Abstract:
The present invention relates to a fiber laser system for processing materials involving a system of interconnected operational components for combining and optionally distributing beams from multiple beam emitters. More particularly, the present invention provides a system for combining and distributing fiber laser beams having different wavelengths and a method for operating the system thereof. Multiple beam combiners may be optionally linked with a beam distribution system. In exemplary use, multiple fiber laser sources generating different wavelength outputs are combined in a single beam incident of a work piece comprising multiple layers.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a system for combining and optionally distributing beams relative to multiple beam emitters. More particularly, the present invention provides a system for enabling combining or distributing fiber laser beams having different wavelengths and a method for operating the system therefore. 
     2. Description of the Related Art 
     Industrial applications of lasers involve the use of laser heads having single collimators receiving single fibers and supporting respective single laser beams. Most commonly, a single wavelength laser from a laser is employed in a working head for cutting or treating a surface or material. 
     Laser connector systems are known in the art in an effort to combine respective laser beams through non-fiber connectors upstream from a laser head. The use of conventional connectors prohibits rapid adaptation to different beam selections or wavelength combinations for a rapid-adaptation and flexible process. Typically, the beams are combined via splicing connectors upstream of a laser head. These arrangements are particularly detrimental where combined materials of a diverse nature require cutting or treating with a single beam and there are rapid material changes. For example, where a first material (for example, a film) covers a second material (for example, a sheet material) or a third materials exists, it is often impossible to select a single wavelength best suited for cutting all. 
     Accordingly, there is a need for an improved system and method for processing of materials using laser beams from a plurality of sources. Further, there is also a need to provide a system for rapidly selecting and combining laser beams for process efficiency. 
     ASPECTS AND SUMMARY OF THE INVENTION 
     In response to at least one of these needs, the present invention relates to a system of interconnecting operational components for combining and optionally distributing beams from multiple beam emitters. More particularly, the present invention provides a system for combining and distributing fiber laser beams having different wavelengths and a method for operating the system thereof. One or more beam combiners may be linked with a beam distribution system. One or more dumps are positioned for safety in case of component failure. In exemplary use, multiple fiber laser sources generating different wavelength outputs are combined in a single beam incident of a work piece. 
     Where specific treatment methods or laser properties such as coherence and short pulse duration, or other manipulation of the lasing source are required, the proposed system and method allows rapid selection, in either sequence or combination, of desired wavelengths to improve process speed and efficiency. 
     In one alternative aspect of the proposed invention a beam combiner configuration is proposed that allows easy combination of beams through a single collimator, either sequentially or simultaneously. 
     In another alternative aspect of the proposed invention a beam distributor allows light to propagate along a light path from a beam source (a single or combined beam) through one or more mirrors to a designated output. 
     It is a further alternative aspect of the present invention that the proposed system allows a process for distributing a combined beam to one or more outputs. For example, the proposed system enables the use of a combined wavelength beam distributed to two or more process heads for simultaneously processing. 
     The above and other aspects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a beam combiner system showing a sequential combination from two beam emitters. 
         FIG. 1  is a schematic view of the workpiece to be processed. 
         FIG. 2  is a perspective view of the beam combiner in  FIG. 1  showing a simultaneous combination from two beam emitters. 
         FIG. 3  is an exemplary perspective view of the beam combiner in  FIGS. 1 and 2  in a process housing. 
         FIG. 4  is an exemplary process schematic of a beam distribution system, wherein an input beam is distributed into three equal beams, or conversely three different beams from collimators are combined into a single beam and a computer process control unit is integrated for system management and control. 
         FIG. 5  is an exemplary process schematic of a beam distribution system, wherein a single input beam is distributed to one output and then to a laser head by a fiber. 
         FIG. 6  is an exemplary process schematic of an integrated beam distribution and combiner system, wherein two inputs are combined to a single input and then distributed to two outputs. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to embodiments of the invention. Wherever possible, same or similar reference numerals are used in the drawings and the descriptions refers to the same or like parts or steps. The drawings are in simplified or schematic form and are not to scale. For convenience and clarity only, directional (up stream/down stream, etc.) or motional (forward/back, etc.) terms are used with respect to the drawings. These and similar directional terms should not be construed to limit the scope of the invention in any manner. 
     Referring now to  FIGS. 1 ,  1 A and  2 , an exemplary beam combiner system  1  operably contains a first emitter and  2  and a second emitter  3  as sources secured in a relative arrangement. Emitters  2 ,  3  generate outputs at different wavelengths. 
     A mirror assembly  4  contains a mirror member  5 , as shown, and an assembly of adjustment elements effective for operation and alignment in beam combiner system  1 . A mirror rotating mechanism  6 , serving as a beam selector, having a pivot axis A is operative to pivot a rotating mirror assembly  7  relative to respective beam paths. One or more mirrors  7 A,  7 B are in rotating mirror assembly  7  (See  FIG. 2 ). For convenience, mirror  7 A ( FIGS. 1 and 2 ) is a 100% mirror, while mirror  7 B is a 50%/%50% mirror ( FIGS. 2 and 3 ), although any other minor or window may be adaptively included without departing from the invention. 
     As a result, via rotational motion M controlled by an external computerized process control unit (not shown) providing digital controlling input to mirror rotating mechanism  6 , combining system  1  rotates mirrors  7 A,  7 B as needed to either sequentially select a beam or simultaneously combine a beam. As noted in  FIGS. 1 and 2  an optical dump  9  is provided for safety if there is a malfunction in mirror rotating mechanism  6 , rotating mirror assembly  7 , or respective mirrors  7 A,  7 B. It is noted, that dump  9  may be located outside the laser head, and indeed may be joined to the laser head only by an operative optical relay (not shown) to allow far distant positioning. 
     In  FIG. 1 , beam emitter  2  emits a beam  2 A reflecting from mirror member  5  to 100% mirror  7 A and fully directed outwardly through an output collimator  8  having an operable adjustment mechanism (shown but not discussed for centering and focus and the like). In  FIG. 1 , beam combiner system  1  is operating selectively between beam emitters  2 ,  3  in a sequential process (one emitter then the other). In the exemplary process, the above-noted sheet material having a film would be cut in two passes, a first pass to cut the film  25  ( FIG. 1A ) using one emitter having a wavelength suitable for the film, and a second pass cutting the sheet material  27  ( FIG. 1A ) using the second emitter having a wavelength suitable for the sheet material. 
     In  FIG. 2 , a simultaneous process is presented wherein both emitter  2  and emitter  3  emit beams, respectively beams  2 A and  3 A emit. Here, mirror rotating mechanism  6  has rotated to position mirror assembly  7  and thus position mirror  7 B (a 50%/50% mirror) along the path of beams  2 A and  3 A. Again, an operative optical dump  9  is effectively positioned for safety in the process. Thus, during the process emitters  2  and  3  emit simultaneously through collimator  8 . In this exemplary process, the above-noted sheet material having a film would be cut in one passes, the single pass combing the wavelengths to cut both the film and the sheet material simultaneously. 
     It will be recognized that beam emitters  2  and  3  may be collimators receiving beams from fiber lasers linked with one or more upstream laser diodes. As a result, those of skill in the art will recognize that beam emitters  2  and  3 , as collimators, may also contain focusing and adjustment features, etc. not discussed herein. Similarly, emitters  2  and  3  and collimator  8  may all employ temperature regulation systems for optimal performance. 
     Referring now to  FIG. 3 , an exemplary laser head unit  10  is provided having a housing  11  supporting input from respective emitters  2  and  3 . It will be noted that mirror rotating mechanism  6  is exposed, but would practically be protected by a cover (removed for the detail). Similarly, it will be possible and desirable for dump  9  to be within laser head unit  10 , but alternatively it will be recognized as possible to locate dump  9  remotely, depending upon system arrangements. 
     In considering beam combining system  1  in  FIGS. 1-3  (working to sequentially or simultaneously combine beams), those of skill in the art will recognize that the system may work in a reverse direction, where a beam entering collimator  8  may be directed, or split, to either beam emitter  2 ,  3 , (now working in reverse to receive the so-directed beam) either sequentially or simultaneously. In considering the next embodiments, this dual direction capability will be recognized. 
     Referring now to  FIG. 4 , a, operable beam distributor system  12  is illustrated. A collimator  15 A receives an initial beam from a laser head or laser combiner unit  19  (shown) which reflects from a mirror  17  along a beam path to a first partially reflective mirror  21 A driven by a process controlled motor  22 A. A partial split or reflection, according to the type of mirror  21 A, distributes a portion of beam at  25 A (noted as 33%) to a collimator  16 A for downstream processing. 
     Thereafter the beam continues to a second partially reflective mirror  21 B driven by a process controlled motor  22 B splitting or distributing a portion of the beam at  25 B (noted as 50%) to a collimator  16 B for downstream processing. 
     Further, the remaining beam continues to reflective mirror  21 C driven by a process controlled motor  22 C directing remainder portion of the beam at  25 C (noted as 50%) to a collimator  16 C for downstream processing. 
     As additional features in system  12 , dumps  18  are provided relative to the beam path and an alternative (and unused collimator  16 D, mirror  21 D and motor  22 D are provided). Further, an anti-reflection window  24  driven by a process controlled motor  23  linked with a further dump  18  is provided before end collimator  16 D. Therefore, as with  FIG. 5  (discussed next), a full beam from collimator  15 A may be transferred (distributed) to collimator  16 D and conversely also within the scope of the current invention. 
     Further, it will be recognized that (operating in the opposite direction) multiple beams from collimators  16 A,  16 B,  16 C, or  16 D could optionally be combined to mirror  17  to collimator  15 A in a process converse to that noted above. Here, as in  FIGS. 1-3 , the dump feature is very important as a safety factor for process control. 
     Finally, it will be recognized that a process control unit  20 , containing suitable computer control features, memory, and a central processing unit (CPU) etc. is operatively connected (represented by multiple double arrows) with each component to enable monitoring, control, and operation of each of the elements. 
     Referring now to  FIG. 5 , an optional beam distributor system  13  is provided having a collimator  15 B receiving a beam from mirror  17  transmitted through an antireflective guard  24 , pivotally controlled by an anti-reflective motor  23 . The beam processes through guard  24  from 100% mirror  21 F operated by motor  22 F and originates from collimator  16 F. For safety, dump  18  is located opposite guard  24 , and a further dump  18  is located proximate the final 100% mirror. 
       FIG. 5  is in simplified form, but it will be recognized that a stand by collimator  16 E is prepared with a standby window mirror  21 E driven by a motor  22 E, is operative should process control  20  (noted earlier but not shown) require a combination with the beam from collimator  16 F. The output via a fiber from  15 B is directed to laser head or laser combiner  19  for further downstream use. Of course, it will be recognized that in distribution system  13  the beam may be permitted to travel conversely without departing from the present invention. 
     Referring now to  FIG. 6 , a further alternative beam distributor system  14  is provided with beam emitter  15 B shown as a collimator directing a combined beam from laser head or laser combiner  19  (shown as two arrows) to mirror  17  along a path to partial mirror (50%/50%)  21 E driven by motor  22 E pivoted into the beam path to create a partial beam  25 E′ to collimator  16 E (noted earlier) while allowing the remaining 50% to pass to reflective mirror  21 F (100% mirror) and thus to a partial beam  25 F′ to collimator  16 F. Here, beams  25 E′ and  25 F′ are further passed by fibers to other laser heads or laser combiners  19 ′,  19 ″ for further downstream use. Here, the initial beam is distributed, or split, but conversely may allow for combination of two beams into a single beam in reverse operation. 
     As a result of considering  FIGS. 5 and 6  it will be understood that beam distributor systems  13  and  14  are substantially related, differing on the additional use of a split mirror  21 E and the direction of beam path. 
     Process control unit  20  and optionally individual process controllers (not shown but introduced in  FIG. 4 ) are operably linked with components of the proposed systems, and include computerized process units (CPUs), an operational process control programs, memory or data storage systems (all not shown). 
     It will be understood by those of skill in the art that any of the rotating mirror assemblies noted in any of the  FIGS. 1-6 , may contain multiple mirrors (as in  FIG. 2 ), allowing for a single pivot motor to operate in a no-mirror position, anti reflection position, partial mirror (for example 33% or 50%, or other), or a full 100% mirror. There is no limitation (other than space) on the number of mirrors used. 
     It will be understood that the phrases split and/or distributed and/or combined when used in the scope of the present invention are illustrative of the exemplary beam systems discussed, and may be used without restriction. Such that a beam may be combined and then distributed before it is split, or the phrase split and distributed may mean the same concept, or a beam that is split may be combined and/or distributed further downstream in this fiber laser arrangement without confusion. The concepts and embodiments herein are exemplary and those of skill in the related art have a technical expertise such that the meaning will be easily understood. 
     It will be further understood from those of skill in the technical arts that the proposed systems may be jointly combined and interchanged to provide an overall beam management system that operates according to the proposed invention. For example, any of the beam emitters in  FIGS. 1-6  may be beam combiners, such that the output beam is then distributed or split at need. 
     It will be further understood that one or more computer process units/control units (CPU&#39;s) provides integrated system management and control with respective components. For example, while not shown in all Figures, each proposed embodiment will be understood as integrated with one or more CPUs. 
     Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it will be apparent to those skills that the invention is not limited to those precise embodiments, and that various modifications and variations can be made in the presently disclosed system without departing from the scope or spirit of the invention. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents. Finally, it will be noted that the phrase ‘fiber’ is not limiting. Indeed ‘fiber laser sources’ may be non-fiber laser sources without departing from the scope and spirit of the present invention. For example, a fiber-laser source may be paired with a non-fiber laser source with suitable configurations—this will all be understood to be within the scope of the present invention.