JP2004538470A - Electron microscope and spectroscopy system - Google Patents

Abstract

The electron microscope (10) is adapted to enable spectroscopic analysis of the specimen (16). The parabolic mirror (18) has a central opening (20), through which the electron beam can pass. The mirror (18) focuses the laser illumination on the specimen from the lateral optical path and collects Raman and / or other scattered light and returns it to the optics (30). The mirror (18) is retractable (in the vacuum of the electron microscope) by the sliding arm assembly (22). An adjustable kinematic mount (44) defines the insertion position of the parabolic mirror (18). A second parabolic mirror (104) is provided to direct scattered or generated light to an optical analyzer. The parabolic mirrors are oriented so as to cancel the distortion so that they correct for errors in the position of the sliding arm assembly (22).

Description

【Technical field】
[0001]
The present invention relates to a sample analysis system. In a preferred embodiment, the electron microscope is combined with a spectroscopy system, for example a Raman spectroscopy system, a photoluminescence spectroscopy system or a cathodoluminescence spectroscopy system.
[Background Art]
[0002]
In U.S. Pat. No. 6,059,067, an analysis system, such as a scanning electron microscope, irradiates a sample with an electron beam along an analytical axis. Generally, a parabolic mirror is mounted on the analysis axis on the specimen, and an opening in the mirror allows the electron beam to pass through and reach the specimen. The mirror is mounted on a mirror holder assembly, which generally has an optical axis that intersects the analysis axis. The mirror holder assembly may be capable of moving the mirror between its active position and an inactive position remote from the analysis axis.
[0003]
[Patent Document 1]
WO 99/58939
[Patent Document 2]
U.S. Pat. No. 5,446,970
[Patent Document 3]
International patent application GBO1 / 00170 specification
[Patent Document 4]
U.S. Pat. No. 4,451,987
[Patent Document 5]
U.S. Pat. No. 4,473,955
[Non-patent document 1]
George Turrel and Jacques Corset "Raman Microscopy, Developments &Applications"
DISCLOSURE OF THE INVENTION
[Problems to be solved by the invention]
[0004]
It is desired that the mirror be accurately and repetitively positioned with respect to both the analysis axis and the optical system positioned along the optical axis.
[0005]
Further, since analysis systems such as scanning electron microscopes can be operated under ultra-high vacuum, it is preferred that the mirrors be adjusted outside the vacuum for both active and inactive positions. is there.
[Means for Solving the Problems]
[0006]
A first aspect of the present invention is for performing an optical analysis of a sample mounted in a sample chamber of another analyzer having an analysis axis and irradiating the sample with an analysis beam substantially along the analysis axis. An adapter,
An optical element arranged to collect scattered or generated light received from the specimen, and directing the light generally along an optical axis that intersects the analysis axis;
An adapter wherein the optical element is adjustable between an active position on the analysis axis and a non-analysis position off the analysis axis;
An adapter is provided wherein the working position is defined by an adjustable mount that limits the displacement of the optical element in six degrees of freedom.
[0007]
Preferably, the adjustable mount is kinematic.
[0008]
Preferably, the interior of the specimen chamber is under reduced pressure, and the reduced pressure is used to bias the optical element toward the operating position.
[0009]
Preferably, said optical element also receives an input light beam along said optical axis, said input light beam being directed to said specimen.
[0010]
Preferably, said optical element is a mirror. Alternatively, the optical element may be an optical fiber focusing element.
[0011]
Preferably, the optical axis is in a direction substantially transverse to the analysis axis.
[0012]
The inoperative position may be determined by a second mount that suppresses the displacement of the optical element in six degrees of freedom. The second mount may be adjustable.
[0013]
A second aspect of the present invention is directed to performing an optical analysis of a sample mounted in a sample chamber of another analyzer having an analysis axis and irradiating an analysis beam substantially along the analysis axis toward the sample. An adapter,
A first optical element having a first focal plane, arranged to collect scattered or generated light received from the specimen, and directing the light generally along an optical axis that intersects the analysis axis;
The first optical element is adjustable between an operating position on the analysis axis and a non-analysis position off the analysis axis;
A second optical element having a second focal plane is provided in fixed relation to the first optical element, wherein the second optical element is directed by the first optical element along the optical axis. To an optical analyzer.
The first and second optical elements include:
When the first optical elements are in the operating position, their focal planes are arranged to be parallel to the direction of movement of the first optical elements;
An adapter is provided which is arranged to at least partially correct an error in positioning the first optical element at its operating position.
[0014]
Preferably, a positioning mount is provided to determine the position of said first optical element at its operating position,
When the first optical element is in the operative position, the ratio of the focal length of the first optical element to the focal length of the second optical element is such that the ratio between the focal point of the first optical element and the positioning mount is different. It is inverted with respect to the ratio of the distance along the optical path to the distance between the focal point of the second optical element and the positioning mount along the optical path.
[0015]
Preferably, the focal lengths of the first and second optical elements are equal and the distance along the optical path between the focal point of the first optical element and the positioning mount when the first optical element is in the operative position. , Equal to the distance along the optical path between the focal point of the second optical element and the positioning mount.
[0016]
Preferably, said first and second optical elements comprise parabolic mirrors.
[0017]
A third aspect of the present invention is an adapter for performing an optical analysis of a sample mounted in a sample chamber of another analyzer that irradiates an analysis beam toward the sample,
An optical element positioned to collect scattered or generated light received from the specimen and directing the light to an optical analyzer generally along an optical axis that intersects the analysis axis;
An adapter in which the optical element is a parabolic mirror,
At least one mirror is provided for coupling light reflected by the parabolic mirror to an optical analyzer, the at least one mirror being adjustable;
An adapter is provided in which distortion in the optical analysis means is corrected by image processing software.
[0018]
Preferably, a second parabolic mirror is disposed between the parabolic mirror and the optical analyzer, and the two parabolic mirrors are arranged so as to cancel aberration. Two further parabolic mirrors are provided between the parabolic mirror and the optical analysis means, and the four parabolic mirrors are arranged in a direction to cancel aberration. it can.
[0019]
For a discussion of the meaning of the terms "kinematic", "kinematically" and similar terms as used herein, reference should be made to U.S. Pat. These terms include not only kinematic support in which point contact is made between each pair of elements on the carrying and receiving members, but also half area or line contact between each element. It also includes kinematic support or pseudo-kinematic support.
BEST MODE FOR CARRYING OUT THE INVENTION
[0020]
Hereinafter, the present invention will be described with reference to the accompanying drawings.
[0021]
FIG. 1 shows an electron microscope 10 having a typical electron beam generation, focusing and scanning system 12. This irradiates the sample 16 with a beam of electrons generally along the analysis axis 14 in a known manner.
[0022]
Instead of a scanning electron microscope, the present invention may be used with other types of analysis systems, including transmission electron microscopes, and ion beam bombardment systems.
[0023]
A parabolic mirror or other concave mirror 18 is generally mounted on the shaft 14 on the specimen 16 and having a central aperture 20 allows the electron beam to pass toward the specimen 16. The parabolic mirror 18 is mounted on a mirror holder arm 22, which has an optical axis 24 substantially perpendicular to the analysis axis 14 of the scanning electron microscope. The mirror holder 22 is capable of moving the parabolic mirror 18 between an active position (shown by a solid line) and a non-active position (shown by a broken line), as shown by a two-way arrow 26. In the non-actuated position, the parabolic mirror 18 is connected to other devices in the scanning electron microscope, such as an X-ray detector that can be used to detect X-rays generated by irradiating the specimen 16 with an electron beam. There is no interference.
[0024]
Also provided in the system is an optical system 28, which may comprise, for example, a spectrometer. When in the operative position, the incident laser beam 27 can be directed along the optical axis 24 via a mirror 25 or other means and focused by the parabolic mirror 18 onto the specimen 16. The laser beam can be, for example, ultraviolet, visible or infrared. The scattered light from the specimen 16 is collected by the parabolic mirror 18, collimated, and fed back in a return direction along the optical axis 24 toward the optical system 28. The light collected may be inelastically scattered light, such as Raman, fluorescence or photoluminescence. Also, laser wavelengths will include elastically scattered (Rayleigh) light. Alternatively or together, the light collected from the specimen 16 by the mirror 18 may be cathodoluminescent, which is produced by the action of the electron beam on the specimen 16 without requiring laser injection.
[0025]
FIG. 1 shows a system in which the optical system 28 is rigidly fixed to the scanning electron microscope chamber. In this case, the parabolic mirror must be accurately positioned with respect to both the optics and the electron beam each time it is placed in the operating position. As another configuration, the optical system can be rigidly fixed to the parabolic mirror so that the entire system can advance and retreat together. This configuration is advantageous in that it is sufficient to accurately position the parabolic mirror with respect to the electron beam, but it does not allow the use of heavy and bulky optical spectrometers and lasers, or components associated with signal acquisition and laser delivery. A disadvantage is that it must be supported by an assembly of holder arms.
[0026]
FIG. 2 shows the functional elements of the retraction mechanism. In the scanning electron microscope, a chamber flange 30 is provided on a wall of the scanning electron microscope chamber 11. The retraction mechanism 32 is attached to the flange 30 of the scanning electron microscope chamber via a mechanism flange 34. When the mechanical flange 34 is mounted in the scanning electron microscope chamber 11, it is fixed relative to the electron beam axis 14, so that all important optical and mechanical arrangements are referenced to this mechanical flange 34.
[0027]
A pair of guide rails 36 (only one is shown) and a retraction screw 38 are attached to the mechanism flange 38. A retraction arm 40 is attached to the guide rail 36 and can be advanced or wound in or out along the guide rail 36 by the retraction screw 38. The retraction screw 38 can be motor driven. The parabolic mirror 18 is transported indirectly by a slide tube 42, which can be mounted concentrically with the retraction arm 40 about the optical axis 24. The position of the sliding tube 42 or parabolic mirror 18 is defined by two sets of mounts with adjustable kinematic mounts. These are a positioning mount 44 and a retreat mount 46. As the retreat arm 40 advances or retreats along the guide rail 36, the slide tube 42 is pressed on the positioning mount 44 (that is, the parabolic mirror is held at the insertion position), or slides on the retreat mount 46. The moving tube 42 is pressed (that is, the parabolic mirror is held at the retracted position). The bellows seal 48 is used to realize a linearly movable vacuum seal. This type of seal has the advantage of allowing tilt, slight rotation and lateral displacement, and is a reliable seal up to ultra-high vacuum pressure. Other seals, such as a sliding O-ring seal, may be used.
[0028]
The bellows seal has a bellows fixing flange 50 at one end and a bellows moving flange 52 at the other end. The bellows fixing flange 50 is attached to the mechanism flange 34 adjacent to the scanning electron microscope chamber 10. The bellows moving flange 52 is attached to both the optical system flange 54 and the withdrawn end of the slide tube 42 remote from the scanning electron microscope chamber 10. The optical system flange 54 includes a vacuum window 56 for extracting light and holds the mirror holder arm 22 that supports the parabolic mirror 18 in the scanning electron microscope chamber 10.
[0029]
The retraction arm 40 can be used to push the slide tube 42 towards the scanning electron microscope chamber 10, where its position is defined by a positioning mount 44. The retraction arm 40 can also push the slide tube 42 away from the scanning electron microscope chamber 10 so that its position relative to the retraction arm 40 is both during retraction and when in the retracted position. 46. The position of the sliding arm 42 or parabolic mirror 18 is always determined by either the positioning mount 44 or the retreat mount 46.
[0030]
The kinematic mount of the positioning mount 44 comprises three V-shaped grooves spaced 120 degrees apart on a circle concentric with the optical axis 24 on the mechanism flange 34 of the retraction mechanism 32. These are provided on the surface of the mechanism flange 34 adjacent to the slide tube 42. Each V-shaped groove may be provided by a pair of parallel cylindrical rollers 60, as shown in FIG. Three bearings with similarly spaced spherical ends are provided on the face of the sliding tube adjacent the mechanism flange 34. As the slide tube 42 is transferred toward the mechanism flange 34, the ball bearings interact with the V-shaped grooves to position the slide tube 42 with respect to the mechanism flange 44 and thus the position of the parabolic mirror 18. Is accurately determined.
[0031]
Since the vacuum in the scanning electron microscope chamber holds the sliding tube in place relative to the mechanism flange, no other method for holding the kinematic elements, such as by magnetic force or spring, is required. is there.
[0032]
It is desirable that the kinematic mount be adjustable, and that the adjustment be ex-vacuo. In this example, the position of each bearing with a spherical end is adjustable parallel to the optical axis 24. As shown in FIGS. 4 and 5, each bearing having a spherical end is provided by a cylindrical rod 62 having a rounded end 64. Each cylindrical rod 62 is housed in a housing 66 arranged in the sliding tube 42. Housing 66 has a central opening 68 extending along its longitudinal axis. This opening is stepped and has an enlarged portion 70 and a reduced portion 72. The cylindrical rod 62 is fitted into an enlarged portion 70 having a step 74 and is locked where it enters the reduced portion 72. The cylindrical rod 62 is held at a predetermined position in the housing 66 by a screw 76. The screw 76 is inserted through an opening 78 on the side of the housing 66 and presses a flat portion 80 on a part of the side of the cylindrical rod 62. The rounded end 64 of the cylindrical rod 62 extends outwardly from the central opening of the housing 66.
[0033]
The outer portion of the housing 66 also has a stepped cylindrical shape. The outer surface of the housing reduction 82 is threaded and threaded into a threaded opening 84 in the slide tube 42 and held in place by a bolt 85. A reduced portion 72 on the inner surface of the housing 66 is also threaded to receive an adjustment screw 86. The adjusting screw allows the position of the housing 66 with respect to the sliding tube 42 to be adjusted in the longitudinal axis direction.
[0034]
The bearings with spherical ends can be individually adjusted parallel to the optical axis 24. Therefore, by individually adjusting the positions of the ball bearings, the mirror holder arm 22 can be tilted by 60 degrees with respect to each of the three axes. The optical arm 58 can also be moved parallel to the retraction axis by globally adjusting the position of the bearing with the spherical end. These alignments are sufficient to position the parabolic mirror 18 three-dimensionally with respect to the scanning electron microscope 14.
[0035]
The rounded end of the cylinder 64 has two contacts for the V-shaped groove. Other shapes with two contacts for the V-groove can also be used, for example a wedge is shown in FIG. The wedge may have an angle of, for example, 60 degrees.
[0036]
To retract the parabolic mirror 18, the retracting arm 40 is retracted to contact the end of the slide tube 42 remote from the scanning electron microscope chamber 10, and the entire mechanism is pulled away from the mechanism flange 34. The contact at the positioning mount 44 is released, and during retraction, the position of the parabolic mirror 18 is defined by the retraction mount 46. Retraction of the parabolic mirror 18 is limited by an adjustable lock (not shown) on the retraction screw.
[0037]
Contact between the retraction arm 40 and the slide tube is provided by an adjustable kinematic mount similar to the positioning mount 44. Here, a bearing having a spherical end is disposed on the retreat arm 40 and contacts the V-shaped groove on the slide tube 42.
[0038]
FIG. 7 shows the end surface of the retreat arm. An opening 92 for the guide rail is provided and a threaded opening 94 for the retraction screw is provided. Four elongated openings 90 are provided, in which housings for bearings with spherical ends are located. These elongated slits allow each housing to be individually adjusted laterally.
[0039]
Thus, the position of the slide tube 42, ie, the position of the parabolic mirror 18, is always determined by the positioning mount 44 (ie, relative to the mechanism flange 34) or by the retraction mount 46 (ie, relative to the retraction arm 40). Will be.
[0040]
After the parabolic mirror 18 is aligned by adjusting the kinematic mount at the positioning mount 44, the kinematic mount is adjusted at the retreat mount 46, and the plane formed by the ball bearing is adjusted to the positioning mount part. To be parallel to the plane of Also, by making a lateral adjustment to ensure that the ball bearing is aligned with the V-shaped groove, any lateral displacement of the slide tube 42 relative to the retraction arm caused by tilt adjustment of the positioning mount 44 is compensated. So that These adjustments help minimize any displacement of the parabolic mirror 18 through the transition from engagement of the positioning mount 44 to engagement of the retraction mount 46. Then, after a change occurs in the alignment of the parabolic mirror 18 due to the adjustment of the positioning mount 44, only those adjustments are required.
[0041]
The adjustable kinematic mount of the present invention is also suitable for use in other applications. For example, a light collecting element (fiber optic light collection element) of an optical fiber as described in Patent Document 3 is used for a specimen and a defect review tool (DRT); an electron for detecting a defect in a semiconductor wafer. Positioning can be accurately performed between the objective lens of a type of microscope). Defects in the wafer can be accurately positioned to be the electron optical center of the electron in the DRT, so that the optical fiber focusing element is also positioned at a known distance from the specimen surface to the electron optical center. It will be moved. Thus, the fiber optic focusing element will be precisely positioned in X, Y and Z, which can be achieved by using the adjustable kinematic mount described above.
[0042]
The present invention is not limited to adjustable positioning mounts. Other adjustable mounts that constrain the position of parabolic mirror 18 with six degrees of freedom are also suitable. Such a mount may, for example, comprise a combination of a ball that limits some displacement against the plate and a planar spring that limits the other displacement, as described in US Pat. It is disclosed in reference 5.
[0043]
FIG. 8 shows an optical configuration for coupling light collected by a parabolic mirror 18 to an optical system, such as a spectrometer. The same reference numbers are used for the same parts as those shown in the previous drawings.
[0044]
Light from the specimen collected by parabolic mirror 18 is reflected via adjustable mirrors 100, 102 toward a second parabolic mirror. The two parabolic mirrors are in a fixed relationship to each other, and their relative alignment can be adjusted in six axes by the two adjustable mirrors 100,102.
[0045]
An objective 106 of the microscope is provided in a fixed position with respect to the mechanism flange 34 of the retraction mechanism 32 (and thus the sample chamber). The microscope objective 106 is located at the focal point of the second parabolic mirror 104 and collimates the light into a suitable parallel beam for the spectrometer. It is desirable that the objective 106 of the microscope be adjustable so that it can be accurately positioned at the focal point of the second parabolic mirror 104.
[0046]
Parabolic mirrors are preferably used over flat mirrors because they provide better light collection efficiency. Parabolic mirrors are more preferably used than ellipsoidal mirrors, because they have two focal points and their alignment is complicated and delicate.
[0047]
The corollary to using a parabolic mirror is that the off-axis image is distorted. This is improved by using two parabolic mirrors. The use of four parabolic mirrors allows for further improvement, but in this case alignment is not easy.
[0048]
FIG. 8 shows a pair of parabolic mirrors 18 and 104 for optically coupling the specimen to the microscope objective section 106 together with the alignment mirrors 100 and 102, but one or four parabolic mirrors are used together with the alignment mirrors. A system can also be used.
[0049]
The use of a parabolic mirror to couple a Raman laser probe to an electron microscope has been previously disclosed in [1]. In this system, as shown in FIG. 9, a pair of parabolic mirrors 110 and 112 are arranged so that their focal points 114 and 116 are in different horizontal planes. This arrangement is disadvantageous in that not all aberrations can be canceled.
[0050]
In the present invention, as shown in FIG. 10, the parabolic mirrors 110 and 112 are arranged so that the focal points are on the same horizontal plane. This configuration of the parabolic mirror cancels aberrations, and in particular corrects aberrations from paraxial rays.
[0051]
Image processing techniques such as image warping are used to correct for residual distortion (such as pin-cushion distortion and barrel distortion).
[0052]
It is desirable to repeatably position the laser spot on the specimen with an accuracy greater than 1 μm. However, if a non-kinematic positioning mount is used (eg, an end stop or plain bearing), or if the kinematic positioning mount becomes dirty, the spot position will be less accurate, eg, due to drift. The decrease in accuracy of the laser spot position on the specimen is compensated by the optical configuration described below.
[0053]
FIG. 11 shows two equal lenses 120, 122 with focal length f working in infinite conjugate mode. As the object O moves upward, the image I inverts by the same amount. This property is used to compensate for small errors in the position of the retraction arm.
[0054]
FIG. 12A shows a simplified form of the optical element used in the retraction arm. Each set of optical elements can include a plane mirror 124, 126 and a lens 128, 130. Alternatively, as illustrated in FIG. 8, the optical element may include a pair of parabolic mirrors. The optics are rigidly attached to each other within the retraction arm, so that insertion / retraction of the retraction arm causes movement of the entire optics assembly. In addition, the optics are a matched pair, so that for small areas related to the image / object, the object is imaged with a magnification factor of 1, focused, and inverted. .
[0055]
FIG. 12A shows two mirror and lens assemblies 124, 128, 126, 130 having equal focal lengths f and equidistant from the center of rotation (ie, the positioning mount).
[0056]
As shown in FIG. 12B, while the entire assembly moves in the X direction, if the object O is fixed, an image I ′ that moves −X with respect to the backward arm is generated. Therefore, the position of the laser spot on the specimen remains unchanged and is not affected by slight movement of the retreat arm. The above compensation applies to the movement of the retreat arm in X, -X, Y and -Y.
[0057]
This system does not compensate for movement of the retraction arm in the Z direction in a similar manner. However, there is no problem if the change in the Z direction within the depth of field of the optical system is small. The depth of field of the parabolic mirror used in the present optical system is, for example, about 20 μm. Since the aim is to position the spot within 1 μm, small displacements of this order of the parabolic mirror are acceptable.
[0058]
The symmetrical arrangement of the optical elements also compensates for slight swings of the retraction arm. FIG. 11 shows two lenses 120, 122 fixed to each other by, for example, a housing 132. Even if the object O is fixed, the housing 132 swings around the rotation center P, and the image I does not move even if a small angle is formed within the depth of field. This is for the same reason as described above. However, this is only true if the rotation axis is at the center of the two optical elements. The retractable arm positioning mount (kinematic or otherwise) acts as the axis of rotation between the optical elements.
[0059]
If the focal lengths of the lenses are not equal, the center of rotation must be moved to a position closer to the lens with the longer focal length. For example, if the ratio of the objective lens focal length f1: the imaging lens focal length f2 is 1: 2, the ratio of the distance from the object to the rotation center: the distance from the rotation center to the image must be 2: 1.
[0060]
When the retreat arm swings, a displacement in Z also occurs. However, if the swing angle is small and the distance from the rotation center to the object is large, the image is not affected.
[0061]
FIG. 13 shows an optical configuration of a retreat arm similar to that shown in FIG. This configuration includes two mirrors 134, 136 for bending the optical path. The positioning mount forms an axis of rotation P and is positioned equidistant from each of the mirror and lens assemblies 124, 128, 126, 130 if the lenses 128, 130 have equal focal lengths.
[0062]
Thus, the use of symmetric optical elements provides a correction for incorrect movement systems. With this arrangement of the optical elements, even if a low-precision positioning mount is used, the position of the retreat arm is corrected even if the position of the retreat arm is somewhat inaccurate, so that it is possible to position the retreat arm with stability and repeatability. Become.
[0063]
If the optics comprises a pair of parabolic mirrors, the degree of correction is a function of the image quality over the image field, as described with reference to FIG. It is necessary to be. The use of a parabolic mirror has the advantage over a plane mirror and lens assembly that it provides better light collection and therefore also faster optics. In addition, the parabolic mirror occupies a small space in the retreat arm and has a large depth of field, so that a large in-Z displacement of the retreat arm can be tolerated.
[Brief description of the drawings]
[0064]
FIG. 1 is a schematic diagram of a scanning electron microscope combined with a spectroscopic system.
FIG. 2 is a schematic view of the retraction mechanism of FIG.
FIG. 3 is an end view of a mechanism flange of the retraction mechanism.
FIG. 4 shows an adjustable kinematic mount of the retraction mechanism.
FIG. 5 is an exploded view of a portion of the adjustable kinematic mount.
FIG. 6 is another kinematic mount.
FIG. 7 is an end view of a retraction arm of a retraction mechanism.
FIG. 8 is a schematic diagram of an optical arrangement between a scanning electron microscope and an optical system.
FIG. 9 shows a conventional connection of a parabolic mirror.
FIG. 10 shows the connection of a parabolic mirror used in the present invention.
FIG. 11 is a diagram of two lenses in an infinite conjugate ratio mode.
FIGS. 12A and 12B show simplified optical elements in the retraction arm.
FIG. 13 shows the optical element in the retraction arm.

Claims (19)

An adapter for performing an optical analysis of a sample mounted in a sample chamber of another analyzer having an analysis axis and irradiating the sample with an analysis beam substantially along the analysis axis,
A first optical element having a first focal plane, arranged to collect scattered or generated light received from the specimen, and directing the light generally along an optical axis that intersects the analysis axis;
The first optical element is adjustable between an operating position on the analysis axis and a non-analysis position off the analysis axis;
A second optical element having a second focal plane is provided in fixed relation to the first optical element, wherein the second optical element is directed by the first optical element along the optical axis. To an optical analyzer.
The first and second optical elements include:
When the first optical elements are in the operating position, their focal planes are arranged to be parallel to the direction of movement of the first optical elements;
An adapter arranged to at least partially correct an error in positioning the first optical element at its operating position. A positioning mount is provided to determine the position of the first optical element at its operating position,
When the first optical element is in the operative position, the ratio of the focal length of the first optical element to the focal length of the second optical element is such that the ratio between the focal point of the first optical element and the positioning mount is different. Inverted relative to the ratio of the distance along the optical path to the distance between the focal point of the second optical element and the positioning mount along the optical path;
The adapter according to claim 1. When the focal lengths of the first and second optical elements are equal and the first optical element is in the operative position, the distance along the optical path between the focal point of the first optical element and the positioning mount is the second 3. The adapter according to claim 2, wherein the adapter is equal to the distance along the optical path between the focus of the two optical elements and the positioning mount. 4. The adapter according to claim 1, wherein said first and second optical elements comprise parabolic mirrors. 5. The adapter according to claim 2, wherein the positioning mount includes an adjustable mount for suppressing displacement of the optical element in six degrees of freedom. 6. The adapter according to claim 5, wherein said positioning mount is a kinematic mount. An adapter for performing an optical analysis of a sample mounted in a sample chamber of another analyzer having an analysis axis and irradiating the sample with an analysis beam substantially along the analysis axis,
An optical element arranged to collect scattered or generated light received from the specimen, and directing the light generally along an optical axis that intersects the analysis axis;
An adapter wherein the optical element is adjustable between an active position on the analysis axis and a non-analysis position off the analysis axis;
An adapter in which the working position is defined by an adjustable mount that limits the displacement of the optical element in six degrees of freedom. 8. The adapter according to claim 7, wherein said adjustable mount is kinematic. 9. The adapter according to claim 7, wherein the optical element is biased toward the operating position. 10. The adapter according to claim 9, wherein the specimen chamber is under reduced pressure, and the reduced pressure is used to bias the optical element toward the operating position. The adapter according to any of claims 7 to 10, wherein said optical element also receives an input light beam along said optical axis, said input light beam being directed to said specimen. The adapter according to any one of claims 7 to 11, wherein the optical element is a mirror. The adapter according to claim 7, wherein the optical element is an optical fiber condenser element. 14. The adapter according to claim 7, wherein the optical axis is in a direction substantially transverse to the analysis axis. 15. The adapter according to claim 7, wherein the inoperative position is determined by a second mount that suppresses the displacement of the optical element to six degrees of freedom. The adapter according to claim 15, wherein the second mount is adjustable. An adapter for performing optical analysis of a sample mounted in a sample chamber of another analyzer that irradiates an analysis beam toward the sample,
An optical element positioned to collect scattered or generated light received from the specimen and directing the light to an optical analyzer generally along an optical axis that intersects the analysis axis;
An adapter in which the optical element is a parabolic mirror,
At least one mirror is provided for coupling light reflected by the parabolic mirror to an optical analysis means, the at least one mirror being adjustable;
An adapter in which distortion in the optical analysis means is corrected by image processing software. The adapter according to claim 17, wherein a second parabolic mirror is disposed between the parabolic mirror and the optical analysis means, and the two parabolic mirrors are arranged in a direction to cancel aberration. . 19. The device according to claim 18, further comprising two parabolic mirrors disposed between the parabolic mirror and the optical analysis means, wherein the four parabolic mirrors are arranged in a direction to cancel aberration. adapter.

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