 microscope 402 microscope bodies 403 lens 404 Collimator 408 first collimator lens 410 second collimator lens 500 System 502 Control

Claims

[1] XY deflection unit (100) for laser light, which has: a tube (110) which has: - a first port (112) for attaching a single-mode optical fiber with a core diameter in the range of 3µm to 5µm, - a lens (114), and - a focus adjustment gear (116) for changing the distance between one end of the optical fiber and the lens (114); a housing (120) which features: - a first and a second deflecting mirror (122, 124), wherein the respective mirror surfaces of the deflecting mirrors (122, 124) have a diameter of at least 10 mm, and - a second port (126) for attaching the XY deflection unit (100) to a microscope; an adjustable connecting element (130), wherein the tube (110) is connected to the housing (120) by means of the adjustable connecting element (130), wherein the connecting element (130) is designed to adjust both a tilting and a transverse displacement of the tube (110) relative to the housing (120); and a drive unit (140) for rotating the deflecting mirrors (122, 124) about an axis each, in order to direct the laser light to a desired location in a sample on the microscope, wherein the lens (114) is designed to direct laser light exiting the end of the single-mode glass fiber onto the deflecting mirrors (122, 124) and the deflecting mirrors (122, 124) are designed to direct the laser light into the microscope, wherein in a first position of the focus adjustment gear (116) the XY deflection unit (100) is in a first operating mode in which the lens (114) is designed to widen the laser light emerging from the end of the single-mode glass fiber into a parallel beam of at least 7 mm in diameter, wherein in a second position of the focus adjustment gear (116) the XY deflection unit (100) is in a second operating mode in which the lens (114) is designed to focus the laser light emerging from the end of the single-mode glass fiber into a focused beam, wherein the adjustable connecting element (130) has a first ring (132) and a second ring (134), wherein the first ring (132) is attached to the housing (120) and the tube (110) is attached to the second ring (134), wherein the second ring (134) is transversely adjustable relative to the first ring (132) by means of adjustment elements, and wherein the first ring (132) is an outer ring and the second ring (134) is an inner ring of the adjustable connecting element (130). [2] XY deflection unit (100) according to claim 1, wherein the XY deflection unit (100) has no further lenses or mirrors other than the lens (114) and the two deflection mirrors (122, 124). [3] XY deflection unit (100) according to claim 1 or 2, wherein the focus adjustment gear (116) has a travel of 20mm or more. [4] XY deflection unit (100) according to one of the preceding claims, wherein the adjustment elements comprise at least one spring (136) and at least two first screws (138-1), wherein the spring (136) is designed to press the second ring (134) against the first screws (138-1). [5] XY deflection unit (100) according to one of the preceding claims, wherein the adjustable connecting element (130) further comprises at least two second screws (138-2) arranged on the first ring (132), wherein the second screws (138-2) are aligned perpendicular to the first screws (138-1) and are designed to adjust the tilt. [6] XY deflection unit (100) according to claim 5, which further comprises: a rubber ring arranged between the first ring (132) and the housing (120), wherein the second screws (138-2) are designed to press the first ring (132) against the rubber ring. [7] XY deflection unit (100) according to claim 5 or 6, wherein the second ring (134) has recesses (134') at the position of the second screws (138-2) to avoid colliding with the second screws (138-2). [8] XY deflection unit (100) according to one of the preceding claims, wherein the XY deflection unit (100) can be attached to the microscope in a cantilevered manner by means of the second port (126). [9] XY deflection unit (100) according to claim 8, wherein the second port (126) is designed as a flange which can be attached to a counter flange of the microscope without adjustment. [10] XY deflection unit (100) according to any one of the preceding claims, further comprising: an electrical connection (142) for applying analog first and second control voltages to the drive unit (140), wherein the first control voltage causes the drive unit (140) to rotate the first deflecting mirror (122) about a first axis and the second control voltage causes the drive unit (140) to rotate the second deflecting mirror (124) about a second axis. [11] XY deflection unit (100) according to claim 10, wherein by applying first and second control voltages that are phase-shifted by 90° the laser light in the sample describes a circle on the microscope. [12] XY deflection unit (100) according to one of the preceding claims, wherein the housing (120) has maximum dimensions of approximately 120mm * 100mm * 100mm and / or the XY deflection unit has a maximum mass of approximately 0.6kg. [13] XY deflection unit (100) according to one of the preceding claims, wherein the XY deflection unit (100) is designed to enable TIRF illumination in the sample on the microscope in the second operating mode, provided that an objective of the microscope into which the laser light is guided by means of the XY deflection unit (100) has a numerical aperture of at least 1.4 and a magnification of at least 60x. [14] Use of the XY deflection unit (100) according to any of the preceding claims on a microscope.

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