DE19601032C1 - Laser working device for brittle material - Google Patents

Abstract

The device has a Fabry-Perot interferometer (3) for dividing a laser beam from a carbon dioxide laser (1) with a rapidly varying division ratio. Both beams are superimposed at the material working point on the workpiece (15). A telescope (9) alters the divergence of the reflected beam (5). The resulting beam (10) is supplied to a second Fabry-Perot interferometer (11), which receives the doubly-transmitted beam (8) from the opposite side via a deflection mirror 21. A focussing element (14) directs the colinear beams from the second Fabry-Perot interferometer on to the workpiece (15).

Description

The invention relates to a device for processing materials Laser radiation, especially for processing brittle materials.

With the help of a known Fabry-Perot interferometer (FPI modulator) becomes a beam splitting with a divider ratio that can be varied quickly between a reflected and a double-transmitted radiation component causes so that the radiation from a single laser, preferably one continuously working CO₂ material processing laser, at the processing location in two parts strikes the parameters, especially the temporal Intensity course and the irradiated areas, flexibly the respective Interaction process can be adapted.

This can result in the machining of materials that are considered "difficult" are classified, e.g. B. brittle materials such as glass, ceramics and porcelain, largely designed optimally, or certain processing forms are made possible in the first place.

There are numerous test results and suggestions for orders with the goal of processing brittle materials using laser radiation, for For example, drilling, cutting, scoring or defined removal are optimal shape. In general, an attempt is made to use targeted methods Build up harmful tensions in the material by machining minimize. The necessary preheating of the processing zone can be done by an additional laser beam, part of the processing beam itself or by heating the workpiece to be machined using classic Heat sources (flames, radiant heaters) take place.

The preheating of the environment of the processing location is, for example, in the DE 43 20 895 C1 described. Here is simply before the material removal by means of a laser beam the glass body to be processed by a gas flame or a radiant heater is heated to just below the softening temperature.

Similarly, in DE 35 46 001 C1 is to be cut Glass part at a high temperature below the softening point of the Glases kept during processing.  

Such methods are relatively inflexible, especially with a view to rapid Dynamics of thermal processes.

There are numerous known arrangements for splitting laser radiation on the one hand and for irradiating the workpiece to be machined with several Partial beams on the other hand. The laser beams are divided by Different arrangements of passive optical elements, in particular Mirror arrangements, the main disadvantage of which is the fixed or is very limited variable division ratio. So z. B. in the DD-WP 1 19 915 in a device for dividing the radiation energy of a gas laser a mirror polygon is used as a deflecting mirror.

A specific arrangement for splitting a CO₂ laser beam and Application of partial beams for processing thermoplastic workpieces described in US Pat. No. 3,989,774. Here the laser beam is simply by means of a splitter plate, and then both partial beams directed onto the workpiece separately by a plane mirror.

Since it is cheap for numerous applications, the workpiece with two Apply partial beams that have different properties, in particular have different spatial or temporal intensity behavior, addresses a number of solutions to this problem. In the simplest Variants are the separate partial beams with separate focusing optics in focused on the same processing volume (cf. US-PS 36 04 890 and DD-WP 2 31 522). These arrangements have the serious disadvantage that both Jets inclined towards each other hit the workpiece so that from the start an anisotropy in the processing plane has to be accepted.

Therefore, attempts are made to close the partial beams again with special arrangements unite and send collinear to the workpiece. Generally will pierced optics used for this. DD-WP 2 51 097 Opportunities for the interlacing of laser beams both at Using focusing lenses as well as using concave mirrors described, however, the partial beams strong after the union have different divergence, so that a common leadership over longer distances is impossible.

In the arrangement according to DE 27 08 039 A1, this disadvantage can occur are bypassed, but this is for the mode structure of the partial beams incisive condition to meet that one of the rays a must have annular energy distribution.  

The subject of DD 2 88 934 A5 is the creation of a generic arrangement for the variable Laser beam division and guidance of the partial beams by means of interference modulator, the intense beam of a CO₂ high-power laser with in wide limits of variable division ratio is divided and then the partial beams modified in their properties so the processing location be supplied that there laser radiation with a changed, the respective Application adapted and in particular quickly variable intensity profile or polarization behavior arises. This arrangement does not allow Generation of working and auxiliary beam with simultaneous wide limits variable, largely independent performance curve over time and time-adjustable auxiliary beam diameter at the processing location.

The object of the invention is to provide an arrangement that allows the radiation from a single laser, preferably one continuously working CO₂ material processing laser, two partial beams, the actual one Machining beam and an auxiliary beam for heat treatment of the workpiece, to be shaped so that, firstly, the machining beam is variable within wide limits Secondly, the auxiliary beam possesses impulse regimes in terms of its power and the irradiated area is also very variable for preheating, for Stress relief during processing with the processing beam and for thermal aftertreatment after the actual machining process can be used so that material processing tasks like that Cutting, scoring, drilling and removing brittle materials, e.g. B. glass, ceramics etc., can be carried out with high quality and effectiveness.

The basic idea of the object according to the invention is to

• - firstly "cut out" a pulsed beam from the cw beam, the P (t) curve is optimal for the actual machining task,
• - second, the complementary part of the total available Radiation (the average power of this part is practical in all Applications are large against the average power of the working beam; at very short impulses cut out, it becomes quasi-continuous a power close to the actual laser power) via a separate one Modify the beam path so that it is in terms of its performance and its Divergence ultimately optimal at the processing location to the actual one Machining process supporting heat treatment can be used can and if necessary
• - third, these two beams collinear in front of the processing location unite that the isotropy of machining is guaranteed.

This object is achieved according to the invention with a device according to claim 1, Claim 2 or claim 3 realized.

In the subclaims 4 to 7, advantageous configurations of the devices of the named three secondary main claims specified.

The radiation of the high-power laser is first of all known Sent modulator based on the principle of a Fabry-Perot interferometer (FPI) is based, an arrangement that defines the incident performance in one reflected portion of the performance PR and a transmitted portion of the performance PT divides itself in the modulator itself with small losses. A The essential requirement for the function of the arrangement is the implementation the smallest possible angle of inclination between the optical axis of the Modulator and the axis of the laser beam. The angle of inclination must on the one hand be large enough so that the bundle reflected by the modulator separates well lets, in particular is not fed back into the laser resonator, and on the other hand, be so small that the function of the modulator is not affected poor interference is affected. The last claim can be Laser radiation (λ = 10.6 µm) well fulfilled up to inclination angles of around 5 degrees if the distance d of the interferometer plates is not 0.1 mm exceeds. Since this angle is also sufficient for bundle separation, the arrangement can be easily implemented.

The radiation component passing through this first modulator is sent back through the modulator by means of two deflecting mirrors, in such a way that it fulfills the angular condition just mentioned, but is well separated from the reflected beam. This "double-transmitted" beam is characterized by a significantly increased contrast between its maximum power P _{DT, max} and its minimum power P _{DT, min}

compared to the single-transmitted beam, in which the contrast between the maximum power P _{T, max} and the minimum power P _{T, min} only

is.  

This gives a very effective way out of the laser beam Cut out radiation impulses, characterized by the following features distinguish:

• 1. The peak pulse power is approximately equal to the cw laser power, that is  ≈ P₀ for small modulator losses,
• 2. there is a high contrast / P _{DT, min} = P _{DT, max} / P _{DT, min} ,
• 3. the pulse duration τ _imp is variable within wide limits,
• 4. The pulse duty factor to pulse pause is within wide limits adjustable,
• 5. the pulse parameters are very stable, especially since the stabilized cw Laser power P₀ represents the reference level.

The basis for the wide range of variations of this pulse generation method is free controllability of the interference modulators used, their maximum Modulation frequencies are in the range of 1 kHz to <20 kHz depending on the type. in the In the low frequency range, the modulators can continuously up to f = 0 are driven.

In conjunction with the typical double transmission characteristics, highly stable pulses with a very well-defined P (t) curve can be generated in the time range 1 µs <τ _imp <100 µs, which are of particular interest for the processing of brittle materials, but in this form cannot be realized using conventional methods (e.g. electrical pulsing).

A serious disadvantage of the first stage of the arrangement described so far would be the high proportion of unused radiation, depending on the chosen one Duty cycle could be more than 90% of P₀.

The second stage of the arrangement addresses this problem. Just that Applications for which the generated impulses are particularly interesting (Drilling, cutting and defined material removal for brittle materials), often require heat treatment for optimal processing, which in one defined time regime, which is predetermined by the respective work task, before, during and after the machining process. Aim this Heat treatment is the reduction of tension in the material and therefore one Increased machining precision (no material spalling) or a stabilization of the processing result without elaborate annealing after laser processing. Often it is even the one you want Interaction can only be achieved with defined material preheating.  

For this purpose, the second one (the one reflected by the first modulator) Radiation share used, which in its properties the requirements of one comes very close to such a beam for heat treatment:

• 1. with the usual conditions used
  "Pulse duration at pulse pause"<1:10 this radiation component can be regarded as quasi-continuous,
• 2. its average power is at least 10 times the average power of the pulsed beam, that means even when irradiating relatively large Areas <1 mm in diameter (this is due to effective stress relief Heat treatment required) is enough power for effective Warming available.

The essence of the invention now takes into account the fact that the Design of the process of heat treatment must be as flexible as possible. So can for an optimal voltage reduction, z. B. at various Materials,

• - very different heat-treated surfaces, possibly also variable in of time, and
• - Different radiation powers, possibly also as a function of Time as well
• - Depending on the processing task, the duration of the pre and post can be freely selected Reheating phases with regard to the actual processing may be required.

According to the invention, this problem is solved as follows:
The radiation component reflected by the first modulator, the auxiliary beam, is sent through a telescope arrangement by means of a corresponding beam guide, which enables a variation in the divergence of the beam. The distance between the telescope optics and thus this divergence can also be made variable in time by means of suitable adjusting elements. The modified bundle is then sent to a second interference modulator and fed to the processing location as a reflected beam.

Within the limits already mentioned, this modulator can now be used the power of the auxiliary beam can be varied as required.

In addition to varying the power of the auxiliary beam, there is the second Modulator within the overall arrangement another important function to: It is used for the collinear superposition of the working beam (the pulsed beam)  and auxiliary beam. For this purpose, the working beam is also placed on this modulator, but from the opposite direction, using suitable mirrors directed that after passing through the modulator it is collinear over the reflected auxiliary beam lies.

By controlling the two modulators and the telescope accordingly then there is a sum ray, which is characterized in that both in it contained radiation components

• 1. Within the framework of the boundary conditions shown, largely independently in their performance history and
• 2. Regulated independently in their divergence and thus for the Machining process can be optimized.

Specifically, this means that after focusing this total beam z. B. the pulsed work beam focused while performing its job task Auxiliary jet the process through a controlled heat treatment (according to the The higher divergence is the diameter at the machining location larger) optimally supported.

Is the collinear impact of the machining and heat treatment beams your workpiece is not absolutely necessary or even a different irradiation geometry required, this can also be achieved by appropriate beam guidance be (see Example 3).

The high flexibility of the arrangement is also reflected in the fact that the conventional one without problems by setting both modulators to T = 1 Working regime, that means processing with the pure laser beam, realized can be.

The arrangements according to the invention have made it possible Laser beam, especially the intense beam of a continuously working one CO₂ material processing laser, to shape so that ultimately for processing two collinear partial beams, the actual processing beam and the Auxiliary jet for heat treatment before, during and after the Machining process, whose parameters are extraordinary can be flexibly adapted to the respective work task.

The invention will be described below with reference to the drawing Embodiments are explained in more detail.

Show it:

Fig. 1: Device with two FPI modulators and a telescope

Fig. 2: Device with two FPI modulators and a perforated mirror

Fig. 3: Device with free choice of the relative angles of incidence of processing and heat treatment beam

Fig. 4: Device with free choice of the relative angles of incidence of processing and heat treatment beam and telescope

Fig. 5: T (.DELTA.d) characteristics of the modulators for single transmission (I) and double transmission (II)

Fig. 6: Principle of pulse generation by means of double transmission on an FPI modulator with sine control

Fig. 7: Principle of pulse generation by means of double transmission on an FPI modulator with rectangular control

Fig. 8: Principle of the generation of the working and auxiliary beam by means of two synchronized FPI modulators

Fig. 9: the relative location and size of processing and heat treatment area on the workpiece.

Figs. 1 to 4 show embodiments of the invention. As the respectively desired pulsed radiation processing can be realized Figs. 5, 6 and 7 illustrate by use of the double transmission characteristics and power characteristic which has the complementary sub-beam.

In the exemplary embodiment shown in FIG. 1, the radiation 2 of the high-power laser 1 falls on the interference modulator 3 , the optical axis of which is inclined at an angle in accordance with the boundary conditions set out above in the direction of the laser beam 2 . The modulator 3 splits this beam into the reflected part 5 and the transmitted part 4 , which is sent through the FPI a second time by means of the deflection mirrors 6 , 7 . This double-transmitted portion 8 is used as the actual processing beam, the reflected portion 5 as the auxiliary beam. The power ratio between these two beams can be varied as desired within the parameters specified by the modulator 3 with frequencies f which are within the interval 0 ff _max also specified by the modulator 3 .

In the further beam guidance of the first exemplary embodiment, the auxiliary beam is then varied in its divergence by means of the telescope 9 in such a way that the desired effect of this beam 12 is achieved at the processing location. Of course, the restrictions regarding the beam diameter given by the apertures of the following optics must be observed. If necessary, this divergence variation can be done more or less quickly by changing the distance of the optics of the telescope 9 to the extent necessary, insofar as the mechanical construction permits.

As shown in FIG. 1, both the working beam 8 and the auxiliary beam 10 are now directed onto a second FPI modulator 11 with the aim of superimposing both of them collinearly. Both sides of each other, beam 8 z. B. using a deflecting mirror 21 , sent to the modulator in such a way that the reflected portion 12 of the auxiliary beam and the transmitted portion 13 of the working beam are collinear.

The total beam formed from the machining beam 13 and the heat treatment beam 12 is finally directed onto the workpiece 15 to be machined by a single focusing element 14 . Normally, this is done so that the machining beam 13 is sharply focused on the workpiece 15 , while the heat treatment beam 12 , the focus of which lies at a greater distance from the focusing element due to its significantly higher divergence, defocuses more or less strongly at the machining point, depending on the setting of the telescope hits.

The two FPI modulators 3 and 11 produce relatively low-power radiation components 16, 17 and 18 , which are not used for processing. They can be intercepted either by simple absorbers or by measuring devices ( 19, 20 ) for the diagnosis and monitoring of processing and auxiliary beams.

The freely selectable control of the three relevant elements of the arrangement, the FPI modulators 3 and 11 and the telescope 9 , enables variable machining conditions within very wide limits and thus extraordinarily favorable possibilities for the optimal machining of different materials.

Another embodiment shown in FIG. 2 shows a version of the solution according to the invention according to FIG. 1 which is reduced in its range of variation . The beam splitting and shaping on the first modulator 3 remains unchanged. However, the telescope 9 is dispensed with and the second modulator 31 is used exclusively for the power variation of the auxiliary beam. The desired collinear union of working beam and auxiliary beam is realized in the following way:

The reflected beam 5 passes the second modulator 31 and falls after deflection by means of a flat mirror 22 onto a focusing element 23 , in the example a mirror for focusing adjustment, which focuses the bundle into the defined bore 24 of a perforated mirror 25 , so that it is the working beam without loss of power 8 , which after appropriate beam guidance by means of a plane mirror 26 falls on the perforated mirror 25 and is reflected by it, is collinearly superimposed. The sum beam is then again focused, analogously to the first exemplary embodiment, on the workpiece 15 via the processing optics 14 , the diameter relations of the working and auxiliary beams on the sample corresponding to those shown in FIG. 9 according to their different divergence.

The advantages of this arrangement are the decoupling of the function of both modulators and the elimination of the telescope. Both are associated with cost savings. By decoupling the second from the first modulator, the modulator 31 can be made much simpler, since the regulation of the auxiliary beam power can in principle take place much more slowly (at least by a factor of 10) than the pulse function of modulator 3 .

The function of the telescope can not be replaced in its full width, but at least partially by using focusing elements 23 adapted to the different applications.

In this exemplary embodiment, too, the radiation components which arise on the modulators 3 and 31 and are not used for processing can be intercepted by absorbers or measuring devices. A cheap solution z. B. the arrangement of a fast detector 27 on the modulator 3 , with the help of which the time profile of the transmitted beam and thus the basic time profile of the working beam can be registered and the arrangement of an integrating detector 28 on the modulator 31 , with the aid of which the average power of the auxiliary beam can be monitored.

In the exemplary embodiments 1 and 2 , two possibilities for the collinear superimposition of the processing and heat treatment beam were shown. However, there are also cases in which the use of these two beams with different angles of incidence is desirable or even necessary. Of course, this option can be easily implemented in both of the variants presented by simply modifying the beam guidance.

FIG. 3 shows an exemplary embodiment of this, with changes to FIG. 2 merely referring to the modified positions of the deflecting mirror 22 and the focusing element 32 and to the use of a simple deflecting mirror 34 at the location of the perforated mirror 25 .

FIG. 4 shows the embodiment of the arrangement according to FIG. 3 with the difference that a telescope 9 for focus adjustment is arranged between the second modulator 31 and the deflecting mirror 22 .

Fig. 5 shows first of which great advantages in terms of the contrast P _max / P _min and the generation of short pulses as possible provides the dual transmission versus single transmission. R = 0.5 was assumed for the reflectivity of the FPI plates, a typical value for practical versions of the FPI modulators.

The generation of radiation pulses by means of sine control of the modulator is illustrated in FIG. 6. The position of the modulator operating point is normally chosen so that the reversal points of the oscillation system, which correspond to the maxima or minima of the control signal, lie in the transmission minima. The transmission spike is then swept over in the state of the fastest tuning of the FPI, so that the shortest possible pulses are cut out of the cw laser beam. In this operating mode, the parameters of the pulsed radiation are largely determined by the frequency f of the control signal, in particular the pulse duty cycle: pulse pause ratio is variable only to a very limited extent. If f is fixed, the radiation parameters can only be varied via U.

The control via rectangular or trapezoidal pulses, see FIG. 7, in contrast, receives the full range of variation of the method. The duty cycle mentioned can be varied practically as desired and the pulse width can also be defined within wide limits via the rise in the control signal.

The solution of the second task of the second FPI modulator 11 , namely the regulation of the effective power of the auxiliary beam at the processing location with at the same time the least possible influencing, in particular the least possible attenuation, of the processing beam is shown in FIG. 8. The illustration shows how it can be achieved by synchronized control of the two modulators that on the one hand the pulse maxima of the machining beam pass through modulator 11 exactly at T = 1, that is to say without loss of power, while on the other hand the desired power level of the modulator 11 is achieved precisely by the amplitude of the control signal portion of the radiation used as the heat treatment beam 12 can be set.

Fig. 9 shows the relative positions of the resulting machining area 29 and the heat treatment region 30.

Reference list

1 CO₂ laser
2 laser radiation
3 first FPI interferometer
4 transmitted radiation component
5 reflected radiation component auxiliary beam
6 , 7 deflecting mirror
8 double-transmitted radiation component working beam
9 telescope
10 auxiliary beam modified in diameter and divergence
11 second FPI modulator
12 heat treatment jet
13 machining beam
14 focusing element
15 workpiece / machining location
16 , 17 , 18 radiation components that can be used for diagnostic purposes
19 , 20 diagnostic units
21 deflecting mirror
22 deflecting mirror
23 focusing element
24 defined holes
25 perforated mirror
26 deflecting mirror
27 fast radiation detector
28 integrating radiation detector
29 Machining area
30 heat treatment area
31 second FPI interferometer for regulating the auxiliary beam power
32 focusing element
33 reflected radiation for diagnostic purposes
34 deflecting mirror
P (t) steel output as a function of time
P _T Power of the transmitted radiation component of an FPI interferometer
P _R Power of the reflected radiation component of an FPI interferometer
FPI Fabry-Perot interferometer
P _{DT, max} maximum power of the double-transmitted radiation component
P _{DT, min} Minimum power of the double-transmitted radiation component
P _{T, min} Minimum power of the transmitted radiation component
P _{T, max} maximum power of the transmitted radiation component
Peak pulse power
P₀ cw laser power
t _imp pulse duration
f Modulation frequency
T FPI transmission
U₁ control voltage of the first FPI interferometer
DT₁ double transmission of the first FPI interferometer
R₁ reflection of the first FPI interferometer
U₂ control voltage of the second FPI interferometer
T₂ transmission of the second FPI interferometer
R₂ reflection of the second FPI interferometer
Dd variation of the FPI plate spacing
R reflectivity of the FPI plates
f _max maximum modulation frequency of an FPI interferometer
DQ divergence variation

Claims (8)

1.Device for processing materials with laser radiation, in particular for processing brittle materials, with a first Fabry-Perot interferometer (FPI modulator) for beam splitting with optionally quickly variable splitting ratio between a reflected and a double-transmitted beam and with means for guiding and shaping of said beams and their superimposition on a workpiece located at the processing location, characterized in that

• - The means consist of a telescope ( 9 ), a second Fabry-Perot interferometer ( 11 ), a deflecting mirror ( 26 ) and a focusing element ( 14 ), wherein
• the telescope ( 9 ) changes the divergence of the reflected beam ( 5 ) in accordance with the apertures of its radiation elements and directs the beam ( 10 ) changed in divergence onto a second Fabry-Perot interferometer ( 11 ),
• - The deflecting mirror ( 26 ) also directs the double-transmitted beam ( 8 ) onto the second Fabry-Perot interferometer ( 11 ), but from the opposite side, so that after transmission through the second Fabry-Perot interferometer ( 11 ) the radiation component reflected on the second Fabry-Perot interferometer ( 11 ) and serving as a treatment beam ( 12 ) is collinearly superimposed as a processing beam ( 13 ), and
• - The focusing element ( 14 ) directs the collinear beams onto the workpiece ( 15 ).

2. Device for processing material with laser radiation, in particular for processing brittle materials, with a first Fabry-Perot interferometer (FPI modulator) for beam splitting with a rapidly variable splitting ratio between a reflected and a double-transmitted beam and with means for guiding and shaping of said beams and their superimposition on a workpiece located at the processing location, characterized in that

• - The means consist of a second Fabry-Perot interferometer ( 31 ), a first and second deflecting mirror ( 22, 26 ) from a first and second focusing element ( 23 , 14 ) and a perforated mirror ( 25 ), wherein
• the second Fabry-Perot interferometer ( 31 ) transmits and changes the divergence of the beam ( 5 ) reflected on the first Fabry-Perot interferometer ( 3 ),
• the first deflecting mirror ( 22 ) directs the beam ( 5 ) transmitted by the second Fabry-Perot interferometer ( 31 ) onto the first focusing element ( 23 ) for focusing on the perforated mirror ( 25 ) which acts as an aperture for the focusing beam,
• - The perforated mirror ( 25 ) the focusing beam coming from the first focusing element ( 23 ) is practically loss-free, the double-transmitted and reflected on the second deflecting mirror ( 26 ) serving as a processing beam ( 13 ) as a heat treatment beam ( 12 ) and is collinearly superimposed
• - The second focusing element ( 14 ) directs the collinear beams onto the workpiece ( 15 ).

3. Device for processing materials with laser radiation, in particular for processing brittle materials, with a first Fabry-Perot interferometer (FPI modulator) for beam splitting with a rapidly variable splitting ratio between a reflected and a double-transmitted beam and with means for guiding and shaping of said beams and their superimposition on a workpiece located at the processing location, characterized in that

• - The means consist of a second Fabry-Perot interferometer ( 31 ), a first, second and third deflecting mirror ( 22 , 26 , 34 ) and a first and second focusing element ( 32 , 14 ), wherein
• the second Fabry-Perot interferometer ( 31 ) transmits and changes the divergence of the beam ( 5 ) reflected on the first Fabry-Perot interferometer ( 3 ),
• - The first deflecting mirror ( 22 ) directs the beam ( 5 ) transmitted by the second Fabry-Perot interferometer ( 31 ) onto the first focusing element ( 32 ), which directs it as a heat treatment beam ( 12 ) onto the workpiece ( 15 ), and
• - The second and third deflecting mirror ( 26, 34 ) direct the double-transmitted beam ( 8 ) as a processing beam ( 13 ) onto the second focusing element ( 14 ), which directs the processing beam ( 13 ) at a different angle onto the workpiece ( 15 ) when the heat treatment beam ( 12 ) is incident on it.

4. Apparatus according to claim 1, 2 or 3, characterized in that the first Fabry-Perot interferometer ( 3 ) can be controlled with variable pulse parameters. 5. Apparatus according to claim 1, 2 or 3, characterized in that the second Fabry-Perot interferometer ( 11 , 31 ) changes the power of the heat treatment beam ( 12 ). 6. The device according to claim 1, characterized in that the telescope ( 9 ) is constructed so that the distance between the telescope optics is variable and the divergence of the beam ( 10 ) can be controlled in time by a corresponding control of this distance variation. 7. The device according to claim 1, 2 or 3, characterized in that on the Fabry-Perot interferometer ( 3 , 11 , 31 ) used in each case and not used for processing radiation components ( 16 , 17 , 18 , 33 ) measuring devices ( 19 , 20 , 27 , 28 ) can be supplied for diagnostic purposes. 8. The device according to claim 3, characterized in that a telescope ( 9 ) is arranged between the second Fabry-Perot interferometer ( 31 ) and the first deflecting mirror ( 22 ).