Optical arrangement and method for light beam shaping for a light microscope

Abstract

Optical arrangement for light beam shaping for a light microscope, comprising - a first liquid crystal or micro-lift mirror region (35A) with several independently adjustable liquid crystal elements or mirrors with which a phase of incident light can be adjusted and changed, characterized by - a second liquid crystal or micro-lift mirror area (35B) with several independently adjustable liquid crystal elements or mirrors with which a phase of incident light can be adjusted to change, - an input / output polarization beam splitter (10) with which incident light (1) of a specific polarization direction can be directed towards the liquid crystal or micro-lift mirror regions (35A, 35B), - a polarization beam splitter (20) which is arranged between the input / output polarization beam splitter (10) and the liquid crystal or micro-lift mirror regions (35A, 35B), - that the polarization beam splitter (20) separates the light (1) coming from the input / output polarization beam splitter (10) depending on polarization into a first partial beam (1A), which is directed to the first liquid crystal or micro-lift mirror area (35A), and into a second partial beam (1B), which is directed to the second liquid crystal or micro-lift mirror area (35B), and - that the polarization beam splitter (20) combines the two partial beams (1A, 1B) returning from the liquid crystal or micro-lift mirror areas (35A, 35B) and directs them together as an outgoing light beam (2) to the input / output polarization beam splitter (10).

Description

[0001] The present invention relates in a first aspect to an optical arrangement for shaping light beams for a light microscope according to the preamble of claim 1.

[0002] In a second respect, the invention relates to a method for shaping light beams for a light microscope according to the preamble of claim 12.

[0003] Spatial light modulators (SLMs) are primarily used for beam shaping, allowing the phase or amplitude, and thus the intensity, of a light beam to be varied. For example, an SLM can convert a Gaussian laser beam into a Bessel beam. This is achieved by modifying the wavefront of the laser beam by shifting the phase differently across the beam cross-section. Beam shaping may be desirable for both illumination and detection applications.

[0004] A generic optical arrangement for light beam shaping in a light microscope comprises a first liquid crystal or micro-lift mirror region. This region includes several independently switchable liquid crystal elements or mirrors with which the phase of incident light can be adjusted. A corresponding generic method for light beam shaping in a light microscope comprises phase modulation of light by means of a liquid crystal or micro-lift mirror matrix, which has several independently switchable liquid crystal elements or mirrors.

[0005] A micro-lift mirror array comprises several mirrors whose lift (i.e., in a direction perpendicular to the mirror surface) can be adjusted independently of each other. This changes the path length traveled by incident light, and thus the phase of the light.

[0006] With a liquid crystal-based selective laser melt (SLM), phase modulation can be achieved for light of a specific polarization direction. The polarization component perpendicular to this direction remains unaffected. Ideally, a light beam should be able to be shaped as arbitrarily as possible, meaning that the phase and amplitude should be variably adjustable across the beam cross-section. This should be accomplished with a compact, stable, and cost-effective setup.

[0007] From DE 11 2014 001 820 T5 an optical module is known which comprises a polarization beam splitter, through which incident light is directed to a first SLM or a second SLM depending on polarization, wherein light returning from the first or second SLM is output by the polarization beam splitter in a common output direction.

[0008] US 2009 / 0180181 A1 describes various optical assemblies with polarization beam splitters. In particular, a projector with a light source is described, from which outgoing light can be directed via a polarization switch and a polarization beam splitter cube to LCoS chips (LCoS: Liquid Crystal on Silicon) and from there via the polarization beam splitter cube to an image surface.

[0009] US patent 2007 / 0247691 A1 discloses an optical assembly with a variable aperture which can provide a specific illumination geometry, especially for light microscopes.

[0010] DE 10 2009 036 566 A1 describes an optical assembly for light microscopes, by which the polarization of illumination light is manipulated in a desired manner.

[0011] One object of the invention can be considered to be to provide an optical arrangement and a method which enable variable light beam shaping as efficiently and simply as possible.

[0012] This problem is solved by the optical arrangement with the features of claim 1 and by the method with the features of claim 12.

[0013] Advantageous variants of the optical arrangement and the method according to the invention are the subject of the dependent claims and are also explained in the following description.

[0014] In the optical arrangement of the type described above, a second liquid crystal or micro-lift mirror region is provided according to the invention. This region comprises several independently switchable liquid crystal elements / mirrors with which the phase of incident light can be adjusted. An input / output polarization beam splitter is provided, which directs incident light of a specific polarization direction towards the liquid crystal or micro-lift mirror regions. Furthermore, a polarization beam splitter is arranged between the input / output polarization beam splitter and the liquid crystal or micro-lift mirror regions.The polarization beam splitter separates the light coming from the input / output polarization beam splitter into two partial beams, one directed to the first liquid crystal or micro-lift mirror region and the other to the second. The polarization beam splitter also combines the two partial beams returning from the liquid crystal or micro-lift mirror regions and directs them together as an outgoing light beam to the input / output polarization beam splitter. The direction of this outgoing light beam at the input / output polarization beam splitter depends on the polarization direction of the outgoing light beam.

[0015] Accordingly, the method of the above-mentioned type comprises the following steps according to the invention: - Guiding light of a specific polarization direction using an input / output polarization beam splitter, - Polarization-dependent splitting of the light coming from the input / output polarization beam splitter into a first partial beam and a second partial beam by means of a polarization beam splitter, - which includes phase modulation of light using a liquid crystal or micro-lift mirror matrix: - Guiding the first partial beam to a first liquid crystal or microlift mirror region of the liquid crystal or microlift mirror matrix and - Guiding the second partial beam to a second liquid crystal or microlift mirror area, - Combining the two partial beams returning from the liquid crystal or micro-lift mirror areas using the polarization beam splitter and - Guiding the combined partial beams as an outgoing light beam to the input / output polarization beam splitter.

[0016] Light is thus split into two partial beams, which are linearly polarized perpendicular to each other. These two partial beams are phase-modulated independently by the two liquid crystal or micro-lift mirror regions. The two partial beams are then recombined, resulting in an outgoing light beam that is both phase-modulated and potentially altered in its polarization / polarization direction. Depending on the phase modulation of the two partial beams, the outgoing light beam can be linearly polarized with a polarization direction rotated relative to the original light, particularly by 90°. With other phase differences, the light beam exiting the input / output polarization beam splitter is elliptically polarized. This polarization change determines the proportions of the outgoing light beam that are transmitted or reflected at the input / output polarization beam splitter.The transmitted or reflected beam component thus has a changed intensity (amplitude), which is adjusted by the two liquid crystal or micro-lift mirror regions. As an advantage, both the phase and the amplitude of a light beam can be variably adjusted across its cross-section. Furthermore, the phase and amplitude can be adjusted independently of each other.

[0017] A liquid crystal or micro-lift mirror region can be configured as a liquid crystal region in which the individual liquid crystal elements can be controlled by a voltage. Depending on the control signal, a rotation of the molecules of a liquid crystal element is induced, thus changing the phase of the passing light. Alternatively, a liquid crystal or micro-lift mirror region can be configured as a micro-lift mirror region comprising several independently adjustable mirrors. The mirrors are arranged side by side and each adjustable in the lifting direction, that is, in a direction perpendicular to the mirror surface. This changes the geometric path length traveled by the incident light and thus also its phase. Therefore, a liquid crystal or micro-lift mirror region, regardless of its specific configuration, causes a phase change in the light.For simplicity, the following terms are generally used interchangeably: liquid crystal region / liquid crystal matrix / liquid crystal element, which stand in for: liquid crystal or micro-lift mirror region / liquid crystal or micro-lift mirror matrix / liquid crystal element / mirror. One difference between a liquid crystal region and a micro-lift mirror region can be that a micro-lift mirror region typically only phase-modulates light of a specific polarization direction, while a micro-lift mirror region generally operates independently of polarization. However, special liquid crystal regions can also be used that enable variable phase modulation for any polarization.

[0018] In one embodiment of the invention, the first and second liquid crystal regions are areas of the same liquid crystal matrix. Using only one liquid crystal matrix instead of two can significantly reduce the overall costs. Furthermore, typical liquid crystal matrices have a high pixel count (number of liquid crystal elements), so a single liquid crystal matrix may suffice. The two partial beams then strike two non-overlapping areas. Often, liquid crystal matrices are not square, meaning they have larger dimensions or more liquid crystal elements in one direction than in the other. In such cases, a single liquid crystal matrix is ​​particularly suitable for shaping both partial beams.

[0019] A single liquid crystal matrix offers variable phase modulation, but only for light of a specific polarization direction. The two partial beams are initially polarized perpendicular to each other. Therefore, the polarization of at least one of the partial beams must be rotated so that both partial beams have the same polarization. For this purpose, a polarization rotator can be arranged between the polarization beam splitter and the first liquid crystal region and / or between the polarization beam splitter and the second liquid crystal region. The polarization rotator should effect a 90° rotation of the polarization direction and could, for example, be a half-wave delay plate that delays a polarization component of the incident partial beam by half a wavelength, thereby rotating the polarization direction of this partial beam by 90°.

[0020] The partial beam traveling from the polarization rotator to the liquid crystal matrix encounters the polarization rotator again on its return path, resulting in another 90° polarization rotation. Immediately after passing the polarization rotator, the beam returns to its original polarization direction. Therefore, this partial beam does not have a different polarization direction upon re-entering the polarization beam splitter than it did initially. Rather, the polarization rotator enables a single liquid crystal matrix to be used for two partial beams with different polarizations.

[0021] For high beam quality of the outgoing light beam, which is composed of the two partial beams, both partial beams should have traversed the same optical path length. For this purpose, at least one transparent delay element can be arranged between the polarization beam splitter and the first liquid crystal region and / or between the polarization beam splitter and the second liquid crystal region. The delay element can be designed such that the optical path length from the polarization beam splitter to the first liquid crystal region is equal to the optical path length from the polarization beam splitter to the second liquid crystal region. The delay element can, in particular, comprise a glass block. Alternatively, the geometric path lengths on the separate beam paths to the first and second liquid crystal regions can be different and selected such that the optical path lengths are equal.

[0022] A beam path from the polarization beam splitter to the first liquid crystal region can be designed such that the first partial beam strikes the first liquid crystal region perpendicularly and travels back along the same path to the polarization beam splitter. Similarly, a beam path from the polarization beam splitter to the second liquid crystal region can be designed such that the second partial beam strikes the second liquid crystal region perpendicularly and travels back along the same path to the polarization beam splitter. Perpendicular incidence on the liquid crystal regions results in better beam quality compared to oblique incidence. Since both partial beams follow the same path to and from the polarization beam splitter to their respective liquid crystal regions, the total number of elements and the space required can be minimized.

[0023] The polarization beam splitter can be arranged in such a way that the transmitted light beam hits the associated liquid crystal area perpendicularly without further deflection.

[0024] The polarization beam splitter can also be designed such that the first and second partial beams exit the splitter parallel to each other and travel parallel to each other towards the liquid crystal regions. For this purpose, one of the partial beams is deflected again within the polarization beam splitter. For example, the polarization beam splitter can consist of two connected elements, similar to a beam splitter cube, with a polarization-dependent splitting into the two partial beams occurring at the interface between the elements. The two partial beams now travel perpendicular to each other within the two elements. One of the elements is designed such that the passing partial beam is reflected. In particular, an outer surface of this element can be at an angle of 45° to the direction of propagation of the passing partial beam, so that the partial beam is reflected at this outer surface by 90°.The outer surface can either be mirrored or undergo total internal reflection. Due to the 90° deflection, both partial beams exit the polarizing beam splitter parallel to each other. Of the two elements, one can have a triangular cross-section and the other a parallelogram shape. Since one side of the triangular element is unused, this side shape can be arbitrary.

[0025] At least two, and in particular all, of the following components can be arranged so that they directly touch without an air gap: the polarization beam splitter, the polarization rotator, the liquid crystal matrix, and optionally the delay element. This can be advantageous for a compact, stable design and high beam quality.

[0026] It may be desirable for the polarization beam splitter to split light into equal proportions into the first and second partial beams. For this to occur, the polarization direction of the incident light must be adjusted accordingly. This can be achieved by a front polarization rotator, which is positioned between the input / output polarization beam splitter and the polarization beam splitter and oriented to rotate the light to the desired polarization direction. The term "front" polarization rotator is used to distinguish this polarization rotator from the other polarization rotator located in front of the liquid crystal matrix; otherwise, both polarization rotators can be formed identically, for example, each using a λ / 2 plate. The front polarization rotator can, in principle, be omitted if the input / output polarization beam splitter and the polarization beam splitter are appropriately oriented relative to each other, for example, by 45°.This means that light reflected or transmitted at the input / output polarization beam splitter should hit the polarization beam splitter in such a way that it is not completely reflected or transmitted, but preferably 50% reflected and 50% transmitted.

[0027] The following explains how amplitude variation is achieved from the phase delays that can be set using the liquid crystal matrix. Amplitude variation is possible pixel by pixel across the beam cross-section. A phase delay can be individually set for each liquid crystal element, by which the phase of incident light is affected. An electronic control unit for setting the output light intensity is configured to variably adjust the phase difference between a phase delay generated by a liquid crystal element in the first liquid crystal area and a phase delay generated by a corresponding liquid crystal element in the second liquid crystal area.A liquid crystal element of the first liquid crystal region and a corresponding liquid crystal element of the second liquid crystal region are to be understood such that the components of the two partial beams guided by these two liquid crystal elements subsequently superimpose. The corresponding liquid crystal elements therefore have identical positions with respect to the respective incident partial beam. Two phase delays can be set using the two corresponding liquid crystal elements. The difference between these phase delays (hereinafter referred to as phase difference) is decisive for the amplitude variation: The phase difference determines how the polarization direction of the combined light beam, which is formed from the two phase-modulated partial beams, is changed or rotated.Depending on the change in polarization direction, the outgoing light beam is partially reflected and partially transmitted at the input / output polarization beam splitter.

[0028] For maximum light intensity, the phase difference can be set to half a wavelength of light, so that the outgoing light beam has a polarization direction rotated by 90° compared to the incoming light and is therefore not directed at the input / output polarization beam splitter in the direction from which the incoming light came.

[0029] For minimum light intensity, the phase difference can be set to 0 or an integer multiple of the light wavelength, so that the outgoing light beam has the same polarization direction as the incoming light and is thus directed at the input / output polarization beam splitter in the direction from which the incoming light came. To set any desired light intensity between 0% and 100% for the portion of the outgoing light beam reflected or transmitted by the input / output polarization beam splitter, a corresponding phase difference is set at the liquid crystal matrix.

[0030] In addition to intensity modulation, phase modulation is also set. For phase modulation, the liquid crystal elements within the same liquid crystal region are set differently. Thus, a phase delay can be individually set for each liquid crystal element, by which the phase of incident light is affected. A control unit for setting a phase pattern across a beam cross-section is configured to set different phase delays using the liquid crystal elements within the same liquid crystal region.

[0031] The following explains how the control unit can simultaneously set both an intensity pattern and a phase pattern. The control unit can set different phase delays on the liquid crystal elements of the first liquid crystal region, which together form the phase pattern. Phase delays are then set on the liquid crystal elements of the second liquid crystal region, which are composed of: A) Phase delays corresponding to those of the liquid crystal elements of the first liquid crystal region for forming the phase pattern, and B) Phase differences to the respective phase delays of the first liquid crystal region to form the intensity pattern.

[0032] The invention also relates to a light microscope with an optical arrangement as described herein. The optical arrangement can be arranged in the illumination beam path, so that the light influenced by the optical arrangement is subsequently directed into a sample area. Alternatively or additionally, the optical arrangement, or a further optical arrangement, can also be arranged in the detection beam path, whereby sample light is influenced by the optical arrangement before it reaches a light detector.

[0033] The properties of the invention described as additional optical arrangement features are also to be understood as variants of the inventive method, and vice versa.

[0034] Further advantages and features of the invention are described below with reference to the accompanying schematic figure. This figure shows: Fig. 1 A schematic representation of an embodiment of an optical arrangement according to the invention.

[0035] Fig. Figure 1 shows an embodiment of an optical arrangement 100 according to the invention for shaping light beams in a light microscope according to the invention. In the right part of Fig. Figure 1 shows how the polarization directions of light are changed as it passes through the optical arrangement 100.

[0036] The optical arrangement 100 enables phase modulation and amplitude modulation of light. The two modulations can be performed independently of each other and pixel-wise across a beam cross-section. Light 1, for example, laser light from a light source of the light microscope (not shown here), is directed to the optical arrangement 100. This arrangement comprises at least one or exactly one liquid crystal or micro-lift mirror matrix 35, which modulates the incident light. Finally, a modulated outgoing light beam 2 exits the optical arrangement 100.

[0037] The liquid crystal or micro-lift mirror matrix 35 comprises several liquid crystal elements / mirrors that can be switched independently of each other.

[0038] For easier understanding, the following describes a design using a liquid crystal matrix with liquid crystal elements. However, the essentially same structure can also be used for a design with a micro-lift mirror matrix.

[0039] Light of a specific polarization direction is variably phase-delayed by the liquid crystal elements depending on their switching state. This alone initially only achieves phase modulation. Amplitude modulation results from the interaction of the components of the optical arrangement 100, as explained below.

[0040] Light 1 first strikes a polarization beam splitter 10, which is referred to here as an input / output polarization beam splitter 10. The input / output polarization beam splitter 10 can, for example, be a polarization beam splitter cube that reflects or transmits light depending on its polarization. In the example shown, transmitted light is directed to the other components of the optical arrangement 100, while light 1 that may be reflected at the input / output polarization beam splitter 10 is not used further in the optical arrangement 100 (in Fig. In this case, incident light 1, which is reflected at the input / output polarizing beam splitter 10, would exit the arrangement to the left. Conversely, light reflected at the input / output polarizing beam splitter 10 could also be directed to the other components of the optical arrangement 100, while transmitted light would not be used further.

[0041] The light 1 can be linearly polarized with a polarization direction by which all of the light 1 is passed through the input / output polarization beam splitter 10 to the other components. Alternatively, unpolarized light can be used, in which case the light 1 passed through the input / output polarization beam splitter 10 is polarized. This polarized light 1 is to be split into two partial beams 1A and 1B, which is done with another polarization beam splitter 20. A polarization rotator 15 can be located between the two polarization beam splitters 10 and 20 so that the light polarization is rotated so that the polarization beam splitter 20 outputs two partial beams 1A and 1B with the same intensity.

[0042] In the illustrated example, the polarization beam splitter 20 has a shape such that one of the partial beams 1B is reflected again at an interface 21 of the polarization beam splitter 20, causing the two partial beams 1A and 1B to exit the polarization beam splitter 20 parallel to each other. Alternatively, further mirrors or prisms can be used to redirect the partial beam 1A and / or 1B so that both strike the same liquid crystal matrix, but different liquid crystal regions 35A and 35B. In this way, the two partial beams 1A and 1B can undergo independent phase modulations.

[0043] Since a liquid crystal matrix 35 can generally only variably phase-modulate light of a specific polarization direction, a polarization rotator 23 is used which rotates the polarization of one of the partial beams 1A by 90°.

[0044] In the illustrated example, a transparent delay element 22 is used between the polarization beam splitter 20 and the liquid crystal matrix 35, so that the beam paths of both partial beams 1A and 1B have the same optical path length. Light incident on the liquid crystal matrix 35 passes through the liquid crystal layer, is reflected at its back side, and passes through the liquid crystal layer again before exiting (with a phase delay). As shown, both partial beams can be directed perpendicularly onto the liquid crystal matrix 35, so that partial beams 1A and 1B travel along the same path from the liquid crystal matrix 35 back to the polarization beam splitter 20, where they are recombined to form a light beam 2, which then proceeds to the input / output polarization beam splitter 10.Depending on the polarization direction present, the returning light 2 is either transmitted or reflected at the input / output polarization beam splitter 10, or partially transmitted and partially reflected. Polarization rotation is achieved by setting different phase delays for the two partial beams at the liquid crystal matrix.

[0045] The change in polarization of the light as it passes through the optical arrangement will now be discussed in more detail with reference to the right-hand part of Fig. 1 described.

[0046] In the example shown, the light 1, with the polarization direction shown in 61, strikes the input / output polarization beam splitter 10 and subsequently has the same polarization direction (see 62). The light 1 then passes through the polarization rotator 15, which can be a half-wave plate, by which the polarization direction of the light 1 is rotated by 45°, as shown in 63. Due to this oblique polarization direction, the light 1 is split at the polarization beam splitter 20 into two partial beams 1A and 1B with mutually perpendicular polarization directions, as shown in 64.

[0047] Partial beams 1A and 1B continue towards the liquid crystal matrix with these two mutually perpendicular polarization directions, see 65. Partial beam 1A is rotated by 90° in its polarization direction by the polarization rotator 23, so that upon impact with the liquid crystal matrix 35, both partial beams 1A and 1B have the same polarization direction, see 66. Depending on a switching state of the liquid crystal elements of the liquid crystal matrix, phase delays for partial beams 1A and 1B can now be variably set. In the example shown, the phase of partial beam 1A is delayed by 180°, or half a wavelength (this phase delay represents the phase difference to the phase delay experienced by the other partial beam 1B). As shown in 67, partial beam 1A now has a phase delayed by 180° compared to partial beam 1B.After passing through the polarization rotator 23 again, the polarization direction of partial beam 1A is rotated by 90°, as shown in Figure 68. At the polarization beam splitter 20, the two partial beams 1A and 1B are combined, with Figure 69 showing the two polarization directions of partial beams 1A and 1B as well as the polarization direction of the resulting outgoing light beam 2. This light beam 2 now has the polarization shown in Figure 70, which is rotated by 135° by the polarization rotator 15, as shown in Figure 71. As shown in Figure 71, the polarization of light beam 2 is rotated by 90° relative to the polarization at Figure 62, with which the light 1 traveled towards the liquid crystal matrix. Therefore, light beam 2 is not guided at the input / output polarization beam splitter 10 in the direction from which the light 1 came.In the example shown, light 1 was transmitted at the input / output polarization beam splitter 10, while light beam 2 is now reflected due to its rotated polarization direction 2. This light beam 2, coupled out at the input / output polarization beam splitter 10, therefore has an unchanged light intensity (a maximum light intensity) when the phase of the partial beams 1A and 1B is affected as shown.

[0048] If, however, the liquid crystal elements on the liquid crystal matrix are set identically for both partial beams 1A and 1B, then in 67 both partial beams 1A and 1B would have the same polarization / phase (the polarization of partial beam 1A would point upwards instead of downwards in 67). As a consequence, the polarization direction of partial beam 1A in 68 would point to the right instead of to the left, and in 69 and 70, the polarization of light beam 2 would be rotated 90° clockwise relative to the case shown. Consequently, the polarization would be the same as initially for light 1, and therefore light beam 2 would be transmitted at the input / output polarization beam splitter 10 in the direction from which light 1 came. This would result in an output or reflection direction of the input / output polarization beam splitter 10 (to the right in 68). Fig. 1) therefore no light would get through (minimal light intensity).

[0049] Thus, the phase delays between the liquid crystal regions of the two partial beams allow the intensity of the coupled-out light beam 2 to be varied between a minimum and maximum intensity. Intermediate intensity values ​​are possible by delaying the phase not by 180° as shown in Figure 67, but by a different value. The resulting light beam 2 is then elliptically polarized, whereby the two mutually perpendicular components of the elliptically polarized light beam 2 can be set to variable values. This allows a variably adjustable portion of the light beam to be transmitted at the input / output polarization beam splitter 10, while the remaining portion is reflected.

[0050] For a mathematical description, the phase delay / phase pattern φ(x,y) is considered, which alters one of the partial beams upon impact with the corresponding liquid crystal region. The spatial dependence (x,y) indicates that different phase delays φ can be set across the cross-section of the incident partial beam. The other partial beam is influenced at the other liquid crystal region by a different phase delay / phase pattern, which differs from the phase delay φ(x,y) by A(x,y).

[0051] The two mutually perpendicularly polarized components of the light beam 2, which strikes the input / output polarization beam splitter 10, can be described as a horizontal field strength component E h and vertical field strength component E v These electric field strengths depend on the phase delay φ(x,y) and A(x,y) in the following way: Eh(x,y,z)∝2cos(A(x,y) / 2)⋅cos(k⋅z−ω⋅t+φ(x,y) / 2) Ev(x,y,z)∝−2sin(A(x,y) / 2)⋅sin(k⋅z−ω⋅t+φ(x,y) / 2)

[0052] Here, z denotes the direction of propagation of the light ray, ω the angular frequency of the light (or electromagnetic wave), and k its wavenumber, i.e., 1 / λ. Depending on the value of A(x,y), the light ray is, according to the polarization divider 20, either linearly polarized in the x- or y-direction, or it is elliptically or circularly polarized. The horizontal component E h (x,y,z) is directed back towards the light source at the input / output polarization beam splitter and is not used further, while the vertical component E v (x,y,z) is directed in the other direction at the input / output polarization beam splitter and used further (that is, in Fig. 1 is reflected). This results in the light that is subsequently used being linearly polarized and amplitude- and / or phase-modulated.

[0053] In the example shown from Fig. At 67, the phase of the first partial beam 1A is shifted by half a wavelength, or π, relative to the phase of the second partial beam 1B. In this example, A(x,y) = π. From the formula above, it can be seen that 2cos(A / 2) = 0, meaning the component reflected back towards the light source is E. h = 0 and all light is reflected. However, without a phase difference, A(x,y)=0 and therefore 2sin(A / 2)=0 and thus also E. v =0, meaning no light is passed on, but all light is transmitted towards the light source.

[0054] It should be noted that the in Fig. The polarization directions specified in 1 refer to a single liquid crystal element of the first liquid crystal region 35A and a single liquid crystal element of the second liquid crystal region 35B. These two liquid crystal elements correspond to each other with respect to the cross-sections of the incident partial beams, so that the light returning from these two liquid crystal elements is spatially superimposed. In the formulas above, these two liquid crystal elements have the same x-value and the same y-value. For other liquid crystal elements, different phase delays can be set so that a varying intensity can be set via the beam cross-section of the coupled light beam 2.

[0055] In addition to this intensity modulation, phase modulation can be achieved by adjusting neighboring pixels within the same liquid crystal region differently. This allows for variable wavefront adjustment.

[0056] In the described embodiment, the liquid crystal regions 35A, 35B can also be understood more generally as liquid crystal or lift-mirror regions 35A, 35B. In a design as lift-mirror regions 35A, 35B, 35 denotes a lift-mirror matrix, and mirrors are present instead of liquid crystal elements.

[0057] With such a design, the polarization rotator 23 can be omitted. Otherwise, the setup can be as described in Fig. 1 can be implemented as shown. Without polarization rotator 23, the micro-lift mirror section 35A can, for example, cause a polarization change of the partial beam 1A from an orientation as shown in image section 65 directly to an orientation as shown in image section 68 (that is, in this example, the phase of the partial beam 1A is changed by half a wavelength by the micro-lift mirror section 35A).

[0058] The invention allows both the amplitude and the phase of a light beam to be variably shaped across its cross-section. This is achieved with a compact and stable arrangement, which is also particularly cost-effective when using a single liquid crystal or micro-lift mirror matrix. Reference symbol list 1 light 1A first partial beam 1B second partial beam 2 outgoing light beam 10 In / out coupling polarization beam splitters 15 polarization rotators 20 polarization beam splitters 21 Interface 22 Delay element 23 polarization rotators 35 Liquid crystal or micro-lift mirror matrix 35A first liquid crystal or microlift mirror area 35B second liquid crystal or microlift mirror area 61-71 Information on the polarization direction of light 1, partial rays 1A, 1B and the outgoing light ray 2

Claims

[1] Optical arrangement for shaping light beams for a light microscope, comprising - a first liquid crystal or micro-lift mirror area (35A) with several independently adjustable liquid crystal elements or mirrors with which a phase of incident light can be adjusted to change, characterized by - a second liquid crystal or micro-lift mirror area (35B) with several independently adjustable liquid crystal elements or mirrors with which a phase of incident light can be adjusted to change, - an input / output polarization beam splitter (10) with which incident light (1) of a specific polarization direction can be directed towards the liquid crystal or micro-lift mirror regions (35A, 35B), - a polarization beam splitter (20) which is arranged between the input / output polarization beam splitter (10) and the liquid crystal or micro-lift mirror regions (35A, 35B), - that the polarization beam splitter (20) separates the light (1) coming from the input / output polarization beam splitter (10) depending on polarization into a first partial beam (1A), which is directed to the first liquid crystal or micro-lift mirror area (35A), and into a second partial beam (1B), which is directed to the second liquid crystal or micro-lift mirror area (35B), and - that the polarization beam splitter (20) combines the two partial beams (1A, 1B) returning from the liquid crystal or micro-lift mirror areas (35A, 35B) and directs them together as an outgoing light beam (2) to the input / output polarization beam splitter (10). [2] Optical arrangement according to claim 1, characterized by , that the first and second liquid crystal or microlift mirror regions (35A, 35B) are regions of the same liquid crystal or microlift mirror matrix (35) and that a polarization rotator (23) is arranged between the polarization beam splitter (20) and the first liquid crystal or micro-lift mirror region (35A) or between the polarization beam splitter (20) and the second liquid crystal or micro-lift mirror region (35B). [3] Optical arrangement according to claim 1 or 2, characterized by , that a transparent delay element (22) is arranged between the polarization beam splitter (20) and the first liquid crystal or microlift mirror region (35A) or between the polarization beam splitter (20) and the second liquid crystal or microlift mirror region (35B), and that the delay element (22) is designed such that an optical path length from the polarization beam splitter (20) to the first liquid crystal or micro-lift mirror area (35A) is equal to an optical path length from the polarization beam splitter (20) to the second liquid crystal or micro-lift mirror area (35B). [4] Optical arrangement according to any one of claims 1 to 3, characterized by , that a beam path from the polarization beam splitter (20) to the first liquid crystal or micro-lift mirror region (35A) is designed such that the first partial beam (1A) hits the first liquid crystal or micro-lift mirror region (35A) perpendicularly and travels the same path back to the polarization beam splitter (20), that a beam path from the polarization beam splitter (20) to the second liquid crystal or micro-lift mirror area (35B) is designed such that the second partial beam (1B) hits the second liquid crystal or micro-lift mirror area (35B) perpendicularly and travels the same path back to the polarization beam splitter (20). [5] Optical arrangement according to any one of claims 1 to 4, characterized by , that the polarization beam splitter (20) is designed such that the first and second partial beams (1A, 1B) converge parallel to each other towards the liquid crystal or micro-lift mirror areas (35A, 35B). [6] Optical arrangement according to claim 4 or 5, characterized by , that at least two, in particular all, of the following components directly touch: the polarization beam splitter (20), the polarization rotator (23), the liquid crystal or micro-lift mirror matrix (35) and optionally the delay element (22). [7] Optical arrangement according to any one of claims 1 to 6, characterized by , that a front polarization rotator (15), in particular a λ / 2 plate, is arranged between the input / output polarization beam splitter (10) and the polarization beam splitter (20) and is aligned such that light at the polarization beam splitter (20) is split into the first and second partial beams (1A, 1B) in equal proportions. [8] Optical arrangement according to any one of claims 1 to 7, characterized by , that a phase delay can be individually set for each liquid crystal element or mirror, by which a phase of incident light is affected, that a control unit for setting an output light intensity is configured to set a phase difference between a phase delay generated by a liquid crystal element or mirror of the first liquid crystal or micro-lift mirror region (35A) and a phase delay generated by a corresponding liquid crystal element or mirror of the second liquid crystal or micro-lift mirror region (35B), wherein: - for maximum light intensity, the phase difference is set to half a wavelength of light, or an integer multiple of the wavelength of light plus half a wavelength of light, whereby the outgoing light beam (2) has a polarization direction rotated by 90° compared to the incoming light (1) and is therefore not directed at the input / output polarization beam splitter (10) in the direction from which the incoming light (1) came, - for a minimum light intensity, the phase difference is set to 0 or an integer multiple of the wavelength of the light, so that the outgoing light beam (2) has the same polarization direction as the incoming light (1) and is thus directed at the input / output polarization beam splitter (10) in the direction from which the incoming light (1) came. [9] Optical arrangement according to any one of claims 1 to 8, characterized by , that a phase delay can be individually set for each liquid crystal element or mirror, by which a phase of incident light is affected, that one or the control unit for setting a phase pattern over a beam cross-section is configured to set different phase delays using the liquid crystal elements or mirrors of the same liquid crystal or microlift mirror area (35A, 35B). [10] Optical arrangement according to claim 9, characterized by , that the control unit is set up to adjust an intensity pattern and a phase pattern: - to set different phase delays on the liquid crystal elements / mirrors of the first liquid crystal or micro-lift mirror area, which together form the phase pattern, - to set phase delays on the liquid crystal elements / mirrors of the second liquid crystal or micro-lift mirror area, which are composed of: C) Phase delays corresponding to those of the liquid crystal elements / mirrors of the first liquid crystal or microlift mirror region for forming the phase pattern, and D) Phase differences to the respective phase delays of the first liquid crystal or microlift mirror region to form the intensity pattern. [11] Light microscope with an optical arrangement according to any one of claims 1 to 10. [12] Method for shaping the light beam for a light microscope, comprising - Phase modulation of light by means of a liquid crystal or micro-lift mirror matrix (35) which has several independently switchable liquid crystal elements or mirrors, characterized by - Forwarding light (1) of a specific polarization direction by means of an input / output polarization beam splitter (10), - Polarization-dependent separation of the light (1) coming from the input / output polarization beam splitter (10) by means of a polarization beam splitter (20) into a first partial beam (1A) and into a second partial beam (1B), - comprising phase modulation of light using a liquid crystal or micro-lift mirror matrix (35): - Guiding the first partial beam (1A) to a first liquid crystal or microlift mirror region (35A) of the liquid crystal or microlift mirror matrix (35) and - Guiding the second partial beam (1B) to a second liquid crystal or microlift mirror area (35B), and - Combining the two partial beams (1A, 1B) returning from the liquid crystal or micro-lift mirror areas (35A, 35B) using the polarization beam splitter (20) and - Guiding the combined partial beams (1A, 1B) as an outgoing light beam (2) to the input / output polarization beam splitter (10).

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