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The present invention relates to a mounting device for a mirror configured to be connected to an optical resonator.

The present invention also relates to an optical resonator comprising at least one such mounting device.

It is known the use in an optical resonator or optical enhancement cavity of supports to which to connect the mirrors to be used to perform high-sensitivity spectroscopy experiments, such as optical filters or for the frequency stabilization of laser sources.

In general, an optical resonator comprises a hollow body containing inside it two highly reflective mirrors, positioned facing each other and arranged parallel to each other. The mirrors are mechanically connected to the opposite ends of a tubular element of rigid material, also referred to as the optical resonator spacer. The high degree of parallelism between the two mirrors determines the so-called alignment condition of the resonance cavity and is a necessary condition so that, starting from the incident electromagnetic wave (laser beam), constructive interference is established between the multiple reflections perfectly superimposed inside the optical resonator. This causes the energy of the electric field inside the cavity to be concentrated around specific frequency values, with peaks that correspond to the resonance modes of the cavity itself, whose FWHM ("Full Width at Half Maximum" half height) is the lower the higher the reflectivity of the mirrors. Reducing the FWHM of the peaks allows to define a high sensitivity of the optical resonator relative to the frequency of the laser radiation.

Putting into service an optical resonator inside which the vacuum is generated generally includes a first phase, during which the resonator is aligned by acting on the mirrors to modify their orientation, so as to be able to arrange them parallel to each other. Then follows a second phase in which the resonator cavity is closed in order to create the vacuum through a pumping apparatus.

Document DE102007027680 discloses an embodiment of an optical resonator.

A problem that afflicts a traditional optical resonator concerns the misalignment between the two mirrors caused by the intake of air from the resonance chamber to obtain a high vacuum. In particular, the pressure gradient that is generated inside the cavity as a result of the suction action tends to modify or even cancel the alignment of the mirrors previously obtained. A further difficulty that afflicts a traditional optical resonator concerns the inability to maintain the predetermined orientation between the mirrors as a result of the thermal gradients to which the cavity is subject.

In addition, the loss of alignment between the two mirrors present inside the resonance cavity may occur due to the presence of mechanical vibrations acting on the cavity itself, for example during the operation of the pumping system to obtain the vacuum.

The loss of parallelism between the two mirrors affects the quality of the resonance modes of the optical resonator, as the signal-to-noise ratio of the peaks in the signal reflected/transmitted by the optical resonator itself is reduced.

The object of the present invention is to allow in a simple, efficient and economical way to produce a mounting device for a mirror configured to be connected to an optical cavity and to allow an easy and stable adjustment of the alignment of the mirror supported therein.

A further object of the present invention is to allow a precise adjustment of the orientation of the mirror supported in the mounting device, as well as a high reproducibility in the alignment of the mirror itself.

Another object of the present invention is to provide a mounting device for a mirror capable of ensuring the achievement of high vacuum values inside it.

Another purpose of the present invention is to provide a mounting device that is easy to install and use as well as easy to transport, usable in precision spectroscopy applications even outside a laboratory environment.

Specific form of the present invention, a mounting device comprising a hollow body and a cover configured to be mutually connected, in a removable way, in a sealed manner, delimiting an internal cavity between them, the hollow body having a bottom from which a lateral portion rises, the cover delimiting a through opening for the entry of electromagnetic radiation into the internal cavity, an optical window for sealing occlusion of said through opening, the bottom delimiting a hole in at least partial facing position on said opening through, in which the through opening and the hole define an optical path through the mounting device, a support for supporting and housing a mirror in the internal cavity so as to face along the optical path, in which the support comprises a plate that delimits a housing in which the mirror is positioned and retained, a retaining element connectable to the plate and configured to hold the mirror in position along the plate, connecting screws to connect the support to the bottom and adjustment members configured to adjust the position and inclination of the support relative to the hollow body, in which the adjustment members comprise a plurality of micrometer screws rigidly connectable to the plate and configured to be placed in abutment with the bottom, when the plate is connected to the bottom, in which each of the micrometric screws comprises a connection portion, configured to rigidly engage a respective threaded opening made passing through the plate, and a movable portion, movable with respect to the connection portion, configured to abut, at one of its ends, against the bottom, elastic elements acting on the plate to keep the support pressed against the bottom, in which the mounting device comprises magnetic rotators connected externally to the cover, by means of a sealed connection, and configured to be operatively connected to the adjustment members.

According to another aspect of the present invention, the plate can have a first surface and a second surface, opposite each other, the housing being configured as a hollow sleeve for housing the mirror and protruding from the second surface, in which the housing has a first end at the first surface which is partially occluded by a shoulder and a second end, opposite to the first, which is open to allow the mirror to be inserted inside it and is configured to be engaged by the retaining element.

According to a further aspect of the present invention, the support can comprise a piezoelectric transducer along the housing, in an interposed position between the shoulder and the mirror.

According to an additional aspect of the present invention, the support can comprise a spacer element along the housing, in an interposed position between the holding element and the mirror.

According to another aspect of the present invention, the holding element can have a stop portion to hold the mirror inside the housing, when the holding element is arranged in an assembly configuration with the housing.

According to a further aspect of the present invention, the movable portion can be shaped like a pin and can have a first end which extends outside the connection portion and defines a slot configured to be engaged by a tool of one of the magnetic rotators to rotate the movable portion around a respective axis of rotation and a second end which extends outside the connection portion, on the opposite side with respect to the first end and is shaped rounded to be arranged against the bottom.

According to an additional aspect of the present invention, each of the elastic elements can be interposed between a head portion of a respective of the connecting screws and an internal shoulder of a respective one among through holes delimited along the plate, in which the internal shoulder is configured to define an abutment for a correspondent among the elastic elements.

According to another aspect of the present invention, the hollow body can delimit a through hole for the passage of conductors to power the piezoelectric transducer and sealing elements for hermetic closure of the through hole.

According to a further aspect of the present invention, the support can have at least one delimited opening at the shoulder, for the passage of power supply conductors of the piezoelectric transducer.

According to an additional aspect of the present invention, the bottom can delimit a recess to house at least partially the housing of the support and limit the axial bulk of the mounting device along the optical path.

According to another aspect of the present invention, the optical resonator can comprise a hollow body and at least one mounting device of the type indicated above, in which a hollow body extends along the optical path and comprises at least at one end of it a flange for the sealing connection of the hollow body with the at least one mounting device, the resonator comprising at least one conduit configured to be connected to a vacuum source.

The present invention also relates to an optical resonator comprising at least one similar mounting device for a mirror.

The advantages offered by the mounting device according to the invention are evident.

The mounting device according to the invention, in fact, is configured to guarantee and maintain a predetermined alignment of the mirror supported inside it also following variations in the pressure or temperature value to which the mounting device is subject in use and, in particular, during the phase of creating the vacuum inside an optical cavity to which the mounting device is operably connectable.

The mounting device according to the invention allows to ensure a high seal in order to be able to reach high vacuum values while ensuring the predetermined alignment of the mirror supported inside it.

Furthermore, the mounting device according to the invention allows to obtain a precise adjustment in the positioning of the mirror that can be positioned inside it, adjustment that can be easily carried out from the outside of the mounting device, to the advantage of a high ease of use.

Furthermore, the mounting device according to the invention has reduced dimensions, to facilitate its use and portability.

The present invention will now be described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the Figures of the attached drawings, in which:

Figure 1 shows an exploded perspective view of a mounting device according to the invention;

Figure 2 shows an exploded perspective view, according to another angle, of the mounting device of Figure 1;

Figures 3 and 4 show detailed perspective views of some components of the mounting device according to the invention in some operating positions;

Figure 5 shows a detailed perspective view of some components of the mounting device according to the invention;

Figure 6 shows a partial section schematic view of some components of the mounting device according to the invention;

Figure 7 shows a side sectional view of some components of the mounting device according to the invention;

Figure 8 shows a detailed exploded view of some components of the mounting device according to the invention;

Figure 9 shows a perspective view of the optical mounting device according to the invention;

Figure 10 shows a partial side sectional view of a component of the mounting device according to the invention;

Figure 11 shows a schematic sectional view of an optical resonator comprising two mounting devices according to the invention.

With reference to the attached Figures it can be observed that a preferred embodiment of a mounting device according to the invention, configured for mounting a mirror to an optical cavity, is indicated as a whole with 1.

The mounting device 1 comprises a hollow body 2 and a cover 3 which can be removably connected to the hollow body 2, to delimit an internal cavity between them.

In particular, the hollow body 2 has a bottom 4 from which a lateral portion 5 rises, configured to laterally delimit the internal cavity.

A head gasket 6 is provided in an interposed position between the cover 3 and the hollow body 2, to define a seal in the connection between the cover 3 and the hollow body 2 themselves.

In the attached Figures, the mounting device 1 is shown cylindrical although it is intended that further conformations are possible, for example parallelepiped, cube or any other conformation without any limitation.

The cover 3 is connected to the hollow body 2 by means of a plurality of screws 7 (see Figure 9) configured to be retained inside through seats 8 made along the cover 3 itself and engageable inside respective threaded seats 9 made along the lateral portion 5 of the hollow body 2, in correspondence with one of its ends opposite to the bottom 4.

The screws 7 allow the cover 3 to be tightened against the hollow body 2, so as to determine the hermetic seal by means of the head gasket 6.

The cover 3 delimits a through opening 10 for the entry of electromagnetic radiation (light radiation) into the internal cavity.

Preferably, the through opening 10 is positioned centrally along the cover 3 (see Figures 1, 7 and 9).

The cover 3 has an optical window 11 occluding the through opening 10.

The optical window 11 is transparent to electromagnetic radiation, so as to allow its passage and, therefore, through the internal cavity of the mounting device 1. Furthermore, as better described below, the optical window 11 is sealed connected to the through opening 10.

The mounting device 1 comprises a connecting element 12, to connect the optical window 11 to the cover 3 at the through opening 10.

The connecting element 12 is configured as a frame element, which delimits inside a seat 13 for housing and retaining the optical window 11 in position (see Figure 1).

The connecting element 12, due to its configuration, delimits an opening to allow the passage of electromagnetic radiation along the mounting device 1.

In the attached Figures, the connecting element 12 is shown annular while meaning that further conformations are possible, for example, square, rectangular, elliptical or, in general, depending on the conformation of the optical window 11.

The connecting element 12 is configured to be connected in a removable way to the internal surface of the cover 3 by means of connecting members. According to a preferred embodiment, the connecting element 12 has a connecting portion provided with a plurality of holes 14 which can be engaged by respective screws, not shown in the attached Figures, which in turn can be engaged in respective blind threaded seats 15 made along the cover 3 through its internal surface (the blind threaded seats 15 are shown in Figures 2 and 7).

The term blind threaded seats 15 means that they do not extend through the entire thickness of the cover 3.

However, alternative embodiments of the connecting members, not shown in the attached Figures, for the removable connection between the connecting element 12 and the cover 3 are possible. By way of example but not limiting, alternative connecting members can comprise a connection to rotation comprising a union that protrudes from one of the internal surface of the cover 3 and the connection element 12 engageable by coupling through sliding contacts to a corresponding flange made in correspondence with the other between the connection element 12 and the internal surface of the cover 3. An alternative embodiment of the connecting members, also not shown in the attached Figures, comprises a threaded connection between the cover 3 and the connecting element 12 in a manner available to the person skilled in the art, which therefore will not be described in detail.

The connecting element 12 rigidly connects the optical window 11 to the cover 3. The seal between the optical window 11 and the cover 3 is determined by means of a first gasket 16, interposed between the internal surface of the cover 3 and the optical window 11, and a second gasket 17, interposed between the optical window 11 and the connecting element 12 (in the attached Figures 1 and 2 the first gasket 16 and the second gasket 17 are illustrated by way of example as annular, although it is understood that further conformations are possible, such as flat, square frame, without any limitation).

The cover 3, along the internal surface has a housing seat 18 (see Figure 2) to at least partially house the first gasket 16, facilitating its correct positioning and simplifying the subsequent connection of the optical window 11 to the cover 3.

The first gasket 16 and the second gasket 17, in addition to determining a hermetic seal in the connection of the optical window 11 to the cover 3, act as a protection for the optical window 11 itself, detecting it and avoiding its damage following direct contact with the internal surface cover 3 or with connecting element 12.

The bottom 4 delimits a hole 19 through which the internal cavity can be placed in fluid communication with a source for the vacuum not shown in the attached Figures, for example a suction pump.

Preferably, the hole 19 is made centrally along the bottom 4.

More generally, the hole 19 is made along the bottom 4 in a position at least partially aligned with the through opening 10. In practice, the hole 19 faces, at least partially, the through opening 10.

The through opening 10 and the hole 19 thus define an optical path 20 which can be travelled by electromagnetic radiation. The optical path 20 develops passing through the entire mounting device 1 (see for example Figures 7 and 11).

The hollow body 2 externally has, at the bottom 4, a connection flange 21 configured for the sealing connection of the mounting device 1 to an optical cavity or resonator (see for example Figures 7 and 11).

The connecting flange 21 is of the ISO-FK, CF type or, more generally, of any other type capable of providing a hermetically sealed connection.

The mounting device 1 comprises a support 22 for supporting and housing a mirror 23 in the internal cavity so as to face the mirror 23 itself along the optical path 20.

The support 22 can be removably connected to the bottom 4 of the hollow body 2, and is configured to support the mirror 23 and to adjust its position relative to the bottom 4 itself.

More in detail, the support 22 comprises a plate 24 which defines a housing in which to position and hold the mirror 23, a retaining element 25, which can be connected to the plate 24 and configured to hold the mirror 23 in position along the plate 24 itself, connecting screws 26 (shown in Figures 3, 4 and 6) to connect the support 22 to the bottom 4 of the hollow body 2 and adjustment members configured to adjust the position and inclination of the support 22 relative to the hollow body 2.

The plate 24 has a first surface 27 and a second surface 28 (see for example Figure 6), opposite each other.

The plate 24, in an assembly configuration, in which it is connected to the bottom 4, has the first surface 27 facing the cover 3 while the second surface 28 faces the bottom 4.

The plate 24 has a housing 29 configured as a hollow sleeve, or in general as a hollow tubular element, which extends from the plate 24 itself, from the second surface 28.

The housing 29 has a first end which is partially occluded by a shoulder 30, at the first surface 27, and a second end, opposite the first, which is open to allow the insertion of the mirror 23 in the support 22.

The housing 29 is configured to facilitate the positioning of the mirror 23 along the support 22, guiding it during assembly.

According to a preferred embodiment, in fact, the housing 29 has a plan development similar to that of the mirror 23. In this way it is possible to slide the mirror 23 inside it, the simple housing 23 or abutment in position.

The housing 29 has a thread 31, which extends externally to the housing 29 at the second end of the same (see, forexample, Figures 5 and 7), configured to be engaged by a corresponding thread present along the retaining element 25.

In general, the second end of the housing 29 is configured to be engaged by the retaining element 25 and connected to it.

The retaining element 25 is configured as a ring nut and has a stop portion to hold the mirror 23 inside the housing 29, when it is placed in an assembly configuration with the housing 29 itself.

In other words, the retaining element 25 acts as a cover for the housing 29.

The retaining element 25, like that described in relation to the connecting element 12, has a through opening to allow the passage of electromagnetic radiation along the optical path 20.

According to an alternative embodiment, the connection between the retaining element 25 and the housing 29 of the support 22 takes place by means of an interlocking or snap-on rotating connection, not illustrated in detail in the attached Figures, according to methods like those described in relation to connecting element 12, to which reference should be made.

The support 22 includes a spacer element 32, configured as a gasket, which can be housed inside the housing 29 in an interposed position between the retaining element 25 and the mirror 23 (see, for example, Figure 1).

The spacer element 32 prevents direct contact between the retaining element 25 and the mirror 23, thus preserving the integrity of the latter.

As mentioned, the support 22 is removably connected to the hollow body 2 by means of connecting screws 26.

The bottom 4 of the hollow body 2 has, along the internal surface, blind bottom seats 33 each engageable by a respective of the connecting screws 26 for connecting the support 22 to the bottom 4 (see Figure 6). The plate 24 has through holes 34 (see Figures 5 and 6), placed externally to the housing 29, so as not to interfere with the mirror 23, each engageable by a respective of the connecting screws 26.

Each of the through holes 34 is configured to be engaged with play by a respective one of the connecting screws 26. The latter, in practice, define connecting and guiding elements for the plate 24 relative to the bottom 4, as better described below.

Each of the through holes 34 is shaped so as to have an internal shoulder 35 (see in particular Figure 6) configured to define a stop for a corresponding elastic element 36 interposed between the head of each connecting screw 26 and a respective one between the through holes 34.

Each elastic element 36 is configured as a spring, provided with one end abutting against the head portion of a respective connecting screw 26 and with an opposite end housed inside a respective between the through holes 34, abutting against the internal shoulder 35 delimited in this hole between the through holes 34.

The purposes of each elastic element 36 will be better understood from the following description.

As mentioned, the support 22 includes adjustment members to adjust the position and inclination of the plate 24 and, consequently, of the mirror 23 housed therein, relative to the bottom 4 of the hollow body 2.

The adjustment members comprise a plurality of micrometric screws 37 (shown in Figures 3-6 and in detail in Figure 10) configured to be rigidly connected to the plate 24 and to be placed against the bottom 4, with the plate 24 itself, in a configuration of connection with the hollow body 2.

The operation of a micrometric screw 37 is considered within the reach of the person skilled in the art and, therefore, the description thereof will be limited to the aspects useful for understanding the operation of the present invention.

Each micrometric screw 37 comprises a connecting portion 38, configured to firmly engage a respective threaded opening 39 made passing through the plate 24, and a movable portion 40, movable with respect to the connecting portion 38, and therefore with respect to the plate 24. The movable portion 40 is configured to abut against the bottom 4 at one of its ends.

More in detail, with reference to the embodiment of the micrometric screw 37 illustrated in the attached Figure 10, the connecting portion 38 is configured as a cylindrical element provided with an external thread 41 (in Figure 10 the external thread 41 has been purposely omitted), configured to engage a respective threaded opening 39 of the plate 24 and an internal thread configured to be engaged by a corresponding thread 42 with micrometric pitch made along at least a portion of the mobile portion 40.

The movable portion 40 of each micrometric screw 37 is shaped as a pin that can be operated in rotation within the connecting portion 38 around a respective axis of rotation 43.

The connecting portion 38 has a gripping portion 44 which has a larger cross section than the plan section of a corresponding threaded opening 39.

In the attached Figures, the gripping portion 44 is illustrated by way of example, hexagonal (see Figures 3-5).

The gripping portion 44 projects at one end of the connecting portion 38 and defines a stop for connecting a micrometric screw 37 to the plate 24.

The movable portion 40 has a first end 45 which extends outside the connecting portion 38 and a second end 46 which also extends outside the connecting portion 38, on the opposite side with respect to the first end 45 (see, for example, Figure 10).

The first end 45 has a recess 47 (dashed in Figure 10) shaped so as to be engageable by a tool in order to be able to rotate the movable portion 40 around the respective rotation axis 43.

The second end 46 is rounded, in particular spherical, and is configured to be placed against the bottom 4, more precisely against the internal surface of the bottom 4, with the support 22 in the configuration of connection to the hollow body 2.

The micrometric screws 37 act as an adjustment element to adjust the separation distance and the relative inclination of the plate 24 with respect to the bottom 4.

In particular, the number and positioning of the micrometric screws 37 along the plate 24 affect the freedom of movement of the plate 24 relative to the bottom 4.

Each micrometric screw 37, in fact, defines a support along which it is possible to approach or move away, and consequently tilt, the plate 24 relative to the bottom 4.

By varying the positioning of the plate 24, the positioning of the mirror 23 relative to the hollow body 2 is varied.

With reference to the preferred embodiment illustrated in the attached Figures, the plate 24 has three threaded openings 39.

Alternative embodiments are possible comprising a greater number of micrometric screws 37 than those described, for example four or five, depending on specific use requirements.

Each micrometric screw 37 is kept with the respective second end 46 in firm abutment against the internal surface of the bottom 4 by the thrust action exerted by the elastic elements 36 against the plate 24.

Each of the elastic elements 36 in fact acts in thrust against the plate 24, defining an element similar to a suspension to ensure the correct maintenance in position of the plate 24 itself.

Preferably, each of the elastic elements 36 is held compressed between the head portion of a respective connecting screw 26 and a respective hole between the through holes 34 of the plate 24, with a degree of compression equal to approximately half of the maximum achievable compression, thus allowing to constrain the plate 24 firmly against the bottom 4 of the hollow body 2. The constraint reactions on the resting points of the individual micrometric screws 37, that is, between the second ends 46 of each micrometric screw 37 and the bottom 4, and the compression reactions of the elastic elements 36 are balanced with the opposing forces generated in tightening the individual screws 26.

Each elastic element 36 thus arranged can stretch or compress further to allow the adjustment of the relative position of the plate 24 along the individual connecting screws 26, to obtain the desired orientation of the plate 24 itself.

The mounting device 1 comprises a piezoelectric transducer 48 housed in the support 22, inside the housing 29, in an interposed position between the shoulder 30 and the mirror 23 (it should be noted that in the sectional view of Figure 7 the piezoelectric transducer 48 has been purposely omitted. In this view, also the head gasket 6 has been purposely omitted).

Preferably, the piezoelectric transducer 48 is hollow cylindrical, although it is understood that alternative embodiments, for example annular, are possible.

The piezoelectric transducer 48 is configured to allow a precision adjustment or fine adjustment of the position of the mirror 23 along the housing 29. The term precision or fine adjustment is intended to indicate an order of magnitude of a few pm. By way of non-limiting example, a corresponding longitudinal expansion of the piezoelectric transducer 48 of approximately 15 pm can be obtained with a power supply interval of about -30÷150V. In particular, the piezoelectric transducer 48 is configured to determine a translation of the mirror 23 along the housing 29 as a function of the electrical voltage applied. In this regard, the hollow body 2 as well as the support 22 are both configured to define a path for the passage of supply conductors for connecting the piezoelectric transducer 48 to an external power source to the mounting device 1.

The hollow body 2 delimits a through hole 49 for the passage of conductors to power the piezoelectric transducer 48 (see Figures 1, 2 and 9). Sealing elements, not shown in the attached figures, are provided to ensure the hermetic closure of the through hole 49.

Preferably, the through hole 49 is made along the lateral portion 5 of the hollow body 2.

The support 22 has at least one opening 50 delimited in correspondence with the shoulder 30, for the passage of supply conductors of the piezoelectric transducer 48 (see Figures 1, 3-5).

In this way it is possible to power the piezoelectric transducer 48 without interfering with the propagation of the electromagnetic radiation along the optical path 20.

The operation of a piezoelectric transducer 48 is within the reach of the person skilled in the art and, therefore, will not be further described hereinafter.

It should be noted that the spacer element 32 in addition to acting as a protection for the mirror 23 inside the housing 29, acts as a resilient element capable of providing an elastic reaction to the axial expansion of the piezoelectric transducer 48 inside the housing 29 and the consequent thrust exerted by the mirror 23 against the retaining element 25.

The mounting device 1 comprises magnetic rotators 51, which can be connected externally to the cover 3 and configured to be operatively connected to the adjustment members so as to allow the actuation of the individual micrometric screws 37 from the outside of the mounting device 1 itself.

Each magnetic rotator 51 comprises an internal shaft 52 on the end of which a tool 53 is constrained (see Figure 8) shaped to engage, by means of a shape coupling, the recess 47 present at the first end 45 of each micrometric screw 37.

In the preferred embodiment of the invention, the tool 53 has the end configured as an Allen wrench.

Magnetic elements are positioned along the internal shaft 52, not illustrated in the attached Figures. The internal shaft 52 and the magnetic elements are inserted inside a cylindrical capsule 54 equipped with a connecting flange 55 for connecting the magnetic rotator 51 to the cover 3 as better described below.

In particular, the internal shaft 52 and the related magnetic elements are coupled to the cylindrical capsule 54 in a rotatable manner thereto, along an axis around which they can be operated in rotation. By way of example, the connection flange 55 is of the CF type, although it is understood that further types of flange configured to ensure a sealed connection are possible.

Each of the magnetic rotators 51 comprises a hollow cylinder 56 inside which the cylindrical capsule 54 is positioned together with the internal shaft 52. The hollow cylinder 56 is rotatably fitted on the cylindrical capsule 54.

The hollow cylinder 56 contains inside a magnet, not shown in the Figures. The rotation of the hollow cylinder 56 causes the internal shaft 52 to rotate by magnetic attraction, thus causing the rotation of the internal shaft 52 relative to the connecting flange 55. During the assembly of each magnetic rotator 51 to the cover 3, the end Allen wrench of the tool 53 of each magnetic rotator 51 is inserted into engagement in a corresponding recess 47 of a respective one of the micrometric screws 37. In this way, by rotating the outer hollow cylinder 56 of each magnetic rotator 51, the actuation is determined in rotation of the movable portion 40 of a corresponding micrometric screw 37.

Each magnetic rotator 51 is configured to be connected in a removable and sealed manner to the cover 3, in correspondence with a respective further through opening 57.

In this regard, the cover 3 comprises along an external surface further blind threaded seats 58 (see Figure 1) in correspondence with each further through opening 57, for the connection with a respective magnetic rotator 51.

It is noted that each further through opening 57 is delimited along the cover 3 so as to face concentric on a respective threaded opening 39 delimited along the plate 24. In other words, each further through opening 57 is delimited along the cover 3 so as to face on a corresponding micrometric screw 37 to allow mutual engagement between the tool 53 of a magnetic rotator 51 and the recess 47 at the first end 45 of a respective micrometric screw 37.

With reference to the embodiment illustrated in the attached Figures, the mounting device 1 comprises three micrometric screws 37 distributed along the plate 24 with a circular symmetry around a central axis which coincides with the optical path 20. In other words, the three screws micrometric 37 are mutually spaced along the same circumference, with an angle of 120 °.

Consequently, the further through openings 57 delimited along the cover 3 are arranged equidistant from each other with a circular symmetry around the central axis and, therefore, are arranged along the same circumference to that indicated in relation to the micrometric screws 37, with a distance reciprocal angle of 120 °.

It is understood that further embodiments are possible, not illustrated in the attached Figures comprising a greater number of micrometric screws 37, and respective further through openings 57, for example four, although falling within the concept of the present invention.

The through hole 49 along the side portion 5 of the hollow body 2 provides a reference for the mutual angular alignment of the further through openings 57 with the threaded openings 39, allowing simple assembly.

The mounting device 1 comprises further gaskets 59, each interposed between the cover 3 and the connecting flange 55 of a respective magnetic rotator 51, to determine a hermetic seal in the connection between each magnetic rotator 51 and the cover 3 itself (see the exploded diagram of Figure 1).

By way of example, the further gaskets 59 are made of synthetic elastomer, for example Viton, or of metallic material, such as copper.

The cover 3 has housing seats 60 for each further gasket 59 in correspondence with each further through opening 57, to facilitate the positioning of each further gasket 59 along the cover 3.

The mounting device 1 according to the present invention has overall a compact size, with particular reference to its development along the optical path 20.

In this regard, it should be noted that at the bottom 4 of the hollow body 2 there is a recess 61 to at least partially house the support 22 (see the exploded diagram of Figure 1 and the sectional view of Figure 7).

In particular, the recess 61 defines a circular seat at the hole 19 delimited along the bottom 4 and allows to house at least partially the housing 29 that protrudes from the plate 24 (see Figure 7). The width of the recess 61 is such as to allow an efficient suction of the air from the internal cavity by the source for the vacuum and the mobility of the housing 29 (inclination) with respect to the central axis of the mounting device 1, without therefore any interference between the bottom 4 and the support 22.

Below we will briefly describe the adjustment of the alignment of the mirror 23 inside the mounting device 1.

A mounting device 1 according to the invention is provided with the mirror 23 housed in the support 22 which, in turn, is connected to the bottom 4 of the hollow body 2.

The cover 3 bears the magnetic rotators 51 sealed connected, in correspondence with its external surface. Each magnetic rotator 51 is operatively connected to a respective micrometric screw 37. In particular, each tool 53 of a magnetic rotator 51 is engaged in a respective recess 47 provided in the micrometric screw 37.

The orientation of the support 22 is adjusted by acting on the individual micrometric screws 37 through the respective magnetic rotators 51 until the mirror 23 is placed in the desired alignment. Then, through a vacuum source operatively connected to the hollow body 2, a vacuum is generated in the internal cavity. Any possible misalignment of the mirror 23, due to pressure or thermal gradients or mechanical vibrations acting on the internal cavity, can be compensated by acting on the individual micrometric screws 37 through the respective magnetic rotators 51.

It must be borne in mind that, since it occurs before the generation of the vacuum, the first adjustment of the orientation of the support 22 can also be carried out before hermetically connecting the cover 3 to the hollow body 2.

The positioning of the support 22, previously adjusted, is guaranteed by the presence of the elastic elements 36 which keep the plate 24 firmly in position.

The thrust action determined by the elastic elements 36 against the plate 24, in fact, keeps the threads of the mobile portion 40 of each of the micrometric screws 37 in constant grip with the threads of a respective connecting portion 38, thus avoiding that backlash or movements occur such as to cancel the alignment of the mirror 23. The person skilled in the art will easily understand how a mounting device 1 according to the invention is able to achieve the intended purposes, allowing an easy and practical adjustment of the alignment of the mirror 23 supported therein as well as to maintain such alignment in the presence of pressure or thermal gradients or mechanical vibrations.

The magnetic rotators 51 described are manually operated, although it is understood that it is possible to provide for the use of motorized and remotely controllable magnetic rotators 51, promoting the use of the mounting device 1 even in environments that are difficult to access and ensuring the correct alignment of the mirror 23 in a continuous way.

An optical resonator comprising at least one mounting device 1 also forms the subject of the present invention.

The attached Figure 11 illustrates an optical resonator 62 which comprises a spacer 63 configured as a hollow body, bearing at each opposite end a mounting device 1 according to the present invention. It is understood that the optical resonator 62 can comprise a single mounting device 1 at one end and a traditional mounting device at the opposite end.

The optical resonator 62 develops along a direction which corresponds to the optical path

20. The optical resonator 62 comprises at least one duct 64 in fluid communication with the interior of the cavity delimited by the spacer 63, configured to be operably connected in a sealed manner with a vacuum source, not shown in the attached Figures.

According to a preferred embodiment, the spacer 63 has at each of its opposite ends a flange 65 configured for sealing connection with at least one mounting device 1. It is evident that an optical resonator 62 according to the invention is easy to use and able to ensure the alignment between two mirrors connected to it. The optical resonator 62, in fact, comprises at least one mounting device 1 configured to adjust the position of at least one mirror, and in particular of the mirror 23 contained therein.

If both mirrors comprised in the optical resonator 62 are supported by a respective mounting device 1 according to the present invention, the possibility of adjusting their relative position, if desired in an extremely precise way, is even more evident in order to obtain the desired alignment.

In the foregoing, the preferred embodiments have been described and variants of the present invention have been suggested, but it is to be understood that those skilled in the art will be able to make modifications and changes without thereby departing from the relative scope of protection, as defined by the claims attached.