JP2022520002A - Laser system - Google Patents

Abstract

The present invention comprises two laser light sources (12a, 12b), two optical input channels (18a, 18b) and two optical output channels (24a, 24b) for shaping a useful light distribution (L). The present invention relates to a laser system (10) including a supply optical system (20) and a beam forming optical system (28). The optical input channels are designed to feed one input beam group (16a, 16b), each containing at least two laser beams (14), and the optical output channels are each one output beam group (26a, 16b). It is designed to guide 26b). In the supply optical system (20), each output beam group (26a, 26b) has at least one laser beam (14) from the input beam group (16a) of the first optical input channel (18a) and a second optical input. The supplied laser beam (14) is configured to be rearranged to have at least one laser beam (14) from the input beam group (16b) of the channel (18b).
[Selection diagram] None

Description

The present invention relates to a laser system or laser device for producing a useful light distribution (L) provided by a plurality of laser beams.

An advantageous but non-exclusive application is a useful light distribution with a linear beam profile, particularly an output beam that extends along the propagation direction and extends along a linear direction with an intensity that does not disappear in the plane of action. The generation of an output beam with a linear beam cross section.

Such linear beam profiles can be used, for example, to process semiconductor or glass surfaces, such as TFT display manufacturing, semiconductor doping, solar cell manufacturing, or glass surface manufacturing aesthetically designed for architectural purposes. Used for. Here, the linear beam profile is scanned perpendicular to the extension direction of the line over the surface to be machined. For example, radiation can trigger surface modification processes (recrystallization, melting, diffusion processes) to achieve the desired processing results.

The laser system includes multiple laser sources to provide the desired useful light distribution in order to produce a high energy density and / or a spatially strongly expanded linear intensity distribution. For example, DE 10 2008 027 229 B4 shows a device for beam shaping and combining several laser beams emitted by multiple laser sources and performed in groups along the way of some of their optical channels. In this device, the laser beams can eventually be combined and transformed into the desired linear beam profile. To convert this into a useful light distribution, laser radiation passes through multiple optics designed to be illuminated by laser beams from various laser sources. Therefore, all laser light sources should be in operation at all times to achieve uniform irradiation of the optics. If the laser light source fails, or if an attempt is made to reduce the intensity of the useful light distribution by weakening or deactivating the laser light source, the optics are no longer evenly illuminated. This can compromise the quality and homogeneity of the useful light distribution.

DE 10 2008 027 229 B4

The present invention is based on the object of improving the functionality and useful light distribution quality of a laser system in the event of power fluctuations or inactivation of individual laser sources.

This object is achieved by the laser system according to claim 1. A laser system as a whole is a device comprising a plurality of devices and / or components. In particular, the laser system comprises at least two laser sources for designating the laser beam and supply optics for the laser beam. The feed optics have at least a first optical input channel and a second optical input channel for the laser beam. Further, the supply optical system includes at least one first optical output channel and a second optical output channel from which the laser beam exits the supply optical system. The laser beam of the feed optics then continues in the beam path through a beam shaping optic designed to form the desired useful light distribution with a linear cross section from the laser beam of the optical output channel. Run.

The first and second optical input channels are each designed to be supplied with an input beam group, each of which may contain at least two laser beams. The first and second light output channels are each designed to guide one output beam group, and each output beam group may in turn include at least two laser beams.

The feed optics are set so that the feed laser beam is re-sorted on the transition from the input channel to the output channel. In particular, supply optics such that each output beam group comprises at least one laser beam from the input beam group of the first light input channel and one laser beam from the input beam group of the second light input channel. Acts on.

As a result, each output beam group contains contributions from both optical input channels. In particular, a laser beam from one of the input channels is present in each of the output beam groups. As a result, for example, if the illumination through the optical input channels is reduced (eg, if one of the laser sources is deactivated), each optical output channel is also illuminated. As a result, the quality and homogeneity of the useful light distribution can be improved, especially when the radiating powers of the various laser sources vary relative to each other, or when the individual laser sources do not emit at all.

In this context, optical channels (input channels, output channels) are guided, in particular, by the fact that a group of laser beams is spatially separated and / or optically separated from other channels within the channel. Characterized. An optical channel can include multiple optically effective elements (lens, mirror, aperture, etc.). In this regard, the input channel is, in particular, a section of feed optics with optical elements capable of irradiating a laser beam or group of laser beams and then traveling separately from other beams or groups of beams. Is. Laser beams with different input beam groups are provided in the supply optical system such that each output beam group contains a laser beam from at least the input beam group of the first optical input channel and the input beam group of the second optical input channel. It is redistributed into the output beam group.

The feed optics basically allow each laser beam in the input beam group to pass through the feed optics and lead to one of the output channels without being mixed with the other laser beams in this input beam group. It can be designed to be used. In this regard, the laser beam is then guided from each input beam channel to the output beam channel without being combined with other laser beams. Mixing of different laser beams (eg, with homogenized optics, cylindrical lens arrays, etc.) is done only in such configurations, eg, in beam forming optics. In principle, it is conceivable that various laser beams emitted through their respective optical input channels travel within the supply optical system within the optical subchannels separated from each other. Mixing in the optical sense can be avoided, for example, by guiding laser beams spatially separated from each other in the feed optics. However, the above configuration is not essential.

The feed optics preferably have at least one optic for each optical input channel, the optic being designed for beam deflection and / or beam guidance. Further, the optical element is supplied so as to detect only one laser beam in the input beam group of each optical input channel or only a subgroup of the laser beam in the input beam group of each optical input channel. Set up and placed within the optical system. With such optics acting selectively only on the laser beam of the input beam group or on each subgroup, the laser beam is rearranged between the input beam group and the output beam group in the manner referred to. be able to.

In particular, the optical element is a laser beam selectively detected by the optical element, or a subgroup of laser beams selectively detected by the optical element is not detected by the optical element in the same optical input channel. It is advantageous if it is designed and arranged to be guided to a different optical output channel. For example, it is conceivable that the optical element selectively directs one of the laser beams of the input beam group to an optical output channel different from the other undetected laser beams.

The feed optics preferably include one or more beam steering elements and / or one or more beam guidance elements, by which means delimit the beam path from the optical input channel to the optical output channel. The beam path preferably has directional changes, especially multiple directional changes. This is especially advantageous if the beam path is folded several times (similar to the shape of the letter Z), for example a Z fold. As a result, a long optical path can be accommodated in a compact installation space. This allows, for example, a telescope or other beam-forming optical system with relatively low refraction intensity and / or relatively large focal length to be used in the beam path. Since an optical system having a low refraction intensity and / or a large focal length usually tends to have a small aberration, the optical accuracy can be improved by folding the beam path.

In another embodiment, the particularly folded beam path runs in a plane perpendicular to the plane of the beam path in subsequent beam shaping optics. In this regard, the beam forming optics also include a plurality of optical elements, the means of which the optical element specifies a beam path, thereby having one or more changes in direction, preferably. Can be folded once or multiple times. In this regard, the folded beam path can in turn be assigned a plane through which the beam path runs.

The feed optics preferably have a first optical input channel and a second optical input channel having, for example, opposite beam directions, in particular a laser beam having different beam directions from the opposite side can be radiated into the channels. Designed to be arranged in such a way. In particular, the feed optics have its own enclosure, with a beam inlet to the first optical input channel and an additional beam inlet to the second optical input channel located on opposite sides of the enclosure. The light. These means make it possible to arrange laser light sources opposite to each other with respect to the supply optical system in the laser system. Additional beam inlets for additional laser sources can also be provided, which are specifically located on the further free side of the enclosure. As a result, the laser sources are spatially separated from each other. This increases operational reliability, for example by allowing cooling and feeding. Maintenance work is also easy.

In another embodiment, the supply optical system for at least one optical output channel is configured to change the optical path of at least one laser beam as compared to the other laser beams of this respective optical output channel. Includes adjustable optics. Such path-adjusting optics are preferably provided for each optical output channel. Optical path conditioning optics are specifically designed to receive only one laser beam from the optical output channel or a subgroup of laser beams from the optical output channel. The optical path adjustment optical system can have, for example, a combination of deflection mirrors, thereby defining an additional variable length optical path. Each detected laser beam or subgroup of each detected laser beam then traverses this additional variable length optical path.

The advantage of this system is that it is modular and scalable. In particular, two or more optical input channels can be provided. Alternatively or additionally, the feed optics can be designed to illuminate more than two input beam groups. It is advantageous that the feed optics are designed so that the beam of the input beam group is divided into several different output beam groups. The feed optics are further preferably designed such that each of the output beam groups contains at least one laser beam from each of the plurality of input beam groups. Such a system is irradiated almost uniformly even when one or more laser sources are deactivated.

In another embodiment, the beam forming optical system has a reforming optical system that receives a laser beam emerging from an optical output channel. The remodeling optics are designed to form a beam package with a beam cross section extending linearly from the detected laser beam. For this purpose, one conversion element is conceivable in which the remodeling optics have several separate conversion elements, each assigned to each output beam group. Since each output beam group contains contributions from several input channels, as described, the formed optical system is uniformly irradiated even when the laser source is not irradiating the laser beam.

However, a design with separate transformation elements is not required. It is also conceivable that the output beam groups are coupled to form a coupled beam in front of the remodeling optical system. In this regard, the beam forming optics are a combination optics configured to combine the laser beams of the output beam groups of the respective optical output channels, or the output beams of some optical output channels prior to the remodeling optics. Further may include combined optics configured to combine laser beams from the group to form a combined beam. The remodeling optics are preferably arranged such that they then receive the combined beam and reshape them into a beam package with a linearly extending beam cross section.

For further refinement, a homogenized optic can be provided downstream of the beam path, i.e. following the reshaped optics, which allows the reshaped optics to give the desired properties to the useful light distribution. The beam packet of the system is detected and further reshaped.

The laser beams of the output beam group can optionally be optically molded independently of each other in the beam forming optical system. For this purpose, the beam forming optics have at least one telescope, particularly an anamorphic telescope, which may act on one or more laser beams in the optical output channel. Telescopes can in particular be equipped with two converging lenses that follow each other in the beam path, such as the Kepler telescope so that their facing focal lengths match, for example, from their additional focal length. Are placed at a distance (by the method of). The telescope is preferably designed as an anamorphic telescope so that the laser beam is transformed into an anamorphic within each channel. In particular, telescopes are designed to cause cylindrical distortion of the image scale along an axis perpendicular to the direction of propagation of the laser beam. For example, beam forming optics are arranged in series in the beam path for each output beam group or for one output beam group acting in two different strain directions (especially with respect to two vertical directions). It is conceivable to have only two anamorphic telescopes. In this way, the beam properties can be adjusted for the two vertical axes. The telescopes mentioned here are specifically placed in the beam path in front of the remodeling optics.

An advantageous aspect of the present invention is that different laser light sources are fed to different optical input channels. Since each light output channel guides the laser beam from some or all input channels, the light output channel is still uniformly illuminated even if the laser light source fails. Therefore, the laser light sources can be operated independently of each other.

Also, an advantageous aspect of the invention consists of the fact that each laser source is designed to emit at least two separate (ie, spatially separated from each other) laser beams. In particular, it is then provided that two laser sources are radiated to different light input channels and at least two laser beams emitted by one laser source form an input beam group. Such a laser source can be implemented, for example, as a frequency doubling laser or a frequency doubling laser, where the remaining converted beams are also reconverted, thus providing more than one output beam. Can be done.

The present invention will be described in more detail below with reference to the drawings.

FIG. 1 is a schematic diagram for explaining a beam path and functional components of a laser system according to the present invention. FIG. 2 is a perspective view of a laser system having a compact structure according to the present invention.

In the following description and figures, the same reference symbols are used for the same or corresponding features.

1 and 2 show a laser system or laser device, which is indicated by reference numeral 10 as a whole. In the illustrated example, the laser system 10 includes two laser light sources 12a, 12b for radiating a laser beam. In the illustrated example, each of the laser light sources 12a, 12b is designed so that two separate laser beams 14 are emitted in parallel.

The laser light from each of the laser light sources 12a and 12b forms the input beam groups 16a and 16b, respectively. It goes without saying that the input beam group can be supplied by, for example, a plurality of laser light sources, each of which emits only one laser beam 14. The input beam groups 16a and 16b are radiated to the supply optical system 20 through the optical input channels 18a and 18b, respectively. In this regard, supply optical system 20 has associated beam inlets 22a or 22b for each optical input channel 18a or 18b (see FIG. 2). The optical input channels 18a or 18b may have, for example, suitable optical elements or optics for coupling the laser beam to the supply optical system 20.

Further, the supply optical system 20 has first and second optical output channels 24a and 24b, respectively. In the supply optical system 20, the laser beam 14 irradiated through the first and second optical input channels 18a and 18b is guided to the optical output channels 24a and 24b by the method described in more detail below. In this regard, the output beam groups 26a and 26b of the laser beam 14 are provided in the first and second optical output channels 24a and 24b, respectively.

Next, the output beam groups 26a and 26b transmitted from the optical output channels 24a and 24b are received by the beam forming optical system 28 and converted into a desired useful light distribution L. The illustrated example has a linear beam cross section.

In order to form a useful linear light distribution L from the laser beam 14 of the output beam groups 26a, 26b, the beam forming optical system 28 usually comprises various optically functional devices. For example, it is conceivable that the laser beam of the output beam group 26a or 26b or a subgroup thereof first passes through one or more telescopes 30. Such a telescope 30 can be specifically designed anamorphic, so that the beam cross section is preformed in a suitable manner.

Following the beam path, the laser beam 14 is then guided, for example, from the laser beams 14 of the output beam groups 26a, 26b through a reforming optical system 32 that forms one or more beam packets with elongated beam cross sections. The laser. The beam packet thus preformed is mixed with, for example, homogenized optical system 34 and smoothed in the intensity profile to provide the desired useful light distribution L.

The remolding optical system 32 may, in principle, have several separate conversion elements 33 (see FIG. 1). For example, it is conceivable that one conversion element 33 acts on the laser beam 14 from only one of the output beam groups 26a and 26b, respectively. However, this configuration is not mandatory. Further, the remolding optical system 32 can include a common conversion element for all the laser beams of the output beam groups 26a and 26b. In this case, the beam forming optical system 28 can have a combined optical system connected upstream of the reforming optical system that couples the laser beams of the various output beam groups 26a, 26b to the coupled beam. According to one embodiment (see FIG. 1), the beam forming optical system 28 can also have a combined optical system 35 that combines the laser beams of the output beam groups 26a and 26b of the respective optical output channels 24a and 24b.

The supply optical system 20 has a plurality of beam steering elements and / or beam guide elements 36, and the beam path 38 is predetermined in the supply optical system 20 by the means thereof. In the illustrated example, the beam path 38 is folded several times so that a relatively long optical path can be covered by a compact installation space, and thus an optical element for shaping the beam characteristics (not shown in detail). Sufficient space is provided for.

The supply optical system 20 is designed so that the laser beams 14 of the input beam groups 16a and 16b initially travel separately from each other and also travel separately from the laser beams of the other input beam groups. .. In the illustrated example, the feed optics 20 also includes an optical element 40 (here, a deflection mirror) for beam deflection and / or beam guidance, which is one laser in each input beam group 16a or 16b. It acts only on the beam.

The optical element 40 is designed to direct the detected laser beam to each other optical output channel 24a or 24b rather than the laser beam 14 of each input beam group 16a or 16b not detected by the optical element 40. .. This is because each output beam group 26a, 26b is from at least one laser beam 14 from the input beam group 16a of the first optical input channel 18a and from the input beam group 16b of the second optical input channel 18b, respectively. Ensure that it contains at least one laser beam 14. In this regard, the supply optical system 20 is grouped into two input beam groups 16a and 16b so that the supply optical system 20 travels in different pairs in the output beam groups 26a and 26b of the optical output channels 24a and 24b, respectively. Designed to relocate.

Further, the supply optical system 20 can include a path adjusting optical system 42 capable of changing the optical path of at least one laser beam with respect to the other laser beam 14. This makes it possible to give the laser system 10 a desired operation over time, for example, during operation by the pulsed laser light sources 12a and 12b.

As can be seen in FIG. 2, the laser system 10 has a particularly modular structure. In particular, the supply optical system 20 and / or the beam forming optical system 28 may each have their own module housing 44. Due to the modular structure, the installation space is relatively small and a compact system can be constructed. For this purpose, it is particularly advantageous when the beam paths in the supply optical system 20 and the beam forming optical system 28 are not linearly adjacent to each other and instead are in an angled or folded configuration. Is. In the illustrated example, the beam path 38 in the supply optical system 20 is folded several times and extends into one plane (see FIG. 1). Thus, the module housing 44 of the feed optics 20 is a flat cubic or box-shaped housing (ie, having an extension perpendicular to the plane, smaller than an extension parallel to the plane). Can be molded as. Next, the laser beam provided in the optical output channels 24a and 24b (output beam groups 26a and 26b) can be passed in another direction. For example, the beam forming optical system 28 can have a beam path extending in a plane essentially perpendicular to the beam path 38 of the supply optical system 20 (see FIG. 1).

In the illustrated example, the beam inlets 22a and 22b for the first optical input channel 18a and the second optical input channel 18b are arranged on different sides of the module housing 44 of the supply optical system 20. For example, the laser light sources 12a and 12b are arranged so as to face each other with respect to the supply optical system 20 and can radiate in opposite beam directions. The various laser sources can, of course, be arranged such that their respective beam directions wrap around an acute or obtuse angle with each other. Further, the laser light source has parallel beam directions and can be arranged so as to be vertically offset from each other, for example. According to a general aspect, the various laser light sources 12a and 12b are arranged so that their housings are separated from each other. In this way, the work on one of the two laser light sources can be performed without affecting the other laser light sources. It also enables a compact structure.

Claims (13)

A laser system (10) for producing a useful light distribution (L) having a linear beam cross section supplied by a plurality of laser beams (14).
At least two laser light sources (12a, 12b) for radiating the laser beam (14), and
It comprises at least a first optical input channel (18a) and a second optical input channel (18b), a first optical output channel (24a) and a second optical output channel (24b) for the laser beam (14). ), And the supply optical system (20),
A beam forming optical system (28) that forms a useful light distribution (L) from a laser beam (14) of an optical output channel (24a, 24b), and
Equipped with
The first optical input channel (18a) and the second optical input channel (18b) are such that they each supply one input beam group (16a, 16b) containing at least two laser beams (14). The first optical output channel (24a) and the second optical output channel (24b) each include one output beam group (26a, 26b) including at least two laser beams (14). Designed to guide you
Further, in the supply optical system (20), each output beam group (26a, 26b) has at least one laser beam (14) and a second light from the input beam group (16a) of the first optical input channel (18a). It is characterized by being designed to rearrange the supplied laser beam (14) to include at least one laser beam (14) from the input beam group (16b) of the input channel (18b). Laser system (10). The supply optical system (20) for each optical input channel (18a, 18b) has at least one optical element (40) for beam deflection and / or beam guidance, said optical element (40). Only one laser beam (14) in the input beam group (16a, 16b) of each optical input channel (18a, 18b), or the input beam group (16a, 16b) of each optical input channel (18a, 18b). The laser system (10) according to claim 1, wherein only the subgroup of the laser beam (14) is designed and arranged to be detected. In the optical element (40), the detected laser beam (14) of each optical input channel (18a, 18b) or the detected laser beam subgroup (14) is not detected by the optical element (40). The laser system (10) according to claim 2, wherein the laser system (10) is designed to enter an optical output channel (26a, 26b) different from the laser beam (14) of the same optical input channel (18a, 18b). The supply optical system (20) is a beam steering element (36) and / or a beam for defining a beam path (38) from the optical input channels (18a, 18b) to the optical output channels (24a, 24b). It comprises an inductive element (36), said beam path (38) having at least one directional change, preferably multiple directional changes, and more preferably several folds. The laser system (10) according to any one of claims 1 to 3. 4. The supply optical system (20) is designed so that the beam path (38) travels in a plane perpendicular to the plane in which the beam path in the beam forming optical system (28) travels. The laser system (10) according to the above. In the supply optical system (20), a laser beam (14) having different beam directions, particularly opposite beam directions, is supplied to the first optical input channel (18a) and the second optical input channel (18b). The laser system (10) according to any one of claims 1 to 5, wherein the laser system is designed as follows. The supply optical system (20) for at least one optical output channel (24a, 24b) comprises a path-adjusting optical system (42), wherein the path-adjusting optical system (42) is an optical output channel (24a, 24b). The laser system (10) according to any one of claims 1 to 6, which is set to provide an optical path for at least one laser beam (14) as compared to another laser beam (14). Two or more optical input channels (18a, 18b) are provided and / or two or more input beam groups (16a, 16b) are provided, and the supply optical system (20) is an output beam group (26a). 26b), respectively, according to any one of claims 1-7, wherein each of 26b) is designed to include at least one laser beam (14) from each input beam group (16a, 16b). Laser system. The beam forming optical system (28) receives the laser beam (14) of the optical output channels (24a, 24b) and converts them into a beam package having a linear extended beam cross section (32). ), The laser system (10) according to any one of claims 1 to 8. The beam forming optical system (28) is a laser beam (14) of an output beam group (26a, 26b) from an optical output channel (24a, 24b) or an output beam group from a plurality of optical output channels (24a, 24b). The reshaped optical system further includes a coupled optical system (35) configured to combine the laser beams (14) of (26a, 26b) in front of the reshaped optical system (32) to form a coupled beam. (32) The laser system according to claim 9, wherein the laser system is designed and arranged so as to receive the combined beam. Claims 1-10, wherein the beam forming optical system (28) comprises at least one anamorphic telescope (30) acting on one or more laser beams (14) of the optical output channels (24a, 24b). The laser system (10) according to any one of the following items. The laser system (10) according to any one of claims 1 to 11, wherein different laser light sources (12a, 12b) are supplied to different optical input channels (18a, 18b). Any of claims 1-12, where each laser light source (12a, 12b) provides at least two separate laser beams (14) and is designed to emit to different optical input channels (18a, 18b). The laser system (10) according to claim 1.

Images